PICU Cardiac Guide

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Disclaimer

This is only a guideline and does not substitute local clinical experience, clinical evaluation and / or judgement of each individual patient! Whilst every effort has been taken to ensure the accuracy of the information in this web application, the contents are subject to review and change from time to time. We make no warranties or representations, expressed or implied, as to the accuracy of information contained in this application and are not liable in anyway.

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Mobile Adaptation

Adapted for viewing in mobile devices by Jubal John.

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Any comments/suggestions much appreciated. Please email marcanders@web.de for issues relating to content.

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Contributions

WITH MANY THANKS TO ALL WHO CONTRIBUTED TO THIS GUIDE LINE !

Andreas Schibler, Bret McVinish, Clare Nourse, Emma Haisz, Jamin Mulvey, Jason Yates, Jim Morwood, Kevin Plumpton, Mark Hayden, Nalini Selveindran, Rachel Teis, Quyen Tu, Rajshree Trivedi

for K

And special thanks to:

Bennett Sheridan - for all the excellent diagrams

Rapsou Rapciewicz and Stephanie Chesneau - for the wonderful drawings

Christian Stocker - for the hard discussions on the TGA chapter and the excellent Single Ventricle chapter

Peter Damen - for the iPhone app and webpage design

1st ed May 2011
2nd ed October 2012
3rd ed March 2013

This is only a guideline and does not substitute local clinical experience, clinical evaluation and / or judgement of each individual patient!

Any comments / suggestions much appreciated, email to marcanders@web.de

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Cardiac Cycle

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THE BASICS: CARDIAC CYCLE

NORMAL VALUES

Threshold

Heart Rate (bpm)

MAP (mmHg)

Term Newborn

120 - 180

45

up to 1yr

100 - 180

55

up to 2yrs

80 - 130

60

up to 7yrs

70 - 110

65

up to 16yrs

50 - 100

65

[1] Pediatr Crit Care Med 2009 Vol. 10, No. 3: Bronicki et al: Cardiopulmonary Interaction.

Initial Post-Operative Care and Problems

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THE BASICS: INITIAL POSTOPERATIVE CARE AND PROBLEMS

Abdominal distension

  • Causes: air in stomach or bowel (usually from mask ventilation at induction of anesthesia) or tension pneumothorax; fluid in bowel or in peritoneal cavity (usually capillary leak, high RA pressure or PD fluid; rarely fluid overload or peritoneal hematoma). Exclude NEC, especially in neonates with parallel circulations or long cross-clamp time.

  • Investigation and management: examine chest and abdomen: percussion; examine fluid drainage from PD catheter and chest drains (amount and redness - measure Hb); aspirate NG tube; repeat CXR (compare with previous, air in stomach or bowel, pneumothorax); monitor abdominal girth; check coagulation and platelets (correct if abnormal and bleeding); abdominal ultrasound if suspect retroperitoneal hemorrhage (femoral line). If capillary leak is the problem, lasts up to 2days (longer in neonates, after long operations, in sepsis and when the cardiac output is low); during this time, fluid restriction doesn't prevent edema or ascites, but only leads to hypovolaemia. Adjust ventilation if necessary to compensate for reduced abdominal compliance.

    Atelectasis

  • Causes: tracheal intubation, thick secretions, inadequate humidification (check humidifier tank and tubing temperatures), inadequate tracheal suction, airway compression or collapse (eg malacia), paralysed hemidiaphragm while spontaneous ventilation

  • Signs: decreasing SaO2, rising PaCO2, may be reduced ipsilateral chest movement, usually involves RUL and LLL.

  • Management: hand-ventilation, instill normal saline (0.25 - 0.5ml) into trachea before suction, physiotherapy, culture tracheal aspirate, X-ray screen diaphragm if clinical suspicion of paralysis, bronchogram if other signs suggest malacia (hyperinflation, wheezing, prolonged expiration).

    Atrial pressure increasing

  • Examine patient; check BP, heart rate, RAP, LAP. AV valve regurgitation. Look for V wave in atrial trace (AV regurgitation or malposition of atrial catheter through AV valve). Over-filling. In aortic or pulmonary stenosis, non-compliant ventricles cause atrial pressures to rise with small increases in volume. Treat by careful diuretics and / or GTN (filling pressures !). Tamponade. Associated with tachycardia and falling BP and cardiac output. Notify surgeons and immediate Echo, but do not delay chest opening if situation serious. In infants, myocardial edema without pericardial fluid can cause tamponade that may be immediately relieved by opening the chest. Deteriorating myocardial performance. Arrhythmia. Pneumothorax.

  • Management: re-calibrate transducers. Examine chest and abdomen; check blood gas, electrolytes and lactate; hand-ventilate and suction ETT; check ECG rhythm; obtain a CXR; notify surgeons if tamponade suspected; trial of vasodilators, diuretics and inotropes.

    Cardiac Tamponade

  • Signs: rising HR; increasing lactate and metabolic acidosis; falling BP with low pulse pressure and narrowing of systolic and diastolic BP; both atrial pressures rise (especially RA); chest drainage may increase (if due to increased bleeding) or (usually) decrease (drainage blocked); heart sounds may be muffled; QRS complexes may be smaller. Milk drains (are they on adequate suction, are the drain reservoirs full). If there is the slightest suspicion of tamponade, notify the surgeon ! (do not delay for investigations).

  • Management: obtain CXR (may show increase in heart size; more globular heart shape; increased distance from pacing wires or LA/PA lines to heart border); obtain Echo; check blood gases and clotting (PT, PTT, fibrinogen, platelets); milk the chest drains; stop vasodilators; give blood or saline 10 ml/kg; maintain the coronary perfusion pressure using inotropes; consider clotting factors or platelets; if ACT >100 sec, give protamine 0.5 mg/kg and re-check ACT; consider aspirating LA or PA lines to check position of their tips (? in pericardial cavity); may need urgent chest opening.to prevent further detoriation.

    Convulsions

    In a paralysed child, a seizure may consist only of increases in HR, BP, PA or atrial pressures or spontaneous variations in pupil size. Review history: pre-op; intra-op and post-op events; check blood glucose, gases and electrolytes (including Ca++ and Mg++); cease muscle relaxants; check autonomic response to IV midazolam bolus; neurological examination when muscle power returns; consider consulting neurologist (is this a fit? prognosis? follow-up ?); monitor EEG during autonomic changes to confirm seizure present; consider CT scan; load with phenobarbitone up to 30mg/kg IV in 5 - 10mg/kg increments (beware hypotension); continue phenobarbitone if fits continue; avoid IV phenytoin (myocardial depressant) after cardiac surgery. Consider Keppra 10mg/kg IV.

    Fever

    All children become febrile after open heart surgery, and most become febrile after any thoracotomy. The fever appears as soon as the child re-warms after the operation, and lasts 24 - 48 hours. During this time, the child can still become septic, but the diagnosis of sepsis depends on other signs. A secondary increase in temperature (after the normal post-op fever has settled) means sepsis until proven otherwise (CRP, PCT, WCC, ITR). High post-operative fever may be associated with marked tachycardia, and an increase in VO2 (11% increase in VO2 per 1oC increase in temperature). Regular Paracetamol (single dose 30mg/kg post-op) to keep core temperature < 37.5oC. If the temperature is > 39oC despite paracetamol and the child is still paralysed, consider using cool peritoneal dialysis (1.5% solution at room temperature in 30minutes cycles, each of 10ml/kg) or surface cooling to normothermia, using a cooling blanket.

    Haemorrhage

  • Causes: thrombocytopenia; poor platelet function; dilution or consumption of clotting factors; residual heparin (usually in the first 4hours post-op); surgical problem.

  • Signs: losses from chest drains remain bright red and increase in amount or fail to decrease normally; tamponade; hypoventilation and / or poor unilateral chest movement; increasing abdominal distension.

  • Investigation and Management: notify surgeon early; measure Hb of chest drain fluid; repeat CXR if suspect tamponade or pneumothorax; check ACT, TEG, coagulation and platelets; give protamine 0.5mg/kg IV and repeat ACT; give platelets 10ml/kg; give FFP 10ml/kg if ACT, PT or APTT remain prolonged despite protamine; give cryoprecipitate if fibrinogen low; consider giving aprotinin if major bleeding persists despite the above; urgent Echo if tamponade is suspected.

    If Aspirin stopped within 4days of surgery, give DDAVP if post-op bleeding is a problem.

    Hypertension

    Common after repair of coarctation beyond the newborn period and after heart transplant. Other causes are pain, awareness, fits, full bladder, hypercarbia, vasoconstriction.

    Examine chest, abdomen, pupils and fontanelle. Check blood gases and glucose. Give a morphine bolus and reassess. Give a midazolam bolus and reassess. Start infusion of sodium-nitroprusside (SNP): start with 0.1mcg/kg/min and increase gradually to 2 - 3mcg/kg/min if required (beware of cyanide toxicity and methaemoglobinaemia, especially rising lactate). In a child > 1year of age, if HR > 100 and still hypertensive, give an IV beta blocker (esmolol) - cave: negative inotropic effect - or alpha blocker (phentolamine). Convert to bolus drugs when stable (atenolol, phenoxybenzamine, captopril). Avoid giving a calcium channel blocker plus a beta blocker.

    Hypotension

  • Causes: hypovolaemia; low cardiac output; excessive peripheral vasodilatation in the face of inadequate or limited cardiac output; has the child received a bolus of vasodilator (intermittently blocked CVC, sudden increase in flow of other fluid through the same line as the vasodilator); anaphylaxis; low-resistance pathway from the aorta (eg central shunt, MAPCAs, AV fistula).

  • Exclude all the causes of inadequate cardiac output. If hypotension is profound, raise the legs. Give a fluid bolus 10ml/kg and repeat if necessary (monitor RAP / LAP, may need > 10mmHg in the early postoperative Phase). If MAP < 25mmHg in a neonate or < 40mmHg in an older child, start external cardiac massage. Notify the cardiac surgeon. Give adrenaline bolus: 0.1ml/kg of 1:10.000; repeat if necessary and start an adrenaline infusion. If there is aorto-pulmonary runoff and a high saturation, reduce the FiO2 to 0.21, increase PaCO2 to 45 - 55mmHg and Hb to 140.

    Hypoventilation

  • Cardinal sign: rising PaCO2.

  • Causes: drugs, brain injury in theatre or post-operative, tracheal secretions, atelectasis, pneumothorax, pulmonary oedema or chest wall oedema, large leak around ETT or in ventilator circuit, changed ventilator settings, gas in stomach or recently started PD, muscle relaxant ceased (reduced chest wall compliance)

  • Signs: tachycardia and sweating, falling saturation and rising PaCO2, rising PA pressure, BP may rise (hypercarbia) or fall (impaired myocardial performance)

  • Management: examine chest and abdomen, blood gas, hand-ventilate, listen to chest, suction ETT yourself; obtain CXR, check ETT and ventilator circuit for leaks, check ventilator settings, increase ventilation or change ventilation mode if necessary, aspirate NG tube, drain ascites, hand ventilate and suction with saline for atelectasis.

    Hypoxaemia

    Falling PaO2 or falling saturation. Causes: any of the causes of hypoventilation; right-to-left shunt: intracardiac or intrapulmonary; parenchymal lung disease; pulmonary oedema; atelectasis; pneumonia; intrapulmonary haemorrhage.

  • Investigation: Is it real? If SpO2 falling, rapidly check the oximeter pulse wave, try the probe on yourself, change probe site. Take a blood gas sample immediately (noting the oximeter reading at the time) and monitor the patient closely for signs of cyanosis, hypotension and low cardiac output. Examine the chest. Manually ventilate and suction the trachea yourself. CXR. Investigate hypoventilation if PaCO2 raised. Take blood from LA and arterial lines and measure saturation to look for intracardiac right-to-left shunt. Bubble-contrast echocardiograph to locate intracardiac R-to-L shunt.

    Pulmonary Hypertension

    Usually occurs on a background of high pulmonary blood flow or left heart obstruction. Acute rises in PA pressure usually occur in response to hypoxia, hypercarbia, acidosis or handling but may also occur with transfusion of platelets or FFP or infusion of Protamine. It can also occur without stimulus or warning. High risk patients:

  • keep well sedated & paralysed for first 4-8 hours. Fentanyl 1 - 2mcg/kg pre suction and handling

  • minimize handling

  • aim for PaCO2 30-35, PaO2 >120 mmHg, pH >7.4

  • dobutamine plus milrinone is a good combination for systemic cardiac output and pulmonary vasodilation

  • start NO (10ppm) if increasing PA pressure causes tachycardia, hypotension, desaturation and signs of poor cardiac output or if mean PA pressure > half mean systemic BP

    In patients without a PA line, pulmonary hypertension may be indicated by acute desaturation, decreased lung compliance, wheeze and hypotension. (→→ Pulmonary Hypertension )

    ETT Suction

    Tracheal stimulation can cause severe increases in PA pressure. When suction is considered necessary, pre-medicate with fentanyl (1 - 2mcg/kg) to ablate airway responsiveness. Suction the ETT cautiously and quickly.

    Sepsis

    Increase in temperature ( →→ Fever and →→ Infection ); decrease in cardiac output; increase in pulmonary artery pressure; warm skin, bounding pulses and reduced aortic diastolic pressure; oliguria; decline in conscious state; increasing lactate and metabolic acidosis; unexplained increase or decrease in blood glucose; increased CRP or PCT; decreased platelet count.

  • Investigation: examine the child for evidence that sepsis is present and for a septic focus: wound, lungs, cannulation sites (including signs of caval thrombosis), meningitis, endocarditis (new murmurs, skin infarcts, fundi, splenomegaly, urinalysis), ears, paranasal sinuses (especially with prolonged nasal intubation), bones, joints, urinary tract. Repeat FBE and CRP. Blood cultures: percutaneous, arterial line and central venous cannula. Do not culture arterial line tip. Consider formal non-bronchoscopic bronchoalveolar lavage if there are lung opacities on chest x-ray. Culture drain fluid. Culture any pus and send a pus smear on a microscope slide for Gram stain. Culture urine from suprapubic aspirate or catheter (not from a bag specimen). Think of fungal sepsis: examine skin, mouth, larynx, fundi. Arrange ultrasound examination of kidneys.

  • Management: consider antibiotics (choice depends on probable organism: flucloxacillin (or vancomycin) plus gentamicin usually appropriate when the organism is unknown; monitor drug levels carefully; add oral nystatin). Review culture results and CRP daily. Cease antibiotics after 48 hours if culture results remain negative and clinical evidence of sepsis gone. Otherwise, continue antibiotics for 5days (longer for severe and intractable infections such as mediastinitis and endocarditis).

    Sweating

  • Causes: pain, awareness, high PaCO2 (inadequate alveolar ventilation), hypovolaemia, low cardiac output, hypoglycaemia, heart failure, drug withdrawal. Examine child (hydration, vein status, response to voice, passive movement and tracheal suction; other signs of sympathetic stimulation (such as pupils); review chart (change in pressures, HR, respiratory rate, temperature and ventilation); hand-ventilate and suction trachea; check gas and glucose; trial of fluid bolus 5 - 10ml/kg; trial of morphine bolus 50mcg/kg, repeat if necessary; try IV midazolam.

    Tachycardia

    An important sign that something is wrong. You must identify the cause: arrhythmia, low cardiac output, pulmonary hypertensive crisis, hypoventilation or hypoxaemia, hypoglycaemia, central (fits, fever, pain or full bladder), drugs (pancuronium or inotropes), anatomy (eg small LV).

    Examine the child: chest, abdomen, pupils, fontanelle. Check the heart pressures, temp, urine output, ECG, atrial electrogram. Check blood gases and electrolytes and glucose. Echo.

    Tachypnea

    If the respiratory rate rises progressively, a cause must be found.

  • Causes: pain or other distress; restrictive lung disease (pulmonary oedema, atelectasis, pulmonary haemorrhage, pneumonia); pneumothorax or pleural effusion; fever; sepsis; metabolic acidosis; pulmonary hypertension; neuromuscular weakness (residual relaxants or other cause).

  • Investigation: examine (chest, abdomen, pupils, muscle power, autonomic signs of distress, response to voice, passive limb movement and tracheal suction); review chart (PA and LA pressure, BP, temperature, urine output); blood gas; hand-ventilate and personally suction trachea; repeat CXR; consider trial bolus of morphine or midazolam; CRP; platelet count; culture blood, urine, tracheal aspirate and drain fluid; observe pattern of ventilation (shallow tachypnoea versus hyperpnoea; coordination with the ventilator). Increase ventilation (mandatory rate or support pressure) if muscle weakness present.

    Ventilator dependence

    A high pCO2 may be appropriate if there is metabolic alkalosis caused by hypochloraemia from diuretic use. Respiratory depression. Drugs or encephalopathy. Irregular, shallow breaths; high PaCO2; sleepy; may be other evidence of encephalopathy (eg fits); often prolonged or high-dose morphine or midazolam infusion; wait (days) for sedatives to be excreted; neurological examination; check fontanelle; cerebral ultrasound (insensitive) ± CT scan (wait several days). Phrenic nerve palsy. Unilateral or (rarely) bilateral; often transient (weeks); no ipsilateral inspiratory movement of abdomen. Diagnosis: ultrasound and / or X-ray image intensifier (screening) - both give false negatives. Plication should be considered early in a small infant with unilateral palsy who has failed extubation, and after a week of failed attempts in an older child (especially in palliative repair).

    Neuromuscular weakness. Residual muscle relaxants; previous period of poor cardiac output; impaired liver or kidney function; edema or ascites fluid store relaxant drugs; prolonged or high dose relaxants (especially if doses given before child moves). Diagnosis: train of four. Management: wait until movement returns (can lift legs off bed) before giving neostigmine-atropine; don't rely on neostigmine-atropine to reverse a profoundly paralysed child. ICU myopathy (prolonged IPPV + relaxants ± steroids ± sepsis; severely ill with normal train of 4); EMG and consult neurologists if suspected; pressure support ventilation + good nutrition + wait (avoid steroids and muscle relaxants)

    Pleural effusion. If drainage required (after discussion), send fluid for culture, cell count, triglycerides. Triglyceride >1.1 mmol/L (if fed) and cells > 1000/ŒºL with lymphocytes > 80% suggests chylothorax; Echo and Ultrasound (exclude SVC obstruction), change to Monogen, or stop feeds and give TPN (77% respond at a mean of 12 days, 45 days if MCT given); if no response by 14 days, consider trial of octreotide 5 mcg/kg/hr IV →→ Chylothorax

    Tracheobronchomalacia. Wheeze, prolonged expiration, and active use of expiratory muscles; gas trapping clinically and on CXR; bronchogram and / or bronchoscopy; use high CPAP (10 - 15 cmH2O); wean CPAP using deep sedation (morphine ± chloral ± diazepam ± chlorpromazine); anticipate days to weeks of repeated attempts to wean.

    Residual cardiac abnormality. Left-to-right shunt; obstruction in left heart or pulmonary veins; left-sided AV valve dysfunction; hypoplastic LV; PA stenosis or distortion in BCPS or Fontan patients. Cardiac catheter ± re-operation.

    [1] Pediatr Cardiol. 2013 Feb;34(2):341-7. McDonald ET AL: Impact of 22q11.2 deletion on the postoperative course of children after cardiac surgery.

    • Patient Discharge from PICU

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    THE BASICS: DISCHARGE FROM PICU

    Patients in the PICU will be evaluated and considered for discharge based on the reversal of the disease process or resolution of the physiological instability that prompted admission to the unit, and it is determined that the need for complex intervention exceeding ward capabilities is no longer needed.

    Transfer and / or discharge will be based on the following criteria:

  • Neurologically stable

  • stable hemodynamic parameters

  • intravenous inotropic support, vasodilators, and anti-arrhythmic drugs are no longer required (minimum for 4hours post ceasing)

  • haemodynamic monitoring catheters removed or capped and well secured. Once the line has been capped it is NOT to be flushed or re-used.

  • cardiac dysrhythmias are controlled

  • Pacing wires are generally removed after 24hours if there is no evidence of arrhythmia

  • stable respiratory status (patient extubated with stable arterial blood gases) and airway patency (minimum 4hours post extubation)

  • minimal oxygen requirements that do not exceed patient care unit guidelines

  • Approval for and timing of discharges must be by the Consultant or Fellow !

    PICU registrar discharge checklist:

  • enter a brief discharge note in the patients record before discharge, summarizing final diagnosis, main PICU therapies, current problems, current medications, and current management plan

  • complete the computer discharge summary

  • all notes and discharge summary need to be printed out and signed by registrar / fellow

  • complete ward drug chart, double check with pharmacist during duty hours for completion and correctness

  • Notify the cardiologist, surgeon and ward registrar, if not already advised

  • Generic PICU to Ward shared Handover to be filled in and signed: Handover given to ward physician, acute pain service informed or ward pain medication written up, plan of care and outstanding issues, blood results reviewed and / or actioned, timing and frequency on medical review, names of registrar / fellow, completed the discharge summary, name of the ward physician, name of the pain team

  • immediately prior to discharge examine the patient, collate investigations including that days x-ray and blood tests, review IV orders and drugs and check the medications and fluids for the ward are written

  • The patient's relatives must be aware of the discharge plan and notified when their child is moved

    • Cardiac Admission

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    THE BASICS: CARDIAC ADMISSION

    General principles: Anticipate the type of patient and potential problems ! Understand lesion/post correction basic physiology and common postoperative issues ! - Ask if needed !

    Admission: Expected admissions should be discussed in the morning ward round. Have a quick read through the PICU Cardiac Guideline or discuss with fellow or consultant about the lesion, surgery, expected problems and management. Theatre staff should call with an expected time of arrival at least 20min in advance. The theatre technician should also write a cardiac patient transfer report with details of procedure, lines, infusions etc. All patients returning from cardiac theatre need to get a cardiac surgical admission, even if they've been in PICU pre-op. If they return to theatre for a second or more procedures they will get cardiac surgical admissions each time.

  • Have cardiac handover sheet ready, write up blood form, CXR form.

  • Basic prescription for cardiac patients prior to arrival on the unit:

  • Venous Heparin flushes including flushes for intracardiac lines: Heparin infusion @ 10U/kg/hr for all babies less than 5kg with CVL

  • Arterial Heparin flush infusion & bolus

  • Sedation infusion & boluses (usually morphine and midazolam separately. Prescribe the STRONG morphine/midazolam for bigger children.)

  • Inotropes as per transfer note

  • Fluid boluses 5 - 10ml/kg NaCl 0.9% or Albumin 5%

  • For ECMO patients prescribe a PRN order for blood, platelets, FFP or Cryo. Also chart the ECLS Heparin flushes, dialysate order. Blood (packed cells and CMV -ve and irradiated for all infants less than 4month or if patient is +ve for 22 q11 or any other suspected immunodeficiency)

  • Antibiotics: Cephazolin 25mg/kg q8h for 3 doses plus Mupirocin 2% local application around nares q12h for 3 days plus Nystatin 100.000U PO q8h as long as on antibiotics in neonates. In open chest continue antiobiotics until chest closure.

  • Paracetamol: < 10kg 7.5mg/kg IV q6h, > 10kg 15mg/kg IV q6h, change to PO/NG as soon as able, up to 15mg/kg q4h.

  • Fluid allowance :

  • all non-bypass cases get 50% maintenance if > 10kg and < 10kg 2ml/kg/hr

  • for bypass cases > 10kg 30% maintenance and < 10kg 1ml/kg/hr; these fluids are upgraded with a general rule of increase of 1mL/kg/hr each day but check first i.e.

  • Day 1 - 30% maintenance or 1ml/kg/hr

  • Day 2 - 50% maintenance or 2ml/kg/hr

  • Day 3 - 75% maintenance or 3ml/kg/hr

  • Day 4 - full maintenance

    Cardiac pre op (if patients are going to OT from PICU):

  • Ensure 4 units packed cells, 2 units platelet, 2 units FFP, 2 units Cryoprecipitate are ready for all pre op cardiac patients if in PICU prior - need to liaise with Blood Bank

  • Crossmatch is on a separate form (pink ones) and MUST ensure that the sample goes in a EDTA top tube with an HANDWRITTEN label (blood bank will reject samples with signed labels)

  • With neonates make sure pre-op Chromosomes & GN FISH for 22q11 has been sent especially in outflow obstructive lesions.

  • These patients will get a routine medical admission and then cardiac surgical if they have surgery or a procedure in cathlab.

  • Prescribe Mupirocin 2% local application around nares q12h, ideally for 2 days prior to cardiac procedure.

  • Examine the patient just prior to scheduled departure time and hand over to anesthetist.

    Transfer of cardiac patient to PICU:

  • Phase 1: Pre handover

  • approximately 30 min before arrival on PICU, "Cardiac Patient Transfer Report" completed by anesthetic technician. PICU informed of ETA by phone.

  • Phase 2: Equipment and Technology handover

  • On arrival on PICU ventilation, monitoring and support pumps are transferred across prior to handover. Discussion should be kept to a minimum at this point.

  • The anesthetist will supervise and direct this transfer with assistance from the anesthetic technician, OR nurse and PICU team.

  • Safety Check: once transfer has occurred the delivery team checks that the patient is stable and ventilation is occurring and checks that the PICU team is ready for handover.

  • At this point the OR nurse may leave if they wish. All activity with the exception of observing the patient and monitoring ceases.

  • Phase 3: Information handover

  • The anesthetist and then the surgeon hands over the patient (preferably without interruption unless a member of the team identifies an urgent issue of stability in which case handover should pause while it is dealt with). The information will be presented in a standard order consistent with the Cardiac Surgical admission sheet.

  • Safety Check: The PICU team listens and takes notes, they use the Cardiac Surgical Admission sheet to ensure that they have all necessary information and ask any relevant questions.

  • Phase 4: Discussion and Plan

    The team discusses the case, anticipate problems and agree on a documented plan.

    The ICU team now assumes responsibility for the patient and commence routine observations and management.

    Notes:

  • The chief operating surgeon, anesthetist and admitting intensivist should all be present at the handover.

  • In the event of an arrest during handover - the anesthetist will run things until the PICU consultant feels they have enough information to do so, or to take over. The person in charge should say something along the lines of "I will run this" so it's clear for all. The handover sheet "Cardiac Surgical Admission" - may be filled out by the anesthetist in theatre if there is adequate time.

    Important details to remember:

  • Operation performed and the duration of CPB and aortic cross clamping (latter being time of 'cardioplegia')?

  • Check if there are any concerns regarding anatomy or repair (e.g. coronaries, size of shunt, etc.) or pulmonary hypertension?

  • Note pressures (RAP/CVP/PA, LAP and MAP), cerebral saturations, cardiac rhythm and oxygen saturations in theatre.

  • Note intra-operative problems and any complications encountered - during induction, arrhythmia, pacemaker use, coming off CPB problems, bleeding and blood products given, and medications given.

  • Ask what blood products are available (unused from theatre).

  • Discuss with consultant about plan/desired parameters and expected problems and their management.

    Initial Assessment:

    Quick assessment focusing on cardiovascular stability and adequate ventilation (vital signs and chest movement) as patient arrives from theatre.

  • Review current support drugs - inotropes and/or vasodilators

  • Review with nurses that the patient is safely connected to ICU support and monitoring equipment. Check ventilator settings

  • Review anesthetic, CPB charts and operation or any intra-operative TOE notes. Look for difficult airway, anesthetic medications given, heart function, and residual lesions

  • Detailed physical examination

  • Request: ABG / VBG / FBC / U&E / Calcium, Mg, PO4 / Coagulation profile, TEG / CXR

  • Document clinical findings and plan in the cardiac surgical admission

  • Review as soon as possible CXR (check position of ETT, temperature probe, lines, drains, any pneumothorax/effusion), and first set of blood results - ventilation settings may need adjustment according to ABG

  • Check baseline ECG

    Ongoing Management:

  • Adequate Opiate Analgesia. Titrate other sedatives as required

  • IV infusion of Muscle relaxant if cardiovascular unstable

  • Support the circulation - see lesion specific modules

  • Treat Arrhythmias ( →→ Arrhythmia )

  • Bleeding > 3ml/kg/hr investigate ( →→ Chest Drains ). If > 10ml/kg/hour or a sudden stop in drainage needs urgent surgical & cardiology review. A quick bedside scan with the ultra-sound machine in the unit maybe useful.

  • Fluid resuscitate, send FBC and coagulation profile. Consider TEG & replace factors as indicated (most likely to need cryoprecipitate and platelets)

  • Watch for tamponade ! If suspected quick bedside scan with the ultra-sound machine in the unit maybe useful →→ Tamponade

  • Packed cells 4 ml/kg raises Hb by 1g/dl

  • Follow unit antibiotic policy

  • Investigations: FBC, U&E, LFT, Ca /Mg / PO4. Coagulation for post-op on first few days or when lines/drains coming out. CRP if previous high value or if suspicion of sepsis

  • If intracardiac lines going to be removed the next day then needs coagulation profile (plus crossmatch with blood available in theatre fridge - important to check that the blood is physically in the theatre fridge, not back in Blood Bank, the bedside nurse will usually do this, just confirm)

    Cardiac handover:

    Keep it short/simple & sweet. Please SPEAK UP!

  • Name, age and day post-op

  • Lesion & procedure done

  • Cardiovascular - HR, rhythm, BP, +/- pacing required, trends

  • Blood products if any given

  • Ventilations: Adequate gas exchange or mention issues if any

  • Gases - include lactates and mixed venous, trends

  • Fluids balance and urine output / PD for last 24 hrs

  • Drain losses - type eg. blood, serous, serosanguineous.

  • Trend of last 6 - 8hrs

  • Mention bloods if something grossly abnormal

  • If CXR done & seen mention briefly.

  • ECMO - flow, sweep, inlet and outlet pressures, ACT's, blood products given, bleeding, circuit (i.e. clots), arterial line trace (pulsatile or non pulsatile)

    The seven vital causes to remember of postoperative Tachycardia:

  • CNS: fever, pain, inappropriate sedation and analgesia, seizures

  • CVS: low cardiac output

  • CVS: Tachyarrhythmia

  • Respiratory: hypoxia, hypercarbia

  • Pulmonary Hypertension

  • Drugs: catecholamines

  • Residual defects

    • Empiric Antibiotics for General Infection

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    THE BASICS: EMPIRIC ANTIBIOTIC GUIDELINES FOR GENERAL INFECTION

    Age

    if meningitis excluded

    if meningitis is NOT excluded

    if Staphylococcus aureus suspected

    < 3 months

    Amoxicillin 50mg/kg q6hr

    Gentamycin 7.5mg/kg q24hr

    Amoxicillin 50mg/kg q6hr

    Gentamycin 7.5mg/kg q24hr

    Cefotaxime 50mg/kg q6hr

    consider especially in infants Aciclovir 20mg/kg q8hr

    Amoxicillin 50mg/kg q6hr

    Cefotaxime 50mg/kg q6hr

    Vancomycin 15mg/kg q6hr

    Clindamycin 15mg/kg q8hr

    > 3 months

    Cefotaxime 50mg/kg q6hr

    Flucloxacillin 50mg/kg q4-6hr

    Cefotaxime 50mg/kg q6hr

    Flucloxacillin 50mg/kg q4-6hr

    Cefotaxime 50mg/kg q6hr

    Vancomycin 15mg/kg q6hr

    Clindamycin 15mg/kg q8hr

    any age group, if immuno-compromised

    Meropenem 20mg/kg IV q8hr

    Vancomycin 15mg/kg q6hr

    Gentamycin 7.5mg/kg q24hr

    if Meningitis is NOT excluded, and suspicion of severe Meningitis (gram stain), replace Flucloxacillin by Vancomycin 15mg/kg q6hr to cover for Penicillin resistant Pneumococcus Meningitis

    Formulae

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    THE BASICS: FORMULAE

    Body Surface Index (BSA) =

    = ( [Height(cm) x Weight(kg) ] / 3600 )½

    Mean Arterial Blood Pressure (MAP) = (SBP + 2 x DBP) / 3

    Transpulmonary Gradient (TPG) =

    = mPAP - PCWP or in Glenn / Fontan: SVC (CVP) - LAP

    Cardiac output (CO) = SV x HR. normal: 2.1 - 3.5 l/min/m2

    Cardiac index (CI) = CO / BSA. normal 3.0 - 5.5 l/min/m2

    Systemic vascular resistance index (SVRI) =

    = 80 x (MAP - CVP) / CI. normal 800 - 1600 dyne*sec/cm5/m2. SVRI / 80 = normal 15 - 30 Wood unit / m2

    Pulmonary vascular resistance index (PVRI) =

    = 80 x (MPAP - LAP) / CI. normal 80 - 240 dyne*sec/cm5/m2. PVRI / 80 = normal 1 - 3 Wood unit / m2

    Stroke Volume (SV) = CO / HR. normal 1 - 1.5 ml/kg

    Ejection Fraction (EF) = (EDV - ESV) / EDV. normal 55 - 75 %

    Fractional Shortening (FS) = (LVEDD - LVESD) / LVEDD. normal 28 - 45 %

    Modified Bernoulli Equation: p1-p2=4 x v2.

    relates the pressure drop (or gradient) across an obstruction

    Flow resistance. Poiseuille's Law: R = 8 x η x L / π x r4

    ( η = viscosity, L = length, r = radius). laminar flow only

    Right ventricular Pressure (RVP) = 4 x TR Vmax2 + RAP

    Pulmonary to systemic blood (Qp : Qs) =

    = (SaO2 - SmvO2) / (SpvO2 - SpaO2). normal 1.0.

    in parallel circulation Qp : Qs ~ 25 : (95 - SaO2)

    Oxygen Delivery (DO2) = CI x Hb (g/l) x SaO2

    Oxygen consumption (VO2) =

    = CI x Hb (g/l) x 1.36 x ((SaO2 - SmvO2) / 100).

    normal: infant 160-180, child 100-130, adult 120-150 ml/min/m2

    QT interval. Bazett's formula: QTc = QT (sec) / SqrRt of previous RR interval (sec). normal approximately < 0.44 sec

    Definitions

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    THE BASICS: DEFINITIONS

    Aortic cross-clamp time. Duration of clamping of the aorta during bypass. Independent risk factor for postoperative mortality.

    CCF. Congestive Cardiac Failure.

    Cardio-pulmonary bypass (CPB). All blood returning to the right atrium is pumped to a device that adds O2 and removes CO2, and the blood is then returned to aorta.

    Circulatory arrest time (arrest time). Duration of total circulatory arrest

    (Cox) - Maze Procdure. Surgical procedure with left atrial, right atrial and atrioseptal incisions to prevent atrial flutter / fibtrillation.

    DHCA. Deep Hypothermic Cardiac Arrest.

    Extracorporeal membrane oxygenation (ECMO). A form of extracorporal life support, but without the means of returning blood lost into the thorax back to the circuit.

    LVEDP. Left Ventricular enddiastolic pressure.

    LVH. Left Ventricular Hypertrophy.

    MR or MI. Mitral Regurgitation / Insufficiency.

    MS. Mitral Stenosis

    PBF. Pulmonary Blood Flow.

    Qp. Pulmonary Blood Flow.

    Qs. Systemic Blood Flow.

    Qp : Qs. Ratio of pulmonary to systemic blood flow. (normal physiology 1 : 1)

    RVH. Right ventricular Hypertrophy.

    RVOTO. Right-ventricular outflow obstruction.

    SmvO2. Mixed Venous Saturation. Indication for oxygen consumption and CO (SaO2 - SmvO2 < 30%)

    TR or TI. Tricuspid Regurgitation / Insufficiency

    TS. Tricuspid Stenosis.

    Ventricular assist device (VAD). Form of extracorporal life support, where a blood pump with axial, laminar or pulsatile flow to augment the function of the left ventricle (LVAD), right vent¬ricle (RVAD), or both (BiVAD - using two pumps).

    Central Venous Catheters

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    THE BASICS: CENTRAL VENOUS CATHETERS

    Use of central venous catheters in the acute care setting is an integral approach to deliver fluids, blood products, nutrients, medications, obtaining blood specimens, maintaining emergency vascular access, and for haemodynamic monitoring.

    Risk factors: mechanical complications (malposition, occlusion, dislodgement, tamponade), infection, pneumothorax, thrombosis

    Insertion:

    Ask nurse to complete the checklist and to stop you if you are about to breach the rules !

  • maximal sterile barriers for insertion

  • use chlorhexidine lollipops - the use of liquid in pot is absolutely forbidden !

  • dedicated equipment cart easily accessed

  • use of a procedural pause "stop the line" if barrier precautions are breached

  • use of chlorhexidine impregnated patch at insertion site

  • appropriate dressings used over insertion site

  • radiographical confirmation of catheter tip position

  • always transduce pressure waveform (with heparin !!)

  • details of insertion documented in patient record

    Maintenance:

  • commence Heparin 10U/kg/hr in patients < 5kg

  • daily review of lines with prompt removal of unnecessary lines

  • use of closed needless mechanical valve on each lumen

    [1] http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5110a1.htm

    [2] The Pediatric Infectious Diseases Journal, 2010; Sept 29(9): 812 -815: Prasad et al: Risk Factors for Catheter-associated Bloodstream Infections in a Pediatric Cardiac Intensive Care Unit.

    • Infection

    Home

    THE BASICS: INFECTION

    Surgical Site Infection (superficial / deep / organ):

  • Prevalence 5 - 10%

  • within 10 - 14days post surgery

  • most common: Staphylococcus aureus

  • risk factors: neonate, HLHS, hospitalization prior surgery, TPN, emergency procedures, long CPB

    Blood Stream Infection:

  • Prevalence 5 - 10%

  • within 10 - 14days post surgery

  • most common: gramnegative organism (Pseudomonas, Enterbacter)

  • risk factors: surgical complexity, open sternum, low body weight, longer duration of central line, prolonged ICU stay

    Pulmonary Infection:

  • Prevalence 10%

  • risk factors: prolonged mechanical ventilation, surgical complexity, low cardiac output syndrome, failed extubation

    Current recommendation for antimicrobial Prophylaxis in Cardiac Surgery: Cefazolin up to 72hrs (prolonged use may increase antimicrobial resistance). In the setting of either a presumed or known Staphylococcal colonization, the institution presence of a high incidence of MRSA, patients susceptible to colonization, or an operation for a patient having prostethic valve or vascular graft insertion, it would be reasonable to combine the beta-lactam with a glycopeptide (Vancomycin) for prophylaxis.

    Special considerations in immunodeficient syndromes (DiGeorge Syndrome, postoperative →→ Chylothorax ).

    See also →→ Sepsis and →→ Fever

    [1] Am J Infect Control 2010 Nov;38(9):706-710: Sohn et al: Risk factors and risk adjustement for surgical site infections in pediatric cardiothoracic surgery patients

    [2] Pediatr Cardiol 2010 May;31(4): 483-9: Abou Elella et al: Impact of bloodstream infection on the outcome of children undergoing congenital heart surgery

    [3] Am J Health Syst Pharm 2008 Nov 1;65(21): 2008, 2010: Survey of congenital heart surgeons' preferences for antimicrobial prophylaxis for pediatric cardiac surgery patients

    [4] Ann Thorac Surg 2007 Apr; 83(4): 1569-76: Engelman et al: The Society of thoracic surgeons practice guideline series: Antibiotic prophylaxis in cardiac surgery, Part II: Antibiotic Choice

    • Frank Starling Mechanisms

    Home

    THE BASICS: FRANK STARLING MECHANISMS

    Increased Preload

    Increased Preload

    (A →B)

    → increased LV Volume

    → increased Stroke Volume

    Increasing Preload above diastolic compliance

    → Failure (F)

    Improved diastolic compliance

    Improved diastolic compliance

    (A → B)

    → increased LV Volume

    → increased Stroke Volume

    Increased Inotropy

    Increased Inotropy

    (A → B)

    → increased Stroke Volume

    Decreased Afterload

    Decreased Afterload

    (A → B)

    → increased Stroke Volume

    Resuscitation Quick Chart

    Home

    RESUSCITATION QUICK CHART

    AGE/WT

    BP SYS

    HR

    RR

    ETT

    ETT lip/nose

    DC Shock 4 J/kg

    Fluid 20 ml/kg

    Term / 3.5

    50

    100 - 180

    40 - 60

    3.0

    8.5 / 10.5

    14

    70

    3 m / 5

    50

    100 - 180

    30 - 50

    3.5

    9.5 / 11

    20

    100

    6 m / 8

    60

    100 - 160

    30 - 50

    4.0

    10 / 13

    32

    160

    1 y / 10

    65

    100 - 140

    25 - 45

    4.0

    11 / 14

    40

    200

    2 y / 13

    65

    80 - 130

    20 - 30

    4.5

    12 / 15

    50

    260

    5 y / 17

    70

    70 - 110

    15 - 25

    5.0

    14 / 17

    70

    340

    10 y / 30

    85

    60 - 105

    15 - 20

    6.0

    17 / 21

    120

    600

    14 y / 50

    90

    50 - 100

    15 - 20

    7.5

    19 / 23

    200

    1000

    17 y+ / 70

    90

    50 - 100

    15 - 20

    7.5

    19 / 23

    360

    1000

    AGE/WT

    Epi 1:10000

    Epi 1:1000

    Amiodarone
    [150mg/3ml]

    Dextrose 10% [ml]

    Mannitol 20%
    [ml]

    Term / 3.5

    0.4

    0.3

    15

    7.5

    3 m / 5

    0.6

    0.5

    25

    12.5

    6 m / 8

    0.8

    0.8

    40

    20

    1 y / 10

    1.0

    0.1

    1.0

    50

    25

    2 y / 13

    1.5

    0.2

    1.3

    65

    32

    5 y / 17

    2.0

    0.2

    1.7

    85

    40

    10 y / 30

    3.0

    0.3

    3.0

    150

    65

    14 y / 50

    5.0

    0.5

    5.0

    250

    125

    17 y+ / 70

    10.0

    1.0

    7.0

    500

    250

    Neonatal Resuscitaion Guideline

    Home

    NEONATAL LIFE SUPPORT

    Resuscitation Drug Chart

    Home

    RESUSCITATION DRUG CHART

    [1] APLS, the pediatric emergency medicine resource,4e; Jones and Bartlett Publishers

    Paediatric Advanced Life Support

    Home

    Paediatric Advanced Life Support

    [1] APLS, the pediatric emergency medicine resource,4e; Jones and Bartlett Publishers

    [2] Resuscitation Council UK

    Analgesia and Sedation

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    ANESTHESIA: ANALGESIA AND SEDATION

    Basic Pharmacology for PICU

    Routes of administration and systemic absorption of drugs:

    Rate of systemic absorption determines onset, intensity and duration of action. Drug solubility and blood flow to the site of absorption are the most important factors:

    Oral/enteral:

  • most convenient & economic route of administration

  • complicated by nausea/emesis & irregularities in absorption

  • principle site of absorption is the small intestine

  • GI mucosa and the liver contribute to extraction and metabolism of drugs

    Oral/nasal transmucosal: drains to the SVC and / or VIJ and bypasses 1st pass hepatic metabolism

    Rectal:

  • highly unpredictable and irritant to rectal mucosa

  • absorption is slow due to the small available surface area

  • distal rectal administration will bypass 1st pass hepatic metabolism

  • proximal rectal administration will not bypass 1st pass hepatic metabolism

    Parenteral:

  • includes subcutaneous, intramuscular and intravenous routes

  • absorption is more reliable and complete

  • IV administration avoids factors that limit systemic absorption by other routes and is a more comfortable way to administer irritant drugs

    Neuraxial:

  • epidural route is used to provide analgesia and anesthesia

  • significant systemic absorption may occur through the epidural venous plexus especially with lipid soluble drugs and continuous infusions (eg. fentanyl)

  • intrathecal or spinal administration rarely causes unwanted systemic effects

    Distribution of drugs after systemic absorption:

    Highly perfused tissues (heart, lungs, brain, kidneys and liver) receive a disproportionate amount of drug and initially sequester it from the plasma. Once plasma concentration falls following a bolus dose, drug will redistribute back into the plasma.

    Following a bolus dose, plasma concentration first falls rapidly during the distribution phase and then more gradually during the elimination phase.

    Remember that increasing an infusion of a drug to increase its desired effect should be preceded by a repeat bolus / load otherwise its effect will take ~5 half times !

    Repeated large doses and / or prolonged infusions will saturate inactive tissues which will then act as reservoirs and prolong the duration of action of drugs.

    Pharmacokinetic variables:

    Volume of distribution (Vd):

  • apparent volume a drug is injected into (calculated from dose and initial plasma concentration before any clearance)

  • determinant of elimination half time (t½β)

  • depicts the distribution characteristics of a drug in the body

  • used to determine loading doses

  • mainly influenced by physicochemical characteristics of the drug

    Metabolism:

  • hepatic microsomal enzymes are responsible for most drug metabolism

  • hepatic extraction may be perfusion dependent (affected by hepatic blood flow) or capacity dependent (affected by ionisation and protein binding)

  • lungs (eg. catecholamines), kidneys (eg. morphine) and the GIT have considerable drug metabolising ability

  • Plasma cholinesterase and non-specific esterases are important in drugs containing ester bonds (eg. Esmolol, Succinylcholin)

  • Hoffman elimination is spontaneous non-enzymatic breakdown (eg. cisatracurium)

    Clearance (Cl):

  • volume of plasma cleared of drug per unit time

  • determinant of elimination half time (t½β)

  • metabolism, excretion and non-organ clearance (eg. ester hydrolysis) all contribute to clearance

  • may be 1st order (proportional to plasma concentration) or zero-order (constant amount of drug cleared independent of plasma concentration)

    Half times:

  • time necessary for the plasma concentration of a drug to decrease by 50% (t½β ~ Vd/Cl)

  • can be during distribution ( t½α) or elimination (t½β)

  • plasma concentration does not always correlate with the clinical effect of the drug

  • elimination half time determines the dosing interval to achieve steady state (~5 half times)

  • context sensitive half time (CSHT) is the time necessary for the plasma drug concentration to decrease by 50% after ceasing a continuous infusion of a specific duration (context = duration of infusion)

    Effect site equilibration time (ESET):

  • delay between IV administration and onset of clinical effect reflects the delay in delivery of the drug to its site of action and subsequent dynamic response

  • mainly determined by physicochemical properties of the drug

  • important in determining dosing intervals when titrating to effect

    Physicochemical properties of drugs:

    Ionization: most drugs are present as both ionized and non-ionized molecules / proportion is determined by the pK of the drug and the pH of the surrounding fluid / only non-ionised drug is free to diffuse across membranes, be metabolized or be excreted

    Protein binding: a variable amount of drug may be bound to various plasma proteins which affects distribution / clinically significant protein binding is > 90% / acidic and neutral drugs generally bind to albumin and alkaline drugs generally bind to alpha1-acid glycoprotein / only unbound drug is free cross membranes, be metabolized or excreted

    Molecular size: small molecules diffuse much more readily than large ones.

    Lipid solubility: ability to physically diffuse through cell membranes (does not necessarily correlate with rapid onset of action).

    Isomerism: mixtures often contain either inactive isomers or isomers that have different and / or adverse clinical effects (racemic and non-enantiopure preparations can be considered mixtures of different drugs).

    Individual variability in dynamic response:

  • The response (therapeutic and adverse effects) to many drugs varies widely among patients.

  • There is up to a five-fold range of plasma concentrations required to achieve the same pharmacologic effect in different individual patients.

  • There is up to a two-fold range of plasma concentrations required to achieve the same pharmacologic effect in the same patient using the same dosing regime.

  • Absorption and bioavailability as well as variations in cardiac, renal and hepatic function contribute to inter- and intra-individual variability.

  • Enzyme activity (eg. induction/inhibition) and genetic factors (eg. fast / slow acetylators) also play a role.

    Effects of age and disease:

    Renal disease will affect drugs excreted by the kidneys to an extent proportional to the degree to which the drug depends on renal excretion.

    Hepatic disease alters plasma protein levels (decreased binding), increases Vd (ascites), reduces metabolism and may alter bioavailability (decreased 1st pass metabolism and / or porto-caval collaterals).

    Neonates and Infants:

  • proportionally more water, larger intravascular volume and larger highly perfused organs

  • immature blood-brain barrier makes them more sensitive to drugs acting in the CNS

  • immature and inefficient hepatic metabolizing capacity and lower plasma protein levels

  • GFR < 10% of adult values will affect clearance

    Sedatives and Analgesics

    Intravenous anesthetic agents (see Table):

  • classified as barbiturates (Thiopentone) and non-barbiturates (Propofol and Ketamine)

  • Thiopentone use is largely limited to induction in status epilepticus and for treatment of raised ICP; it has no analgesic properties and is in fact anti-analgesic at sedative doses.

  • Propofol is suitable for induction (bolus) and maintenance of sedation / anesthesia (infusion); it is suitable for discrete painful procedures but has only minimal analgesic properties at sedative doses and so must be combined with a suitable analgesic.

  • Propofol is a direct myocardial depressant and so should be used in caution in patients in (or at risk of) low cardiac-output syndrome (LCOS). It obtunds the normal baroreceptor reflex and so causes a decrease in blood pressure and heart rate.

  • Ketamine is a dissociative anesthetic that is also a potent analgesic; it is suitable for discrete painful procedures but increases respiratory secretions and is complicated by psychadelic phenomena. Midazolam is suitable to treat or obviate Ketamine's emergence phenomena but will prolong recovery time.

  • combined Ketamine and Propofol in a ratio ranging from 1:1 to 1:4 (Ketofol) is becoming a popular awake-sedative to facilitate medical procedures.

    Narcotics (see Table):

  • Morphine, Fentanyl and Methadone are effective analgesics and sedatives; Oxycodone is also a popular analgesic but is less sedating.

  • Levels of sedation, analgesia and respiratory depression do not correlate (patients may be well sedated and have respiratory depression but not have adequate analgesia).

  • Morphine is not a suitable narcotic for discrete painful procedures due to its long and unpredictable effect site equilibration time (Fentanyl is more appropriate).

  • Fentanyl is often used epidurally and results in significant systemic absorption of drug and resulting side effects.

  • Sufentanil, Alfentanil and Remifentanil are phenylpiperidine narcotics used to provide the analgesic component of general anesthesia. They are very infrequently used in PICU.

  • All have predictable effects which include respiratory depression, cough suppression, sedation, meiosis, biliary spasm, constipation, nausea and vomiting, urinary retention and cutaneous flushing (especially about the face).

    Benzodiazepines (see Table):

  • Midazolam and Diazepam are effective sedative agents commonly used in PICU.

  • They are direct myocardial depressants via blockade of voltage-gated calcium channels (use carefully in patients with LCOS).

  • Midazolam is also used to acutely treat seizures in bolus doses and in infusions (up to 1mg/kg/hour).

  • They are less likely to produce withdrawal syndromes than barbiturates and narcotics (but no analgesic effect).

    Alpha2 agonists (see Table):

  • Clonidine and Dexmedetomidine are sedative / anaesthetic agents employed as sedatives in PICU; they also treat symptoms of drug withdrawal.

  • Their main advantage is lack of respiratory depression which allows quicker weaning of mechanical ventilation.

  • They obtund central (brain and spinal cord) sympathetic outflow resulting in negative inotropy and chronotropy and so should not be combined with direct myocardial depressants (Benzodiazepines, Propofol etc.) in patients at risk of (or in established) LCOS.

  • They cannot be bloused as this can lead to transient alpha1-agonism and severe hypertension.

    Local anaesthetics:

  • Local anaesthetics block voltage gated sodium channels and so prevent conduction along central and peripheral nerve pathways.

  • Lignocaine is commonly locally infiltrated for short painful procedures (eg. suturing, insertion of chest drains etc).

  • Bupivacaine and Ropivacaine are generally used for regional blocks and neuraxial infusions.

  • Levobupivacaine (S-bupivacaine) and Ropivacaine are enantiopure preparations. Cardiotoxicity is less.

  • 0.5% solutions contain 5mg/mL; 1% solutions contain 10mg/mL; 2% solutions contain 20mg/mL etc. (1% = 10mg/ml)

  • Onset of effect is related to the pKa of the drug; potency is related to lipid solubility; and duration of action is related to protein binding.

  • Systemic absorption of local anaesthetics depends on site of infiltration: intercostal > subarachnoid > epidural > brachial plexus > femoral > subcutaneous.

  • Vasoconstrictors (Adrenaline) slow systemic absorption and increase the maximum safe dose

  • EMLA is a mixture of 2.5% Lignocaine and 2.5% Prilocaine used for topical anaesthesia prior to cannulation / incision; Prilocaine can induce Methaemoglobinaemia and application to mucous membranes will result in rapid systemic absorption of drug.

  • CNS toxicity manifests first as excitatory phenomena (circumoral tingling, tinnitus, dizziness and tremors / seizures) followed by CNS depression (unconsciousness, apnoea and coma).

  • CVS toxicity manifests as systemic hypotension, myocardial depression, ventricular arrhythmias and cardiovascular collapse.

  • Treatment of local anaesthetic toxicity is by supportive therapy (airway management, treatment of seizures with Benzodiazepines, fluids +/- inotropes / vascoconstrictors) and administration of 20% lipid emulsion (Intralipid) if in cardiac arrest: 1.5mL/kg over 1 minute followed by an infusion of 0.25-0.5ml/kg/min; repeat bolus doses every 5 minutes during CPR.

    Non-steroidal anti-inflammatory drugs (NSAIDs):

  • Classified as specific (COX-2 eg. Parecoxib) or non-specific (COX-1 and COX-2 eg. Ibuprofen).

  • Adverse GI effects are due to decreased mucosal blood flow and decreased secretion of mucus and bicarbonate.

  • Platelet thromboxane A2 is produced from prostaglandins and so NSAIDs impair platelet aggregation.

  • Prostaglandins are vasodilators involved in physiologic control of vasomotor tone (especially in the kidneys) and their inhibition leads to unopposed vasoconstriction.

  • Inhibition of prostaglandin synthesis leads to shunting of arachnidonic acid to lypoxygenase which is a bronchoconstrictor.

  • Specific COX-2 inhibitors are considered to lack effects on platelets and the GIT but will still affect vasomotor tone.

  • Their use in PICU needs careful consideration due to their wide range of potential side effects.

  • Paracetamol is generally considered a (central) COX-3 inhibitor; it also acts peripherally by inhibiting bradykinin-chemoreceptor associated pain impulse generation.

    Other (see Table):

  • Chloral hydrate is a prodrug that produces the halogenated alcohol Chloroethanol; its mechanism is poorly understood but probably acts in a similar way to the volatile halogenated gases via central GABA-A receptors.

  • First-generation antihistamines (eg. Promethazine, Cyclizine etc.) are also effective sedatives by virtue of their anticholinergic properties; they are generally only used when specific antihistaminergic and / or anticholinergic properties are desired (eg. antisialogogue for secretions, anti-tussive).

    Table: intravenous anesthetic agents

    Thiopentone

    Propofol

    Ketamine

    Type/class

    Barbiturate

    Isopropylphenol

    Phencyclidine

    Mechanism

    GABAA & glycine agonist

    GABAA & glycine direct agonist and central nicotinic antagonist

    (Possible 5HT3 blockade)

    NMDA non-competitive antagonist & blocks central catecholamine reuptake

    Oral bioavailability

    -

    -

    25%

    Oral dose

    n/a

    n/a

    5mg/kg

    IV Bolus

    2-7mg/kg

    1.5-2.5mg/kg

    0.25-0.5mg/kg (analgesia)

    1-5mg/kg (GA)

    IV Infusion

    1-5mg/kg/hour

    1-4mg/kg/hour (sedation)

    5-15mg/kg/hour (GA)

    10-40mcg/kg/hour

    Onset time IV

    < 30seconds

    < 30seconds

    30-60seconds

    ESET

    30 seconds

    < 30 seconds

    60seconds

    pKa

    7.6

    11

    7.5

    UNionised fraction

    60%

    > 99%

    45%

    Protein binding

    80%

    99%

    25%

    Vd

    2.5L/kg

    4L/kg

    3L/kg

    Clearance

    3mL/min/kg

    50mL/min/kg

    15mL/min/kg

    t ½-dist

    8minutes

    4 minutes

    12minutes

    t ½-elim

    12hours

    30-60minutes

    2-3hours

    Metabolism

    Hepatic (may become zero-order with prolonged infusion)

    Some active metabolites

    -Hepatic (CYP2C9 & 2B6) & extrahepatic (site/s unknown)

    Inactive metabolites

    Hepatic

    Active metabolites

    Excretion

    Urine

    Urine

    Urine

    Hepatic failure

    No effect

    No effect

    Decreased clearance

    Renal failure

    Active metabolites will accumulate

    No effect

    No effect

    Pros

    Rapid onset

    Anticonvulsant

    Can produce isoelectric EEG (maximal decreased cerebral metabolic O2 demand)

    Rapid onset & titratability

    Bronchodilator

    Will obtund airway reflexes

    Anticonvulsant

    Antiemetic & antipruritic properties at low doses

    Can produce isoelectric EEG

    Mild analgesic properties

    Stable CSHT (< 40mins even after > 8 hrs infusion)

    Intense analgesia at low dose

    Favourable haemodynamic profile due to increased central sympathetic outflow

    Bronchodilator

    Prevents & treats opioid tolerance

    No respiratory depression / apnoea

    Cons

    Resp depression / apnoea

    Antanalgesic

    Can produce paradoxical excitement

    Will accumulate with prolonged infusion (long CSHT)

    Tolerance & withdrawal are a problem

    Resp depression / apnoea

    Myocardial depressant

    Can cause a refractory bradycardia (need β-agonist)

    Rarely causes propofol-infusion syndrome

    Formulation contains soybean oil & egg lecithin

    Myocardial depressant

    Emergence delirium (especially in older patients - consider midazolam)

    Increased secretions (consider glycopyrrolate)

    BrainZ/BIS inaccurate

    Other points

    ¯BP (¯SVR)

    ­HR (reflex)

    Wont obtund airway reflexes

    Racaemic formulation

    ¯BP

    (¯SVR & ¯CO)

    ¯HR (obtunded baroreceptor reflex)

    EEG dissociation between thalamus & cortex

    Wont obtund airway reflexes

    Typical induction agent in asthma & sepsis

    Table: Benzodiazepines

    Midazolam

    Diazepam

    Flumazenil

    Type/class

    BDZ

    BDZ

    BDZ

    Mechanism

    GABAA receptor indirect-agonist

    GABAA receptor indirect-agonist

    BDZ receptor competitive antagonist

    Oral bioavail

    40%

    95%

    25%

    Oral dose

    0.5mg/kg up to 20mg

    0.05-0.2mg/kg

    n/a

    IV Bolus

    0.05-0.2mg/kg

    up to 5mg/dose

    0.05-0.4mg/kg

    up to 10mg/dose

    8-15mcg/kg

    up to 200mcg/dose

    IV Infusion

    10-100mcg/kg/hour

    n/a

    2-10mcg/kg/hour

    Onset time IV

    1-2mins

    1-2mins

    1-2mins

    ESET

    5mins

    5mins

    5-10mins

    pKa

    6.2

    3.3

    1.8

    % UNionised

    90%

    >99%

    >99%

    Protein binding

    95%

    95%

    50%

    Vd

    1.5L/kg

    1.5L/kg

    0.5L/kg

    Clearance

    10mL/min/kg

    1mL/min/kg

    20mL/min/kg

    t ½-dist

    5mins

    5mins

    5mins

    t ½-elim

    1-4 hours

    24-36 hours

    60mins

    Metabolism

    Hepatic (CYP3A4)

    Active metabolites

    Hepatic (CYP3A4/5)

    Active metabolites

    Hepatic

    No active metabolites

    Excretion

    Urine

    Urine

    90% urine
    10% bile

    Hepatic failure

    Decreased clearance

    Decreased clearance

    Decreased clearance

    Renal failure

    Active metabolite may accumulate

    Active metabolites will accumulate

    No effect

    Pros

    Sedation, amnesia & anxiolysis

    Anticonvulsant

    Decreases cerebral metabolic O2 demand

    Effective orally

    Sedation, amnesia & anxiolysis

    Anticonvulsant

    Decreases cerebral metabolic O2 demand

    Allows specific reversal of BDZ component of resp depression and / or polypharmacy overdose

    Rarely causes acute anxiety &/or agitation

    Cons

    Myocardial depressant

    Resp depression

    Can cause paradoxical excitement

    Myocardial depressant

    Resp depression

    Can cause paradoxical excitement

    Painful on injection

    Can precipitate seizures in epileptics on maintenance BDZs

    Other points

    ¯BP
    (¯SVR & ¯CO)

    [­HR (reflex)]

    ¯BP
    (¯SVR & ¯CO)

    [HR (reflex)]

    Is probably a partial agonist

    Table: Narcotics

    Morphine

    Fentanyl

    Methadone

    Naloxone

    Type/class

    Phenanthrene opiate

    Phenylpiperidine opioid

    Diphenyl-propylamine opioid

    Phenanthrene opioid

    Mechanism

    Non-specific OR agonist

    MOR agonist with some mild activity at KORs

    MOR agonist (L-isomer) & NMDA antagonist (D-isomer)

    Non-specific OR competitive antagonist

    Oral Bioavail.

    30%

    n/a

    75%

    <1%

    Oral dose

    0.2-0.5mg/kg q4-6h

    n/a

    0.1-0.2mg/kg q6-24h

    n/a

    IV bolus dose

    0.05-0.2mg/kg

    1-10mcg/kg

    0.1mg/kg

    10mcg/kg

    IV infusion

    5-100 mcg/kg/hr

    1-10 mcg/kg/hr

    n/a

    10 mcg/kg/hr

    Onset time IV

    15-30mins

    1-2mins

    10-20mins

    1-2mins

    ESET

    30-90mins

    3-6mins

    10-20mins

    5-10mins

    pKa

    8.0

    8.4

    9.2

    7.9

    % UNionised

    25%

    10%

    1%

    30%

    Protein binding

    35%

    85%

    90%

    50%

    Vd

    3L/kg

    4L/kg

    3.5L/kg

    0.2L/kg

    Clearance

    25
    mL/min/kg

    10-20 mL/min/kg

    1-3 mL/min/kg

    30 mL/min/kg

    t ½-dist

    2-3mins

    1-2mins

    1-2 mins

    -

    t ½-elim

    2-4hours

    2-4hours

    18-36 hours

    45-60mins

    Metabolism

    Hepatic & renal

    10% to active M6G

    Hepatic (CYP3A4)

    No active metabolites

    Hepatic (CYP3A4)

    No active metabolites

    Hepatic

    No active metabolite

    Excretion

    90% urine
    10% bile

    90% bile
    10% urine

    50% urine
    50% bile

    Urine

    Hepatic failure

    May precipitate encephalopathy

    No effect

    reduced clearance

    reduced clearance

    Renal failure

    Morphine & M6G will accumulate

    No effect

    No effect

    No effect

    Pros

    No myocardial depression

    Sedation & euphoria

    Antitussive

    No myocardial depression

    Sedation & euphoria

    Antitussive

    No histamine release

    Effective enterally

    Helpful in withdrawal syndromes

    Suitable for chronic pain (NMDA actions)

    Acts rapidly & is titratable

    Antiinflammatory properties

    Cons

    Respiratory depression

    Histamine release

    Nausea & vomiting

    Pruritis

    Urinary retention

    Constipation

    Respiratory depression

    Nausea & vomiting

    Pruritis

    Urinary retention

    Constipation

    Prolonged CSHT

    Respiratory depression

    Nausea & vomiting

    Constipation

    Histamine release possible but rare

    Prolongs QT interval

    Can precipitate acute withdraw

    Rarely may cause pulmonary oedema & Arrhythmia

    Usually needs repeat dosing

    Other points

    Meiosis

    ¯ HR & BP (¯SVR)

    Meiosis

    ¯ HR & BP (¯SVR)

    Meiosis

    ¯ HR & BP (¯SVR)

    1mcg/kg effective for narcotic pruritis

    BP may rise or fall

    Table: Alpha2 agonists

    Clonidine

    Dexmedetomidine

    Type/class

    Synthetic imidazoline

    Synthetic imidazoline

    Mechanism

    α2 adrenoceptor partial agonist

    α2 adrenoceptor agonist

    Oral bioavail

    >99%

    15%

    Oral dose

    1-5mcg/kg up to 300mcg

    n/a

    IV bolus dose

    1-5mcg/kg

    1-2mcg/kg

    IV infusion dose

    0.5-2mcg/kg/hour

    0.2-0.7mcg/kg/hour (sedation)

    5-10mcg/kg/hour (GA)

    Onset time IV

    10-30minutes

    10minutes

    ESET

    20-30minutes

    10-20minutes

    pKa

    8.0

    7.1

    UNionised %

    20%

    50%

    Protein binding

    20%

    95%

    Vd

    2L/kg

    1.5L/kg

    Clearance

    5mL/min/kg

    10mL/min/kg

    t ½-dist

    30minutes

    10 minutes

    t ½-elim

    12-18hours

    2-3hours

    Metabolism

    50% hepatic

    50% excreted unchanged

    Hepatic

    No active metabolites

    Excretion

    Urine (50% unchanged)

    Urine

    Hepatic failure

    No effect

    Decreased clearance

    Renal failure

    Active drug will accumulate

    No effect

    Pros

    Effective sedative

    No respiratory depression

    Spinal-mediated analgesia (very effective neuraxially)

    Known to be useful in opioid & alcohol withdrawal syndromes

    Raises the shivering threshold

    Prolongs regional block by local anaesthetics

    Effective sedative

    No respiratory depression

    Spinal-mediated analgesia

    Useful for symptoms of opioid withdrawal

    Raises shivering threshold

    Prolongs regional block by local anaesthetics

    Short(er) half time

    Cons

    Rapid IV administration will agonise α1 receptors (¬≠BP)

    Negative inotropy & chronotropy

    Dry mouth

    Rebound hypertension can occur (worse if patient is on a TCA or β-blocker)

    Long half time

    Rapid IV administration will agonise α1 receptors (¬≠BP)

    Negative inotropy & chronotropy

    Dry mouth

    Cannot be used neuraxially due to glycine in preparation

    Other points

    ¯HR & ¯BP

    ¯CO

    Dry mouth may be used therapeutically if secretions are an issue

    ¯HR & ¯BP

    ¯CO

    Dry mouth may be used therapeutically if secretions are an issue

    Table: Others

    Chloral hydrate

    Promethazine

    Type/class

    Halogenated alcohol

    Phenothiazine

    Mechanism

    Prodrug - below data is for trichloroethanol (active drug)

    Probably a GABAA agonist

    H1 receptor antagonist & anticholinergic (antimuscurinic)

    Oral bioavail

    >99%

    25%

    Oral dose

    10-100mg/kg

    0.25-1.5mg/kg

    IV bolus dose

    n/a

    0.25-1.5mg/kg

    IV infusion dose

    n/a

    n/a

    Onset time IV

    15minutes (oral)

    30-60minutes

    ESET

    30-60minutes (oral)

    1-3hours

    pKa

    12.7

    9.1

    UNionised %

    >99%

    <1%

    Protein binding

    50%

    80%

    Vd

    1L/kg

    7L/kg

    Clearance

    not known

    15mL/min/kg

    t ½-dist

    n/a

    1-2hours

    t ½-elim

    4-8hours

    12hours

    Metabolism

    Hepatic

    Metabolites of trichloro-ethanol are inactive

    Hepatic (CYP2D6)

    Inactive metabolites

    Excretion

    Urine

    Urine

    Hepatic failure

    Decreased clearance

    Decreased clearance

    Renal failure

    No effect

    No effect

    Pros

    Effective sedative & anxiolytic

    Rapid onset following enteral administration

    Mild anticonvulsant

    Relatively wide therapeutic index

    Minimal interference with REM-sleep

    Effective antihistamine & antiemetic at low doses

    Effective sedative/hypnotic at high doses

    Antitussive

    Effective in motion sickness

    Useful in allergic pruritis but not opioid induced pruritis

    Respiratory depression is rare

    Cons

    Respiratory depression in high doses

    Irritant to GI mucosa

    Arrhythmias in high doses

    Trigger for porphyria

    Patients can develop tolerance & withdrawal

    Anticholinergic effects (dry mouth, blurred vision, urinary retention etc)

    Central anticholinergic syndrome in overdose

    Prolonged QT-interval & AV-block

    Paradoxical excitement may occur

    Other points

    ¯BP (¯SVR)

    ­HR (reflex)

    Actual half time of chloral hydrate is minutes (metabolised by esterases)

    [­HR & ­BP]

    Antidopaminergic properties

    Local anaesthetic properties

    • Inotropes and Vasopressors

    Home

    ANESTHESIA: INOTROPES AND VASOPRESSORS

    Definition:

    Inotropes: sympathomimetic agent which act on the sympathetic (or adrenergic) nervous system (β-receptors) resulting in positive inotropic (increase in contractility), chronotropic (increase in heart rate), dromotropic (increase in conduction of impulse) and lusitropic effect (improved diastolic relaxation)

    Vasopressors: sympathomimetic agent which act on the sympathetic (or noradrenergic) nervous system (α-receptors) resulting in vasoconstrictor effect.

    The ideal vasoactive support agent: effect on cardiac output / effect on SVR / effect on myocardial oxygen consumption / no tachyphylaxis does not exist !

    a) Sympathomimetics: endogenous catecholamines:

    Adrenaline (β1 >> β2 and α1 > α2 agonist) via cAMP

    Dose

    mcg/kg/min

    α1

    α2

    β1

    β2

    Clinical effect

    - 0.05

    ++

    ++

    ↑ HR, SV, CO

    (↓) SVR

    0.05 - 0.10

    +++

    ↑ HR, SV, CO

    0.10 - 0.20

    +++

    +++

    +++

    ↑ HR, SV, SVR

    (↓) CO

    Side effects: increasing myocardial oxygen requirement, Tacharrhythmias, worsening diastolic function, Tachyphylaxis, Hyperglycaemia, Lactate increase

    Noradrenaline (α1 > α2 and β1 >> β2 agonist) via cAMP ?

    Dose

    mcg/kg/min

    α1

    α2

    β1

    β2

    Clinical effect

    - 0.10

    +++

    ++

    +++

    ↑ SVR, HR

    (↓) CO

    0.10 - 0.20

    ++++

    +++

    +++

    ↑ SVR, HR, SV

    ↓ CO

    Side effects: increasing myocardial oxygen requirement, can cause decrease in CO, Tachyphylaxis, Hyperglycaemia

    Dopamine (D1 and D2, higher doses: β1 >> β2 and α1 > α2 agonist) via cAMP. Precursor of norepinephrine

    Dose

    mcg/kg/min

    α1

    α2

    β1

    β2

    Clinical effect

    0.5 - 2

    ↑ increased splanchnic perfusion

    2 - 5

    ++

    ↑ HR, SV, CO

    5 - 10

    ++

    ++

    ↑ HR, SV, SVR

    (↓) CO

    > 10

    +++

    ↑ SVR

    ↓ CO

    Side effects: increasing myocardial oxygen requirement, can cause decrease in CO, Tacharrhythmias, Tachyphylaxis, Hyperglycaemia, immunsuppressive effect, inhibition of thyrotropin releasing hormone

    b) Sympathomimetics: synthetic catecholamines

    Dobutamine (β1 >> β2)via cAMP

    Dose

    mcg/kg/min

    α1

    α2

    β1

    β2

    Clinical effect

    2.5 - 10

    ++

    ++

    ↑ HR, SV, CO

    (↓) SVR

    > 10

    +++

    ↑ HR, SV, CO

    Side effects: increasing myocardial oxygen requirement, Tacharrhythmias, worsening diastolic function, Tachyphylaxis, Hyperglycaemia

    Isoprenaline (β)via cAMP

    Dose

    mcg/kg/min

    α1

    α2

    β1

    β2

    Clinical effect

    0.01 - 1

    +++

    +

    ↑ HR, SV, CO

    Side effects: increasing myocardial oxygen requirement, Tacharrhythmias, worsening diastolic function, Tachyphylaxis, Hyperglycaemia

    c) Sympathomimetics: synthetic noncatecholamines

    Phenylephrine (α1 >> α2 agonist) - resuscitation in Fallot spells

    Dose

    mcg/kg/min

    α1

    α2

    β1

    β2

    Clinical effect

    0.1 - 5

    +++

    ++

    +++

    ↑ SVR

    ↓ HR (reflex), CO

    Side effects: increasing myocardial oxygen requirement,

    can cause decrease in CO, Tachyphylaxis, Hyperglycaemia

    d) Phosphodiestarase Inhibitors

    Milrinone via cAMP

    Dose

    mcg/kg/min

    Clinical effect

    Load: 50mcg/kg

    0.2 - 1

    ↑ CO (positive inotropic and lusitropic effect)

    ↓ PVR, (SVR)

    Side effects: arrhythmia, hypotension (ensure appropriate volume load)

    e) Myofilament calcium sensitizers

    Levosimendan via increasing sensitivity to calcium

    Dose

    mcg/kg/min

    Clinical effect

    Load: 1.25mcg/kg

    over 10min

    Infusion: 0.2

    ↑ CO (positive inotropic and lusitropic effect)

    Side effects: arrhythmia, hypotension in the first hours

    f) vasoregulatory agents

    Vasopressin (V1 - arterial and V2 - tubular agonist)

    Dose

    IU/kg/hr

    V1 & V2

    Clinical effect

    0.01 - 0.06

    +++

    ↑ SVR

    Side effects: increasing myocardial oxygen req

    irement, can cause decrease in splanchnic perfusion

    [1] Am Heart J 2002 Jan; 143(1) : 15-21: Hoffman TM et al: Prophylactic intravenous use of milrinone after cardiac operation in pediatrics (PRIMACORP) study.

    [2] Lancet 2002, 306: 196-202: Follath F et al: Efficacy and Safety of intravenous levosimendan compared with dobutamine in severe low-output heart failure (the LIDO study); a randomised double-blind trial.

    [3] Curr Opin Crit Care. 2010 Oct;16(5):432-41: Parissis et al: Inotropes in cardiac patients: update 2011

    [4] Curr Opin Anaesthesiol. 2009 Aug;22(4):496-501: Salmenperä et al: Levosimendan in perioperative and critical care patients.

    [5] Pediatr Cardiol. 2004 Nov-Dec;25(6):623-46: Barnes et al: The pediatric cardiology pharmacopoeia: 2004 update

    [6] Pediatr Crit Care Med. 2006 Sep;7(5):445-8: Namachivayam P et al: Early experience with Levosimendan in children with ventricular dysfunction.

    [7] N Engl J Med. 2008 Feb 28;358(9):877-87: Russel et al: Vasopressin versus norepinephrine infusion in patients with septic shock

    Intubation

    Home

    ANESTHESIA: INTUBATION IN PICU

    Indication:

  • to secure the airway: severe airway obstruction / inadequate protective reflexes (coma or prolonged seizures)

  • to facilitate ventilation: hypoxaemic and / or hypercarbic respiratory failure

    Intubation should NOT be attempted by the inexperienced if more skilled personnel are available ! Two doctors always present if possible !

    Assessment:

  • how urgent is the intubation ?

  • anatomical abnormality, which would predict difficult intubation ?

  • any evidence of airway obstruction ?

  • cardiovascular status - any hypovolaemia / hypotension ?

  • is the patient fastened ?

    Preperation equipment:

  • Intubation drugs

  • Volume replacement (10ml/kg NaCl 0.9%)

  • ETT (size = age / 4 + 4 - for uncuffed ETT for cuffed ETT size = age / 4 + 3.5), one size above and one size below calculated ETT

  • Styllete, gum elastic bougie

  • Laryngoscope with blade (check light bulb and battery)

  • Magill's forceps

  • Face Mask

  • Guedel and nasopharyngeal airways

  • self inflating bag and anaesthetic circuit

  • suction equipment: Yankauer's sucker and suction catheters

  • connector, cuff inflating syringe, tape

  • CO2 detector

    Procedure:

  • monitor cardiovascular and respiratory status (ECG, SpO2, BP non-invasive / invasive)

  • explain to patient / parents

  • empty stomach if nasogastic tube is in situ

  • position patient: neutral position in neonates, young children - sniffing position in older children, adolescents

  • preoxygenation for minimum two minutes

  • consider atropine 20mcg/kg IV

  • give analgesic agent

  • give sedative agent

  • apply gentle pressure to the cricoid

  • check for bag and mask ventilation possible with appropriate visual inflation / deflation and chest wall movement

  • give paralysis agent

  • continue bag and mask ventilation, while continuing to apply gentle cricoid pressure, except in circumstances where bag and mask ventilation is contraindicated (see rapid sequence induction)

  • intubate orally, release cricoid pressure

  • check ETT position: chest wall rise, auscultation and CO2 detector (→→ Resuscitation drug chart )

  • once patient stabilized and appropriate ventilation, consider to change to a nasal ETT

  • once ETT position confirmed, tape ETT

  • insert nasogastric tube, empty stomach

  • CXR to confirm position of ETT and nasogastic tube

  • consider ongoing Analgesia and Sedation

  • document event

    Intubation Drugs:

    →→ Analgesia and Sedation in PICU

    Analgesia

    Sedation

    Paralysis

    cardiovascular stable, no airway obstruction > 1 year

    Fentanyl

    1 - 2mcg/kg

    or

    Morphine

    100mcg/kg

    Propofol

    1 - 2.5mg/kg

    Vecuronium 0.1mg/kg

    cardiovascular stable, with airway obstruction > 1 year

    Fentanyl

    1mcg/kg

    or

    Morphine

    100mcg/kg

    Ketamine

    1 - 2mg/kg

    Vecuronium 0.1mg/kg

    cardiovascular stable, no airway obstruction < 1year

    Fentanyl

    1 - 2mcg/kg

    or

    Morphine

    100mcg/kg

    Midazolam

    50 -100mcg/kg

    Vecuronium 0.1mg/kg

    cardiovascular stable, with airway obstruction < 1 year

    Always seek senior assistance !

    Consider induction with volatile anaesthetic !

    cardiovascular unstable, any age

    Fentanyl

    1 - 2mcg/kg

    or

    Morphine

    100mcg/kg

    Vecuronium

    0.1mg/kg

    Rapid Sequence Induction

    Fentanyl

    1 - 2mcg/kg

    or

    Morphine

    100mcg/kg

    Midazolam

    50 -100mcg/kg

    Rocuronium

    1mg/kg

    patients with raised ICP

    Fentanyl

    1 - 2mcg/kg

    or

    Morphine

    100mcg/kg

    Thiopentone

    2 - 7mg/kg

    Rocuronium

    1mg/kg

    anticipated difficult airway

    Always seek senior assistance !

    Consider induction with volatile anaesthetic !

    Unexpected difficult intubation:

  • call for help !

  • restart bag and mask ventilation with gentle cricoid pressure

  • optimize patient position

  • consider bougie or stylete

  • consider different laryngoscope blade

    Cannot ventilate - Cannot Intubate:

  • call for help !

  • consider reposition of head

  • jaw thrust

  • insert Guedel / nasopharyngeal airway

  • use both hands to hold mask

  • release cricoid pressure

  • consider laryngeal mask (LMA)

    • Inotropes and Vasodilators

    Home

    ANESTHESIA: INOTROPES AND VASODILATORS

    Vasodilators: decreasing the pressures against which the heart works (systemic and pulmonary afterload) decreases the work of the heart hence myocardial O2 demand. Usual indications for vasodilator therapy are: systemic vasodilation (LV afterload reduction), pulmonary vasodilatation (RV afterload reduction), systemic hypertension, improving coronary blood flow. Beware that infants, in response to low CO, increase afterload to maintain BP. The use of vasodilators leads to increase in vascular capacitance and may require volume replacement. Avoid or use judiciously with lesions where there is obstruction to blood flow or fixed stroke volume.

    Sodium-nitroprusside (SNP) via release of endogenous NO

    Dose

    mcg/kg/min

    Clinical effect

    0.2- 6

    Direct smooth muscle cell relaxation

    arterial > venous vasodilation

    Side effects: severe hypotension (titrate slowly), worsening V/Q mismatch, Cyanide and Thiocyanate intoxication, Methaemoglobinemia, tachyphylaxis

    Glyceryl-trinitrate (GTN) via release of endogenous NO

    Dose

    mcg/kg/min

    Clinical effect

    1 - 10

    Direct smooth muscle cell relaxation

    venous > arterial vasodilation

    improved coronary perfusion

    Side effects: severe hypotension (titrate slowly)

    Phenoxybenzamine via irreversible alpha-blockage

    Dose

    mcg/kg/min

    Clinical effect

    Load: 1 mg/kg over 1hr

    Vasodilation

    TDS or BD:

    0.5mg/kg

    Side effects: severe hypotension

    Hydralazine via direct vasodilation by decreasing intracellular Ca++

    Dose

    mcg/kg/min

    Clinical effect

    10 - 50

    Vasodilation

    Side effects: reactive Tachycardia

    Prostacyclin = PGI2 (Epoprostenol) via increase in NO

    Dose

    ng/kg/min

    Clinical effect

    2 - 20 (40)

    Pulmonary vasodilation, treatment of PHT

    Side effects: systemic hypotension, haemorrhagic diasthesis due to Platelet aggregation inhibition

    Prostaglandine = Alprostadil = PGE1 via release of endogenous NO

    Dose

    ng/kg/min

    Clinical effect

    5 - 100

    Pulmonary Vasodilation

    Maintaining PDA patency

    Side effects: systemic hypotension, fever, hypoventilation and apnea, antiplatelet function

    Inhaled Nitric Oxide (iNO) →→ NO and →→PHT

    Sildenafil →→ NO and →→ PHT

    Clonidine via presynaptic alpha 2 adrenergic action

    Dose

    mcg/kg/hr

    Clinical effect

    0.5 - 2

    Vasodilation

    Sedation

    Analgesia

    Side effects: systemic hypotension, avoid in Porphyria, may decrease CO

    Dexmedetomidine via presynaptic alpha 2 adrenergic action

    Dose

    mcg/kg/hr

    Clinical effect

    0.2 - 1

    Vasodilation

    Bradycardia (can be used therapeutically)

    Sedation

    Analgesia

    Side effects: systemic hypotension, decreases CO, avoid in LCOS

    Captopril (ACE-I) via angiotensin converting enzyme inhibition

    Dose

    mcg/kg

    Clinical effect

    Test dose: 0.1

    Vasodilation

    Improve in CO

    TDS or QID, increase dose by 0.1mg/kg until clinical effect achieved

    Side effects: systemic hypotension, renal dysfunction

    Weaning Opiods and Sedation

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    ANESTHESIA: WEANING OPIODS AND SEDATION

    Withdrawal from drugs (principally opioids) prolongs hospital admissions and causes morbidity !

    Gradual weaning of drug dosing aims to prevent the onset of withdrawal abstinence syndromes:

  • regime one: 10% reduction in original dose per day weaning over 10days or

  • regime two: 20% reduction in original dose per day weaning over 5 days

  • regime three: 20% reduction in original dose every 2nd day weaning over 10days

    All are equally effective and the shorter 5-day wean is not associated with any increased withdrawal symptoms requiring reinstitution of drug therapy !

    The choice of regime is typically arbitrary based on length of therapy and clinician choice.

    DOSE CONVERSION of IV and ENTERAL

    Dose escalation and / or opioid rotation are both effective ways to combat tolerance (although there is an inevitable amount of cross tolerance) but not physical dependence.

    Converting between opioids and route of administration involves documenting the total 24-hour dose being administered and then using the conversion table and calculating a total daily dose of the new drug via the new route.

    Drug

    IV equivalent

    IV : morphine ratio

    enteral equivalent

    IV : enteral ratio

    Morphine

    10mg

    1 : 1

    30 mg

    1 : 3

    Codeine

    100mg

    10 : 1

    200mg

    1 : 2

    Oxycodone

    10mg

    1 : 1

    20mg

    1 : 2

    Fentanyl

    100mcg

    0.01 : 1

    n/a

    n/a

    Methadone

    10mg

    1 : 1

    20mg

    1 : 2

    DOSE CONVERSION for iv Midazolam INTO oral Diazepam

    [Midazolam IV [rate in mcg/kg/min] x weight x 24 ] x 0.5 = Diazepam oral

    [1] Brunton, L et al (2010), Goodman and Gillman's the Pharmacological Basis of Therapeutics 12th Edition, McGraw Hill Medical, New York

    [2] Macintyre, PE et al (2010), Acute Pain Management: Scientific Evidence 3rd Edition, Australian and New Zealand College of Anaesthetists and Faculty of Pain Medicine, Melbourne

    [3] Miller, RD et al (2009), Miller's Anesthesia 9th Edition, Churchill Livingstone Elsevier, Philadelphia

    [4] Peck, TE & Hill, S (2008), Pharmacology for Anaesthesia and Intensive Care 3rd Edition, Cambridge University Press, Cambridge

    [5] Sasada, M & Smith, S (2003), Drugs in Anaesthesia and Intesive Care 3rd Edition, Oxford University Press, Oxford

    [6] Stoelting, RK & Hillier, SE (2005), Pharmacology and Physiology in Anesthetic Practise 4th Edition, Lippincott, Williams and Wilkins, Philadelphia

    [7] Pediatrics 2010 May;125(5):e1208-25: Anand et al: Tolerance and withdrawal from prolonged opioid use in critically ill children.

    • Tolerance and Withdrawal

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    ANESTHESIA: TOLERANCE AND WITHDRAWAL

    Definition: Tolerance is the development of the need to increase the dose of a drug to achieve the same effect previously achieved with a lower dose.

  • Duration of therapy is the major factor associated with onset of tolerance and physical dependence and continuous infusions induce tolerance more rapidly than intermittent and enteral therapy.

  • Tolerance begins within 48 hours of continuous infusion but typically takes 2 - 3 weeks of regular intermittent use to develop to a clinically significant extent

  • Long-term pharmacodynamic tolerance can persist for months-years in some individuals.

  • The mechanisms are poorly understood but probably involve changes in receptor number (down-regulation) and modulation of intracellular signalling pathways leading to receptor desensitisation.

  • Genetics also play a role in both response to opioids and the development of tolerance and physical dependence but its clinical importance is still being defined.

  • Physical dependence also develops to some degree after only 48 hours of continuous infusion but requires 4 weeks of regular intermittent use to become established.

  • Discontinuing a drug after physical dependence is established will produce a typical withdrawal abstinence syndrome.

    • Muscle Relaxation

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    ANESTHESIA: MUSCLE RELAXATION

    Definition: Muscle relaxants block transmission at the neuromuscular junction (NMJ) by interfering with nicotinic cholinergic receptors (AChRs). They are large polar molecules with small volumes of distribution that are not orally bioavailable and do not cross the placenta or blood-brain barrier. They have no analgesic, anaesthetic or amnestic properties and so should never be given without appropriate sedative / anaesthetic drugs.

    The clinical indications for muscle relaxation are:

  • to facilitate intubation of the trachea

  • to improve surgical and / or procedural working conditions

  • to facilitate intra-hospital and inter-hospital transfers

  • to prevent shivering in patients being therapeutically cooled

  • to facilitate mechanical ventilation including using mechanical ventilation to manipulate PaCO2 and acid-base status

  • to improve post-operative stability (especially in high-risk cardiac surgery and laryngo-tracheal surgery with or without complex / abnormal airway anatomy)

    Drugs are classified as depolarising (mimic the actions of ACh) and non-depolarising (interfere with the actions of ACh).

    Suxamethonium is the only depolarising neuromuscular blocking drug still in clinical use.

    Non-depolarising neuromuscular blocking drugs are classified as long-acting (pancuronium), intermediate-acting (rocuronium, vecuronium, atracurium & cisatracurium) and short-acting (mivacurium).

    Drug selection is influenced by desired speed of onset, duration of action and the possibility of drug induced side effects (see table of drugs).

    Among suxamethonium's myriad of adverse effects it is also a known trigger for malignant hyperthermia (genetically abberant muscle sarcoplasmic reticulum calcium channels) - the treatment is active cooling and Dantrolene 1mg/kg up to 10mg/kg.

    Patients with genetically abdnormal pseudocholinesterase will have prolonged neuromuscular blockade with suxamethonium (choline apnoea) - they need supportive care until it is cleared (severe cases require dialysis to clear the drug) and an assessment of their pseudocholinesterase function (dibucaine number).

    Suxamethonium and rocuronium (see Table: Muscle relaxans rapid onset) are the only drugs capable of producing intubating conditions in 60 - 90 seconds and so are the only drugs used for rapid sequence induction (RSI). Suxamethonium has a brief duration of action where as an RSI-dose of rocuronium will have a prolonged duration of action.

    The duration of action of non-depolarising neuromuscular blocking drugs is prolonged by hypokalaemia, hypocalcaemia, hypoproteinaemia, hypermagnesaemia, dehydration, acidosis and hypercapnoea.

    Potency of neuromuscular blocking drugs is described by the effective dose (ED) necessary to depress single-twitch depression by 95% in the adductor pollicis muscle - ED95 (Intubating doses are generally two times the ED95 dose; the RSI-dose for rocuronium is four times its ED95); potency is Centrally located muscles (larynx, jaw and diaphragm) develop neuromuscular blockade faster, experience less profound block and recover more quickly than in more peripherally located muscles (adductor pollicis). Eyelash reflex and orbicularis inversely related to onset time.

    Monitoring of depth of neuromuscular blockade:

    Nerve stimulators are used to monitor the depth of neuromuscular blockade.

    There is a margin of safety regarding nAChRs at the NMJ and the generation of a myocyte action potential such that >75% of nAChRs must be occupied by drug before clinically significant (and detectable) blockade is apparent.

    Neuromuscular blocking drugs must occupy at least 75% of nAChRs before there is clinically significant and detectable blockade (this is the margin of safety with regard to nAChR numbers and transmission at the NMJ).

    The ulnar or radial nerves are commonly used with the negative electrode on the volar surface of the wrist directly over the nerve to be stimulated and the positive electrode at least 3cm distal where it cannot interfere with the relevant muscle groups.

    A current of 60mA (maximum 80mA) is applied for 0.1ms (maximum 0.3ms) per stimulation; the patterns of stimulation used in PICU are the train-of-four (TOF) count, tetanic (>30Hz) stimulation and post-tetanic count.

    The TOF ratio is the ratio of the height of the first twitch (T1) to the fourth twitch (T4) - this is not easily interpretable if only using visual and tactile evaluation of the response. The TOF count (absolute number of twitches) is easier to detect and interpret:

  • T4 begins to reduce in height at >70% receptor occupancy;

  • T1 starts to reduce in height at >80% occupancy;

  • T4 disappears at >90% occupancy;

  • T1 disappears at >95% occupancy.

    Tetanic stimulation (usually 50Hz) is known to increase subsequent twitch height either by mobilising ACh stores and / or increasing calcium influx into the nerve ending; When the TOF count is zero (>95% blockade) then a tetanic stimulation and a post-tetanic (TOF) count can help define deep neuromuscular blockade.

    The effects of tetany last for up to 6 minutes and this must be taken into consideration if repeat testing occurs.

    If the TOF-count is zero and the post-tetanic count is also zero - this signifies either very deep neuromuscular blockade or a malfunctioning nerve stimulator (test it on yourself).

    Reversal of neuromuscular blockade:

    Antagonist-assisted reversal of neuromuscular blockade using anticholinesterases (edrophonium, neostigmine or pyridostigmine) reflects their inhibition of acetylcholinesterase (AChE) and the resulting increased ACh at the NMJ to compete for nAChR binding sites.

    Neostigmine is generally used at a dose of 4 - 7mcg/kg and is more suitable for reversing deeper levels of block.

    Anticholinesterases produce typical and expected muscarinic side effects (mainly bradycardia, bronchoconstriction, increased secretions & GI hyper-peristalsis) and so should be given with an antimuscarinic anticholinergic drug such as Atropine (20mcg/kg) or Glycopyrrolate (10mcg/kg).

    Sugammadex is a cyclodextrin that encapsulates rocuronium and vecuronium and effectively neutralises them; remaining drug diffuses away from the NMJ and its effects are reversed.

    It acts within 2 minutes and has no other effects (as yet). The complex is excreted in the urine. The dose for routine reversal is 2 - 4mg/kg; the dose for emergent reversal in a cant intubate-can't ventilate scenario is 16mg/kg.

    Table: Muscle Relaxans rapid onset

    Suxamethonium

    Rocuronium

    Type/class

    Dicholine ester

    Aminosteroid

    (intermediate acting)

    ED95

    0.3mg/kg

    0.3mg/kg

    Intubating dose

    1mg/kg (adults)
    2mg/kg (children)
    3mg/kg (neonates)

    0.6mg/kg
    1.2mg/kg (RSI)

    Onset time

    30-60seconds

    30-90seconds

    Recovery time

    3-5minutes

    20-35minutes

    Infusion dose

    n/a

    5-15mcg/kg/min

    VD

    0.17L/kg

    0.3L/kg

    Protein binding

    99%

    30%

    Clearance

    40mL/kg/min

    4mL/kg/min

    t½-elim

    3-5minutes

    80minutes

    Metabolism

    Plasma pseudocholinesterase

    No significant metabolism

    Excretion

    Resulting choline is taken up into nerves

    <5% unchanged in urine

    Bile (50% unchanged)

    Urine (30% unchanged)

    Hepatic failure

    No effect

    t½-elim up to 100 minutes

    Renal failure

    No effect

    t½-elim up to 100 minutes

    Pros

    Rapid onset & intense paralysis make it suitable for RSI

    Suitable for RSI due to shorter onset time

    No histamine release

    Minimally affected by renal & hepatic impairment

    May be reversed with sugammadex

    Cons

    Raised intra-gastric, intra-ocular & intra-cranial pressures

    Fasciculations that can lead to severe myalgia & even rhabdomyolysis

    Bradycardia (muscarinic) +/- brady-arrhythmias

    Hyperkalaemia (more so with neuromuscular disease & burns)

    Malignant hyperthermia

    Choline apnoea

    Anaphylaxis

    Will accumulate with prolonged infusions (ensure monitoring of depth of blockade)

    Other points

    80% of an administered dose is hydrolysed before reaching the NMJs

    Repeat doses should always be accompanied by an anticholinergic (consider routine anticholinergic administration in infants)

    There are rare reports of anaphylaxis

    It does cause a small increase in intra-occular pressure

    Table: Muscle Relaxans slow onset

    Vecuronium

    Pancuronium

    Cisatracurium

    Type/class

    Aminosteroid

    (intermediate acting)

    Aminosteroid

    (long acting)

    Benzylisoquinolinine

    (intermediate acting)

    ED95

    0.05mg/kg

    0.06mg/kg

    0.05mg/kg

    Intubating dose

    0.1mg/kg

    0.1mg/kg

    0.1mg/kg

    Onset time

    3-5minutes

    3-5minutes

    3-5minutes

    Recovery time

    20-35minutes

    60-90minutes

    20-35minutes

    Infusion dose

    0.5-2mcg/kg/min

    n/a

    1-10mcg/kg/min

    VD

    0.27L/kg

    0.26L/kg

    0.2L/kg

    Protein binding

    60-90%

    15-30%

    unknown

    Clearance

    5mL/kg/min

    2mL/kg/min

    5mL/kg/min

    t½-elim

    60minutes

    132minutes

    25minutes

    Metabolism

    Hepatic with some active metabolites

    Hepatic with some active metabolites

    Hoffman elimination (no active metabolites)

    Excretion

    Urine (25% unchanged)

    Bile (25% unchanged)

    Urine (80% unchanged)

    Bile (10% unchanged)

    Urine

    Hepatic failure

    t½-elim up to 3 hours

    t½-elim up to 6 hours

    No change

    Renal failure

    t½-elim up to 2 hours

    t½-elim up to 48 hours

    No change

    Pros

    Commonly used medication with predictable onset & duration of action

    No histamine release

    May be reversed with sugammadex

    Long acting
    (decreased dosing requirements)

    Non-organ clearance makes it unaffected by renal and/or hepatic impairment

    Stable offset time after prolonged infusions due to rapid Hoffman elimination

    No histamine release

    Cons

    Will accumulate with prolonged infusion (ensure monitoring of depth of blockade)

    Minimally metabolized so sensitive to effects on hepatic & renal function

    Risk of arrhythmias in patients on digoxin

    Potent drug with prolonged onset time

    Other points

    Large doses may cause a slight (10-15%) drop in SVR and BP

    10-15% increase in HR (mainly anticholinergic effect)

    Mild increase in BP secondary to increased HR (no inotropy)

    Useful for obviating HR effects of induction doses of narcotics

    It may decrease the PT and APTT

    One of 10 stereoisomers of atracurium (atracurium is not used often anymore due to histamine release and has a metabolite that can cause convulsions).

    • Heart Transplantation

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    HEART FAILURE: HEART TRANSPLANTATION (HTX)

    Indication: life expectancy < 2years and/or unacceptable quality of life, end stage CHD, DCM, HCM ( →→ Cardiomyopathy )

    Risk Profile: PVR (low risk: PVR ≤ 4WU or TPG ≤ 10mmHg, medium risk: PVR 5 - 9 WU or TPG 10 - 20mmHg, high risk/contraindicated: PVR > 9WU or TPG ≥ 15mmHg. In high risk patients: trial with pulmonary vasodilator in Cardiac Cath (NO, Prostacycline). Donor: Size mismatch up to 4:1, good systolic function (EF > 50%), Serology for EBV, CMV, HIV, HTLV, Hepatitis, Syphilis, Toxoplasmosis

    Contraindication: Recipient (MDT decision), metastatic incurable neoplasm, severe Sepsis, fixed PHT (consider Heart-Lung Tranplantation). Donor: Aids, HTLV Infection or Hepatitis B Antigen positive.

    Preoperative Preparation:

    ECG, CXR, FBE, Clotting, U&C, Electrolytes, BNP, LFTs, ABO, HLA, CMV, EBV, HSV, HIV, VZV, Measles, Hepatitis serology, ECHO, Cardiac Cath (PVR, TPG), Angio CT, MRI, V/Q scan

    Surgery: Previous biatrial, now commonly bicaval technique

    Postoperative Management:

  • keep intubated, ventilated, sedated for 24hrs, (longer with open chest →→ Open Chest )

  • inotropes: Dobutamine or Isoprenaline, Milrinone plus Adrenaline (despite denervation the donor heart responds well to exogenous inotropes), SNP for increased SVR. Consider potential combination of Milrinone and Adrenaline 0.05mcg/kg/min

  • haemodynamics: age donor / recipient adjusted. Early recovery systolic function. Diastolic function longer impaired (Milrinone)

  • respiratory: normoxaemia, normocapnea, may consider NO for RV afterload reduction ( →→ NO )

  • fluid restriction: 1ml/kg/hr

  • haemostasis

  • Antibiotic prophylaxis until drains removed. PJP prophylaxis. Ganciclovir if donor CMV positive/recipient negative

  • Immunosuppression: Methylprednisolone 15 - 20mg/kg/dose BD for 2days, Thymoglobulin 1.5mg/kg/dose OD for 5days or Basiliximab, consider IVIG 0.4g/kg/dose OD for 5days, Calci-neurininhibitor: Cyclosporine or Tacrolimus (0.05mg/kg/dose BD) adjusted to level, Mycophenolate mofetil (MMF) 30mg/kg/dose BD or Azathioprine 3mg/kg/dose OD adjusted to level

    Specific Problems:

  • early graft failure: dominant left heart failure → mechanical support, Retransplantation

  • right heart failure (especially in setting of preoperatively increased PVR/TPG): → iNO ( →→ NO), Milrinone, Dobutamine or Adrenaline ( →→ Inotropes ), consider mechanical support

  • low CO: keep paralysed, don't wean inotropes < 24hrs, pacing (infant 140bpm, adolescent 100bpm), consider mechanical assist

  • acute rejection (rare in the first 7 - 10days): LV dysfunction, arrhythmia. Diagnosis: Biopsy shows lymphocytic infiltrates. Therapy: Methylprednisolone high dose

    Longterm Morbidity & Mortality:

    Renal failure, Cardiac Allograft Disease (CAD), Lymphoma, Neoplasia, PTLD (Post Transplant Lymphoproliferative Disease; usually EBV related. Therapy: temporarily decrease immunosuppression, (antiviral treatment), Retuximab

    Outcome:

    1y 90%, 5y 80%, 10y 70%

    [1] Paediatric Heart Transplant Society: www.uab.edu/phts/

    [2] Curr Cardiol Rev. 2011 May;7(2):72-84: Chinnock et al: Heart transplantation for congenital heart disease in the first year of life.

    [3] Eur J Cardiothorac Surg. 2012 Jun 24. Seddio et al: Is heart transplantation for complex congenital heart disease a good option? A 25-year single centre experience.

    [4] Curr Treat Options Cardiovasc Med. 2011 Oct;13(5):425-43: Gazit et al: Perioperative management of the pediatric cardiac transplantation patient.

    [5] Lancet. 2006 Jul 1;368(9529):53-69: Webber et al: Heart and lung transplantation in children.

    • Berlin Heart VAD EXCOR

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    HEART FAILURE: BERLIN HEART VAD EXCOR®

    Definition: paracorporal, pneumatically driven, pulsatile flow mechanical support device driven by a central driving unit (Ikus®) and different sizes of blood pumps (10, 25, 30, 50, 60, 80ml), can be used as RVAD, LVAD or BIVAD.

    Aim: Bridge to Transplant or Bridge to Recovery

    Standard Settings:

    Driving pressures for Systole and Diastole
    (Chamber Size / LVAD / RVAD)

    10 ml

    225 / 175

    - 50 / - 50

    25 ml

    175 / 150

    - 50 / - 50

    30 ml

    175 / 150

    - 50 / - 50

    50 ml

    175 / 150

    - 25 / - 25

    60 ml

    200 / 150

    - 25 / - 25

    80 ml

    225 / 175

    - 25 / - 25

    Anticoagulation guide:

    Medications / Dosing / Target

    start UFH

    + > 24hr post OP

    + no bleeding

    + platelets > 20.000

    + normal TEG

    start with

    a) < 12month:
    15 U/kg/hr (no bolus) and increase after 6hrs to 28U/kg/hr

    b) >12month:

    10U/kg/hr (no bolus) and increase after 6hrs to 20U/kg/hr

    aPTT 1.5 - 2.5 of normal (check every 6hrs)

    or Anti-Xa 0.35 - 0.50U/ml (draw level 4hrs after 2nd dose)

    start LMWH

    + creatinine normal

    + no bleeding

    or if

    + unable to tolerate PO

    + unstable INRs

    + convert after UFH and no bleeding

    start with Enoxaparin

    a) < 3month: 1.5mg/kg BD

    b) > 3month: 1mg/kg BD

    or if low INR 2.0 - 2.7: 1mg/kg/ OD

    or if low INR < 2.0:

    1mg/kg BD

    Anti-Xa 0.6 - 1.0U/ml (draw level 4th after 2nd dose until stable)

    start Vitamin K Antagonist
    (bridge with LMWH)

    + if age > 12month

    + enteral feeds tolerated

    Warfarin 0.2mg/kg/day

    (maximum 5mg/day)

    INR 2.7 - 3.5

    (use LMWH if unstable INRs)

    start Platelet inhibitors

    Dipyramidole

    + if Platelets > 40.000

    + postop Day 2 and

    ADP > 50%

    + Aspirin

    + if platelets > 40.0000

    + postop Day 4 and drains removed and ARA > 50%

    Dipyramidole 1mg/kg/dose QID (maximum 15mg/kg/day)

    Aspirin 1mg/kg/day

    ADP activity < 50%

    ARA activity < 30%

    Trouble Shooting: always inform PICU consultant for any changes !

    Insufficient filling of VAD (VAD Diastole)

    Hypovolaemia

    check Hb and drain losses → replace volume

    changes in intrathoracic pressure

    check CXR (Pneumothorax ?), Ventilation settings → aim for early extubation to increase CO (negative impact of positive intrathroacic pressure)

    Tamponade

    ECHO warranted, inform surgeon ASAP

    increased PVR

    lower PVR →→ Pulmonary Hypertension , check right heart function on ECHO

    Kink in inflow cannula

    check for mechanical obstruction: extracorporal / intracorporal (ECHO)

    right heart failure

    (LVAD only)

    check right heart function with ECHO → inotropic support of right heart (Dobutamine, Milrinone), →→ NO , RVAD

    too low negative vacuum pressure

    increase negative vacuum pressure (be careful not to suck air in) → Driving pressures

    VAD rate too high

    lower VAD rate, decrease % systole

    Insufficient emptying of VAD (VAD Systole)

    increased PVR (in RVAD)

    lower PVR →→ Pulmonary Hypertension

    increased SVR (in LVAD)

    lower SVR →→ Vasodilators

    Kink in outflow cannula

    check for mechanical obstruction

    systolic drive pressure too low

    increase systolic driving pressure (→ Driving pressures)

    [1] J of Cardiovasc Trans Res (2010) 3:612-617: Bryant 3rd: Current Use of the EXCOR Pediatric Ventricular Assist Device

    [2] Artif Organs. 2010 Dec;34(12):1082-6: Humpl et al: The Berlin Heart EXCOR Pediatrics-The SickKids Experience 2004-2008

    [3] Ann Thorac Surg. 2005 Jan;79(1):53-60; discussion 61: Groetzner et al: Cardiac transplantation in pediatric patients: fifteen-year experience of a single center

    [4] J Heart Lung Transplant. 2009 Apr;28(4):399-401. Irving et al: Successful bridge to transplant with the Berlin Heart after cavopulmonary shunt

    [5] Am Heart J. 2011 Sep;162(3):425-35.Almond et al: Berlin Heart EXCOR Pediatric ventricular assist device Investigational Device Exemption study: study design and rationale

    [6] J Thorac Cardiovasc Surg. 2011 Mar;141(3):616-23, 623: Hetzer et al: Single center experience with treatment of cardiogenic shock in children by pediatric ventricular assist devices

    [7] Artif Organs 2012 Jul;36(7):635-9: Sharma et al: Ventricular assist device support in children and adolescents with heart failure: the Children's Medical Center of Dallas experience

    Cardiomyopathy

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    HEART FAILURE: CARDIOMYOPATHY [CM] - (DILATIVE DCM / HYPERTROPHIC HCM)

    Basic Investigation: ECG, CXR, ECHO, FBE, Clotting, U&C, Electrolytes (incl. Ca++, Mg++, Fe++, PO4---), CRP, ESR, Albumin, LFT, TFT, BNP, Troponin I, Troponin T, Lactate, ABG, VBG.

    Extended Investigation: Cardiac MRI. 24hr Holter Monitor. Blood: Amino acids, Carnitine, Acyl-Carnitine, Ammonia, Cu, Caeruloplasmin, Transferrin-Isoforms, Pyruvate, Selenium, Vitamins. Urine: Amino acids, Organic acids, Oligosaccharide screen, MPS screen. Autoimmune: ANA, ENA. Genetic: FISH. Endomyocardial Biopsy.

    Investigation for Myocarditis: Blood & Urine for viral cultures (Echo, Adeno, Parvo, Coxsachie, CMV, Parainfluenza, Influenza, HIV, Hepatitis screen) and for bacterial (incl. atypical) / fungal / rickettsial / protozoal and helminithic culture. NPA. ETA.

    Identifying the High Risk Patient: LVEF < 20% or LVEDD > 70mm or increased C/T ratio > 0.7 or MR > 3 or complex ventricular arrhythmia (NSVT).

    All high risk patients require PICU admission !

    Acute Management Guideline for DCM

    Is there low perfusion ?

    Is there congestion ?

    NO

    YES

    NO

    Ward Management

    ACEi

    β - Blocker

    oral diuretics

    PICU admission

    iv Frusemide infusion

    consider NIV CPAP

    observe for minimum of 48 hr

    watch BNP & renal function

    YES

    PICU admission

    NIV CPAP

    iv Adrenaline
    (max. 0.05 ≈≥g/kg/min)

    observe closely

    for need for ECLS

    PICU admission

    iv Frusemide infusion

    consider NIV CPAP

    introduce carefully Milrinone

    consider β agonists

    observe for 4 days

    1. CPAP or BIPAP. Only intubate when ECLS is on Stand-By

    2. Fluid and Water Restriction to 25% maintenance

    3. Commence iv Frusemide infusion. Aim for euvolaemic state in DCM. Mild hypervolaemia may be needed in HCM. Watch renal function. Avoid hypovolaemia.

    4. Commence Spironolactone (1mg/kg BD)

    5. Commence Milrinone if tolerated

    6. Commence β-agonists as indicated. Dopamine, Dobutamine or Adrenaline up to 0.05mcg/kg/min

    7. Consider Levosimendan

    8. Consider biventricular pacing

    9. Consider antiarrhythmic therapy. Consult cardiology. Do not use β-blocker when on β -agonists. β - Blocker might be useful in HCM

    10. Consider anticoagulation therapy

    11. Ensure appropriate nutrition. Supplemental therapy with carnitine, co-enzyme Q10, vitamins as indicated.

    11. Early use of ECLS if patient is deteriorating or not improving →→ ECMO

    12. specific guided therapy in Pompe disease: myozyme

    ECMO

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    HEART FAILURE: ECMO

    ExtraCorporal Membrane Oxygenation: for cardiovascular or respiratory or combined cardiovascular

    Inclusion criteria: > 34 / 40 weeks gestation age, reversible cardiac, pulmonary, or cardiopulmonary failure, mechanical ventilation < 14 days.

    Exclusion criteria: major intracranial hemorrhage, lethal malformation, severe neurological injury, untreatable cardiac or pulmonary malformation.

    Clinical Indications: failure to wean off cardiopulmonary bypass, Oxygenation Index > 40 on two or more ABG despite maximum therapy [OI = (MAP * FiO2 * 100) / PaO2], intractable metabolic acidosis, progressive intractable pulmonary or cardiac failure

    Flow rates on full VA ECMO support:

  • in patients < 10kg aim for 100 - 150ml/kg/min

  • in patients > 10kg aim for CI 2.4L/min/m2

  • consider higher flow rates in septic patients, univentricular hearts with open systemic-pulmonary shunts and extracardiac shunts

    Flow rates on full VV ECMO support:

  • in patients < 10kg aim for 70 - 140ml/kg/min

  • in patients > 10kg aim for CI 1.8L/min/m2

  • consider higher flow rates in septic patients, univentricular hearts (cave: inappropriate high SmvO2 might indicate recirculation)

    Cannulation: ABG, FBE, Coags, Urea & Creatinine & Electrolytes, Ca++, Mg++, LFT, SBR, ABG, obtain blood culture / urine for mcs / ETT aspirate for mcs, optimize coagulation if possible, consider blood sample storage for genetic analysis, Cephazolin (50mg/kg iv) 30 - 60min prior to procedure, CXR, ECHO, cranial Ultrasound, arterial line placed and secured, central line placed (not RIJ or R Subclavian) and secured, chest drain placed, if required and secured, position child: neck cannulation: position patient head outwards in bed space and neck overextended with roll under shoulders / transthoracic cannulation: supine position with roll under back, 2 x venous line extension, Fentanyl 5mcgg/kg iv bolus, Vecuronium 0.1mg/kg iv, consider fluid resuscitation / enhance inotropic support if needed, surgical preparation, give Heparin on surgical request (50 - 100U/kg if appropriate for pt situation), surgical cannulation & connection of tubing (< 15kg → ¼", > 15kg → 3/8" circuit), set FiO2 100% and sweep gas flow, turn RPM to 1000 - 1200, unclamp venous line, unclamp arterial line, increase slowly RPM to desired flow, reduce inotropic / vasoconstrictor accordingly, observe ABP / inlet pressure / outlet pressure / CVP, recheck ACT every 30min, commence Heparin infusion 20U/kg/hr once ACT < 250, once on full flow, change to ventilation rest settings (PEEP 10, PS + 10, Vt 6ml/kg, RR 10, FiO2 30 - 40% in VA ECMO FiO2 60% in VV ECMO), secure cannula position, commence analgesia & sedation & paralysis, CXR, ECHO, fluid restriction to 60%.

    Anitcoagulation: Keep ATIII level > 80%: No. IU = (desired - actual level) X Wt, Heparin [Patients < 10kg: 5 KU / 50 ml 0.9% NaCl, Patients > 10kg: 25 KU / 50 ml 0.9% NaCl]

    Commence Heparin on 20U/kg/hr, adjust in regards to ACT.

    ACT

    Bolus (U/Kg)

    % rate change

    <160

    50

    +15%

    160-180

    30

    +10%

    180-200

    20

    +10%

    200-220

    0

    0

    220-240

    0

    -10%

    240-260

    0

    -10%

    260-280

    0

    -10%

    Weaning in VA ECMO: ensure volume status is adequate, ventilate patient with acceptable settings (as blood flow through lungs increased), decrease pump flows by 10ml/min every 60min down to a minimum of 40ml/kg or 250ml/min total flow through oxygenator, ABG 15min post each wean of flow, ECHO at lower flows, [do NOT turn sweep gas off - all flow going through circuit bypasses lungs. Minimum sweep gas setting is 200ml/min], bridge or decannulate

    Weaning in VV ECMO: commence full ventilation, sweep gas FiO2 at 0.21 for approx 10 minutes to flush O2 from oxygenator, turn sweep gas to minimum setting of 200 ml/min, run ACT's 200-220 whilst pt still on ECMO circuit, observe patient saturation, ABG after 30min (oxygenator continues to oxygenate for approx 20min after sweep gas flow is ceased), organize for decannulation

    [1] Cardiol Young, 2007; Sep;17 Suppl 2:104-15: Cooper et al: Cardiac extracorporeal life support: state of the art in 2007

    [2] http://www.elso.med.umich.edu/

    [3] Lancet, 1996 Jul 13; 348(9020):75-82: UK collaborative randomised trial of neonatal extracorporeal membrane oxygenation. UK Collaborative ECMO Trail Group

    [4] Cochrane Database Syst Rev. 2008 Jul 16;(3):CD001340: Mugford et al: Extracorporeal membrane oxygenation for severe respiratory failure in newborn infants.

    [5] Lancet. 2009 Oct 17;374(9698):1351-63: Peek et al: Efficacy and economic assessment of conventional ventilatory support versus extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR): a multicentre randomised controlled trial.

    [6] Intensive Care Med (2012) 38:210-220: MacLaren et al: Contemporary extracorporeal membrane oxygenation for adult respiratory failure: life support in the new era

    [7] Artif Organs. 2013 Jan;37(1):21-8. Kotani et al: Evolution of technology, establishment of program, and clinical outcomes in pediatric extracorporeal membrane oxygenation: the "sickkids" experience.

    • ECMO Antibiotics

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    HEART FAILURE: ANTIBIOTICS FOR ECMO PATIENTS

    Indication

    Prophylaxis

    Timing

    Duration

    ECMO (cannulation, chest revision, reoperation on ECMO, decannulation) - if not on anitbiotics with both gramnegative and grampositive cover already

    Cephazolin 50mg/kg up to 1g IV

    or (if Cephazolin unavailable)

    Cephalothin 50mg/kg up to 2g IV

    Optimal timing for Beta-Lactams: administer 30 - 60min before incision

    2nd dose 25mg/kg if operation > 3hrs, continue 25mg/kg 8hrly, remember to cease after 24hrs

    Known MRSA infection or colonization, currently or in the past

    Cephazolin 50mg/kg up to 1g IV

    plus

    Vancomycin 25mg/kg up to 1.5g (child < 12yrs: 30mg/kg up to 1.5g)

    Optimal timing for Beta-Lactams: administer 30 - 60min before incision; for Vancomycin: slow infusion, starting 60min before, and finishing immediately before incision, CVL not required

    2nd dose 25mg/kg if operation > 3hrs, continue 25mg/kg 8hrly, remember to cease after 24hrs; no further doses of Vancomycin required

    Penicillin / Cephalosporin allergy

    Vancomycin 25mg/kg up to 1.5g (child < 12yrs: 30mg/kg up to 1.5g) IV

    plus

    Gentamicin 2mg/kg IV

    Optimal timing for Beta-Lactams: administer 30 - 60min before incision; for Vancomycin: slow infusion, starting 60min before, and finishing immediately before incision, CVL not required

    No further doses required

    ECMO (cannulation, chest revision, reoperation on ECMO, decannulation) - if on anitbiotics with both gramnegative and grampositive cover already

    No further prophylaxis required

    n/a

    n/a

    [1] Therapeutic Guidelines: Antibiotic, 2006: Therapeutic Guidelines Ltd, Melbourne.

    [2] Ann Thorac Surg 2006, 81:397-404: The Society of Thoracic Surgeons Practice Guideline Series: Antibiotic Prophylaxis in Cardiac Surgery, Part 1: Duration.

    [3] The Society of Thoracic Surgeons Practice Guideline Series: Antibiotic Prophylaxis in Cardiac Surgery, Part 2: Antibiotic Choice. Ann Thorac Surg 2007;83:1596-76.

    ABO incompatible HTX

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    HEART FAILURE: ABO INCOMPATIBLE HTX

    UNOS Policy: ABO incompatible HTX for children up to 2years (with acceptable isohemoglutinin titres - less than 1:4)

    Recipient

    Donor compatible

    Donor incompatible

    Antibodies to avoid

    Plasma / Platelets

    RBC

    0

    0

    0

    0

    AB

    Anti A

    Anti B

    AB

    0

    0

    A

    Anti A

    AB or A

    0

    0

    B

    Anti B

    AB or B

    0

    A

    A

    A

    0

    A

    AB

    Anti A

    Anti B

    AB

    A or 0

    A

    B

    Anti A

    Anti B

    AB

    A or 0

    B

    B

    B

    0

    B

    AB

    Anti A

    Anti B

    AB

    B or 0

    B

    A

    Anti A

    Anti B

    AB

    B or 0

    AB

    AB

    AB

    AB

    A

    AB

    AB

    B

    AB

    AB

    0

    AB

    Preoperative Preparation:

    Isohaemagglutinin titres. Avoid transfusion. Consider transfusion in regards to guide.

    Perioperative Management:

    if elevated Iso-titre: Plasma exchange once on CPB, Iso-haemagglutinin quick test before AoCx release, repeat Plasma exchange as required.

    Postoperative Management:

    Isohaemaggluttinin titres daily of ABOi HTX. Repeat Plasma exchange if required

    Outcome:

    Similar long term outcome. Reduced rate of infection and rejection compared to ABO compatible HTX

    [1] Paediatric Heart Transplant Society: www.uab.edu/phts/

    [2] Heart Lung Transplant. 2012 Feb;31(2):173-9: Henderson et al: ABO-incompatible heart transplantation: analysis of the Pediatric Heart Transplant Study (PHTS) database.

    Heart Failure & VAD

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    HEART FAILURE: HEART FAILURE AND VAD

    Modified Ross Heart Failure Classification

    Class

    Symptoms

    I

    Asymptomatic

    II

    mild tachypneoa or diaphoresis with feeding

    Dyspnea on exertion in older children

    III

    marked tachypnea or diaphoresis with feeding; marked Dyspnea on exertion

    prolonged feeding time with failure to thrive

    IV

    Tachypnea, retractions, grunting or diaphoresis at rest

    Causes: congenital, skeletal myopathy with cardiac involvment (eg Duchenne, Becker, Barth Syndrome, Myotonic Dystrophy), metabolic disorders with cardiac involvement (Carnitine deficiency, Glykogen Storage disease, mitochondrial disease), Cardiomyopathy (primary, secondary) →→ Cardiomyopathy , acquired (rheumatic heart disease, myocarditis →→ Myocarditis , Tachyarrythmia, toxic, antineoplastic drugs, nutritional deficiency)

    Treatment: Treatment of the underlying cause and →→ Cardiomyopathy

    Mechanical Treatment Options (ECLS):

    Short term support: IABP (diastolic augmentation), Impella axial flow (minimum weight 25kg), centrifugal pumps (Levitronix), ECMO →→ ECMO

    Mid Term support / Bridge to transplantation / Bridge to recovery: Thoratec, →→ Berlin Heart

    [1] European Journal of Pediatrics, 2010, 169, 403 - 410: Kantor et all: Clinical Practice: Heart Failure in Children. Part II. Current maintenance therapy and new therapeutic approaches

    [2] Circulation 110:975-981: Stevenson LW: Left ventricular assist device as destination for patients undergoing intravenous inotropic therapy: a subset analysis from REMATCH (Randomized Evaluation of Mechanical Assistance in Treatment of Chronic Heart Failure).

    [3] Ann Thorac Surg 1999; 67: 1415-20. Akomea-Agyin: Intraaortic balloon pumpi in children.

    [4] J. Thorac. Cardiovasc. Surg., July 1, 2011; 142(1): 60 - 65. Lamarche et al: Comparative outcomes in cardiogenic shock patients managed with Impella microaxial pump or extracorporeal life support

    [5] John et al. J Thorac Cardiovasc Surg.2011; 141: 932-939. Outcomes of a multicenter trial of the Levitronix CentriMag ventricular assist system.

    [6] Reinhartz O, Keith FM, El-Banayosy A, et al. Multicenter experience with the thoratec ventricular assist device in children and adolescents. J Heart Lung Transplant 2001; 20: 439-48.

    [7] Current Cardiology Reviews, 2010, 6, 46-53. Gazit et al: Mechanical Circulatory Support of the Critically Ill Child Awaiting Heart Transplantation.

    [8] J Heart Lung Transplant. 2011 Feb;30(2):115-23: Stevenson et al: Third INTERMACS Annual Report: the evolution of destination therapy in the United States.

    [9] Interact Cardiovasc Thorac Surg. 2012 Sep;15(3):426-31. The profile of the systemic inflammatory response in children undergoing ventricular assist device support.

    Myocarditis

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    HEART FAILURE: MYOCARDITIS

    See →→ Cardiomyopathy , but cardiac MRI or Endomyocardial Biopsy to confirm Diagnosis

    Symptoms: Very nonspecific in children: malaise, fever, poor appetite, tachypnea, tachycardia, chest pain, abdominal pain, myalgia, fatigue, cough, oedema, hepatomegaly, murmur.

    Investigations: See also cardiomyopathy. Nonspecific T changes on ECG. Cardiac enzymes are not elevated in most patients with myocarditis. Echo is mandatory to assess function (systolic and diastolic dysfunction).

    Treatment:

    1. Symptomatic: see →→ Cardiomyopathy

    2. IVIG: early, high dose IVIG: 2g/kg over 24hrs

    3. in chronic DCM: consider Interferon with persistent viral genomes

    Common Differential Diagnosis of CM in regards to age

    < 1 year Myocarditis, Endocardial Fibroelastosis, Barth Syndrome, Carnitine Deficiency, Selenium Deficiency, Anomalous Left Coronary Artery, Kawasaki Disease, Critical Aortic Stenosis, Supraventricular Tachycardia, Arterio-Venous Malformation, Calcium Deficiency, Hypoglycemia, Left Ventricular Non-Compaction, Mitochondrial Cardiomyopathy, Nemaline Myopathy, Minicore-Multicore Myopathy, Myotubular Myopathy

    > 1 year and < 10 years Familial DCM, Barth Syndrome, Myocarditis, Arrhythmogenic RV dysplasia, Endocardial Fibroelastosis, Carnitine Deficiency, Selenium Deficiency, Anomalous Left Coronary Artery, Kawasaki Disease, Supraventricular Tachycardia, Toxic (Adriamycin), Ketothiolase Deficiency, Ipecac Toxicity, Systemic Lupus Erythematosis, Polyarteritis Nodosa, Haemolytic-Uremic Syndrome, Mitochondrial Cardiomyopathy, Nemaline Myopathy, Minicore-Multicore Myopathy, Myotubular Myopathy

    > 10 years Familial DCM, X-linked DCM, Myocarditis, Supraventricular Tachycardia, Congenital Heart Disease, Mitochondrial CM, Chagas Disease, Arrhythmogenic RV dysplasia, Eosinophilic Cardiomyopathy, Toxic (Adriamycin), Phaeochromocytoma, Duchenne/Becker muscular dystrophy, Emery-Dreifuss muscular dystrophy, Hemochromatosis, Limb-Girdle Muscular Dystrophy, Myotonic Dystrophy, Peripartum Cardiomyopathy, Alcoholic Cardiomyopathy

    [1] Academic Emergency Medicine, 2008, 15, 355 - 362: Tallmann et all: Noninvasive ventilation outcomes in 2430 acute decompensated heart failure patients: an ADHERE registry analysis

    [2] European Journal of Pediatrics, 2010, 169, 269 - 279: Kantor et all: Clinical Practice: Heart Failure in Children. Part I. clinical evaluation, diagnostic testing and initial management

    [3] American Journal of Medicine, 2006, 119, S37 - S44: Hill et all: Beyond diuretics: management of volume overload in acute heart failure syndromes

    [4] New England Journal of Medicine, 1999, 341, 709 - 717: Pitt et all: The Effect of Spironolactone on Morbidity and Mortality in Patients with Severe Heart Failure

    [5] Circulation. 2003;107: 996 - 1002: Hoffmann et all: Efficacy and Safety of Milrinone in Preventing Low Cardiac Output Syndrome in Infants and Children After Corrective Surgery for Congenital Heart Disease

    [6] Journal of Intensive Care Medicine, 2006, 21, 183 - 187: Egan et all: Levosimendan for Low Cardiac Output: A Pediatric Experience

    [7] Current Cardiology Reviews, 2009, 5, 40 - 44: S. Batra et all: Cardiac Resynchronization Therapy in Children

    [8] The Journal of Pediatrics, 2001, 138(4), 457-458: Bruns et all: Carvedilol as therapy in pediatric heart failure: An initial multicenter experience

    [9] New England Journal of Medicine, 2006, 355, 1873 - 1884: Birks et all: Left ventricular assist device and drug therapy for the therapy of heart failure

    [10] Circulation, 2004, 109, 1250 - 1258: Mahrholdt: Cardiovascular MRI assessment of human myocarditis: a comparison to histology and molecular pathology

    [11] Circulation, 1994, 89, 252-257: Drucker et all: Gamma-globulin treatment of acute myocarditis in the pediatric population

    [12] Circulation, 2003, 107, 2793 - 2798: Kuhl et all: Interferon-beta treatment eliminates cardiotropic viruses and improves left ventricular function in patient with myocardial persistence of viral genomes and left ventricular dysfunction.

    Prolonged QT Syndrome

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    PICU: PROLONGED QT SYNDROME

    Definition: prolonged QTc interval, calculated by Bazett's formula: QTc = QT : sqr (previous RR interval). normal < 440ms (460ms in women and children).

    Congenital pQTS (Jervell and Lange-Nielsen syndrome, Romano-Ward syndrome, idiopathic) or Acquired pQTS (metabolic: hypokalemia, hypomagnesemia, hypocalcacemia, drugs: Quinidine, Procaine, Amiodarone, Sotalol, Erythromycin, Terfenadine, Haloperidol, TCA, Risperidone, Methadone, Droperidol, Organophosphates, or myocardial ischemia, HIV, Hypothermia)

    Diagnosis: pQTS measured via Bazett's formula, Torsades de pointes, T-Wave alternans, Syncope, family history

    Treatment:

    1. acute: haemodynamically unstable patient: DC 2J/kg, MgSO4 (0.2mmol/kg), Lignocaine (1mg/kg over 2min), Isoprenaline infusion (0.05 - 1mcg/kg/min), overdrive pacing

    2. chronic: β-Blocker, pacemaker, ICD, sympathectomy

    [1] American Heart Journal, 1957, 54, 59 - 68: Jervell et all: Congenital deaf-mutism, functional heart disease with prolongation of the Q-Y interval and sudden death

    [2] Circulation, 2000, 102, 782 - 784: Splawski et all: Spectrum of mutations in long QT syndrome genes: KVLQT1, HERG, SCN5A, KCNE1, and KCNE2

    [3] JAMA, 2003, 23, 2041 - 2044: Moss: Long QT Syndrome

    Arrhythmias

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    PICU: ARRHYTHMIA

  • prevalence of postoperative arrhythmia: 15 - 48%

  • at risk: young age, low body weight, long CPB time, complex surgery, presence of residual defects

  • Prevalence of postoperative arrhythmia is up to 50%

  • Haemodynamic impairment in > 50%

  • Aggressive treatment in > 50% required

  • Most common is sinus bradycardia with / without junctional escape > premature complexes > supraventricular tachycardia > AV block > JET

  • Mechanisms: Re-entry: on / off, inducible, overdriveable, cardiovertable; automatic / ectopic: warm up, not inducible, not overdriveable, not cardiovertable

  • Prevention and unspecific treatment: strict maintenance of normothermia, avoid triggering drugs, avoid volume overload, avoid acidosis, Mg++ >1.0, Ca++ >1.0, K+ 4.5 - 5mmol/L

    Bradyarrhythmia

  • Sinusbradycardia: increased vagal tone, elevated ICP, drugs (Digoxin, β-blocker, Amiodarone, Dexmedetomidine,‚Ķ), respiratory (hypoxia), metabolic (Hypoglycaemia, Hyper / hypocalcaemia, Hypomagnesiaemia), post-surgical (Fontan Circulation, Mustard / Senning) → correction of underlying cause, Atropine 0.02mg/kg, Isoprenaline 0.1 - 2mcg/kg/min infusion, Pacing: AAI, DDD, DDI →→ Pacing

  • AV Block: congenital, increased vagal tone, drugs, respiratory, metabolic, post-surgical (VSD, AVSD, ccTGA, TGA, Fontan Circulation) → correction of underlying cause, Pacing: VVI, DDD, DDI →→ Pacing

    Tachyarrhythmia

  • Sinustachycardia: six causes: central (pain, awake, fever, seizure), cardiovascular (hypovolaemia, LCOS →→ LCOS , PHT →→ Pulmonary Hypertension ), respiratory (hypoxia, hypercarbia), heart failure → correction of underlying cause, sedation, fluid bolus, general prevention and treatment

  • Intraatrial Reentry Tachycardia (IART ≈ atypical atrial flutter): causes: post-surgical (Fontan Circulation, Mustard / Senning, ccTGA, TOF, Ebstein's anomaly, VSD, ASD, TGA) → diagnostic: Adenosine (100mcg/kg iv, increasing up to 300mcg/kg iv), treatment: overdrive pacing if rate low enough ( →→ Pacing ), Cardioversion (1 J/kg), Amiodarone (loading 25mcg/kg/hr for 4 hours in Guardrail (set VTBI) followed by 5 - 15mcg/kg/min infusion for rate control or Digoxin (20mcg/kg iv in infants, 30 - 40mcg/kg iv in children). Titrate for effect. AV reciprocating tachycardia (WPW if preexcitation on baseline ECG). Treatment: Adenosine (100mcg/kg iv, increasing to 300mcg/kg iv). Consider Overdrive pacing. Consider Cardioversion 1J/kg. If recurrent/ongoing consider beta-blocker or Digoxin or Amiodarone if concerned in regards to function.

  • Atrial Ectopic Tachycardia (AET ≈ chaotic atrial tachycardia) difficult to control pharmacologically: β -blocker: Esmolol (bolus up to 500mcg/kg iv followed by 100 - 1000mcg/kg/min infusion) or Propranolol (bolus 10 - 100mcg/kg slowly iv), Digoxin, Procainamide, Flecainide (3 - 6mg/kg/day), Sotalol (2 - 6mg/kd/day), Amiodarone, overdrive-pacing if rate low enough, catheter ablation. Consider sedation if compromised cardiac output.

  • Atrial Fibrillation: preexcitation-syndromes, post-surgical (ASD, Fontan Circulation, AS) → Amiodarone, overdrive pacing, Cardioversion (1J/kg). Consider anticoagulation if persistent > 48hrs

  • Junctional Ectopic Tachycardia (JET): 180 - 250bpm: congenital, post-surgical (ASD, VSD, AVSD, TOF, Fontan Circulation) → decrease adrenergic drugs if feasible, electrolyte correction (Mg++and K+), sedation and paralysis, overdrive pacing, pharmacologically: Amiodarone, surface cooling to 35°C to slow heart rate (and allow AV sequential pacing)

  • Premature Ventricular Contraction (PVC): < 1 / min acceptable, otherwise → treatment of underlying cause. Beta-Blocker if clinically indicated.

  • Ventricular Tachycardia: respiratory, metabolic (inborn errors of metabolism), drugs (Class I, Class III, Digitalis toxicity), anatomical (myocarditis), post-surgical, idiopathic → in unstable patient: immediate Cardioversion (1 J/kg → 4 J/kg) and CPR, correction of underlying cause, Amiodarone (loading over 20min: 5mg/kg iv) or Procainamide (loading over 30min: 10 mg/kg iv), catheter ablation, ICD

  • Torsade de Pointes (polymorph VT): causes: TCA intoxication, long QT Syndrome, dyselectrolytaemia, see also VT, MgSO4 (0.2mmol/kg), consider Beta-Blocker or pacing if recurrent.

  • Ventricular Fibrillation: immediate DC and CPR → Resuscitation

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Arrhythmia

    [2] Am J Emerg Med. 2008 Mar;26(3):348-58: O'Connor et al: The pediatric electrocardiogram part II: Dysrhythmias

    [3] Anaesth Intensive Care. 2009 Sep;37(5):705-19: Skippen et al: Diagnosis of postoperative arrhythmias following paediatric cardiac surgery

    [4] Nat Clin Pract Cardiovasc Med. 2008 Aug;5(8):469-76. Snyder: Postoperative ventricular tachycardia in patients with congenital heart disease: diagnosis and management

    [5] Pacing Clin Electrophysiol. 2008 Feb;31 Suppl 1:S2-6: Roos-Hesselink et al: Significance of postoperative arrhythmias in congenital heart disease

    [6] Circulation. 2007 Jun 26;115(25):3224-34: Walsh: Interventional electrophysiology in patients with congenital heart disease

    [7] Circulation. 2007 Jan 30;115(4):534-45: Walsh et al: Arrhythmias in adult patients with congenital heart disease

    [8] Z Kardiol. 2004 May;93(5):371-80: Haas et al: Postoperative junctional ectopic tachycardia (JET)

    [9] Circ Arrhythm Electrophysiol. 2010 Apr 1;3(2):134-40: Chang et al: Amiodarone versus procainamide for the acute treatment of recurrent supraventricular tachycardia in pediatric patients

    [10] Pediatr Emerg Care. 2007 Mar;23(3):176-85; Manole MD: Emergency department management of the pediatric patient with supraventricular tachycardia

    • Blood Products

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    PICU: BLOOD PRODUCTS

    Pump Blood

    Pump blood is the blood remaining in the bypass circuit on the completion of bypass. It is a mixture of the patient's own blood, other fluids and any bank blood used to prime the bypass circuit.

    Unfiltered pump blood has a low Hct and contains large amounts of heparin and inflammatory cytokines. The use of CUF (continuous ultrafiltration) during bypass or MUF (modified ultrafiltration) after bypass concentrates the pump blood and removes some heparin and cytokines. If pump blood is used, additional Heparin reversal will be needed. It should not be used if excessive bleeding or if the Hb is low.

    Protamine sulphate is used to reverse the heparin in pump blood. The dose is 1 mg per 25ml of pump blood. Recheck ACT after 10ml/kg pump blood. Rapid infusion may cause pulmonary hypertension.

    Packed Red Blood Cells (PRBC)

    Each unit of pack cells contains ~ 300ml and has an Hct of 0.5 - 0.7 (Na+ ~ 20, K+ up to 20mmol/l, especially if irradiated)

    Warning: Neonates should be transfused with blood which is as fresh as possible, and sufficiently slowly to minimise any adverse effect from hyperkalaemia and citrate toxicity (hypocalcaemia).

    Used for treatment of anaemia and the management of active bleeding. Must be compatible with recipients ABO and Rh groups and clinically significant red cell antibodies.

    Transfusion of 4ml/Kg increases Hb by approximately 1g/dl. In rapid transfusion situations alternate red cell units with colloid solutions eg. FFP.

    Store only in a designated blood refrigerator (2 to 6°C). Use within 4 hours of removing from refrigerator and always use a leucocyte filter.

    Request irradiated products if suspicion of immunodeficiency (eg Di George anomaly) or in any neonate <1month undergoing cardiac surgery.

    Donor blood exposes the patient to risk of infection and transfusion reaction. Pump blood, however is blood to which the patient has already been exposed.

    Platelets

    Cardiopulmonary bypass frequently leads to both thrombocytopenia (dilutional) and more importantly platelet dysfunction (early onset). Platelet transfusion should be considered for excessive bleeding, irrespective of the absolute platelet count. Transfused platelets have a storage (function) defect lasting 2 - 4hrs.

    Platelet transfusion should not be used for "routine" volume expansion. Should be ABO compatible to prevent haemolysis caused by donor anti-A and anti-B. Female infants and children (all females <45 years) should receive RhD negative platelets. The dose is 10ml/kg - repeat platelet count and/or TEG.

    Fresh Frozen Plasma

    Plasma separated from one donation of blood. Contains normal

    levels of stable clotting factors, albumin and immunoglobulin. Factor VIII levels are ~70% normal while plasma proteins (immunoglobulins and clotting factors) are slightly diluted

    . It should be ABO compatible to prevent haemolysis by donor anti-A or anti-B.

    Should be used for microvascular bleeding following massive transfusion or cardiopulmonary bypass, emergency reversal of warfarin effect (in addition to Vitamin K), bleeding resulting from hepatic failure and proven coagulopathy (factor deficiency or DIC).

    Loss of clotting factors may occur as a result of excessive loss of peritoneal, pleural fluid or ascites (via PD catheter). If replaced with NaCl 0.9% alone this may lead to a dilutional coagulopathy.

    Dose is 10 - 20ml/kg iv. FFP should ideally administered slowly (<40ml/kg/hr) as rapid administration can result in cardiovascular collapse by several mechanisms including calcium chelation by citrate (check patient iCa if concerned).Infection risk similar to other blood components. Transfusion should not be used for "routine" volume expansion.

    Cryoprecipitate

    The cold precipitated fraction derived from FFP. Contains factor VIII, fibrinogen, von Willebrand factor and factor XIII.

    Should be used for significant fibrinogen deficiency associated with clinical bleeding, DIC, trauma or during invasive procedures. Suitable for haemophilia and von Willebrand disease specific factors are unavailable. Dose is 5ml/kg iv. One bag is usually 20 - 30ml. Infection risk is similar to other blood components.

    Human Albumin Solutions

    Albumex 4%

    Albumex 20%

    Protein 40 g/l

    Protein 200 g/l

    Na 140mmol/l

    Na 48 - 100mmol/l

    Volume expansion

    Hypoproteinaemia

    50, 250, 500ml bottle

    10, 100ml bottle

    5 - 10ml/kg aliquots

    5ml/kg aliquots

    Albumex 20% is hyperoncotic and in an ideal situation (ie. normal capillary permeability) should expand circulating volume by a factor of 5.

    [1] Cochrane Database Syst Rev. 2011 Mar 16;3: Perel et al: Colloids versus crystalloids for fluid resuscitation in critically ill patients.

    [2] SAFE Study Investigators, Finfer et al: Effect of baseline serum albumin concentration on outcome of resuscitation with albumin or saline in patients in intensive care units: analysis of data from the saline versus albumin fluid evaluation (SAFE) study.

    [3] Pediatr Crit Care Med. 2007 Sep;8(5):459-64: Jatana et al: Deletion 22q11.2 syndrome--implications for the intensive care physician.

    [4] Peditar Crit Care Med 2011 Vol.12, No2: Isthaphanous: Red blood cell transfusion in critically ill children: A narrative review

    Chylothorax

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    PICU: CHYLOTHORAX

    Definition: accumulation of lymphatic fluid or chyle in the pleural space (triglyceride level > 1.1mmol/l or total cell count > 1000cells/ml with > 80% lymphocytes).

    Congenital Chylothorax in lymphangiectasia, congenital heart disease, mediastinal malignancy, chromosomal abnormalities, H-type TracheoesophagealFistula.

    Acquired Chylothorax is usually due to surgery or trauma. Post cardiac surgery incidence up to 4%, depending on type of surgery (Fontan Circulation, TOF repair, HTX, BCPS) or also clot formation in the thoracic large veins.

    Pathophysiological Chylothorax can develop because of disruption of the thoracic duct or increased pressure within the intrathoracic lymphatic system due to increased central venous pressure. Congenital due to abnormal lymphatic drainage.

    Complications due to loss of fatty acids and lymphyocytes: hypovolemia, cellular and humoral immunodeficiency, loss of ATIII, malnutrition due to loss of Lipids

    Diagnosis: Triglyceride level > 1.1mmol/l or total cell count > 1000cells/ml with > 80% lymphocytes in pleural effussion

    Treatment:

    1. conservative:

  • management of the underlying disease

  • dietary modification (low fat diet, medium chain triglyceride diet [monogen] )

  • TPN only (75% respond within 2 weeks)

  • Octreotide (decrease of splanchnic and hepatic blood flow → reducing the flow of chyle, side effects: glucosemetabolism disturbance, transient hyperthyroxinemia, abdominal distension, NEC)

  • Immunoglobulin supplementation if needed (ie Di-George syndrome)

    2. surgical: pleurodesis, surgical abrasion, ligation of the thoracic duct or pleuroperitoneal shunt

    [1] Cochrane Database Syst Rev., 2010, Sep 8: Das et all: Octreotide for the treatment of chylothorax in neonates.

    [2] Ann Thorac Surg, 2005, 80, 1864 - 1871: Chan et all: Postoperative Chylothorax after cardiothoracic surgery in children

    • Fluids

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    PICU: FLUIDS

    Anion Gap = Na+ + K+ - (Cl- + HCO3-). normal 8 - 12 mEq/l.

    Total body water (TBW) = intracellular fluid (ICF) plus extracellular fluid (ECF). [Weight x 600 ml in adults (500 ml in female), Weight x 650 ml in paeds, Weight x 700 ml in neonates]

    ECF = intravascular fluid (plasma and lymph in the vessels) plus interstitial fluid (between cells)

    Osmolality = 2 x Na+ + K+ + Glucose (mmol/l) + Urea (mmol/l).

    Osmotic Gap = measured Osmolality - calculated Osmolality

    Na+ deficit [mmol/l] = (Na+Target - Na+Current) x TBW / 1000

    Cl- deficit [mmol] = (Cl-Target - Cl-Current) x 0.2 x Weight

    Water deficit = 4 ml x Weight x (Na+Target - Na+Current)

    Maximum change in Osmolality in hyper- or hypoosmolaric: 1 mmosmol/l per hour. Cave central pontine Myelinolysis !

    Body water and Blood volume composition with age

    Adult bodies are 60% water (20% ECF, 40% ICF). Blood volume 70 ml/kg. Term neonate bodies are 75% water (40% ECF, 35% ICF), and term neonates usually lose 5-10% of their weight in the first week of life, almost all of which is water loss. Blood volume 80 ml/kg. Preterm neonates have more water (at 23 weeks' gestation, 90% water composed of 60% ECF and 30% ICF), and they may lose 10-15% of their weight in the first week of life. Small for gestational age (SGA) preterm infants may have a higher proportional body water content (90% for SGA infants vs 84% for appropriate for gestational age [AGA] infants at 25-30 weeks' gestation).

    Maintenance Fluid [ml/hr] for active Children > 2 days

    ≤ 10 kg:

    11 kg & < 20 kg

    ≥ 21 kg

    4 ml/kg/hr

    40 ml/hr +
    2 ml/kg/hr

    60 ml/hr +
    1 ml/kg/hr

    Day 1

    Day 2

    Day 3

    Maintenance Fluid [ml/hr] active Neonates ≤ 3 days

    2 ml/kg/hr

    3 ml/kg/hr

    4 ml/kg/hr

    Na+ Requirements for active Neonates ≤ 3 days

    1 - 3 mmol/kg/d

    3 - 5 mmolk/kg/d

    2 - 4 mmol/kg/d

    K+ Requirements for active Neonates ≤ 3 days

    1 - 2 mmol/kg/d

    2 - 3 mmol/kg/d

    1 - 2 mmol/kg/d

    Normal maintenance fluid:

    NaCl 0.9 % or NaCl 0.9 % in 5 % Dextrose or NaCl 0.9 % in 2.5 % Dextrose or Ringer Lactate or Hartmann Solution

    [1] Pediatrics, 1957, May;19(5):823-32: Holliday at all: The maintenance need for water in parenteral fluid therapy.

    [2] Kidney Int., 2005, Jan;67(1):380-8: Friedman: Pediatric hydration therapy: historical review and a new approach.

    [3] Pediatr Nephrol. 2005, Dec;20(12):1687-700: Moritz ML at all: Preventing neurological complications from dysnatremias in children.

    [4] Arch Dis Child, 2006, 91(3):226-32: Neville at all: Isotonic is better than hypotonic saline for intravenous rehydration of children with gastroenteritis: a prospective randomised study.

    [5] N Engl J Med 2011;364:2483-95: Maitland et al: Mortality after Fluid Bolus in African Children with Severe Infection

    Nitric Oxide

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    PICU: NITRIC OXIDE (NO, INO)

    Definition: Nitric oxide (NO) is produced by the endothelium by eNOS (endothelial nitric oxide synthase). It works beside other chemical mediators, to regulate vascular tone. NO induces soluble guanylate cyclase to increase cGMP reducing cellular calcium levels and thus producing smooth muscle relaxation10 and pulmonary vasculature relaxation and a decrease in PAP. Half-life is 15 - 30sec, when inhaled, at doses of 5 - 80ppm. When it enters the bloodstream it binds to Hb producing nitrosylmethemoglobin (forming methemoglobin and nitrate), rendering it ineffective at producing systemic vasodilation. It oxidizes to form NO2 (nitrous dioxide) when exposed to oxygen, which can be toxic to the alveolar or vascular cells so levels of NO2 > 2ppm should be avoided.

    Indications:

  • conditions where pulmonary hypertension is present

  • hypoxic respiratory failure (e.g. meconium aspiration, ALI, ARDS)

    Monitoring for effectiveness:

  • PaO2 rise of > 20% → impoving V/Q mismatch9

  • reduction in PAP (but doesn't need to occur to produce PaO2 rise)

  • reduction of R → L shunt

    If no significant beneficial effect is shown NO should be immediately discontinued prior to tolerance occurring. If benefit is shown this must be documented in the notes. NO can only be commenced with PICU consultant approval !

    Monitoring for side effects:

  • systemic hypotension (with improved pulmonary venous return to a functionally impaired left ventricle)

  • daily measurements of methemoglobin levels (ABG results) avoiding levels > 2% → avoid NO > 22ppm

    Setup;

    Testing of the INOvent prior to use should be done by a person deemed competent by their institution. Once the unit has been shown to be working properly the following should be present6:

  • that the NO2 alarm should be set to an upper limit of 2ppm

  • that the anaesthetic bag is connected to the INOvent, whilst the patient is on iNO therapy.

  • that the O2 and NO settings are reading what has been prescribed.

  • exhaust gases from the breathing circuit must be scavenged to minimize environmental pollution.

    Higher doses of iNO up to 80ppm have been described, but usually no more than 20ppm is recommended, as higher doses showed increased side effects, but no improvement in outcome !

    Weaning:

    Weaning can result in rebound PHT and dose reductions should be made cautiously with some references recommending over 12 - 24hrs, while other recommending reductions to be made every 2hrs.

  • wean iNO every 30min by 1ppm

  • when iNO is weaned to 2ppm increase FiO2 to 60%

  • give Sildenafil 0.4mg/kg orally

  • cease iNO 60min after Sildenafil dose given

  • wean FiO2 to previous settings

    In children mean plasma levels 1 h after doses of Sildenafil 0.5-2.0 mg/kg are similar to the maximum plasma concentrations reported in adults receiving doses within the therapeutic range.

    Sildenafil has also been used as a short term prophylactic therapy post-operatively in those undergoing palliative or definitive surgery for congenital heart disease with varying improvements in PAP and / or SpO2.

    [1] Am J Respir Crit Care Med. 2006 Nov 1;174(9):1042-7: Namachivayam et al: Sildenafil prevents rebound pulmonary hypertension after withdrawal of nitric oxide in children.

    [2] Pediatr Cardiol. 2010 May;31(4):515-20. Epub 2010 Jan 7: Uhm et al: Postoperative use of oral sildenafil in pediatric patients with congenital heart disease.

    [3] Pediatric Cardiology. 31 pp 515 - 520. 2010: Uhm JY, Jhang W, Park J, Seo D, Yun S & Yun T. Postoperative use of oral sildenafil in pediatric patients with congenital heart disease.

    [4] Lancet. 1992 Oct 3;340(8823):819-20: Kinsella et al: Low-dose inhalation nitric oxide in persistent pulmonary hypertension of the newborn.

    [5] In: Up To Date. Available online at: http://www.uptodate.com/online/content/topic.do?topicKey=ven_pulm/7537&source=preview&selectedTitle=4~150&anchor=H3#H3 . Accessed on: 11/1/2011: Taichman DB. Inhaled nitric oxide in adults with pulmonary hypertension.

    [6] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S30-6: Barr et al: Inhaled nitric oxide and related therapies

    [7] Anesth Analg. 2010 Sep;111(3):693-702: Liu et al: Special article: rescue therapies for acute hypoxemic respiratory failure

    [8] Clin Chest Med. 2000 Sep;21(3):519-29: Payen: Inhaled nitric oxide and acute lung injury.

    [9] JAMA. 1996 Oct 9;276(14):1189-92: Murad et al: The 1996 Albert Lasker Medical Research Awards. Signal transduction using nitric oxide and cyclic guanosine monophosphate

    [10] J Perinatol. 2004 May;24(5):290-4: Guthrie: Initial dosing of inhaled nitric oxide in infants with hypoxic respiratory failure

    [11] N Engl J Med. 2000 Feb 17;342(7):469-74: Clark et al: Low-dose nitric oxide therapy for persistent pulmonary hypertension of the newborn. Clinical Inhaled Nitric Oxide Research Group

    • Nutrition

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    PICU: NUTRITION

    Facts:

    1. Nutritional support for children in PICU is important to prevent deficiency and remain in a positive or neutral neutrogen balance

    2. Overfeeding is associated with adverse effects

    3. There is no clear evidence supporting PN over TPN

    4. If the bowel works, use it !

    5. Always slowly introduce lipids !

    5. Cautiously introduce enteral feeding where there is low CO !

    Energy requirements in healthy children

    premature

    110 - 120 kcal/kg/d

    0 < age < 1

    90 - 100 kcal/kg/d

    1 < age < 7

    75 - 90 kcal/kg/d

    7 < age < 12

    60 - 75 kcal/kg/d

    12 - 18

    30 - 60 kcal/kg/d

    Feeding the healthy neonate

    Day

    Dextrose

    Protein

    Lipids

    g / kg /d

    1

    4 - 8

    1 ( - 3)

    1

    2

    4 - 8

    1 ( - 3)

    2

    3

    5 - 10

    1 ( - 3)

    3

    4

    5 - 12

    2 ( - 3)

    3

    5

    6 - 15

    2.5 ( - 3)

    3

    6

    7 - 16

    2.5 ( - 3)

    3

    Feeding the healthy child

    Age

    Dextrose

    Protein

    Lipids

    g / kg /d

    < 1 mo

    7 - 16

    2.7

    1 - 3

    < 6 mo

    7 - 16

    1.5

    1 - 3

    < 1 y

    7 - 16

    1 - 1.5

    1 - 3

    < 7 y

    5 - 15

    0.9

    1 - 2

    < 12 y

    5 - 15

    0.9

    1 - 2

    > 12 y

    5 - 10

    0.9

    1 - 2

  • 1 Kcal = 1 Calorie = 1000 cal = 4184 joules

  • 1 g Dextrose = 3.8 Kcal

  • 1 g Protein = 4 Kcal

  • 1 g Lipid = 9 Kcal

    [1] Intensive Care Med, 2004, 30(9), 1807-13: van der Kuip M: Nutritional support in 111 pediatric intensive care units: a European survey

    [2] Cochrane Database Syst Rev. 2009, 15;(2):Joffe et all: Nutritional support for critically ill children

    [3] Ger Med Sci, 2009 Nov 18;7, Doc15: Fusch et all: Neonatology/Paediatrics - Guidelines on Parenteral Nutrition, Chapter 13

    [4] J Parenter Enteral Nutr. 2009 May-Jun;33(3):260-76: A.S.P.E.N. Clinical Guidelines: Mehta et al: nutrition support of the critically ill child

    [5] J Parenter Enteral Nutr. 2010 May-Jun;34(3):247-53: Jaksic et al: A.S.P.E.N. Clinical guidelines: nutrition support of neonates supported with extracorporeal membrane oxygenation JPEN

    Table: Nutrition in EBM / Formula

    Formula / Additive

    kCal

    /ml

    Prot (g)

    / 100ml

    Fat (g)

    / 100ml

    CHO (g)

    / 100ml

    INFANT FEEDS 0 - 12 MONTHS or < 8kg

    Human Milk/ EBM

    0.69

    1.0

    4.3

    7.2

    Human Milk + 2 blue scoops Karicare

    0.83

    1.3

    4.9

    8.8

    Karicare Gold Plus 1 ¼ strength

    0.83

    1.7

    4.4

    9.1

    Infatrini FS

    1.0

    2.6

    5.4

    10.3

    Pepti-junior Gold FS (partially hydrolysed)

    0.67

    1.8

    3.6

    6.9

    Pepti-junior Gold 1 ¼ strength

    0.84

    2.25

    4.5

    8.6

    Neocate LCP FS (extensively hydrolysed)

    0.70

    1.9

    3.4

    7.9

    Neocate LCP 1 ¼ strength

    0.87

    2.4

    4.2

    9.9

    Monogen FS (MCT based feed - chylothorax)

    0.75

    2.0

    2.1

    12.0

    Monogen 1¼ Strength

    0.93

    2.5

    2.6

    15

    Kindergen FS (renal)

    1.0

    1.5

    5.3

    11.8

    Kindergen 1¼ Strength

    1.25

    1.9

    6.6

    14.8

    Neocate advance FS (>12months)

    1.0

    2.9

    5.1

    10.5

    PAEDIATRIC FORMULAE 1-6 YEARS

    * Nutrini Multi-fibre
    (0.8g fibre per 100ml)

    1.0

    2.8

    4.4

    12.3

    Nutrini

    1.0

    2.8

    4.4

    12.3

    Nutrini Energy

    1.5

    4.1

    6.7

    18.5

    ADULT FORMULAE >12 YEARS or 45kg

    * Nutrison multi-fibre (1.5g per 100ml)

    1.0

    4.0

    3.9

    12.3

    Nutrison Standard

    1.0

    4.0

    3.9

    12.3

    Nutrison Energy

    1.5

    6.0

    5.8

    18.5

    Nutrison Energy multi-fibre (1.5g per 100ml)

    1.5

    6.0

    5.8

    18.5

    ADDITIVES (per 100ml) - per gram or ml

    Duocal 1x Blue Scoop (1.2g)

    5.9

    0

    0.27

    0.87

    Polyjoule 1x Blue Scoop (1.2g)

    4.6

    0

    0

    1.1

    Protifar 1x Blue Scoop (0.85g)

    3.1

    0.75

    0.014

    0.013

    Per ml MCT oil

    8.4

    -

    0.95

    -

    Karicare Gold 1x Blue Scoop

    6.9

    0.15

    0.37

    0.72

    • Chest Drains

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    PICU: CHEST DRAINS

    If losses > 10ml/kg/hr in a postoperative patient, notify surgeon immediately !

    In the first two hours, losses may be up to 5ml/kg/hr, thereafter it should be less than 2ml/kg/hr. If losses exceeds these levels, check ACT, aPTT, PT, Fibrinogen, Platelets and TEG, and transfuse accordingly.

    If significant losses continue, notify surgeons immediately !

    Insertion of Chest Drains

    If surgical patient offer procedure to surgeons first !

    Preparation and Equipment:

    1. THAL-Quick Chest Tube Set and Tray

    2. choose appropriate size

    3. CXR before procedure

    4. identify insertion site via ultrasound (ensure distance from liver, kidneys, spleen or heart)

    5. prepare chest tube insertion site with antiseptic solution and sterile drapes in standard fashion (sterile gown, gloves, head and face mask)

    6. consider local anaesthetic (ie Lignocaine; remember: 1% = 10mg/ml, maximum Lignocaine dose 5mg/kg without adrenaline).

    7. attach introducer needle to syringe and advance slowly and carefully needle over the superior border of the rib into the pleural space. Fluid or air should be aspirated to verify intrapleural position.

    8. When the appropriate drainage site and depth has been identified, de-attach syringe and slowly introduce the J-tip of the guidewire: the guidewire should pass through and into the pleural space without any resistance !

    9. remove the needle, but leave wire in situ.

    10. while maintaining the wire position, dilate the tract by supplied dilator (hold dilator always at the tip, next to the skin, rotate it carefully to prevent the wire from kinking)

    11. remove dilator, the guidewire in situ, advance slowly the chest tube into the pleural space (if any resistance, ensure the guidewire is still in situ, re-dilate skin / pleural opening, if necessary)

    12. remove guidewire, leaving the chest tube in situ

    13. use sutures or steri-strips to secure the chest tube

    14. attach 3-way tap and connect the tip of the chest tube via connector to a chest tube (use minimal suction - 10 cmH2O)

    15. CXR to confirm position and success !

    16. Observe ventilation pressures and FiO2 always before, during and after the procedure !

    Removal Of Chest Drains

    If surgical patient not to be removed until documented order in notes by surgeon !

    Preparation and Equipment:

    1. keep patient fastened. Food / Formula 6 hours, breast milk 4 hours, clear fluids 2 hours.

    2. continue monitoring ECG, SpO2, BP.

    3. all emergency equipment available.

    4. appropriate analgesia.

    Age

    < 6 month

    > 6 month

    Morphine

    20mcg/kg

    Ketamine

    0.5mg/kg

    if dysphoric response with Ketamine, consider
    midazolam 0.1mg/kg, can be repeated once

    5. remove drain in aseptic technique during exspiration.

    6. repeat CXR 30min after drain removal to exclude pneumothorax

    7. patient must be alert and rousable prior to ward discharge !

    Open Chest

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    PICU: OPEN CHEST

    Facts:

    Negative impact on haemodynamics and respiratory parameters after median sternotomy first described in 1975, emphasizing on "compression of the heart and produce a cardiac tamponade".

    Indications for delayed sterna closure and Open Chest:

  • "large" heart syndrome

  • haemodynamic instability after temporal sternal approximation

  • low cardiac output post CPB

  • ECMO or VAD cannulation

  • severe arrhythmia

  • severe bleeding complications

  • severe contamination requiring frequent reexploration

    Potential complications due to delayed sterna closure with increased rate of infection, longer PICU stay.

    Effects of sternal closure:

  • increase in intrathoracic pressure

  • decrease in total lung compliance

  • decrease in systolic / mean BP

  • decrease in SV → decrease in CO

  • decrease in cerebral oxygenation

    Indication for chest closure: when the patient is ready !

  • haemodynamically stable (age appropriate MAP with minimal inotropic support, stable CVP, LA, PAP, stable heart rate /and rhythym, appropriate CRT)

  • respiratory stable (acceptable ventilation settings, FiO2 requirements)

  • stable fluid status (oedema ?, fluid balance over last 12 / 24hrs)

    Preperation for sterna closure in PICU:

  • sterile surgical field (gown, mask)

  • standard monitoring (ECG, invasive BP, CVP (LA, PAP,‚Ķ), Pacemaker, SaO2, etCO2, Ventilation parameters)

  • standard setup: standby for inotropic support with Adrenaline or Dobutamine (Noradrenaline infusion), Adrenaline 10mcg/kg Bolus, fluid resuscitation with NaCl 0.9%, Human Albumin and PRBC (minimum 2 units crossmatched), good floating fluid line and separate inotropic line, accessible outside the surgical field

  • Cephazolin 25 - 50mg/kg IV minimum 30min preceding the surgical procedure

  • Fentanyl 5mcg/kg IV Bolus and Midazolam 100mcg/kg IV Bolus plus Vecuronium 0.1mg/kg IV Bolus to provide adaequate Anaesthesia and muscle relaxation

    Observe during and post sternal closure: haemodynamic / respiratory / fluid and metabolic stability

    [1] J Thorac Cardiovasc Surg. 2010 Apr;139(4):894-900: Horvath et al: Cerebral and

    somatic oxygen saturation decrease after delayed sternal closure in children after cardiac surgery

    [2] Cardiol Young. 2009 Dec;19(6):573-9. Vojtovic P et al: Haemodynamic changes due to delayed sternal closure in newborns after surgery for congenital cardiac malformations.

    [3] J Thorac Cardiovasc Surg. 1997 May;113(5):886-93: Tabbutt et al: Delayed sternal closure after cardiac operations in a pediatric population

    • T3 in Cardiac Surgery

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    PICU: TRIIODOTHYRONINE IN CARDIAC SURGERY

    Definition: Triiodothyronine levels decrease in infants and children after cardiopulmonary bypass. Lower T3 concentration is associated with more complicated recovery in PICU after congenital heart surgery. T3 is safe and has proven clinical benefit in infants less than 5 months of age. Given prophylactically before and after cardiopulmonary bypass, T3 decreases ventilation time and inotrope requirement and improves cardiac function compared to placebo.

    Patient selection: Infants less than 5mths of age having congenital heart surgery with cardiopulmonary bypass.

    T3 Treatment Regimen:

  • 0.4mcg/kg immediately prior to going on to CPB

  • 0.4mcg/kg on release of aortic cross clamp

  • 0.2mcg/kg at 3hrs after cross clamp removal

  • 0.2mcg/kg at 6hrs after cross clamp removal

  • 0.2mcg/kg at 9hrs after cross clamp removal

    T3 is available from the Level 3 Inpatient Pharmacy and also kept in PICU pharmacy. 'Goldshield Triiodothyronine' (20mcg per vial, $200) does not need to be refrigerated before use, is cheaper and but has a shorter shelf life. 'Thyrotardin-inject' (100mcg per vial, ~$1000) needs to be refrigerated and should only be used when 'Goldshield Triiodothyronine' is unavailable.

    A SINGLE VIAL CAN BE USED FOR MULTIPLE DOSES for a single patient up to 24hrs after opening, but must be kept in the fridge once open.

    T3 use require a TGA Special Access Scheme Category A form. 1 form per patient. Can be done retrospectively. See PICU pharmacist.

    T3 Monitoring:

    In order to improve our understanding of the pharmacology of T3 and for quality assurance T3 concentration will be monitored routinely. Please only order 'free T3' routinely - DO NOT order other thyroid hormones unless specifically indicated !

    Please request 'free T3' with other routine blood testing according to the following…

  • pre-operatively in infants that it is planned to use T3

  • prior to the first dose of T3 in the OR

  • with PICU admission bloods

  • with the routine morning bloods on the day after surgery and

  • with the routine morning bloods on the second day after surgery

    [1] Bartkowski, R., et al., Thyroid hormones levels in infants during and after cardiopulmonary bypass with ultrafiltration. Eur J Cardiothorac Surg, 2002. 22(6): p. 879-84.

    [2] Plumpton, K. et al, Identifying infants at risk of marked thyroid suppression post-cardiopulmonary bypass. Intensive Care Med, 2005. 31(4): p. 581-7.

    [3] Plumpton, K.R., B.J. Anderson, and J. Beca, Thyroid hormone and cortisol concentrations after congenital heart surgery in infants younger than 3 months of age. Intensive Care Med, 2009. 36(2): p. 321-8.

    [4] Portman, M.A., et al., Triiodothyronine Supplementation in Infants and Children Undergoing Cardiopulmonary Bypass (TRICC): a multicenter placebo-controlled randomized trial: age analysis. Circulation, 2010. 122(11 Suppl): p. S224-33.

    • Low Cardiac Output Syndrome

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    PICU: LOW CARDIAC OUTPUT SYNDROME (LCOS)

    Definition: oxygen delivery provided by CO does not meet oxygen demand or CI < 2.1l/min/m2 due to inflammatory response of CPB, myocardial ischemia from aortic crossclamp, hypo-/hyperthermia, reperfusion injury and surgical treatment (ventriculotomy). Lowest CO usually 6 - 18hrs post cross clamp removal, return to baseline after 24hrs; approximately 25% of all children undergoing CHD have critical LCOS.

    Monitoring Cardiac Output

  • arterial blood pressure, but MAP ~ CO x SVR !

  • cardiac filling pressures: CVP 9 - 12mmHg, MPAP < 1/3 MAP, LAP 9 - 15mmHg in biventricular heart without shunt

  • peripheral perfusion (capillary refill time)

  • core - peripheral temperature difference

  • urine output

  • base deficit

  • lactate trend

  • mixed venous saturation (aim SmvO2 > 70% in biventricular heart without shunt)

  • ECHO (EF, wall motion abnormality, valve dysfunction)

  • Thermodilution (Gold-Standard)

  • others: NIRS, esophageal Doppler, bioimpedance measurement, arterial pulse pressure

    Management Strategies in LCOS

  • exclusion of residual defects which compromise CO (→ ECHO)

  • pre-bypass strategies (Methylprednisolone 10mg/kg)

  • pre - surgical strategies (eg PFO/ASD in compromised RV function after biventricular repair, Baffle fenestration in Fontan Circulation)

  • post-surgical strategies: delayed sternal closure or chest reopening

  • ensure appropriate analgesia and sedation

  • consider muscle paralysis (to reduce oxygen demand)

  • preload adjustement: monitor filling pressures in regards to underlying lesion: optimize Hb (100 - 140 mg/dl in non-cyanotic, 140 - 160 mg/dl in cyanotic lesions), NaCl 0.9% bolus or Albumin 4% bolus

  • pharmacological support: Inodilator therapy (Milrinone 0.5 - 1 mcg/kg/min) or Phenoxybenzamine (0.5 mg/kg 8hrly) to reduce afterload; β-adrenergic drugs (Dopamine 5 - 10mcg/kg/min, Dobutamine 5 - 10mcg/kg/min, Adrenaline 0.05 - 0.1mcg/kg/min), but can increase diastolic dysfunction; short-term use of vasoconstrictors to maintain appropriate perfusion pressure (Noradrenaline 0.05 - 0.1mcg/kg/min, Vasopressin 0.02 - 0.05U/kg/hr) →→ Inotropes

  • exclude rhythm abnormality ( →→ Arrhythmia and →→ Pacing )

  • cardio-pulmonary interaction: aim for early extubation in Fontan circulation, TOF, Glenn Shunt if feasible

  • Hypothermia: cooling to 34 - 35°C to reduce oxygen consumption

  • Calcium-infusion (CaCl2 2 - 10mg/kg/hr or 0.01 - 0.07mmol/kg/hr), aim for Ca++ : 1.4 - 1.6mmol/l

  • Triiodothyronine substitution in selected cases →→ T3 in cardiac surgery

  • Steroid replacement (Hydrocortisone 1 mg/kg every 6hrs)

  • consider PD

  • ECLS: ECMO or VAD

    [1] Circulation. 1995 Oct 15;92(8):2226-35: Wernovsky et al: Postoperative course and hemodynamic profile after the arterial switch operation in neonates and infants. A comparison of low-flow cardiopulmonary bypass and circulatory arrest

    [2] Eur J Cardiothorac Surg. 1999 Apr;15(4):515-8: Dalrymple-Hay et al: Induced hypothermia as salvage treatment for refractory cardiac failure following paediatric cardiac surgery

    [3] Pediatr Crit Care Med. 2005 Nov;6(6):655-9: Suominen et al: Hemodynamic effects of rescue protocol hydrocortisone in neonates with low cardiac output syndrome after cardiac surgery

    [4] Am Heart J. 2002 Jan;143(1):15-21: Hoffmann, Wernovsky et al: Prophylactic intravenous use of milrinone after cardiac operation in pediatrics (PRIMACORP) study. Prophylactic Intravenous Use of Milrinone After Cardiac Operation in Pediatrics

    [5] J Cardiothorac Surg. 2010 Nov 17;5:112: Coskun et al: Extracorporeal life support in pediatric cardiac dysfunction

    [6] Cardiology in the Young (2009), 19, 573-579: Vojitovic et al: Haemodynamic changes due to delayed sternal closure in newborns after surgery for congenital cardiac malformations

    [7] Pediatr Crit Care Med. 2009 May;10(3):313-22: Bronicki et al: Cardiopulmonary interaction

    [8] Curr Opin Cardiol. 2010 Mar;25(2):77-9: Absi et al: Noninvasive cardiac output monitoring in the pediatric cardiac Intensive Care Unit

    [9] Crit Care Med. 2001 Oct;29(10 Suppl):S220-30: Wessel et al: Managing low cardiac output syndrome after congenital heart surgery

    [10] Arch Dis Child. 2003 Jan;88(1):46-52: Tibby et al: Monitoring cardiac function in intensive care

    • Maintenance Fluids

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    PICU: MAINTENANCE FLUIDS

    Maintenance Fluid [ml/hr] requirements for ≤ 10 kg

    Wt / kg

    3

    5

    7

    9

    10

    Active

    12

    20

    28

    36

    40

    Inactive

    6

    10

    14

    18

    20

    Fever

    add 10 % for every 1 o Celsius

    Hypothermia

    deduct 12 % for every 1o Celsius

    30 % post OP Cardiac Day 1

    4

    6

    9

    12

    13

    50 % post OP Cardiac Day 2

    6

    10

    14

    18

    20

    Burns

    add 4 % for every 1 % burnt (day 1)
    add 2 % for every 1 % brunt (day 2)

    Maintenance Fluid [ml/hr] requirements for ≥ 11 kg & < 20 kg

    Wt / kg

    11

    13

    15

    17

    20

    Active

    42

    46

    50

    54

    60

    Inactive

    21

    23

    25

    27

    30

    Fever

    add 10 % for every 1 o Celsius

    Hypothermia

    deduct 12 % for every 1o Celsius

    30 % post OP Cardiac Day 1

    14

    15

    17

    18

    20

    50 % post OP Cardiac Day 2

    21

    23

    25

    27

    30

    Burns

    add 4 % for every 1 % burnt (day 1)
    add 2 % for every 1 % brunt (day 2)

    Maintenance Fluid [ml/hr] requirements for ≥ 21 kg

    Wt / kg

    21

    30

    40

    50

    60

    Active

    61

    70

    80

    90

    100

    Inactive

    30

    35

    40

    45

    50

    Fever

    add 10 % for every 1 o Celsius

    Hypothermia

    deduct 12 % for every 1o Celsius

    30 % post OP Cardiac Day 1

    20

    23

    27

    30

    33

    50 % post OP Cardiac Day 2

    30

    35

    40

    45

    50

    Burns

    add 4 % for every 1 % burnt (day 1)
    add 2 % for every 1 % brunt (day 2)

    Pacing

    Home

    PICU: PACING

    NBG Code

    I

    II

    III

    IV

    V

    Paced

    Sensed

    Mode

    Modulation

    Multi-site

    0-none

    0-none

    0-none

    0 -none

    A-Atrium

    A-Atrium

    T-triggered

    R-rate modulated

    A-Atrium

    V-Ventricle

    V-Ventricle

    I-inhibited

    D-dual

    D-dual

    D-dual

    Modes of Pacing

    Description

    Indication

    Limitation

    AOO

    asynchronous atrial

    Bradycardia w/ intact AV, poor atrial sensing

    vulnerable Phase → AF

    VOO

    asynchronous ventricular

    Bradycardia w/ conduction problems and poor ventricular sensing

    vulnerable Phase → VF

    AAI

    demand atrial

    Bradycardia w/ intact AV

    not possible in Atrial Tachycardia

    VVI

    demand ventricular

    Bradycardia w/ conduction problems / SSS / AF / Overdrive

    no atrial seqeuential mode

    DOO

    asynchronous AV sequential

    Bradycardia, which benefits w/ sequential

    vulnerable Phase → AF or VF

    DVI

    ventricular inhibited, AV sequential

    Desire for dual chamber pacing with poor atrial sensing

    risk of AF

    DDI

    dual sensing, AV sequential

    all possible

    DDD

    AV universal

    all possible, except atrial tachyarrhythmia

    not in atrial tachycardia

    Specific Indications:

  • AVRT: Consider overdrive pacing in AAI

  • AF: VVI

  • Overdrive pacing - when JET rate controlled pacing 10% faster in AAI or DDD to regain atrial kick with AV conduction

  • Pace termination of reentry tachycardia (either atrial or AVRT): pace AAI 10 - 20% faster than atrial rate for short burst. If rapid reinitiation after successful capture try gradually slowing pacing rate after reversion (risk of atrial fibrillation)

  • Atrial ECG: bipolar - attach atrial wire to right arm and left arm lead (atrial ECG prominent in I), unipolar - attach atrial wire to V1 and V2 (atria ECG prominent in V1 and V2)

    Problems & Troubleshooting:

  • Daily pacemaker check: underlying rhythm, sensing and capture threshold (set threshold twice as measured)

  • Failure to pace: causes and treatment: threshold (increase output), ischemia, electrolyte-disturbance (correct), post DC, lead malfunction, medication (Flecainide, Sotalol, Propafenone, Lignocaine, Procainamide), cross-talk inhibition (reduce sensitivity, reduce output), oversensing (increase sensitivity), can also try to reverse polarity, or addition of skinlead

  • Failure to capture: threshold (increase output), ischemia, electrolyte disturbance (correct !), post DC, medication (Flecainide, Sotalol, Propafenone, Lignocaine, Procainamide) - can also try to reverse polarity

  • Failure to sense: causes and treatment: sensing threshold (decrease sensing threshold)

  • Pacemaked-mediated Tachycardia (change mode to DDI, adjust post ventricular atrial refractory period)

  • Failure to track in DDD mode: adjust PVARP, AV interval and upper track rate

    Checking and Testing the Pacemaker:

    Patient non-pacing dependent

  • Start setup: atrial & ventricular leads connected to pacemaker (PM) cables, cables unplugged from PM, PM off

  • Turn PM on, default settings appear (DDD, rate 80, atrial (A) output 10mA, ventricular (V) output 10mA, A sensing threshold 0.5mV, V sensing threshold 2mV

  • Testing the sensing thresholds

    o Set rate at least 20% below patient's rate

    o Turn A and V outputs to 0.1mA

    o Turn A and V sensing to 'asynchronous'

    o Slowly increase V sensing by decreasing the number on scale, and observe the V red light

    o Record measured V sensing threshold (?? red light blinking)

    o Set V sensing to default 2mV

    o Slowly increase A sensing by decreasing number on scale, and observe the A red light

    o Record measured A sensing threshold (?? red light blinking)

    o Set A sensing threshold to default 0.5mV

  • Testing the output thresholds

    o Set rate at least 20% above patient's rate

    o Slowly increase A output by increasing the number on the scale, and observe ECG for distinct rate change

    o Record measured A capturing threshold

    o Turn A output threshold back to 0.1mA

    o Slowly increase V output by increasing the number on the scale, and observe ECG for distinct rate and QRS shape change

    o Record measured V capturing threshold

    o Turn V output threshold back to 0.1mA

    o Turn rate back down to at least 20% below patient's rate

  • Final PM setting in backup mode

    o Check V sensing on 2mV and V light blinking red

    o Check A sensing on 0.5mV and A light blinking red

    o Set pacing rate at acceptable backup rate below patient's own rate

    o Turn A output up to 2x measured A output threshold

    o Turn V output up to 2x measured V output threshold

    Patient pacing dependent by PICU, Cardiology or Cardiac Surgical Consultant only !

    [1] Anaesthesia. 2007 Apr;62(4):364-73: Reade: Temporary epicardial pacing after cardiac surgery: a practical review. Part 2: Selection of epicardial pacing modes and troubleshooting

    [2] Pediatr Crit Care Med 2010 Vol. 11, No. 1: Skippen et al: Pacemaker therapy of postoperative arrhythmias after pediatric cardiac surgery

    • Renal Failure

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    PICU: RENAL FAILURE

    Definition: Acute Kidney Injury (AKI): failure of the kidneys to regulate electrolyte, acid-base and fluid homeostasis adequately with concomitant reduction in glomerular filtration rate (GFR). pRIFLE (paediatric Risk, Injury, Failure, Loss, End-Stage Criteria).

    Causes: multi-organ failure, congenital heart surgery, nephrotoxic substances, Stem-Cell transplantation, Sepsis, HUS.

    pRIFLE

    Grade

    estimated Crea Clearance

    Urine Output

    Risk

    decrease by 25 %

    < 0.5 ml/kg/hr for 8 hours

    Injury

    decrease by 50 %

    < 0.5 ml/kg/hr for 16 hours

    Failure

    decrease by 75 % or

    < 35 ml/min/1.73m2

    < 0.3 ml/kg/hr for 24 hours or anuric for 12 hours

    Loss

    persistent failure > 4 w

    End Stage

    persistent failure > 3 mo

    Definition: Chronic Renal Failure: hyperfiltration, estimated creatinine clearance < 75 ml/min/1.73m2 , hypertension, microalbuminuria.

    Causes: AKI, dysplasia, renal reflux, obstructive nephropathy, chronic GN.

    Options for Renal Replacement Therapy (RRT): CVVHD (continuous venovenous haemodialysis - clearance via diffusion), CVVH (continuous venovenous haemofiltration - clearance via convection), CVVHDF (continuous venovenous haemodiafiltration - clearance via convection and diffusion), most commonly done, PD (peritoneal Dialysis), SCUF, IHD (intermittent haemodialysis).

    Comparison of Renal Replacement Therapy

    Variable

    PD

    CRRT

    IHD

    Convection

    +

    +++

    Diffusion

    ++

    ++

    Fluid control

    -

    ++

    ++

    Uraemia control

    -

    ++

    +

    Vascular access

    Tenkhoff

    required

    required

    Anitcoagulation

    not applicable

    required

    required

    [1] Kidney International 71, 2007, 1028 - 1035, Akcan-Arikan et al: Modified RIFLE criteria in critically ill children with acute kidney injuryAKI in critically ill children.

    [2] Am J Kidney Dis. 2005, Jan;45(1):96-101: Hui-Stickle et al: Pediatric ARF epidemiology at a tertiary care center from 1999 to 2001.

    [3] Adv Chronic Kidney Dis, 2008 July ; 15(3): 278-283: Goldstein et al: PROGRESSION FROM ACUTE KIDNEY INJURY TO CHRONIC KIDNEY DISEASE: A PEDIATRIC PERSPECTIVE: An invited review for Advances in Chronic Kidney Disease

    [4] Pediatr Nephrol, 2009, 24: 37-49: Walters et al: Dialysis and pediatric acute kidney injury: choice of renal support modality

    [5] Pediatr Nephrol. 2005 Jul;20(7):972-6: McNiece et al: Adequacy of peritoneal dialysis in children following cardiopulmonary bypass surgery.

    [6] Schrier: www.kidneyatlas.org

    Anticoagulation

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    PICU: ANTICOAGULATION & THROMBOLYSIS

    Unfractionated Heparin (UFH)

    Indications: Low dose heparin infusions are used in the maintenance of central venous lines, arterial lines and the prevention and treatment of deep vein thromboses. This protocol may need to be altered according to individual patient requirements.

    Administration: Heparin can be administered by intravenous and subcutaneous routes. This protocol applies to the intravenous route only. Heparin is compatible with 5% Dextrose, 0.9% NaCl and 0.45% NaCl.

  • Obtain patient weight and baseline FBC, aPTT, INR

  • For maintenance of central line in infants less than 5kg commence 10U/kg/hr

  • For Shunt prophylaxis in any patient commence 10U/kg/hr once no major postoperative bleeding.

  • For antithrombotic treatment commence see "Standard Therapeutic IV UFH Protocol"

  • The need for monitoring will be individualised for each patient. In general it is recommended an aPTT be obtained at 24hours, and some stable patients may require aPTT only every 2 - 3 days.

  • Twice weekly FBC must be obtained to monitor for heparin induced thrombocytopaenia (consider HIT ELISA screen)

  • Coagulation studies required for other reasons should not be obtained from a line containing heparin.

    Adverse Events: Bleeding whilst on low dose heparin is uncommon, but can occur. If bleeding occurs, cease heparin infusion. Check FBC, clotting and TEG. Consider seeking Haematology consult. Antidote: Protamine

    Precautions: In patients with renal failure this low-dose heparin infusion may result in therapeutic anticoagulation.

    Standard Therapeutic IV UFH Protocol

    Age

    < 1year

    > 1year

    Adult

    Loading

    75U/kg

    75U/kg

    5000U

    Maintenance

    25U/kg/hr

    20U/kg/hr

    1500U/hr

    Obtain venous blood sample for aPTT 4hours post completion of loading infusion (NOT earlier). Adjust heparin infusion rate to maintain aPTT 60 - 85s the baseline aPTT or within the range determined as optimal for that patient.

    Normogram for adjusting UFH IV Dose

    aPTT (sec)

    Bolus (U/kg)

    Hold (min)

    Rate Change (U/hr)

    repeat aPTT

    < 50

    50

    0

    + 20%

    4hrs

    50 - 59

    0

    0

    + 10%

    4hrs

    60 - 85

    0

    0

    No change

    24hrs

    86 - 95

    0

    0

    - 10%

    4hrs

    96 - 120

    0

    30

    - 10%

    4hrs

    >120

    0

    60

    -15%

    4hrs

    Monitoring of Therapy: Heparin is usually monitored by aPTT. However, this may be inaccurate in certain clinical circumstances. An alternative is an anti-Xa assay.

    Heparin Antidote: If anticoagulation with heparin needs to be discontinued for clinical reasons, termination of the heparin infusion will usually suffice. If an immediate effect is required, consider administering protamine sulfate. Protamine is a medication that requires a high level of caution when being prescribed and administered. Outside cardiac surgery and ICU, consultant or fellow approval is required for the use of protamine - do not allow this to lead to delayed administration in the case of bleeding. Contact the appropriate senior person immediately.

    Protamine sulfate neutralises heparin by virtue of its positive charge. Following IV administration, neutralisation occurs within 5 minutes. The maximum dose of protamine sulfate, regardless of the amount of heparin received is 50mg except for reversal of heparin following cardiopulmonary bypass. Protamine sulfate is usually administered in a concentration of 10mg/ml at a rate not to exceed 5mg/minute. If administered too quickly, protamine sulfate may cause cardiovascular collapse (severe pulmonary hypertension). Patients with known hypersensitivity reactions to fish, and those who have received protamine-containing insulin or previous protamine therapy may be at risk of hypersensitivity reactions to protamine sulfate.

    Obtain blood for PT and aPTT 15min after the administration of protamine sulfate.

    The dose of protamine sulfate is based on the amount of heparin received in the previous 2hrs as follows:

    Time since last
    Heparin dose

    Protamine dose (mg) per 100U Heparin received

    < 30min

    1mg

    30 - 60min

    0.5 - 0.75mg

    60 - 120min

    0.375 - 0.5mg

    > 120min

    0.25 - 0.375mg

    Low molecular weight Heparin (LMWH)

    Indications: Low Molecular Weight Heparins are used for the prophylaxis or treatment of deep vein thrombosis. The decision to use LMWH instead of standard heparin (or warfarin) will depend upon the clinical scenario and individual patient factors such as risk of bleeding or availability of venous access.

    The following are guidelines only and may need to be adapted in individual circumstances.

    Administration:

  • Obtain patient weight and baseline FBC, aPTT, PT.

  • Dose as follows, administering via subcutaneous route, either via an insuflon catheter, or by rotating sites of subcutaneous injections.

  • Timing of commencement of therapy (especially post-procedural) should be individualised.

  • Duration of therapy is determined on an individualised basis, based up on indication for treatment.

    LMWH (Enoxaparin) in infants and children

    Age

    < 2mths

    2mth - 18yrs

    Treatment

    1.5mg/kg/dose BD

    1mg/kg/dose BD

    Prophylaxis

    0.75mg/kg/dose BD

    0.5mg/kg/dose BD

    LMWH (Dalteparin) in adults (100U = 1mg)

    Treatment

    100U/kg/dose BD

    Prophylaxis

    2500 - 5000U OD

    Normogram for LMWH therapy

    Anti-Xa level (U/ml)

    ? Hold next dose

    Dose change

    ? repeat Anti-Xa level

    < 0.35

    No

    + 25%

    4hrs post next dose

    0.35 - 0.49

    No

    + 10%

    4hrs post next am dose

    0.5 - 1.0

    No

    No change

    Once per week / 4hrs post am dose

    1.1 - 1.5

    No

    - 20%

    4hrs post next am dose

    1.6 - 2.0

    3hrs

    - 30%

    Trough level pre next dose, then 4hrs post next am dose

    > 2.0

    Until Anti-Xa < 5U/ml

    - 40%

    Trough level pre next dose and if not <0.5U/ml repeat BD

    Adverse Events: The major adverse event related to treatment with LMWH is bleeding. If a patient on LMWH develops a major bleed, withhold further doses and seek an urgent Haematology consult. HIT is rare in LMWH treatment, but consider if rapid fall in platelet count. Antidote: Protamine

    Precautions: In patients with renal failure this low-dose heparin infusion may result in therapeutic anticoagulation. It is recommended that prior to any surgery or spinal or epidural procedure, 2 doses of LMWH be omitted. Haematology consult to advise on management around such procedures is advised.

    Heparin Antidote: If anticoagulation with LMWH needs to be discontinued for clinical reasons, termination of the heparin infusion will usually suffice. If an immediate effect is required, consider administering protamine sulfate. Protamine is a medication that requires a high level of caution when being prescribed and administered. Outside cardiac surgery and ICU, consultant or fellow approval is required for the use of protamine - do not allow this to lead to delayed administration in the case of bleeding. Contact the appropriate senior person immediately.

    Protamine sulfate neutralises heparin by virtue of its positive charge. If protamine is given within 8hrs of the LMWH then a maximum neutralizing dose is 1mg Protamine/1mg (or 100U)) of LMWH given in the last dose. If more than 8hours have passed since the dose of LMWH was given, administer 0.5mg Protamine per 1mg (or 100U) of LMWH given. Protamine is administered by slow IV infusion (over 10 mins) to avoid a hypotensive reaction.

    Aspirin

    Aspirin is a medication only available for oral administration (in Australia). Tablets are available in enteric and non-enteric coating. Dispersible tablets are also available. For infants and small children it may be necessary to either crush tablets or use a dispersible tablet and administer the aspirin in liquid form. These guidelines are for the use of aspirin for its antiplatelet activity.

    Indications: Aspirin is commonly used in patients with cardiac disease and those with a history of arterial stroke. There are also certain indications for the use of Aspirin in pregnancy. It is more commonly used in patients with or at risk of arterial thrombosis. There is no data to support the use of aspirin in the treatment / prevention of venous thromboembolism.

    Administration and Maintenance:

  • Aspirin is commenced only when patients are permitted oral

  • Commence 3 - 5mg/kg/day to a maximum of 100mg

  • Continue aspirin therapy as clinically indicated. For primary and secondary prophylaxis at least 3months therapy is recommended.

  • Post Norwood Procedure or in Patients with Shunt. Prophylaxis is required until surgical correction.

    Therapeutic monitoring is not required !

    Precautions: A significant association between Reyes Syndrome and the ingestion of aspirin by children with influenza-like illness or chicken pox has been reported in the literature. Parents should be educated regarding the risk of developing Reyes Syndrome secondary to aspirin therapy. It should be clearly explained that aspirin therapy must be stopped in the presence of fever and/or chicken pox or measles. Paracetamol is permitted in this scenario. The concurrent use of non-steroidal anti-inflammatory medications and Aspirin is not recommended.

    Mechanism: irreversible platelet inactivation. Once therapeutic doses are taken, antiplatelet effect remains for the lifespan of the platelet population which is 7 - 10days. Patients scheduled to undergo surgical procedures should in general, stop aspirin 7 - 10days prior to surgery. Perioperative Aspirin therapy may increase the risk of perioperative bleeding. The timing of cessation of aspirin therapy is the decision of the primary physician.

    Adverse Effects: Patients on aspirin therapy are at a slightly increased risk of bleeding and bruising. Usually this is not significant. If a patient develops significant bleeding or bruising whilst on aspirin, prompt referral to a haematologist is required.

    Clopidogrel

    Clopidogrel is a theinopyridine derivate, that produces its antiplatelet effect through an active metabolite, which irreversibly modifies the ADP purinergic P2Y12 platelet receptor.

    Indications: Clopidogrel is widely used in adult cardiac and cardiovascular ischemic disease (MATCH Trial), however the use in children is based on single center experience or safety trials (PICOLO Trial)

    Administration and Maintenance:

  • Clopidogrel is commenced only when patients are permitted oral

  • Commence 0.2mg/kg/day

  • Continue aspirin therapy as clinically indicated. For primary and secondary prophylaxis at least 3months therapy is recommended.

  • Post Norwood Procedure or in Patients with Shunt after surgical consultation. Prophylaxis is required until surgical correction.

    Adverse Effects: Patients on Clopidogrel therapy are at a slightly increased risk of bleeding and bruising. Usually this is not significant. If a patient develops significant bleeding or bruising whilst on Clopidogrel, prompt referral to a haematologist is required.

    THROMBOLYSIS with r-TPA (ALTEPLASE)

    These guidelines are for systemic thrombolytic therapy. There is no data to support the use of local thrombolytic therapy in infants and children except for line blockages.

    Indications: Massive pulmonary embolism / Pulmonary embolism not responding to heparin / Arterial occlusions / Potential for acute, extensive DVT threatening organ or limb viability.

    Contraindications: Active bleeding / Significant potential for serious local bleeding / General surgery within the previous 2 days / Neurosurgery within the previous 3 weeks / AV malformations / Recent severe trauma.

    Preparation for infusion:

  • Obtain patient weight, FBE, INR/PT, aPTT and Fibrinogen. Platelet count must be >100. Fibrinogen must be > 2.0. Administer FFP infusion 20ml/kg (plus Frusemide) if clinically indicated, especially in neonates < 1month (low plasminogen levels). Consider appropriate staffing requirements are in place to monitor infusion.

  • Ensure adequate venous access to: infuse thrombolytic therapy and obtain blood specimens during infusion.

  • Establish heparin infusion of 10U/kg/hour to be administered continuously throughout thrombolytic infusion. If possible heparin should be administered for 6 hours prior to lysis as this may be advantageous for thrombolytic action.

  • Premedicate with paracetamol and/or promethazine due to potential for allergic reactions.

    Administration:

    Loading

    Infusion

    FFP

    20ml/kg in neonates

    < 1month

    Heparin

    Preferably commence 10U/kg/hr,

    6hrs prior r-TPA

    10U/kg/hr during r-TPA treatment

    r-TPA

    No

    0.5mg/kg/hr

    for 6hrs

    Monitoring:

  • HR and BP hourly.

  • All puncture sites hourly during infusion and for 4hours post infusion.

  • check Fibrinogen at 3hours into infusion and at completion.

  • if any signs of bleeding and / or bruising occur- cease infusion, check FBC, clotting and TEG and seek urgent Haematology consult !

  • If treating a peripheral artery thrombosis, observe limb hourly for pulse, colour, temperature and capillary return.

    After r-TPA: cease lytic therapy at 6 hours and increase heparin to 20U/kg/hour aiming for aPTT 60 - 85s (no bolus). Arrange clinical review (eg Doppler-Ultrasound) to determine response or need for further thrombolysis.

    Complications:

    In 30 - 50% of patients a bleeding event will occur. This is usually in the form of oozing from a wound or puncture site. Treatment with local pressure is usually sufficient. Major bleeding (intracranial, retroperitoeal, external) can develop in up to 10% of patients. If bleeding occurs, cease infusion and seek an urgent Haematology consult.

    Precautions

  • No IM injections during thrombolytic therapy.

  • Minimize patient handling during infusion.

  • Avoid concurrent use of warfarin and antiplatelet agents.

  • Delay any invasive procedures such as urinary catheterization, re-siting venous/arterial access, or perform such procedures pre-thrombolytic infusion.

    Blocked CVL Line

    Indications: CVLs that will not infuse properly or CVLs that will not allow for the withdrawal of blood samples when this is an essential function of that line. (eg. Haemodialysis, oncology patients).

    Initial Management: Obtain CXR to confirm line placement and absence of kinking. Ultrasound to rule out major vessel thrombosis.

    Initial Action if Blood Related Blockage:

    If unable to draw blood sample, unable to infuse blood or there is blood back-up in infusion line;

  • Attempt to aspirate.

  • Flush with 0.9% N/saline.

  • If unsuccessful flush with strong heparin solution (100U/ml) to a maximum of 5ml.

  • Give r-tPA in each obstructed lumen: <10kg (0.5mg r-TPA each lumen) or >10kg (2.0mg r-TPA each lumen) and leave for 2 - 4hrs. Try to withdraw thereafter and flush with NaCl 0.9%.

  • If able to flush line but no blood return, arrange diagnostic imaging as clinically indicated.

  • If unable to flush line obtain surgical consult or consider venography and / or ultrasound

    [1] CHEST 2008; 133:887S-968S: Monagle P. et al: Antithrombotic Therapy in Neonates and Children. American College of Chest Physicians Evidence-

    Based Clinical Practice Guidelines (8th Edition)

    [2] CIRCULATION 2008, 117:553-559: Li et al: Dosing of Clopidogrel for Platelet Inhibition in Infants and Young Children: Primary Results of the Platelet Inhibition in Childen On cLOpridogrel (PICOLO) Trial

    • Pulmonary Hypertension

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    PICU: PULMONARY HYPERTENSION (PHT)

    Definition: systolic PAP > 35mmHg or mean PAP > 25mmHg, clinically if systolic PAP : systolic BP < 0.5

    WHO Classification

    I.

    Pulmonary arterial hypertension

    I.1

    Idiopathic

    I.2

    Familial

    I.3

    Associated with collagen vascular disease, portal hypertension, HIV, Drugs & Toxins, congenital systemic-pulmonary shunts, others

    I.4

    Persistent PHT in the Newborn

    I.5

    Pulmonary veno-occlusive disease

    II.

    Pulmonary Hypertension w/ left heart disease:

    left sided atrial, valvular or ventricular disease (TAPVR, MS, AS, Coarctation)

    III.

    PHT associated with disorders of the respiratory system: COPD, sleep apnea, central hypoventilation Syndrome, high altitude, CLD

    IV.

    PHT due to chronic thrombotic or embolic events

    V.

    Miscs: Sarcoidosis, Histiocytosis, others

    Diagnosis:

  • PA pressure: most reliable, invasive line

  • LA pressure: Differentialdiagnosis: LV dysfunction !

  • Echocardiography: measurement of TR jet velocity (modified Bernoulli equation: RVSP = 4 * v2 + RAP), movement of the interventricular septum, identify anatomical problems

  • Cardiac Catheterisation: right heart catheter (mPAP > 25 mmHg or PVR > 3 Wood units/m2) → vasodilator therapy challenge to guide further therapy

  • Cardiac MRI: RV structure and function (limited in neonates)

  • High resolution chest CT with contrast: parenchymal lung disease, thromboembolism, others

    Physiology: increase in RV afterload → RV volume and pressure increase → RV systolic dysfunction (→ TR) and diastolic dysfunction (→ RV diastolic HTN → increased right to left shunt if exists → Hypoxia) → reduced RV output → reduced LV filling → reduced CO and reduced coronary artery perfusion pressure → RV ischemia and ventricular interdependence → RV systolic dysfunction

    Neonatal PHT: Incidence 2 : 1000, most common due to MAS, RDS, Pneumonia, also idiopathic or in congenital diaphragmatic hernia

    Postoperative PHT:

  • preoperative predisposition: increased PVR, increased PBF, increased PVR and PBF, increased pulmonary venous pressure, lesion related (TAPVD, AVSD, VSD, IAA, Truncus, Shunt Ops)

  • cardiopulmonary Bypass: decreased NO production, ischemia-reperfusion injury, attendant inflammatory response (thromboxane, microemboli, leucosequestration, HPV)

  • standard cardiovascular monitoring: early signs are tachycardia and hypotension; Hypoxia occurs early only due to intracardiac shunts or as a late sign !

    Prophylaxis for postoperative PHT:

    maintain adequate analgesia and sedation (Fentanyl 1mcg/kg iv before painful stimuli), consider paralysis, normothermia, normal pH, aim paCO2 30-35mmHg, paO2>75mmHg in non-cyanotic lesion, prevent hyper- and hypoinflation, minimize intrathoracic pressures, consider Milrinone infusion, consider iNO

    Therapy for acute PHT crisis:

  • increase FiO2 to 1.0: O2 is the best pulmonary vasodilator

  • support cardiac output: →→ Resuscitation , if required, Dopamine (5 - 10mcg/kg/min), Dobutamine (5 - 10mcg/kg/min), Adrenaline (0.02 - 0.1mcg/kg/min), Milrinone (0.25 - 0.75mcg/kg/min) as a PDE3 Inhibitor increases cAMP → PVR vasodilation

  • NO donator: increased cGMP → vasodilation: commence NO 20 ppm ( →→ Nitric Oxide ), SNP (0.5 - 4mcg/kg/min), GTN (0.5 - 5mcg/kg/min)

  • Prostacyclin (= Prostaglandin I2 = Epoprostenol): increased cAMP → vasodilation, commence infusion (5 - 15ng/kg/min), or nebulized; half-life: 3min., can increase PBF and promote pulmonary edema

  • Surfactant in neonates: promotes lung expansion, commence stat dose of Poractant alpha (200mg/kg)

  • consider HFO: promotes lung expansion, avoid hyperinflation

  • consider ECMO

    Therapy for chronic PHT:

  • Sildenafil: (PDE5 Inhibitor → increased cGMP), test dose 0.1 mg/kg, then increase slowly to maximum 2mg/kg q4hr. FDA recommends against the use in Sildenafil in chronic PHT in children, as lower doses were not effective, higher doses increased mortality. The implication its use in PICU is unclear.

  • Prostacyclin

  • Bosentan (1 mg/kg BD, increase to 2mg/kg BD after 4weeks)

  • Lung Transplantation

    [1] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S79-84: Steinhorn: Neonatal pulmonary hypertension

    [2] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S27-9: Taylor et al: Fundamentals of management of acute postoperative pulmonary hypertension

    [3] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S23-6: Mullen: Diagnostic strategies for acute presentation of pulmonary hypertension in children: particular focus on use of echocardiography, cardiac catheterization, magnetic resonance imaging, chest computed tomography, and lung biopsy

    [4] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S15-22: Bronicki et al: Pathophysiology of right ventricular failure in pulmonary hypertension

    [5] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S30-6: Barr et al: Inhaled nitric oxide and related therapies

    [6] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S41-5: Ivy: Prostacyclin in the intensive care setting

    [7] Pharmacotherapy. 2010 Jul;30(7):728-40: Buckley et al: Inhaled epoprostenol for the treatment of pulmonary arterial hypertension in critically ill adults

    • Renal Failure - Haemofiltration and Dialysis

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    PICU: HAEMOFILTRATION & DIALYSIS

    Indications:

  • Correction of water overload

  • To remove larger quantities of water from the body than the kidney is able to achieve in order to enable the administration of therapeutic fluids such as parenteral nutrition.

  • To remove excess electrolytes

  • Correction of disorders of acid/base homeostasis, including inborn errors of metabolism, particularly metabolic acidosis

  • Liver failure (but it does not substitute liver function!).

  • Removal of urea and other waste products of metabolism in cases of renal failure or hypercatabolic state

  • Removal of ingested poisons, drugs or toxins in sepsis.

  • Most common used: continuous veno-venous haemofiltration (CVVH or CVVHF) or continuos veno-venous haemodiafiltration (CVVHDF). In CVVHF the filtrate depends on blood flow rate (aim for 3-5ml/kg/min), the transmembrane pressure = TMP (convection), change in oncotic pressure along the filter (and so the TMP), prefilter dilution (decreases urea-/creatinine clearance) and the sieving coefficient (ratio between filtrate concentration and plasma concentration for a given molecule, eg urea=1, albumin=0).The filtrate is replaced by a glucose/electrolyte solution (replacement fluid). In CVVHDF the clearance of small and middle sized molecules is enhanced by counter-current dialysate flow (diffusion).

    Anticoagulation:

  • UFH →→ ECMO / Anticoagulation, aim ACT 160 - 180sec

  • UFH / Protamine: 1mg Protamine post-filter for every 100U Heparin administered pre-filter

  • Citrate Anticoagulation: 1ml Citrate per 30ml blood flow, aiming for pre-filter Ca++<0.4mmol/l and replace post-filter with Ca++> 1.2mmol/l (Cave Mg++, Citrate accumulation → Acidosis)

    Replacement Fluid:

  • for Non-Citrate Anticoagulation: Na+ 140mmol/l, Ca++ 2mmol/l, Mg++ 0.5mmol/l, Cl- 110mmol/l, HCO3- 32mmol/l, Lactate 3mmol/l /

  • for Non-Citrate Anticoagulation and Lactate free: Na+ 140mmol/l, Ca++ 1.75mmol/l, Mg++ 0.5mmol/l, Cl- 113.5mmol/l, HCO3- 35mmol/l, K+ 4mmol/l, Glucose 5mmol/l /

  • for Citrate Anticoagulation: Na+ 136mmol/l, Cl- 106mmol/l, Citrate 10mmol/l, Citric Acid 2mmol/l

    Catheter/Blood Flow/Filter:

    Always aim Blood Flow / Filtrate Flow ratio > 5:1!

    Patient size

    Catheter Size

    Usual Blood Flow Rate

    Maximum
    recommended
    Blood Flow

    Haemofilter

    < 3 kg

    5.0F

    5 ml/kg/min

    50 mL/min

    HF20; Filtrate 200-300mL/hr

    < 8 kg

    6.5F

    5 ml/kg/min

    75 mL/min

    HF20; Filtrate 200-300mL/hr

    10 - 15 kg

    8.0F

    5 ml/kg/min

    150 ml/min

    ST60; Filtrate 900-1400mL/hr

    >15 kg

    11F

    5 ml/kg/min

    300 ml/min

    ST100; Filtrate 6000mL/hr

    Adult

    14F

    5 ml/kg/min

    2000 ml/min

    ST150; Filtrate 6000mL/hr

    Patient monitoring:

  • Electrolytes (Glucose, Na+, K+, Cl-, HCO3-, Ca++) every 4hrs, hourly for 1st 4 hours if they were abnormal.

  • Magnesium and Phosphate twice daily

  • Fluid Balance per hour = IV fluids in per hour + enteral feeds per hour - urine - insensible losses - drain losses - Patient Fluid removed per hour

    Mode

    Clinical Use

    QDF (Diffusion)

    UFR (Convection)

    QRF

    Total Clearance

    SCUF

    Water removal

    Nil

    =

    Filtrate flow

    Nil

    UFR

    CVVH

    Clearance depends on TMP, QBF, Sieving

    Nil

    =

    Filtrate flow

    = QRF

    UFR

    CVVHD

    Clearance depends on QBF, QDF

    QDF

    =

    QDF + UFR (small)

    Nil

    QD + UFR (small)

    CVVHDF

    Improved clearance of small and middle size

    QDF

    =

    QDF + UFR

    = QRF

    QDF + UFR

    [1] Pediatr Nephrol 2012 Feb28: Sutherland et al: Continuous renal replacement therapy

    [2] Curr Opin Pediatr 2011 Apr;23(2)181-5: Goldstein: Continuos renal replacement therapy: mechanism of clearance, fluid removal, indications and outcome

    [3]Crit Care 2011 Jan 24;15(1)202: Oudemans-van-Straaten et al: Clinical review: anitocagulation for continuous renal replacement therapy - heparin or citrate ?

    • Single Ventricle Physiology

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    CARDIAC DEFECTS: SINGLE VENTRICLE PHYSIOLOGY - FUNCTIONALLY UNIVENTRICULAR HEART, PARALLEL CIRCULATION (PC)

    Definition:

    Either natural or palliated situation where blood to the pulmonary circulation is supplied in parallel rather than serial to the systemic circulation by the same pumping chamber(s).

    Anatomy: A single ventricle (SV) physiology or PC exists in:

    a. True SV anatomy maintained by natural (Ductus Arteriosus or MAPCAS) or artificial systemic-to-pulmonary artery shunts (classic or modified Blalock-Taussig Shunt / central shunt / Sano shunt).

    b. Two ventricle anatomy with obstructed pulmonary or systemic outflow (PA/VSD, IAA, critical PS, AS, Coarctation) maintained by natural (Ductus Arteriosus or MAPCAS) or artificial systemic-to-pulmonary artery shunts (classic or modified Blalock-Taussig Shunt, central shunt).

    c. Two ventricle anatomy with unobstructed pulmonary or systemic outflow, but large, non-restrictive intra- or extracardiac shunt lesion (ASD, VSD, AVSD, AP Window, Truncus arteriosus, PDA).

    Pathophysiology:

    Nature foresees a maximally dilated pulmonary vascular bed (eg nitric oxide pathway) compared to a variably constricted systemic vascular bed (PVR«SVR), therefore, the common pathophysiologic feature in PC is an unrestrictive pulmonary blood flow with increased pulmonary (Qp) compared to systemic (Qs) blood flow - Qp/Qs>1 - resulting in volume overload, and subsequent failure of the systemic ventricle(s). The acuity of the latter is dependent on the underlying anatomy (a>b>c), age of the infant (physiologic drop in PVR after birth), associated cardiac lesion (AV valve competency), and concurrent illness (bronchiolitis etc).

    Further specific pathophysiologic consideration:

    Ad a. More critical heart failure in single right ventricle anatomy. Deep cyanosis due to mixing at various levels. Potential for acute pulmonary stealing in the distressed child, with sudden loss of systemic cardiac output.

    Ad b. Moderate cyanosis. Impaired gut perfusion with increased risk of NEC in the lesions with systemic outflow obstruction.

    Ad c. Pulmonary vascular endothelial dysfunction with vascular hyper-reactivity and mainly postoperative risk of PHT.

    Management:

    Whether pre- or postoperatively, core concept in managing SV physiology or PC is to balance the circulation, ie to optimize systemic output and control pulmonary blood flow. The optimal Qp/Qs for a balanced circulation is 0.8 - 1. The latter can be estimated from formula (SaO2-SmvO2) / (SpvO2 - SpaO2). Simplification 1: SmvO2 = SpaO2, and SpvO2 = 100. Simplification 2: if SaO2 > 80 in room air, then Qp : Qs > 1.0

    General considerations: Anticipate →→ LCOS (clinical, Lactate, ΔSmvO2 [30 ± 5], ΔpCO2 [7 ± 1]), Optimise oxygen balance (DO2↑ [HR x Hb x SaO2 x PL x Contr x AL] ≈ VO2↓ [MV, analgesia, sedation, paralysis, normo-/hypothermia]) early, and Avoid resuscitating inaedequate haemodynamic indices late. Manipulation of Qp: PVR↑ (SaO2 ≤ 80, pCO2↑, PEEP↑, IT↑, Hct↑). Manipulation of Qs: SVR↓ (vasodilatation)

    [1] Cardiol Young 2003;13:316-322. Lawrenson J et al. Manipulating parallel circuits.

    [2] Cardiol Young 2004;14(Suppl 1):52-60. Nelson DP et al. Neonatal physiology of the functionally univentricular heart.

    [3] Arch Dis Child Fetal Neonatal Ed 2005;90:F97-F102. Theilen U et Shekerdemian L. The intensive care of infants with hypoplastic left heart syndrome.

    [4] NeoReviews 2011;10(5):e239-e244.Mastropietro CW et al. Parallel Circultations: Managing Single-Ventricle Physiology.

    [5] Congenit Heart Dis. 2012 Sep-Oct;7(5):466-78. Lowry: Resuscitation and perioperative management of the high-risk single ventricle patient: first-stage palliation.

    Atrial Septal Defect

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    CARDIAC DEFECTS: ATRIAL SEPTAL DEFECT (ASD)

    Definition: Congenital defect of the atrial septum which is either isolated or associated with other cardiac abnormailities: primum (15% isolated, 30% total), secundum (50 - 70%), sinus venosis (10%) and patent foramen ovale (ostium secundum which is < 3mm)

    Physiology: usually shunts left to right through the defect. However this depends on the size of the defect and the compliance of the ventricles. Certain situations can reverse the shunt to right to left: PA, PHT, pulmonary vascular obstructive syndrome, Tricuspid Atresia and severe Ebstein's anomaly

    Clinical Findings: Isolated ASDs are usually asymptomatic in childhood. Most likely clinical findings are failure to thrive with a 2-3/6 ESM heard loudest upper LSE +/- a widely split S2. CXR usually non specific, may show cardiomegally. ECG may show right axis deviation with signs of RVH. May also show RBBB with rsR in V1.

    Diagnosis: ECHO

    Preoperative Management: Usually asymptomatic so no preoperative management required. May need additional nutritional support if FTT.

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone in neonates

    Surgery: Defect closed using a patch of pericardium or Dacron. Direct closure (suturing) can be performed if the defect is small. Due to being intracardiac - cardiopulmonary bypass is required.

    Percutaneous Repair: Several devices used, does not require CPB and rarely needs PICU admission post operatively

    Timing: PFO and small ASDs only require observation. The majority of small (< 6mm) isolated ASDs spontaneously close by 2yrs of age. Usually ASDs are closed if the Qp:Qs ratio is greater than 2:1 (large left to right shunt) or if there is moderately RVH. Reversible PHT is another consideration. Qp:Qs ratio is generally obtained via cardiac catheter.

    Postoperative Management:

  • Usually able to be extubated 4 hours post return from theatre - very common for patient to be unsettled on first night

  • inotropes: usually not required

  • haemodynamics: age adjusted, in neonates: SBP > 60 mmHg, MAP > 40mmHg, increasing over time, CVP 8 - 12 mmHg)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1 ml/kg/hr, early feeding

  • haemostasis

    Specific Problems:

  • Problems unusual

  • Pericardial effusion / tamponade 2 - 5%

  • cardiac arrhythmias - SVT, AV block - approx 2%

  • Embolisation of device 2 - 6%

    Outcome:

    Very good long term survival > 95%. Minimal difference between surgical vs percutaneous closure

    [1] Nelson's Textbook of Pediatrics 18th Edition.

    [2] UpToDate 2010. Management and Outcome of Isolated Atrial Septal Defects in Children. Vick, W, Bezold, L, Fulton, D, Triedman, J, Kim, M

    [3] J Am Coll Cardiol 1193; 22:851. Predictive Factors for Spontaneous Closure of Atrial Septal Defects Diagnosed in the First 3 Months of Life. Radzik, D, Davignon, A, van Doesburg, N, et al.

    [4] UpToDate 2007. Devices for Percutaneous Closure of a Secundum Atrial Septal Defect. Weigers, S, St John Sutton, M, Graham Jr, T, Triedman, J, Connolly, H, Yeon, S

    [5] F1000 Medicine Reports 2010, 2:8. Recent Advances in Closure of Atrial Septal Defects and Patent Foramen Ovale. Qureshi, A, Latson, L

    [6] Heart 1999; 82:300-306. Transcatheter Closure of Atrial Septal Defect and Interatrial Communications with a New Self Expanding Nitinol Double Disc Device (Amplatzer Septal Occluder): Multicentre UK Experience. Chan, K, Godman, M, Walsh, K, Wilson, N, Redington, A, Gibbs, J

    • Ebstein's Anomaly

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    CARDIAC DEFECTS: EBSTEIN'S ANOMALY

    Definition: "atrialization" of the right ventricle with inferior placement of the septal and posterior leaflet of the tricuspid valve, most common redundant anterior leaflet. Associated defects: ASD. Prevalence: < 1% of congenital heart disease. Incidence: 0.5 - 2.5 : 100.000

    Physiology: various clinical picture, depending on position of leaflet: TR, RV hypoplasia, RVOTO, systolic and diastolic dysfunction of LV and associated defects. RA enlargement and accessory pathways predispose to arrhythmias

    Diagnosis: Echo (Gose Score), CXR (cardiomegaly)

    Differential Diagnosis: aberrant tendinous chords

    Preoperative Management:

  • Neonates: CCF due to TR and RV dysfunction, commence Prostaglandin E1 = Alprostadil (starting dose 20ng/kg/min) to augment PBF, however a large PDA with left → right shunt can cause systemic hypoperfusion (circular shunt due to PR) → cease Alprostadil

  • Adolescents / Adults: right heart failure due to TR →→ Cardiomyopathy and →→ Arrhythmia

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10 mg/kg 12 hrs and 6 hrs pre surgery in neonates.

    Surgery: depending on clinical and anatomical presentation: Tricuspid Valve repair: Annuloplasty +/- prosthetic ring, Tricuspid Valve replacement (mechanical or bioprosthetic), 1 ½ ventricle repair →→ Glenn , →→ Fontan surgery

    Postoperative Management:

  • in Tricuspid Valve repair or replacement: anticipate RV dysfunction: Milrinone (0.25 - 1mcg/kg/min), Arrhythmias →→ Arrhythmia , Anticoagulation: commence Heparin 10U/kg/hr once no bleeding, increase Heparin dose further to adjust for therapeutic aPTT. Vitamin K Antagonist in mechanical valve (INR 2.5 - 3.5) once stable and all drains removed. Continue UFH until INR > 2.0 for two consecutive days →→ Anticoagulation

  • 1 ½ ventricle repair →→ Glenn Shunt

  • Fontan surgey →→ Fontan circulation

    Specific Problems:

  • arrhythmia (accessory pathways !) →→ Arrhythmia

    Outcome:

    Depending on presentation, clinical, anatomical presentation and type of surgery

    [1] Heart. 2008 Feb;94(2):237-43: Paranon et al: Ebstein's anomaly of the tricuspid valve: from fetus to adult: congenital heart disease.

    [2] Semin Thorac Cardiovasc Surg Pediatr Card Surg Ann 2009.12:63-65: Bove et al: How I Manage Neonatal Ebstein's Anomaly

    • Hypoplastic Left Heart Syndrome

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    CARDIAC DEFECTS: HYPOPLASTIC LEFT HEART SYNDROME (HLHS)

    Definition: abnormal left heart development, resulting in underdevelopment of LV, aortic valve, Aorta, mitral valve and aortic arch. Incidence 0.2 : 1000 of all live births.

    Physiology: PDA dependant systemic perfusion → PDA closes results in acidosis, hypoxaemia and shock; in patient with restrictive ASD / PFO cardiogenic shock develops right after birth

    Diagnosis: prominent loud single II. heart sound, ECHO

    Differential diagnosis: Coarctation, critical AS, IAA (all PDA dependant systemic lesions)

    Preoperative Management:

  • secure vascular access (two peripheral IVs or UVC) - no multiple attempts !

  • commence Prostaglandin E1 (20ng/kg/min) to maintain systemic perfusion. Watch for apnea, manage conservatively if tolerated.

  • If detoriating with pulmonary over-circulation (increasing saturations, decreasing perfusion). Intubate and sedate to lower oxygen consumption with Hypoventilation to higher PVR (aim pH 7.30 - 7.35) and to lower SVR (hypercarbia), SNP (0.5 - 4mcg/kg/min to lower SVR - aim MAP > 35mmHg in neonates).

  • with restrictive ASD / PFO: immediate Intubation and Resuscitation, urgent BAS or septectomy (10% of HLHS)

  • no enteral feeds until surgical correction, consider gastric protection

    Management of low CO preoperative:

  • SpO2 > 85 - excessive pulmonary blood flow → Intubation, Sedation, Filling, SNP

  • Impaired systemic ventricular function (+/- tricuspid regurgitation) → consider Intubation, Dobutamine, Milrinone

  • SpO2 < 65% and Acidosis: confirm Diagnosisof restrictive ASD via ECHO → Intubation, Resuscitation, urgenat BAS

  • restrictive PDA (variable SpO2) → increase Prostin

    Preoperative Preperation:

    ECG, CXR, CUS, renal US, FISH, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: [primary cardiac transplantation - not done in Australia or consider also compassionate care]. Staged repair: Norwood procedure (preferably if stable on Day 3 or 4 of life) or Hybrid procedure (bilateral PA band, PDA stenting) →→ Glenn Shunt (4 - 8mth) →→ Fontan (18mth - 4yrs).

    Norwood procedure: reconstruction of aortic root and aortic arch, disconnection of pulmonary trunk and incorporating the RV stump into systemic circulation; lung perfusion by BT Shunt (diastolic runoff) or Sano-Shunt (obstruction)

    Postoperative Management:

    →→ Transposition of great arteries

  • keep intubated, ventilated, sedated and paralysed for 24 - 48hrs

  • inotropes: Milrinone plus Dopamine or Adrenaline (plus Noradrenaline, aim MAP > 40mmHg in neonates), aim for maximal vasodilation to reduce strain on RV

  • haemodynamics: SBP > 60mmHg, MAP >40mmHg, increasing over time, CVP 8 - 12mmHg)

  • respiratory: balance circulation (SpO2 70 - 85%), normocapnea

  • fluid restriction: 1ml/kg/hr

  • haemostasis

  • introduce feeds when haemodynamically stable (not before Day 2)

  • introduce Captopril gradually when tolerating feeds and haemodynamically stable

  • commence Aspirin 5mg/kg OD once enteral full feeds established

  • consider Clopidogrel 0.2mg/kg OD (all surgical lines and pacing lines must be removed prior)

  • consider long term central venous access (Broviac) for feeding intolerance and need for long term parenteral nutrition

    Specific Problems:

  • low CO: keep paralysed, don't wean inotropes < 24hrs → adaption of the RV for systemic circulation

  • anatomical coronary artery problems (check ECG, Troponin) → early investigation (Echo, Cathlab)

  • coronary artery spasm (start GTN 5 - 10mcg/kg/min)

  • arrhythmia: →→ Arrhythmia and →→ Pacing

  • low urine output: start PD

  • ECHO assessment: function of systemic RV, patency of BT shunt / Vmax across Sano shunt, degree of Tricuscpid regurgitation, adequacy of ASD, evaluation of Neoaorta and Arch

  • feeding intolerance: → consider feeding protocol

    Outcome:

    Mean ICU stay: 5days. Mortality 30days: up to 40%; HLHS w/ restrictive ASD and BAS: mortality up to 50%

    [1] Lab Invest 1952, 1(1): 61-70: Lev M: Pathologic anatomy and interrelationship of hypoplasia of the aortic tract complexes

    [2] Pediatr Clin North Am 1958, 5(4):1029-1056: Noonan et al: The hypoplastic left heart syndrome; an analysis of 101 cases

    [3] Cardiol Clin 1989; 7:377-385: Norwood: Hypoplastic left heart syndrome

    [4] Ann Thorac Surg 1991; 52:688-695: Norwood: Hypoplastic left heart syndrome

    [5] N Engl J Med 1983; 308:23-26: Norwood et al: Physiologic repair of aortic atresia-hypoplastic left heart syndrome

    [6] Circulation 2004;109;2326-2330: Vlahos et al: Hypoplastic Left Heart Syndrome With Intact or Highly Restrictive Atrial Septum: Outcome After Neonatal Transcatheter Atrial Septostomy

    [7] Am Heart J. 2011 Jan;161(1):138-44: Trivedi et al: Arrhythmias in patients with hypoplastic left heart syndrome

    [8] Korean Circ J. 2010 Mar;40(3):103-11: Honjo et al: Hybrid palliation for neonates with hypoplastic left heart syndrome: current strategies and outcomes

    [9] Pediatric Anesthesia 2010 20: 38-46: Naguib et al: Anesthetic management of the hybrid stage 1 procedure for hypoplastic left heart syndrome (HLHS)

    [10] N Engl J Med 2010;362:1980-92: Ohye et al: Comparison of Shunt Types in the Norwood Procedure for Single-Ventricle Lesions

    [11] Eur J Cardiothorac Surg. 2013 Mar 7. Münsterer et al: Treatment of right ventricle to pulmonary artery conduit stenosis in infants with hypoplastic left heart syndrome.

    [12] Circulation. 2012 Sep 11;126(11 Suppl 1):S123-31. Baba et al: Hybrid versus Norwood strategies for single-ventricle palliation.

    • Coarctation of the Aorata

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    CARDIAC DEFECTS: COARCTATION OF THE AORTA (COA)

    Definition: obstructive anomaly of the aortic arch; classification by Amato et al: I. CoA with or without PDA (a. with VSD, b. with other defects), II. CoA with isthmus hypoplasia with or without PDA (a. with VSD, b. with other defects), III. CoA with tubular hypoplasia of the isthmus with or without PDA (a. with VSD, b. with other defects). Prevalence 5 - 8% of all CHD. Incidence 4 : 10.000 of all life births. Genetic association to Trisomy 13 and 18. [Shone's syndrome: CoA, supravalvular MS, parachute MV and subaortic stenosis]

    Physiology: with PDA closure → acute increase in LV afterload → decreased CO, increased LVEDP → CCF (in extreme: myocardial ischemia) and shunt reversal along PFO (and VSD if present) → increased PBF → severe CCF with systemic hypotension; in older children with less obstruction, physiology is less severe → LVH and aortic collateralisation

    Diagnosis: rarely referred in newborn period (PDA): Hypertension of upper limbs usually not present before Day 5, usually after PDA closure with signs of CCF of various degree, ECG: signs of RVH, later RVH and LVH, CXR: cardiomegaly and pulmonary congestion, cardiac catheterization (diagnostic and interventional), MRI

    Preoperative management:

  • commence Prostaglandine E1 (20ng/kg/min) to maintain systemic perfusion. Intubate and sedate to lower oxygen consumption. Hypoventilation to higher PVR and to lower SVR.

  • balanced circulation with PDA open and / or VSD present (aim SpO2 75 - 85%)

  • Dopamine (5 - 10mcg/kg/min), Dobutamine (5 - 10mcg/kg/min) or Adrenaline (0.02 - 0.1mcg/kg/min) may be required to stabilize for low CO →→ LCOS

  • careful fluid resuscitation (obstructive lesion, not hypovolaemic)

  • in older children: treat hypertension with β-Blocker (ie Propanolol 1.5mg/kg/d oral or Metoprolol 0.1mg/kg/dose IV or Esmolol infusion)

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, FISH, PRBC(4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10 mg/kg 12 hrs and 6 hrs pre surgery in neonates, arterial line on right upper limb

    Surgery: resection of the stenotic segment and end-to-end or end-to-side anastomosis, patch augmentation, subclavian-flap aortoplasty or extended resection with primary anastomposis. Prosthetic graft in older children or adolescents. Angioplasty (balloon) or stent insertion in selected cases.

    Postoperative Management:

  • keep intubated, ventilated, sedated and paralysed for 24 hours for patients with preceding high PBF; elective cases can be extubated within 4hrs

  • inotropes: milrinone plus dopamine or adrenaline

  • haemodynamics: age adjusted, in neonates: SBP > 60mmHg but < 80mmHg, MAP > 40mmHg; prevent hypertension (SNP infusion or Esmolol infusion →→ Vasodilators )

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1 ml/kg/hr, trophic feeds only

  • haemostasis, Hb 120 - 140

  • keep normothermia

    Specific Problems:

  • acute hypertension (increase of Noadrenaline release due to sympathetic stimulation during repair): SNP or Esmolol infusion

  • postcoarctectomy syndrome: hypertension, abdominal pain, ileus (2 - 3days post repair) → antihypertensive treatment

  • PHT if high PBF was preceding (VSD or ASD) →→ PHT

  • thoracic duct injury with chylothorax

  • laryngeal nerve injury

  • spinal cord injury (A. spinalis anterior injury): 0.4 - 1.5%

  • aneurysmatic dilation (up to 35%)

    Outcome:

    Perioperative Mortality: < 1% in isolated CoA, but 5 - 7% in CoA plus VSD, up to 50% in CoA plus HLHS or other defects. Recoarctation 5 - 50%. Long term antihypertensive treatment required in 30% Long term survival after 30 years: 80%

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Coarctation of the Aora

    [2] Pediatr Cardiol. 2010 Dec 25: Gillett et al: Underrecognition of Elevated Blood Pressure Readings in Children After Early Repair of Coarctation of the Aorta

    [3] Ann Thorac Surg. 2009 Dec;88(6):1923-30; discussion 1930-1: Brown et al: Recurrent coarctation: is surgical repair of recurrent coarctation of the aorta safe and effective?

    [4] Curr Opin Cardiol. 2009 Nov;24(6):509-15: Tanous et al: Coarctation of the aorta: evaluation and management.

    [5] Am J Cardiol. 2013 Feb 19: Gray et al: Long-Term Follow-Up of Neonatal Coarctation and Left-Sided Cardiac Hypoplasia.

    • Tetralogy of Fallot

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    CARDIAC DEFECTS: TETRALOGY OF FALLOT (TOF)

    Definition: TOF is the most common cyanotic congenital heart disease, accounts for 5% to 10% of all congenital heart disease, and has an incidence of approximately 1 : 2000 live births. Classically described with the cardiac constellation of, 1. ventricular septal defect (usually large), 2. overriding aorta, 3. right ventricular outflow tract obstruction (subvalvular, valvular, supravalvular), 4. right ventricular hypertrophy. A wide spectrum of TOF exists, including the variants of pulmonary stenosis (TOF-PS), pulmonary atresia (TOF-PA/MAPCA) and absent pulmonary valve (TOF-APV). Right sided arch 25% of cases.

    Physiology: decreased pulmonary blood flow (TET-spells) due to RVOT obstruction and increased PVR or / and congestive cardiac failure (diuretics, Digoxin, nutrition)

    Diagnosis: Echo

    Management of cyanotic spells:

  • oxygenation

  • volume expansion: 10 ml/kg IV colloid/crystalloid

  • sedation: IV Morphine 10 - 50mcg/kg; or Fentanyl 1 mcg/kg

  • posture: head down position/knee chest (increase VR; mild pressure over femoral arteries to increase SVR)

  • vasopressor: Metaraminol 5 - 10mcg/kg IV or Phenylephrine 5 10mcg/kg, then 1 - 5mcg/kg/min IV/(SC)

  • Esmolol 100mcg/kg - 500mcg/kg (titratable) +/- infusion

    Preoperative Preparation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: Timing: dependant on anatomical associations, degree of pulmonary stenosis and development of pulmonary arteries:

    1. Complete correction at 3 - 6mths

  • Patch repair VSD

  • resection of infundibular muscle

  • Pulmonary valvotomy +/- transannular patch.

    2. Staged procedure with BTS ( →→ BT-Shunt ) in severe cyanosis or hypercyanotic spells in neonatal period.

    10 - 15% require re-operation to relieve RVOTO, +/- residual VSD. Majority require pulmonary valve replacement for incompetence in the medium-to-long term.

    Postoperative Management:

    →→ Transposition of great arteries

  • keep intubated, ventilated, sedated and paralysed for 24hrs

  • inotropes: Milrinone plus Dopamine or Noradrenaline

  • haemodynamics: age adjusted, in neonates: SBP > 60mmHg, MAP >40mmHg, increasing over time, LAP 8 - 12mmHg, CVP 8 - 12mmHg)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1ml/kg/hr, trophic feeds

  • haemostasis

  • keep normothermia (except in JET → cool to 35°C)

    Specific Problems:

  • low cardiac output state: expect 6 - 12 hrs post bypass, mainly diastolic dysfunction

  • Arrthymias: JET; decrease inotropes, overdrive pacing, add noradrenaline, cooling, Amiodarone ( →→ Arrhythmia )

  • diastolic RV dysfunction: restrictive physiology, usually transient phenomena lasting 48 - 72hrs. may require inotropes for improving of diastolic dysfunction.

  • residual RVOTO: ECHO confirmation +/- reoperation

  • pulmonary regurgitation: as above

  • residual VSD: as above

    Outcome:

    Perioperative; 3 - 8%. Long term survival 85 - 90%.

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Tetralogy of Fallot with and without pulmonary atresia

    [2] Lancet, 2009; 374: 1462-71: Apitz et al: Tetralogy of Fallot

    [3] World J Surg, 34: 658-668; 2010: Starr J: Starr et al: Tetralogy of Fallot: Yesterday and Today.

    [4] DVD 2004: Something the Lord made (Alan Rickman, Mos Def)

    [5] Pediatr Cardiol. 2013 Mar 5. Dodgen et al: Characteristics and Hemodynamic Effects of Extubation Failure in Children Undergoing Complete Repair for Tetralogy of Fallot.

    • Tricuspid Atresia

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    CARDIAC DEFECTS: TRICUSPID ATRESIA

    Definition: complete obstruction RA → RV (muscular TA, membranous, valvular TA and Ebstein's anomaly) with presence of PFO / ASD, VSD, and increased MV annulus → hypertrophic LV, hypoplastic RV

    Physiology: depends on position of great arteries and VSD physiology: 60% normal great arteries with restrictive VSD and pulmonary stenosis or atresia causes decreased PBF and cyanosis (PBF depending on VSD and PDA), 10% normal great arteries with unrestrictive VSD causes increased PBF and CCF, 30% with D-TGA (10% with pulmonary stenosis or atresia, 20% without pulmonary stenosis)

    Diagnosis: ECG (left axis, LVH, P tricuspidale), ECHO, [Angiography]

    Management preoperatively:

    with decreased PBF:

  • PGE1 infusion (20ng/kg/min) to maintain PDA patency

  • BAS or Blade Septostomy in older children if ASD restrictive

  • Intubation and ventilation, hence lowering PVR

  • aim for SpO2 75 - 85%

    with increased PBF:

  • anticongestive treatment

  • aim for SpO2 75 - 85%

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: dependant on anatomical associations and PBF:

    with decreased PBF: BT-Shunt, modified BT Shunt in newborns

    with increased PBF: PA Banding (careful in subaortic obstruction !) or Damus-Kaye-Stansel (end-to-side anastomosis PA to the ascending aorta) for patients with LVOTO; in older children: bidirectional Glenn Shunt or Total-cavopulmonary connection (Fontan)

    Postoperative Management for Tricuspid-Atresia:

  • →→ BT-Shunt

  • →→ Glenn Shunt

  • →→ Fontan Circulation

    Postoperative Management for TA and PA-Banding:

  • commence morphine sedation, paralyze with cis-atracurium for 12hrs until pulmonary and systemic blood flow have balanced (discuss specifically at handover plan)

  • respiratory: SpO2 75 - 85%, may need some time to settle pulmonary blood flow and achieve stable saturations

  • inotropes: usually not required

  • haemodynamics: SBP > 60mmHg, MAP > 40mmHg, increasing over time, LAP 8 - 12mmHg, CVP 8 - 12mmHg)

  • fluid restriction: 3 ml/kg/hr, early feeds if stable

  • haemostasis

    Specific Problems:

  • persistent low SpO2 indicate a too tight PA band (Differential Diagnosis: Hypovolaemia, low CO →→ LCOS )

  • persistent high SpO2 indicate a too loose band → child is growing into it; manipulate Qp:Qs by pH (Acidosis), pO2(decrease FiO2), pCO2(mild hypercapnea), systemic vasodilators (SNP)

    Outcome:

  • depending on the underlying lesion; average PICU stay: 2 days

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Tricuspid Atresia

    [2] Surg Gynecol Obstet 1952;95:213: Muller et al: The treatment of certain congenital malformations of the heart by the creation of pulmonic stenosis to reduce pulmonary hypertension and excessive pulmonary blood flow: a preliminary report.

    • Fontan Circulation

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    CARDIAC DEFECTS: FONTAN CIRCULATION
    (TOTAL CAVOPULMONARY ANASTOMOSIS, TCPC)

    Definition: separates pulmonary and systemic blood flow in single ventricle physiology; accomplished by intraatrial lateral-tunneling of the IVC flow into RPA or extracardiac via conduit (extracardiac Fontan)

    Physiology:

  • better systemic oxygenation

  • reduced volume load to systemic ventricle

  • may be fenestrated to obtain adequate CO postoperative

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2).

    Risk assessment for Fontan candidates:

  • elevated PVR (> 4 Wood units or mPAP > 15mmHg)

  • impaired ventricular function (EF < 45%)

  • impaired ventricular diastolic function

  • AV valve incompetence (LVEDP > 12mmhg)

  • small PA size (McGoon ratio)

  • subaortic obstruction

    Postoperative Management:

    Discuss Anticoagulation with surgeon at handover !

  • Option: commence Heparin 10U/kg/hr once no major bleeding , further long-term anticoagulation with Vitamin-K antagonist (INR 2 - 3)

  • respiratory: normoxaemia, in fenestrated Fontan SpO2 > 80%, normocapnea (mild hypercapnea improves oxygenation !), try to extubate early if feasible

  • inotropes: usually not required, if so milrinone to decrease PVR and SVR and improve ventricular dysfunction

  • goal is to lower PVR as possible, as main determinant factor for CO in postoperative Fontan circulation, extubate early !

  • fluid restriction: 2ml/kg/hr for the first day, feed early

  • haemostasis (restrictive transfusion strategy if stable)

    Specific Problems:

  • pleural effusions → replace losses (full / half / quarter)

  • low CO: Hypovolemia (low CVP, low LAP) → volume

  • Obstruction SVC / PA anastomosis (high CVP, low LAP) → ECHO, Angio

  • high PVR (high CVP, low LAP) → lower PVR: Milrinone, iNO →→ Nitric Oxide

  • exclude pulmonary venous obstruction (ECHO)

  • ventricular dysfunction (high CVP, high LAP) → commence low dose Milrinone (0.25mcg/kg/min) as more common diastolic dysfunction, exclude AV valve regurgitation (ECHO)

  • persistent hypoxaemia: fenestration, low CO → ECHO, low SmvO2, unrecognized abnormal systemic connection → ECHO, Angio, lung disease

  • systemic venous hypertension → pleural effusion, ascites → drain early; if chronic: protein-loosing enteropathy

  • dysrrhythmias → avoid inotropic, chronotropic support if feasible →→ Arrhythmias

    Outcome:

  • low perioperative mortality < 2%

  • freedom of death or transplantation after 1 y: 80%, 5 yrs: 77%, 10 yrs: 75%, 25 yrs: 54%

  • major morbidity: tacharrhythmias, thrombotic events, PLE

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Tricuspid Atresia

    [2] Pediatr Crit Care Med. 2010 Mar;11(2 Suppl):S57-69: Giglia et al: Preoperative pulmonary hemodynamics and assessment of operability: is there a pulmonary vascular resistance that precludes cardiac operation?

    [3] Interact Cardiovasc Thorac Surg. 2010 Mar;10(3):428-33: Gewillig et al: The Fontan circulation: who controls cardiac output?

    [4] Interact Cardiovasc Thorac Surg. 2010 Feb;10(2):262-5. Gewillig et al: Volume load paradox while preparing for the Fontan: not too much for the ventricle, not too little for the lungs

    [5] Pediatr Cardiol. 2007 Nov-Dec;28(6):448-56: Deal t al: Arrhythmia management in the Fontan patient.

    [6] Circulation. 2008 Jan 1;117(1):85-92: Khairy et al: Long-term survival, modes of death, and predictors of mortality in patients with Fontan surgery.

    [7] Pediatr Crit Care Med. 2011 Vol. 12, No.1: 39-45: Cholette et al: Children with single-ventricle physiology do not benefit from higher haemoglobin levels post cavopulmonary connection: Results of a prospective, randomized, controlled trial of a restrictive versus liberal red-cell transfusion strategy

    • TGA - Transposition of Great Arteries

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    CARDIAC DEFECTS: TRANSPOSITION OF GREAT ARTERIES (TGA)

    Definition: Defined as aorta arising from anatomic RV, and PA arising from anatomic LV. Most common form: AV concordance and VA discordance with associated VSD (40%), Coarctation / IAA (10%), LVOTO (10%), coronary branching anomalies (> 30%, Leiden classification). Less common forms: Taussig-Bing anomaly (TGA with outlet VSD & DORV); congenitally corrected TGA (ccTGA, VA discordance and AV discordance).

    Physiology: Amount of mixing crucial. TGA/VSD cyanotic and more prone to CHF, TGA/IVS deep cyanosis and postnatal CVS collapse. While the RV is abnormally thick walled, the LV is usually thin, and pLV is determing timing of surgery.

    Diagnosis: ECHO, postductal SpO2 may be higher than preductal SpO2

    Preoperative Management:

    Ideal Monitoring: ECG, pre- and postductal SpO2, NIVBP, NIRS.

    Ideal Installations: Leave UVC and UAC if surgery within 24 -48 hrs; patients on PGE1 require 2x iv access at all times. Consider PICC line if on PGE1 for > 48hrs.

    Proposed Investigations Echo immediately upon admission, then as per need, or once per week. Echo will attempt to define coronary artery anatomy but recognition there will be limitation to administration.

    One cranial ultrasound between BAS & surgery, more as per clinical indication.

    Probable Therapeutic Interventions Prostaglandin E1 (PGE1, Alprostadil) 200mcg/kg in 50ml Dextrose 5% at 10 - 100ng/kg/min as per Guardrail. Balloon Atrio-Septostomy Indications: If SaO2 <70% on PGE1 performed via umbilical or femoral vein under echo or fluoroscopic control. Requires anaesthesia, IPPV, and close non-invasive monitoring. Most children do not need intra-arterial monitoring or insertion of a central line for inotropic administration. Usual post-procedure plan: wake, wean & extubate, and attempt wean off PGE1 asap. Suggested Fluids / Nutrition Oral or NG feeds

    Preoperative Preperation: ECG, CXR, CUS, FBE, Clotting, U&C, FISH, Electrolytes, PRBC (4, irradiated), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: Timing: depending on pLV and defect (TGA / IVS 10days, TGA / VSD 3mths, Taussig-Bing 9mths), Technique: Arterial Switch Operation (ASO), PAB and systemic shunt in unprepared LV, Mustard/Senning for atrial switch, Rastelli Operation for patients with malalagniment of VSD and/or LVOTO. Note: ASO possible after Mustard / Senning; may need PAB to retrain LV function.

    Ideal Monitoring: Invasive systemic BP, CVP or RAP, LAP, NIRS, transcutaneous SaO2, inline SvO2 (PediaSat), urine output, core temperature

    Ideal Installations: Right radial arterial line, 3-lumen PediaSat right IJV, or 2-lumen PediaSat right IJV plus direct RA line, direct left atrial line, 2x peripheral iv access, IDC, advance naso-pharyngeal to -esophageal temperature probe, naso-gastric tube, double atrial and ventricular pacing wires

    Proposed Investigations:

  • On admission: CXR, ABG and VBG (for PediaSat recalibration), ACT (and TEG), clotting, FBC, RFT, LFT, electrolytes, BNP, Troponin I, 12-lead ECG

  • Transthoracic echo as per discussion at handover (LVsystF, LVdiastF, RVF, PAP, PS, AI, coronary blood flow).

  • ABG (and VBG if no PediaSat) 1 - 2hrly for the first 6 - 12hrs, more frequently in periods of instability or manipulation of inotropes

  • Subsequent daily checks: CXR, Echo, ABG and VBG (for PediaSat recalibration), clotting, FBC, RFT, LFT, electrolytes, BNP, Troponin I, 12-lead ECG

    Probable Therapeutic Interventions

  • Airway and Ventilation: aim for TV 6 - 8ml/kg and pCO2 35-40mmHg, PEEP min 5cmH2O. If stable @ 2hrs after PICU admission: ET suctioning and standard lung recruitment maneuvre (PEEP no greater than 15 cmH2O for 2mins, decrements by 5cmH2O every 30secs to 5 cmH2O), which should be repeated after each airway disconnection.

  • Antibiotic Prophylaxis →→ Cardiac Admission

  • Prophylactic Triiodothyronin →→ T3 in cardiac surgery

  • Analgesia and Sedation: Morphine infusion up to 50mcg/kg/min, Midazolam infusion maximum 30mcg/kg/min, iv Paracetamol from admission on; if required add Dexmedetomidine 0.2 - 0.7mcg/kg/min after cessation of paralysis

  • Paralysis: Cisatracurium iv bolus 0.15mg/kg, then continuously @ 1 - 10mcg/kg/min as per Guardrail until next morning after Echo

  • Bleeding from wound or chest drains should be closely observed at all times from time of admission on; output of > 10ml/kg anytime, > 5ml/kg/hr in the first 2hrs, or > 1ml/kg/hr beyond 4hrs postop should result in readiness for administration of blood products, coagulation tests (platelets, INR, aPTT, fibrinogen and TEG), and notification of the cardiac surgical fellow. Beware of sudden increase in output as well as sudden stop !

  • Cardiovascular Agents;

  • Dopamine 5 - 10mcg/kg/min plus Milrinone 0.25 - 0.75mcg/kg/min preferably via separate lines, or

  • Adrenaline max 0.03 - 0.08mcg/kg/min plus Milrinone 0.25 0.75mcg/kg/min via direct RA line if available; Adrenaline can go with Dopamine line, but preferably not with Milrinone

  • Substitution of or switching off inotropes should not be undertaken in the first 6 - 12hrs post-op

  • Accepted vasodilators in acute phase: Milrinone (if renal failure max 0.3mcg/kg/min) and Dexmedetomidine

  • Do not cease inotropic support until after extubation (except in longterm MV patients)

    Aim for Haemodynamic Steady-State

  • Defined as SBP > 65mmHg, MAP ≥ 45mmHg, LAP 5 - 8mmHg, SvO2 ≥ 60%, Lactate < 3mmol/L

  • If intotropic score exeeds 15 (Dopamine dose + [100] x Adrenaline dose + [10] x Milrinone dose in mcg/kg/min: vigorous investigation of causes, and consider reopening of sternum.

  • If inotropic score exeeds 20, causes need to vigorously be investigated and / or elective ECLS (VAD or VA ECMO) considered.

  • The pace maker should be readily available, and the sensitivity and output thresholds of pacing wires measured / tested and recorded, unless already provided by Anaesthesia or otherwise agreed on at the handover ( →→ Pacing )

  • Vigorous temperature control (36.5 ± 0.5¬∫C) from admission on is of crucial importance.

  • Peritoneal dialysis should be started with low threshold indication; begin with Physioneal 1.37%, 10ml/kg cycle volumes @ room temperature, 1hrly cycle times, and no additives (Heparin or KCl).

    Suggested Fluids / Nutrition / Electrolytes: Fluid restriction 30% first 24hrs, as of day 2 50% until extubated, increments of 20ml/kg per day thereafter - max TF (=100%) for iv 120ml/kg/d, for enteral 150ml/kg/d. For maintenance use Hartmann's & 5% Dextrose. Start NG feeds @ 1ml/hr (EBM or substitute) 6hrs post-CPB. Vigorous fluid restriction, avoid fluid boluses. Keep Mg++ >1mmol/l, K+ 4 - 5mmol/l, and Ca++ >1.2mmol/l at all times, but avoid fast bolus.

    Specific Problems:

  • low CO 6 - 12hrs post CPB: keep paralysed, don't wean inotropes < 24 hours) → adaption of the LV for systemic circulation →→ LCOS

  • anatomical coronary problems. Higher risk if single coronary, or intramural course, or coronary looping (LAD and/or Cx off RCA and vice-versa). May cause ischaemic ECG changes, or ventricular ectopics or arrhythmias. (check ECG, Troponin) → early investigation (ECHO, Cathlab)

  • arrhythmia: SVT, JET, AV Block (exclude coronary abnormality) →→ Arrhythmia

  • low urine output: start PD

  • pulmonary artery hypertension (rare) →→ PHT

    Expected Schedule: Cease paralysis within 24hrs; start wake and wean day 2; remove intracardiac lines, chest drains, PD and pacing wires day 2 or 3; extubation expected day 3 (48hrs post-op); discharge to ward day 4; discharge home day 14. Surgical mortality TGA/IVS < 2%, TGA/VSD < 4%, Taussig Bing 6%.

    Proposed Pre-Discharge Preparations:

  • if required low flow nasal-prong oxygen

  • Inotropes ceased

  • On increasing enteral, and decreasing iv fluids/feeds

  • FBC, electrolytes, RFT, LFT, coag, BNP, Troponin I

  • 12 lead ECG and CXR and ECHO not older than 24hrs

  • Usual medication with Frusemide 1mg/kg 8hrly and Spironolactone 1mg/kg BD, additional afterload reduction with Lisinopril 0.1mg/kg daily as per discussion with cardiologist and cardiac surgeon

  • →→ PICU discharge

    [1] J Thorac Cardiovasc Surg, 1981 Oct;82(4):629-31: Lecompte at al: Anatomic correction of transposition of the great arteries.

    [2] Surgery. 1959 Jun;45(6):966-80: Senning: Surgical correction of transposition of the great vessels

    [3] Surgery. 1966 Feb;59(2):334-6: Senning: Surgical correction of transposition of the great vessels

    [4] Circulation, 2003;107;996-1002: Hoffmann et al: Efficacy and Safety of Milrinone in Preventing Low Cardiac Output Syndrome in Infants and Children After Corrective Surgery for Congenital Heart Disease

    [5] Pediatr Crit Care Med. 2010 Mar;11(2):234-8: Gaies et al: Vasoactive-inotropic score as a predictor of morbidity and mortality in infants after cardiopulmonary bypass

    [6] Am J Cardiol. 2013 Feb 19. Junge et al: Comparison of Late Results of Arterial Switch Versus Atrial Switch (Mustard Procedure) Operation for Transposition of the Great Arteries.

    • Anomalous Left Coronary Artery

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    CARDIAC DEFECTS: ANOMALOUS LEFT CORONARY ARTERY (ALCAPA)

    Definition: anomalous origin of left coronary artery (LCA) from pulmonary artery; also known as Bland-White-Garland syndrome; reaching 100% mortality if untreated. Prevalence: 0.2 - 0.5% in all congenital heart defects. Incidence: 1 : 300.000; ARCAPA (anomalous right coronary artery from pulmonary artery) possible

    Physiology: high PVR in infant period supports an appropriate LCA perfusion pressure; while PVR falls → coronary steal from LCA → myocardial ischemia, papillary muscle infarction, MR (left sided coronary blood flow depending on collaterals and dilated right coronary artery

    Diagnosis: average onset at 6mo - 1yr with poor weight gain, exercise intolerance, CHF, ECG abnormalities (Q wave, negative T, inversed T, LVH, MI), Echo (WMA, MI, MR), Angio

    Preoperative Management:

    treatment of congestive heart failure

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: excision of ALCAPA and aortic reimplantation (direct or via tunnel - Takeuchi Operation)

    Postoperative Management:

    →→ Transposition of great arteries

  • keep intubated, ventilated, sedated and paralysed for 24 - 48hrs

  • inotropes: milrinone plus dopamine or adrenaline (plus noradrenaline, aim MAP > 40mmHg in neonates), aim for an appropriate coronary perfusion pressure

  • haemodynamics: age adjusted, SBP > 60mmHg, DBP > 30mmHg, MAP > 40mmHg in neonates, increasing over time, CVP 8 - 12mmHg, LAP 8 - 12mmHg)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1ml/kg/hr

  • haemostasis

    Specific Problems:

  • low CO (most common): keep paralysed, don't wean inotropes < 24hrs) → early mechanical assist !

  • anatomical coronary artery problems (check ECG, Troponin) → early investigation (Echo, Cathlab)

  • coronary artery spasm (start GTN 5 - 10mcg/kg/min)

  • arrhythmia: SVT (Adenosine, Digoxin), JET (slowly Amiodarone), Bradycardia (pacing), AV Block (Pacing) →→ Arrhythmia

  • Mitral Valve Regurgitation → functional MR, treat underlying cause, correct Arrhythmia, decrease SVR

  • low urine output: start PD

    Outcome:

    Mean ICU stay: 8 days. Mortality 30 days: up to 20 %; normal cardiac function within 1 yr post surgery

    [1] Am Heart J 8:787-801; 1993: Bland et al: Congenital anomalies of

    the coronary arteries: report of an unusual case associated with cadiac hypertrophy

    [2] Interact Cardiovasc Thorac Surg. 2010 Jan;10(1):70-5: Ojala et al: Excellent functional result in children after correction of anomalous origin of left coronary artery from the pulmonary artery--a population-based complete follow-up study

    [3] Interact Cardiovasc Thorac Surg. 2013 Mar 7: Kazmierczak et al: Repair of anomalous origin of the left coronary artery from the pulmonary artery in infants

    • Atrioventricular Septal Defect

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    CARDIAC DEFECTS: ATRIO-VENTRICULAR SEPTAL DEFECT (AVSD, AVC)

    Definition: Atrioventricular septal defect is also known as an endocardial cushion defect (embryological defect of the endocardial cushion). Complete AVSD are characterized by a primum ASD and an inlet VSD with a common AV valve (Prevalence 3% of CHD, most common congenital lesion associated with Trisomy 21). Partial AVSD consist of a primum ASD and TV/MV clefts. Complete lesions will be classified according to Rastelli's classification - Type A, B and C. These are classified according to the common AV valves dominance to either side.

    Physiology: The shunt in AVSD is in keeping with their respective ASD and VSD - left to right usually. The degrees of shunt can be influenced by whether the common AV valve is left or right sided dominant, degree of MR/TR or MS/TS and the type of AV connection re: DILV. Can be complicated by LVOTO due to accessory valve tissue, AV conduction abnormalities and left AV valve regurgitation. In Trisomy 21, the onset of pulmonary vascular disease occurs earlier which often means earlier surgical repair.

    Clinical Findings: Partial lesions mimic ASD signs. Complete usually present with FTT, repeated respiratory tract infections +/- CHF. 3-4/6 pansystolic murmur at the lower LSE. Mid diastolic rumble due to relative TS/MS. Systolic thrill and hyperactive precordium may be found. CXR shows cardiomegaly; in complete AVSD: increased pulmonary vascular markings. May show PA prominence. ECG: RVH and RBBB.

    May have 1st degree Heart block and LVH. Superior QRS axis.

    Diagnosis: ECHO and cardiac catheter

    Preoperative Management: Diuretic therapy may be instituted to treat CHF. May benefit from an ACE inhibitor. Thorough and detailed transthoracic echo to assess the morphology of the common AV valve as well as bridging leaflets (Rastelli's).

    Preoperative Preparation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone in neonates

    Surgery: Either a one or two patch technique. One patch involves direct closure of the VSD and repair of the common AV valve leaflets by suturing the leaflets to the crest of the ventricular septum. A Dacron patch is then applied to the ASD. The two patch technique involves two Dacron patches to both septal defects and then a separate repair of the valve leaflets. The other point of controversy is whether the valve cleft should be closed to form a 2 leaflet valve as opposed to a 3 leaflet valve. The literature leans towards closure of the cleft if possible without causing stenosis. Timing: Generally before 6 - 12month. Most operations occur between 3 - 6months. This is to reduce the incidence of PHT.

    Postoperative Management:

    →→ Transposition of great arteries

  • keep intubated, ventilated, sedated and paralysed for 24hrs

  • inotropes: milrinone plus dopamine or adrenaline (plus noradrenaline)

  • haemodynamics: age adjusted, in neonates: SBP > 60mmHg, MAP > 40mmHg, increasing over time, LAP 8 - 12mmHg, CVP 8 - 12mmHg)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1ml/kg/hr, trophic feeds

  • haemostasis

    Specific Problems:

  • most common: →→ Pulmonary Hypertension (especially in children with prior pulmonary vascular disease)

  • postoperative pulmonary venous obstruction (in the immediate postoperative period) → check for left AVVR → decrease afterload if blood pressure allows

  • arrhythmia: SVT, JET, Bradycardia (pacing), AV Block (pacing) →→ Arrhythmia →→ Pacing

  • low urine output: start PD

  • left AV valve regurgitation is the most common reason to re-operate on these children

  • left AV valve regurgitation is

    Outcome: Long term survival very good between 80 - 95%. Some papers suggest mortality for Trisomy 21 is now 0%. The natural history of this lesion without an operation has a survival rate of only 4%.

    [1] Nelson's Textbook of Pediatrics 18th Edition.

    [2] Pediatric Cardiology for Practitioners 5th Edition. Park, M

    [3] Heart 2006; 92:1879-1885: Craig et al: Atrioventricular Septal Defect: From Fetus to Adult

    [4] Orphanet Journal of Rare Diseases 2006; 1:8: Calabro et al: Complete Atrioventricular Canal

    [5] Ann Thoracic Surg. 2010 February; 89(2): 530-536: Minich et al: Partial and Transitional Atrioventricular Septal Defect Outcomes

    • Truncus Arteriosus

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    CARDIAC DEFECTS: PERSISTENT TRUNCUS ARTERIOSUS

    Definition: single arterial trunk, overriding VSD, arising from normally formed ventricles. Absent or diminutive PDA. Classification by Collett and Edwards or Van Praagh in regards to position of PAs. 100% mortality within the first year if untreated. Prevalence 3% in CHD. Incidence 5 - 15 : 100.000

    Physiology: parallel circulation. With decreasing PVR → increased PBF and increased flow to LA and LV → CCF

    Diagnosis: presents usually 1 - 2weeks postnatally (decreasing PVR) and subsequently CCF with failure to thrive, dyspnea, diaphoresis. Echo, in selected cases, Cardiac Catheterization

    Preoperative management:

  • balanced circulation (aim for SpO2 75 - 85%)

  • Hypoventilation to higher PVR and to lower SVR, SNP (0.5 - 4mcg/kg/min to lower SVR - aim MAP > 35mmHg in neonates). Intubate and sedate to lower oxygen consumption.

    Preoperative Preparation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, FISH, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: Timing: detaching of the PAs, ventriculotomy to close the VSD, valved RV-PA conduit. In severe truncal valve insufficieny → aortic homograft with reimplantation of coronary arteries

    Postoperative Management:

    →→ Transposition of great arteries

  • keep intubated, ventilated, sedated and paralysed for 24 hours

  • inotropes: Milrinone plus Dopamine or Norepinephrine, aim MAP > 40mmHg in neonates)

  • haemodynamics: age adjusted, in neonates: SBP > 60mmHg, MAP > 40mmHg, increasing over time, LAP 8 - 12mmHg, CVP 8 - 12mmHg)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1 ml/kg/hr, trophic feeds

  • haemostasis

  • keep normothermia

    Specific Problems:

  • low cardiac output state: expect 6 - 12 hrs post bypass

  • Pulmonary Hypertension crisis: especially in neonates →→ Pulmonary Hypertension

  • Arrthymias: JET → decrease inotropes, overdrive pacing, add Noradrenaline, cooling, Amiodarone ( →→ Arrhythmia )

  • diastolic RV dysfunction: restrictive physiology, usually transient phenomena lasting 48 - 72 hrs

  • residual truncal valve insufficiency: mild to moderate is usually well tolerated, however if severe may need reinvestigation

    Outcome:

    Perioperative Mortality: 10%. Long term survival after 5, 10, 15 years: 90%, 85%, 83%

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Peristent Truncus arteriosus

    [2] Surg Clin North Am. 1949 Aug;29(4):1245-70: Collett et al: Persistent truncus arteriosus; a classification according to anatomic types.

    [3] Am J Cardiol. 1965 Sep;16(3):406-25: Van Praagh et al: The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications. A study of 57 necropsy cases

    [4] Cardiol Young. 2005 Feb;15 Suppl 1:125-31: Backer et al: Techniques for repairing the aortic and truncal valves

    • Left Ventricular Outflow Obstruction

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    CARDIAC DEFECTS: LEFT VENTRICULAR OUTFLOW OBSTRUCTION (LVOTO)

    Definition: wide morphological spectrum with mild aortic stenosis (AS) to HLHS; most common valvular AS (70 - 80%), followed by subvalvular AS (10 - 20%) and supravalvular AS (rare), which is common in Williams Syndrome (1 : 20.000 live birth: mental retardation, behavioral traits, elfin facies with AS and peripheral PA stenosis). All LVOTO can be associated with other defects.

    Physiology: LVH due to increase in afterload, subendocardial ischemia → coronary ischemia with cardiomyopathy; reduced blood fow through LVOT → hypoplasia of mitral valve, LV and aortic arch

    Diagnosis: ECG (left axis, LVH), ECHO, in critical AS → early presentation with cardiogenic shock when PDA closes, in mild forms: failure to thrive, increased WOB. Only 15% present under age 1yr.

    Management preoperatively with critical AS:

  • PGE1 infusion (20ng/kg/min) to maintain PDA patency for systemic perfusion

  • Intubation and ventilation as required

  • Milrinone (0.25 - 0.5mcg/kg/min) and Noradrenaline (0.02 - 0.1mcg/kg/min) to improve CO, avoid β-adrenergic drugs (worsening diastolic dysfunction, Tachycardia)

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: dependant on morphological structures, development of LV and LVOT and associated defects (aortic root and mitral valve diameter, LV/RV ratio): single ventricle pathway (→→ HLHS ) or two-ventricle surgery for AS: surgical valvotomy, percutaneous balloon valvotomy, dilation of LVOTO (Konno procedure) and/or aortic valve replacement with pulmonary autograft and pulmonary homograft (Ross procedure) or combined: Ross-Konno procedure.

    Postoperative Management:

    →→ Transposition of great arteries

  • keep intubated, ventilated, sedated and paralysed for 24 - 48hrs

  • inotropes: Milrinone plus Dopamine or Adrenaline (plus Noradrenaline, aim MAP > 40mmHg in neonates)

  • haemodynamics: SBP >60 mmHg, MAP >40mmHg, increasing over time, LAP 8 - 12mmHg, CVP 8 - 12mmHg)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1ml/kg/hr, trophic feeds

  • haemostasis

    Specific Problems:

  • low CO: keep paralysed, don't wean inotropes < 24hrs

  • anatomical coronary artery problems (check ECG, Troponin) → early investigation (ECHO, Cathlab)

  • coronary artery spasm: start GTN 5 - 10mcg/kg/min

  • arrhythmia: SVT (adenosine, digoxin), JET (slowly amiodarone), Bradycardia (pacing), AV Block (pacing) →→ Arrhythmia

  • low urine output: start PD

  • severe AI (15 - 20%) mainly in balloon valvotomy

  • residual AS

  • no anticoagulation required in Ross-Konno procedure (in valved conduits consider anticoagulation)

    Outcome:

  • depending on the underlying lesion; average PICU stay: 5 - 8dys

  • pulmonary homograft needs reoperation with age

  • autograft may develop AI

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Left Ventricular Outflow Obstruction

    [2] J Thorac Cardiovasc Surg. 1966 Apr;51(4):484-92: Cornell et al: Supravalvular aortic stenosis

    [3] Eur J Cardiothorac Surg. 2007 Jun;31(6):1013-21: Alsoufi et al: Management options in neonates and infants with critical left ventricular outflow tract obstruction

    [3] Circulation. 2006 Nov 28;114(22):2412-22: Aboulhosn et al: Left ventricular outflow obstruction: subaortic stenosis, bicuspid aortic valve, supravalvar aortic stenosis, and coarctation of the aorta

    [4] Ann Thorac Surg. 2003 Nov;76(5):1398-411: Brown et al: Surgery for aortic stenosis in children: a 40-year experience

    [5] J Card Surg. 2012 Jan;27(1):103-11. Anagnostopoulos et al: Surgical management of left ventricular outflow tract obstruction.

    • Pulmonary Artesia with IVS

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    CARDIAC DEFECTS: PULMONARY ATRESIA WITH INTACT VENTRICULAR SEPTUM (PA with IVS)

    Definition: atretic pulmonary valve leads to an hypertrophic and hypoplastic RV cavity. Pulmonary blood flow depends on PDA. Incidence 3 : 10.000

    Physiology: decreased pulmonary blood flow (TET-spells) due to RVOT obstruction and increased PVR or / and congestive cardiac failure (diuretics, Digoxin, nutrition)

    Diagnosis: ECHO, Angiography for coronary anatomy and to rule out ventriculocoronary fistula

    Management preoperatively:

  • PGE1 infusion (20ng/kg/min) to maintain PDA patency

  • for persistent hypoperfusion with restrictive intraatrial communication → BAS

  • aim for SpO2 75 - 85%

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery.

    Surgery: dependant on anatomical associations, degree of right ventricular hypoplasia and development of pulmonary arteries (Z-score of tricuspid valve):

  • in selected patients: balloon valvotomy (would require ongoing PGE1 infusion as the RV needs time for remodeling)

  • univentricular approach (Z-score < - 4): systemic-pulmonary shunt ( →→ BT-Shunt ) →→ Glenn Shunt →→ Fontan Circulation

  • biventricular repair (Z-score > -2) →→ TOF

  • partial biventricular repair (1.5 ventricle repair) →→ Glenn Shunt

    Postoperative Management:

    As per →→ BT-Shunt , →→ Glenn-Shunt or →→ Fontan Circulation Protocol

    Specific Problems:

  • high inotropic support and / or severe cyanosis may be indicators for inappropriate RV size and function

  • To prevent shunt thrombosis commence Heparin 10U/kg/hr once no major bleeding

    Outcome:

    Long Term Survival: 86%

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Pulmonary Atresia with intact ventricular septum

    [2] Cardiol Young. 2005 Oct;15(5):447-68: Freedom et al: The significance of ventriculo-coronary arterial connections in the setting of pulmonary atresia with an intact ventricular septum

    [3] Ann Thorac Surg. 2013 Feb 28. Mainwaring et al: Hemodynamic Assessment After Complete Repair of Pulmonary Atresia With Major Aortopulmonary Collaterals.

    • Blalock-Taussig Shunt

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    CARDIAC DEFECTS: BLALOCK-TAUSSIG SHUNT (BTS) OR MODIFIED BTS (MBTS)

    Definition: MBTS: Goretex graft from subclavian or innominate artery to the ipsilateral PA to augment PBF; BTS: direct anastomosis between the transected subclavian artery (or the innominate artery) and the pulmonary artery

    Indication: to provide adequate but not excessive pulmonary blood flow, hence minimizing the risk of congestive cardiac failure and pulmonary hypertension: TOF, TA, PAIVS, Ebstein's Anomaly, HLHS

    Physiology: aiming for a balanced circulation (SpO2 75 - 85% aiming for a Qp : Qs = 1 : 1); Qp:Qs ~ 25 : (95 - SaO2)

    Postoperative Management:

  • commence Heparin 10U/kg/hr once no major bleeding

  • start Aspirin (5 mg/kg) on first postoperative day, once feeds tolerated, cease Heparin if no CVL in situ

  • commence morphine sedation, paralyze with cis-atracurium for 12hrs until pulmonary and systemic blood flow have balanced (discuss specifically at handover plan)

  • respiratory: SpO2 75 - 85%, may need some time to settle pulmonary blood flow and achieve stable saturations

  • inotropes: usually not required

  • haemodynamics: SBP > 60mmHg, MAP > 40mmHg, increasing over time, LAP 8 - 12mmHg, CVP 8 - 12mmHg)

  • fluid restriction: 3ml/kg/hr, avoid hypovolaemia, trophic feeds

  • haemostasis; Hb 130 - 150g/l

    Specific Problems:

  • Prostaglandin infusion should be weaned slowly, especially if infant was commenced on more than 48hours

  • low diastolic BP usually indicates good shunt flow (diastolic run off), but also lower coronary artery perfusion pressure and risk of splanchnic hypoperfusion

  • if low SpO2 exclude shunt occlusion (change in murmur ?, ECHO → Heparin 50 U/kg, inform surgeons), Hypovolaemia (→ volume bolus), Hypotension (→ volume bolus and / or inotropes), inadaequate CO ( →→ Inotropes ), shunt size ?

  • if high SpO2 with pulmonary overcirculation leading to pulmonary oedema (unilateral) may indicate a too large shunt or PDA, which was not ligated: if still intubated: decrease FiO2 to 0.21, allow mild hypercapnea, correct hypovolaemia, increase Hb, PDA ligation if necessary, try to extubate if feasible, non-invasive Ventilation to support CO

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Tricuspid Atresia

    [2] J Card Surg 2009;24: 101-108: Yuan et al: The Blalock-Taussig Shunt

    [3] Ann Thorac Surg 2011;92:642-52: Petrucci et al: Risk Factors for Mortality and Morbidity After the Neonatal Blalock-Taussig Shunt Procedure

    [3] Partners of the Heart: Vivien Thomas and His Work with Alfred Blalock, by Vivien T. Thomas (originally published as Pioneering Research in Surgical Shock and Cardiovascular Surgery: Vivien Thomas and His Work with Alfred Blalock), University of Pennsylvania Press, 1985

    CENTRAL SHUNT

    Definition: anastomosis between the ascending aorta and the main pulmonary artery made of PTFE

    [1] Ann Thorac Surg. Nov 1991;52(5):1132-7: Watterson et al: Very small pulmonary arteries: central end-to-side shunt.

    SANO SHUNT

    Definition: right ventricle-to-pulmonary artery shunt in an attempt to overcome the obstacles noted with a systemic-to-pulmonary artery shunt (diastolic runoff and low coronary artery perfusion pressure); disadvantages: Sano Shunt becomes obstructive over time

    [1] J Thorac Cardiovasc Surg. Aug 2003;126(2):504-9; discussion 509-10: Sano et al: Right ventricle-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome

    [2] J Card Surg. 2009 Mar-Apr;24(2):101-8: Yuan et al: The Blalock-Taussig shunt

    • Glenn Shunt

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    CARDIAC DEFECTS: GLENN SHUNT

    (BIDIRECTIONAL CAVOPULMONARY ANASTOMOSIS, BCPC)

    Definition: transection of the SVC, which is anastomosed to RPA Hemi-Fontan: confluence of SVC and RA anastomosed to RPA; redirection of IVC and coronary sinus via baffle through ASD into LA

    Physiology:

  • aim for SpO2 75 - 85%

  • LV preload and cardiac output maintained by IVC flow

  • Pulmonary blood flow maintained by SVC flow. Transpulmonary gradient: SVC (CVP) - LAP

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2).

    Postoperative Management:

  • commence Heparin 10U/kg/hr once no major bleeding, change to Aspirin (5 mg/kg) orally once enteral feeds tolerated

  • respiratory: SpO2 75 - 85%, may need some time to settle pulmonary blood flow and achieve stable saturations, normocapnea (hypercapnea to improve oxygenation), try to extubate early if feasible

  • inotropes: usually not required, if so milrinone to decrease PVR and SVR and improve ventricular dysfunction

  • fluid restriction: 2ml/kg/hr for the first day, feed early

  • haemostasis. Restrictive transfusion if stable.

  • remove all central lines as soon as possible

    Specific Problems:

  • persistent hypoxaemia (SpO2 < 70%) may indicate a mechanical obstruction of SVC - RPA (> 2 - 5mmHg) anastomosis

  • elevated PVR leading to hypoxaemia (increased transpulmonary gradient >18 mmHg) → if intubated, aim for extubation if feasible; try higher FiO2, normal pH, trial of NO. Do not hyperventilate → decreased cerebral blood flow ! Evacuate any pleural effusion early !

  • increased LAP pressure (> 12mmHg) → commence milrinone, check ECHO for ventricular function, AV valve regurgitation

  • consistent pulmonary venous congestion → check for anomalous connection SVC to LA

  • risk of air embolism due to right → left shunt (from IVC territory)

    Outcome:

  • good palliation in younger children; but as child grows IVC blood flow increases → desaturation →→ Fontan Circulation

  • 1 ½ ventricular repair preferable: forward-flow / pulsatile flow into the PA in selected patients to prevent pulmonary AV fistulas

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Tricuspid Atresia

    [2] Ann Thorac Surg. 1999 Sep;68(3):976-81; discussion 982: Mavroudis et al: Bidirectional Glenn shunt in association with congenital heart repairs: the 1(1/2) ventricular repair

    [3] Arch Surg 1963;86:101: Shumacker: Discussion of Reed WA, Kittle CF, Heilbrunn A: Superior vena cava-pulmonary artery anastomosis

    [4] Acta Med Scand 1956;154: 151-61.Robicsek et al: A new method for the

    treatment of congenital heart disease associated with impaired pulmonary circulation

    [5] Pediatr Crit Care Med. 2011 Vol. 12, No.1: 39-45: Cholette et al: Children with single-ventricle physiology do not benefit from higher haemoglobin levels post cavopulmonary connection: Results of a prospective, randomized, controlled trial of a restrictive versus liberal red-cell transfusion strategy

    • Ventriclar Septal Defect

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    CARDIAC DEFECTS: VENTRICULAR SEPTAL DEFECT (VSD)

    Definition: interventricular septal communication, defined by their location, whereas the IVS can be divided into a muscular and membranous portion, hence perimembranous VSD (80%) or muscular VSD (inlet / trabecular / outlet = infundibular region); most common CHD: incidence: 1.7 - 53 : 1000 of all live birth; Prevalence: 20% as a single lesion, 50% as part of lesion in CHD

    Physiology: depending on size, PVR, RVP and LVP → in neonates with increased PVR → minimal shunting, while drop in PVR and as more unrestrictive → left to right shunt → volume load LA and LV → CCF → if long standing → Eisenmenger Syndrome

    Diagnosis: Auscultation: holosystolic murmur, cyanosis and clubbing in Eisenmenger syndrome, ECG (LVH), CXR (increased PBF, in Eisenmenger: reduced PBF), ECHO (size, location, shunt, haemodynamic evaluation), MRI (limited), Cardiac Catheterization (PVR, response to pulmonary vasodiltators, Qp : Qs)

    Preoperative Management:

    treat CCF: CPAP / IPPV if required: Digoxin, Frusemide (1mg/kg up to QID), Spironolactone (1mg/kg BD), aim for afterload reduction: Milrinone 0.25 - 0.5mcg/kg/min or Captopril (0.1 - 2mg/kg TDS)

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: PAB ( →→ TA ) for protection of pulmonary circulation in neonate with multiple VSD and CCF; in children > 3mths (Qp : Qs > 1.5 : 1), surgical closure via transatrial approach, sometimes by right ventriculotomy, rarely by left apical ventriculotomy. Catheter closure by amplatzer device. Heart-Lung Transplantation in Eisenmenger Syndrome.

    Postoperative Management:

  • inotropes: Milrinone plus Dopamine or Adrenaline (plus Noradrenaline, aim MAP > 40mmHg in neonates)

  • haemodynamics: age adjusted, in neonates: SBP > 60mmHg, MAP > 40mmHg, increasing over time, CVP 8 - 12mmHg)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1ml/kg/hr, early feeds

  • continue preoperative diuretic therapy

  • haemostasis

  • if Catheter closure: Aspirin 5mg/kg OD once feeds tolerated

    Specific Problems:

  • risk of PHT ( →→ Pulmonary Hypertension) in older children and Qp : Qs > 1.5 : 1

  • arrhythmia: complete heart block, SVT, JET ( →→ Arrhythmia )

    Outcome:

    Average ICU stay: 2days; mortality < 1% in isolated VSD, but up 5 - 10% in multiple defects; residual shunts in 30% after surgical closure, majority closes spontaneously

    [1] Br Heart J. 1980 Mar;43(3):332-43: Soto et al: Classification of ventricular septal defects

    [2] Circulation. 2006 Nov 14;114(20):2190-7: Minette et al: Ventricular septal defects

    [3] Cardiol Young. 2007 Jun;17(3):243-53: Butera et al: Percutaneous closure of ventricular septal defects

    • Patent Ductus Arteriosus

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    CARDIAC DEFECTS: PATENT DUCTUS ARTERIOSUS (PDA)

    Definition: postnatal communication between MPA and descending aorta. Incidence 0.3 - 4 : 10.000

    Physiology: functionally closure of DA within 10 - 15hrs postnatally (triggered by rise in paO2 and decrease in PGE2 and PGI2, however VLBW and especially ELBW infants have a symptomic PDA persistent (reduced sensitivity to all above). PDA leads to increased PBF and increased LV volume load

    Diagnosis: Echo (PDA > 1.4mm/kg, LA or LV enlargement, diastolic flow reversal in descending aorta indicate haemodynamic significance), BNP > 1000pg/ml

    Problems in PDA:

  • Neonates: prolonged ventilation → BPD / CLD, IVH, PVL, NEC

  • Children / Adolescents: LVH (→ CCF), Eisenmenger syndrome, growth restriction, aneurysmal dilation of PDA, calcification, infective Endocarditis

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, PRBC (2), FFP (2), Platelets (1), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates

    Surgery: transcatheter PDA closure or surgical ligation by left posterolateral thoracotomy or VAT

    Postoperative Management:

  • usually unproblematic postoperative course, nil support required, early extubation if feasible

    Outcome:

    Low mortality and morbidity (potentially adverse events: laryngeal nerve damage, chylothorax, pneumothorax, bleeding)

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Aortopulmonary Septal Defects and Patent Ductus Arteriosus

    [2] Ann Surg. 46:33; 1907: Munro: Surgery of the vascular system, I. Ligation of the ductus arteriosus

    [3] Ann Pediatric Card. 2009;2: 36-40:Azhar et al: Transcatheter closure of patent ductus arteriosus: evaluating the effect of the learning curve on outcome.

    • TAPVD

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    CARDIAC DEFECTS: TOTAL ANOMALOUS PULMONARY VENOUS RETURN (TAPVR)

    Definition: connection of the pulmonary to remnants of embryologic venous circulation rather than the left atrium. This may include all four pulmonary veins (TAPVR) or only part of it (PAPVR). Classification by Darling, Rothney and Craig: supracardiac 50% (pulmonary veins drain via innominate vein intro RA), infracardiac 20% (pulmonary veins drain via portal vein into RA), intracardiac 20% (pulmonary veins drain via coronary sinus into RA) and mixed type 10%. An ASD is always present. 1/3 of all patients have associated other defects. Incidence 8 : 100.000 of live birth. Prevalence 2.2% in CHD

    Physiology: depending on the PBF, which is anatomically dependant on the left to right shunt (abnormal pulmonary venous drainage), the obstruction of the pulmonary drainage - if present - and on the right to left shunt (ASD and PDA). If severely obstructed pulmonary venous drainage → decreased PBF: severe pulmonary edema and PHT associated with severe right to left shunt (ASD and PDA) → hypoxaemia, both leading to severely depressed CO. In mild to moderate pulmonary venous obstruction, usually increased PBF with falling PVR → CCF with PHT. If no pulmonary venous obstruction than only mildly increased PBF, mild cyanosis → CCF develops later

    Diagnosis: depending on the degree of pulmonary venous obstruction and PBF: early presentation with severe cyanosis, low CO in neonatal period in severely obstructed patients, later presentation usually implies mild to moderate obstruction only CHO, cardiac catherisation, Angiography, MRI

    Differentialdiagnosis: Sepsis, PPHN, Cor triatrium

    Preoperative Management:

  • no or mild obstruction require usually no special treatment

  • moderate obstruction presenting with CCF require anti-failure treatment ( →→ Cardiomyopathy )

  • severe obstruction: Intubation, ventilation and sedation, stabilization of cardiac output (→→ Inotropes ) and treatment of →→ Pulmonary Hypertension , even →→ ECMO . Commence Prostaglandin E1 (20 ng/kg/min) to maintain systemic perfusion, however this may decrease further PBF and pronounce cyanosis

    Surgery: depending on age, presentation, anatomy: various technique with ligation of the aberrant vein and reanastomosis to the left atrial appendage or intracardiac baffle

    Postoperative Management:

  • keep intubated, ventilated, well sedated (Fentanyl for any noxious stimulus) and paralysed for 24 - 48hrs

  • inotropes: Milrinone plus Dopamine or Adrenaline (plus Noradrenaline, aim MAP > 40mmHg in neonates)

  • haemodynamics: SBP > 60mmHg, MAP > 40mmHg, increasing over time, CVP 8 - 12mmHg, PAP < ½ SBP

  • respiratory: balanced circulation (SpO2 75 - 85%) in single-ventricle physiology, normoxaemia in biventricular, normocapnea

  • fluid restriction: 1ml/kg/hr, trophic feeds

  • haemostasis

    Specific Problems:

  • most common: →→ Pulmonary Hypertension (especially in post pulmonary venous obstruction patients and younger patients)

  • postoperative pulmonary venous obstruction (in the immediate postoperative period) →→ Chylothorax

  • arrhythmia: SVT (adenosine, digoxin), JET (slowly amiodarone), Bradycardia (→→ Pacing ), AV Block ( →→ Pacing ) →→ Arrhythmia

  • low urine output: start PD

    Outcome:

    Mean ICU stay: 5days. Mortality 30days: up to 90% in single-ventricle TAPVR, but 5 - 35% in two-ventricle physiology. Reobstruction of pulmonary venous flow possible (2.5 - 13%)

    [1] Lab Invest. 1957 Jan-Feb;6(1):44-64: Craig et al: Total pulmonary venous drainage into the right side of the heart; report of 17 autopsied cases not associated with other major cardiovascular anomalies.

    [2] Tex Heart Inst J. 1985 Jun;12(2):131-41: Reardon et al: Total anomalous pulmonary venous return: report of 201 patients treated surgically

    [3] Ann Thorac Surg. 2005 Feb;79(2):596-606; discussion 596-606: Hancock Friesen et al: Total anomalous pulmonary venous connection: an analysis of current management strategies in a single institution.

    • Interrupted Aortic Arch

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    CARDIAC DEFECTS: INTERRUPTED AORTIC ARCH (IAA)

    Definition: obstructive anomaly of the aortic arch; classification by Celoria et al: Type A (20%): IAA distal to left subclavian artery, type B (78%) between left subclavian and left carotid artery, type C (2%) proximal to left carotid artery. Most of them associated with VSD or other defects. Prevalence 1% of all CHD. Incidence 4 : 10.000 of all life births. Genetic association to Di-George-Syndrome

    Physiology: with PDA closure → acute increase in LV afterload → decreased CO, increased LVEDP → CCF (in extreme: myocardial ischemia) and shunt reversal along PFO (and VSD if present) → increased PBF → severe CCF with systemic hypotension

    Diagnosis: Hypertension of upper limbs usually not present before Day 5, usually after PDA closure with signs of CCF of various degree, ECG: signs of RVH. CXR: cardiomegaly and pulmonary congestion, ECHO, cardiac catheterization (diagnostic and interventional), MRI

    Preoperative management:

  • commence Prostaglandin E1 (20ng/kg/min) to maintain systemic perfusion. Intubate and sedate to lower oxygen consumption. Hypoventilation to higher PVR and to lower SVR.

  • balanced circulation with PDA open and / or VSD present (aim

    SpO2 75 - 85%)

  • Dopamine (5 - 10mcg/kg/min), Dobutamine (5 - 10mcg/kg/min) or Adrenaline (0.02 - 0.1mcg/kg/min) may be required to stabilize for low CO →→ LCOS

  • carefully fluid resuscitation (obstructive lesion, not hypovolaemic !)

  • Calcium infusion if Di-George Syndrome →→ Inotropes

    Preoperative Preperation:

    ECG, CXR, CUS, FBE, Clotting, U&C, Electrolytes, FISH, PRBC(4), FFP (2), Platelets (2), Cryoprecipitate (2). Methylprednisolone 10mg/kg 12hrs and 6hrs pre surgery in neonates.

    Surgery: preferred single stage repair with end-to-end or end-to-side anastomosis, patch augmentation, subclavian-flap aortoplasty or extended resection with primary anastomosis and also VSD closure. In patients with severe LVOTO →→ HLHS

    Postoperative Management:

  • keep intubated, ventilated, sedated and paralysed for 24 hours for patients with preceding high PBF; elective cases can be extubated before

  • inotropes: milrinone plus dopamine

  • haemodynamics: age adjusted, in neonates: SBP > 60mmHg but < 80mmHg, MAP >40mmHg; prevent hypertension (SNP infusion or Esmolol infusion)

  • respiratory: normoxaemia, normocapnea

  • fluid restriction: 1ml/kg/hr, careful trophic feeds

  • haemostasis, Hb 100 - 140

  • keep normothermia

    Specific Problems:

  • acute hypertension (increase of Noradrenaline release due to sympathetic stimulation during repair): SNP or Esmolol infusion

  • postcoarctectomy syndrome: hypertension, abdominal pain, ileus (2 - 3dys post repair) → antihypertensive treatment

  • PHT if high PBF was preceding (VSD or ASD) →→ Pulmonary Hypertension

  • thoracic duct injury with Chylothorax →→ Chylothorax

  • laryngeal nerve injury

  • spinal cord injury (A. spinalis anterior injury): 0.4 - 1.5%

  • neurological injury due to DHCA

    Outcome:

    Perioperative Mortality: 5 - 7%. Recoarctation 5 - 50%. Long term antihypertensive treatment required in 30%. Long term survival after 10yrs: 94% (IAA and VSD), 72% (IAA and TGA), 5 yrs: 47% (IAA and other defects)

    [1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Interrupted Aortic Arch

    [2] Eur J Cardiothorac Surg. 2009 Apr;35(4):565-8: Kobayashi et al: Outcomes following surgical repair of aortic arch obstructions with associated cardiac anomalies

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