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Anesthesia for Congenital Heart Disease. Glynne D. Stanley MB.ChB. FRCA. Introduction. Appropriate to distinguish between: Congenital cardiac surgery Non-cardiac surgery for patients with congenital cardiac disease. Congenital Cardiac Surgery. General Principles: Pre-operative management
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Anesthesia for Congenital Heart Disease Glynne D. Stanley MB.ChB. FRCA
Introduction • Appropriate to distinguish between: • Congenital cardiac surgery • Non-cardiac surgery for patients with congenital cardiac disease
Congenital Cardiac Surgery • General Principles: • Pre-operative management • Intra-operative Management • Cardiopulmonary bypass • Deep hypothermic arrest
Congenital Cardiac Surgery • Specific Considerations: • Simple procedures • Complex procedures • Closed procedures
Congenital Cardiac Surgery • Selected Specific Conditions/Procedures: • Patent Ductus (PDA) • Coarctation of the Aorta • Tricuspid atresia (TA) • Tetralogy of Fallot/Pulmonary Atresia • Transposition of the great vessels (TGV) • Hypoplastic Left Heart Syndrome (HLHS)
Congenital Cardiac Surgery • Preoperative Management • Preoperative evaluation • Wide spectrum of disease • Simple ASD to severe life-threatening HLHS • Remember psychological factors esp. family • Team oriented approach • Laboratory data ranges from minimal to very extensive
Congenital Cardiac Surgery • Laboratory data • Cyanosis leads to polycythemia • May consider phlebotomy esp if no CPB • Leads to coagulation problems • Anemia may be “relative” and need transfusion • Newborn infant has immature systems including renal/hepatic/coagulation • Hypoglycemia is much more common
Congenital Cardiac Surgery • Laboratory data: • Cardiac catheterization • Anatomic diagnosis • Saturation data – shunt analysis • Pressure data – gradients/diastolic function • Angiographic data – systolic function/flow patterns • Prior surgery delineated – line placement • Interventions in cath. Lab – e.g. septoplasty or trial of 100% oxygen
Congenital Cardiac Surgery • Premedication • Very varied practices • < 6 months 9 • Atropine ( 0.01-0.02 mg/kg IM) • 6-12 months • Pentobarbital (2-4mg/kg) po • Atropine and morphine (0.1-0.15 mg/kgIM) • > 12 months • Scopolamine (.015mg/kg IM up to .04mg max) or morphine or midazolam (0.3 –1.0 mg/kg), ketamine (3mg/kg IM) • combinations are common
Congenital Cardiac Surgery • Preoperative medication • D/C diuretics and digoxin unless heart failure is poorly controlled or digoxin is being used primarily for rhythm • Continue inotropes • Continue prostaglandin infusions
Congenital Cardiac Surgery • Intraoperative Management • Physiologic Monitoring • Again very varied depending on the case • ECG, SpO2 x 2, ETCO2, precordial stethoscope, NIBP are standard • A-lines +/- CVP (Atrial line placed intraop often more valuable) • TEE
Congenital Cardiac Surgery • Intraoperative Management • Induction and Maintenance • Titrate to effect • Very dependent on age and cardiac reserve • Good cardiac reserve – inhalational or IV • Neonates – opiate-relaxant technique • Beware of PVR changes with inhalational induction due to changes in PaO2, PaCO2, intrathoracic pressure
Congenital Cardiac Surgery • Cardiopulmonary Bypass • Differences from adult • Lower temperatures (15-20 degrees C) • Lower perfusion pressure (20-30mmHg) • Very significant hemodilution (3-15 times greater) • Pump flows range from 200ml/kg/min to zero! • Different blood pH management (alpha-stat vs pH stat) • Tendency to hypoglycemia • Cannula placement is much more critical
Congenital Cardiac Surgery • Deep hypothermic circulatory arrest (DHCA) • Neonates and small infant usually < 10 kg • Oxygen consumption falls 2-2.5 times per 10 degree fall in temperature • Allows more controlled complex surgery in a bloodless field • Often total CPB time is actually shortened by this technique
Congenital Cardiac Surgery • Weaning from CPB • Heart assessed by direct visualization and right or left atrial filling pressure, central cannula or TEE • Pulse oximetry is also very helpful • Problems weaning are due to: • Inadequate repair, • pulmonary hypertension • And/or left or right ventricular dysfunction
Congenital Cardiac Surgery • Weaning from CPB • Problems weaning diagnosed by • Intraoperative cardiac catheterization • Echo-doppler • Leaving the operating room before correcting the problem leads to a significant INCREASE in morbidity
Congenital Cardiac Surgery • Anesthesia for “simple” open heart procedures • Relatively straightforward repair • Uncomplicated hemodynamics • Uneventful post-op course anticipated • Examples: • ASD, VSD and some case of Tetralogy of Fallot • Usually involve CPB, sometimes DHCA
Congenital Cardiac Surgery • Anesthesia for “simple” procedures: • Inhalation induction usually well tolerated but delayed if significant Right to Left shunt • Have agents available to maintain SVR (phenylephrine) and reduce PVR (oxygen, halothane and opioid) • Beware increases in PVR if high RVOT obstruction
Congenital Cardiac Surgery • Anesthesia for “simple” procedures • Right atriotomy usually OK for most ASDs and some membranous VSDs • Some VSDs need a ventricular incision which may lead to • AV node dysfunction • mechanical ventricular dysfunction • Simple Fallot’s involve VSD repair and some surgery to RVOT/pulmonic valve
Congenital Cardiac Surgery • Anesthesia for Complex Procedures: • Except for Left to Right shunt repairs and uncomplicated Tetralogy, most procedures are considered complex • Multiple defects • Complicated hemodynamics • Inhalation induction after pre medication still usual technique unless very compromised child • Nasotracheal intubation often preferred • Arterial line placed
Congenital Cardiac Surgery • Anesthesia for closed heart operations, performed without CPB • Corrective • PDA ligation • aortic coarctation repair • Non-corrective • Pulmonary banding • Blalock-Taussig shunt • Balloon Atrial Septostomies (Rashkind procedure) • (perfomed in the catheterization lab)
Congenital Cardiac Surgery • PATENT DUCTUS ARTERIOSUS • 1/8000 live births, associated with prematurity and female predominance of approx 3:1 • Left to right shunt causes pulmonary edema • Occasionally right to left cause lower body cyanosis • SpO2 probe on Right hand and lower limb • Confirms correct vessel ligated • Vagal reflex is pronounced by lung traction • Antibiotics required to prevent endocarditis
Congenital Cardiac Surgery • PATENT DUCTUS ARTERIOSUS • Usually left thoracotomy or thoracoscopy, sometimes procedure performed in the NICU, Lung retraction causes hypoxemia/hypercarbia • Air embolism, massive hemorrhage and recurrent laryngeal nerve damage are possible complications • LV overload can occur post-correction • Needs intercostal blocks or epidural for pain
Congenital Cardiac Surgery • COARCTATION OF THE AORTA • 1/12,000 Male:female 2-5:1 • Associated mitral and aortic valve disease • When severe, systemic perfusion depends on right to left shunt across the PDA • Upper body hypertension may be severe • Perioperative paraplegia in 0.5%
Congenital Cardiac Surgery • COARCTATION OF THE AORTA • Left thoracotomy, may need DLT • Right radial a-line and lower NIBP or a-line • May need PGE1 to keep open ductus arteriosus • Allow upper body hypertension on X-clamp • Nitroprusside may be necessary if pressure too high but beware distal hypoperfusion and cord ischemia
Congenital Cardiac Surgery • Tricuspid atresia • 1/10,000 live births, third most common cyanotic congenital heart disease • No connection between RA and RV • Maybe associated with transposition (TGA) • Obligatory flow through a PFO or ASD • If these are restricted then there is systemic venous congestion
Congenital Cardiac Surgery • Tricuspid atresia • Palliative and definitive procedures are applicable to any patient with univentricular physiology • The single ventricle always becomes the systemic ventricle • Initial palliative procedures either increase or decrease pulmonary flow depending on the lesions.
Congenital Cardiac Surgery • Tricuspid atresia • More than 70% patients are severely cyanosed due to inadequate pulmonary flow through the PDA • Need a systemic to pulmonary shunt • Variety used, most common Blalock-Taussig, this RSC to RPA direct or via Gortex • Where pulmonary flow is high the PA is banded • Assessment of RV function is important here
Congenital Cardiac Surgery • Tricuspid atresia • Definitive repair leads to a cavopulmonary anastamosis (Fontan) and this is sometimes two staged, i.e. Hemi-Fontan or Bidirectional Glenn being the intermediary stage. • Patients present for BT shunt often on PGE1 • Meticulous airway management is key to maintain flow balances
Congenital Cardiac Surgery • Tetralogy of Fallot • 1/5000 live births, risks of Tet Spells • Mortality in repair approx. 6% • Anatomy • RVOT Obstruction and RVH • Infundibular narrowing • Pulmonary stenosis and pulmonary hypoplasia • VSD (single or multiple) • Overriding aorta • LAD arises from RCA in 5% cases
Congenital Cardiac Surgery • Tetralogy of Fallot • Perioperative concerns • Increase in PVR or decrease in SVR leading to Right to Left shunt • Tet Spells pre induction (crying/anxiety) • Polycythemia and bleeding • Air embolus • RV failure
Congenital Cardiac Surgery • Tetralogy of Fallot • Preoperative Preparation • Heavy premedication • Consider IM ketamine or inhalation induction but get rapid control of airway. • Keep SVR up and PVR down, maintain heart rate • Intraoperative TEE
Congenital Cardiac Surgery • Tetralogy of Fallot • Weaning from CPB, ratio RV:LV pressure should be < 0.8 • May need to keep PVR low with NTG, milrinone, dobutamine phentolamine, PGE1 • May need RV inotrope post op • May need temporary pacing wire
Congenital Cardiac Surgery • Transposition of the Great Vessels • >5% congenital cardiac defects • Associated with VSD and LV outflow obstruction • Without intervention, V. High mortality, 30% 1st week, 45% 1st mo. 90% 1st year. • Pre-op ductal patency may be life-sustaining
Congenital Cardiac Surgery • Transposition of the Great Vessels • Usual treatment is PGE1followed by a balloon atrial septostomy (Rashkind) then either an arterial switch (Jatene) or (often older child) an atrial switch (Mustard) • Older child will be polycythemic, CHF is frequently present • CVA is possible due to poor perfusion, coagulopathy and hyperviscosity
Congenital Cardiac Surgery • Transposition of the Great Vessels • Periop • Maintain Cardiac output with adequate HR • Continue PGE1 • Reduce PVR and maintain SVR • Opioid/pancuronium technique • Blood loss may be significant
Congenital Cardiac Surgery • Transposition of the Great Vessels • Problems and concerns: • Atrial switch • Venous obstruction with low CO or SVC syndrome • Wide specturm of dysrhymias • RV dysfunction if Right ventriculostomy • Arterial switch • Ischemia due to kinking of reimplanted vessels or air • Inadequate LV function due to ischemia or low LV mass
Congenital Cardiac Surgery • Hypoplastic Left Heart Syndrome • Anatomy • Aortic atresia and LV and mitral hypoplasia • Systemic blood flow occurs across a PDA • Pathophysiology • As ductus closes there is severe systemic hypoperfusion and acidosis
Congenital Cardiac Surgery • Hypoplastic Left Heart Syndrome • Two options: • Cardiac transplantation • 2 or 3 stage procedure: • New aorta created from the pulmonary artery • Atrial defect is created to completely mix blood • Pulmonary flow improved by shunt e.g. BT • Later • Fontan (+/-preceded by a hemi Fontan)
Congenital Cardiac Surgery • Hypoplastic Left Heart Syndrome (HLHS) • Anesthetic Management • Maintain HR, preload and PGE1 • Balance SVR and PVR • Avoid too high PaO2 • May need CO2 to avoid pulmonary over perfusion and hence systemic hypo perfusion • Inotropic support may be necessary to support the ventricular
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Congenital cardiac abnormalities are in 1% live births • Rapid growth in corrective and palliative procedures • Increasingly likely that anesthesiologists will encounter these cases coming for non-cardiac surgery
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Overview • Spectrum of disease • Management algorithms • Anatomy and implications of diseases • Cardiovascular factors • Antibiotics and anticoagulation • Specific problems……
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Specific problems: • The cyanosed neonate • Tetralogy of Fallot • Obstetrics and congenital heart disease • Patients with a single ventricle • Recipients of a heart transplant
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Spectrum of disease: • Congenital heart disease NOT YET treated • Surgically corrected and symptom-free • Surgically corrected but with residual problems • Surgically palliated but stable • Surgically palliated but still with severe symptoms or new problems
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Questions to ask: • Should the patient be referred for specialist cardiology service before surgery? • Is entire procedure more suited to a specialist center? • If we decide to proceed or are forced by an emergent event to proceed what do we need to know?
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Specific lesions, anatomic/pathophysiologic considerations • VSD • L-R shunts and pulmonary overload pre-correction • Endocarditis and arrhythmias post-correction • ASD • L-R shunts and pulmonary overload pre-correction • Potential for paradoxical air embolus • Endocarditis and arrhythmias post-correction
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • PDA • Late problems rare once corrected • Atrioventricular septal defect • Common in Down’s syndrome • Can cause heart failure and pulmonary HTN • Mitral regurgitation may persist after correction • Endocarditis and arrhythmias post-correction
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Hypoplastic Left Heart Syndrome • Before surgery pulmonary circulation needs a patent duct • Three stage palliative surgery lead to single ventricle and pulmonary flow through cavopulmonary connections • Palliation may lead to heart failure and arrhythmias
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Transposition of Great Vessels • Balloon septoplasty in first few hours of life • Arterial/atrial switch performed depending age • Residual risks of endocarditis, arrhythmias and right ventricular (systemic) failure.
Anesthesia for Non-Cardiac Surgery in Patients with Congenital Heart Disease • Pulmonary atresia • Treatment and outcome depend on a VSD • Repeat palliations and residual cyanosis possible