Congenital Heart Disease

1. Congenital Heart Disease GregGordon MD 2 Feb 05 24 May 06 31 May 07

2. Training for Career in Pediatric Cardiac Anesthesia Specific Fellowship: Rare Suggested training (US & UK): • Pediatric Anesthesia: 12 months • Adult Cardiac Anesthesia: 6 months • Pediatric Cardiac Anesthesia: 6 months • Pediatric Critical Care: 6 months Baum V & De Souza DG. Pediatric Anesthesia 17:407, 2007 White MC & Murphy TWG. Pediatric Anesthesia 17:421, 2007

3. ? • PDA ligations • Murmurs preop • CHD patients for • noncardiac surgery

4. Adults with CHD in US today 2,140,000 Growing 5% per year Cahalan MK. Anesthetic Management of Patients with Heart Disease. IARS 2003 Review Course Lectures

5. 3 y/o with TOF s/p right BTS For dental restorations • Turns blue with crying • Scheduled to undergo cardiac repair • in 3 months • SpO2 93 • Systolic ejection murmur • Slight clubbing of fingers • Hct 52 Tammy

6. (Recent oral board case) 5 y/o for T&A Systolic murmur • VSD • Needs surgical closure • Cardiologist recommended T&A first Victor

7. 11 y/o with tricuspid atresia s/p Fontan procedure For scoliosis repair • Temporary BTS at age 3 weeks • Modified Fontan at age 3 years • Meds: digoxin, captopril • SpO2 88 on RA, 98 in O2 • P 67, BP 99/42 • First degree AV block Fran

8. Objectives Participants will be able to more intelligently discuss: • Newborn heart and lungs • Initial evaluation the child’s heart • Pathophysiology of selected CHDs • Anesthetic implications of CHD

9. The Newborn Heart CHOP “Duct Busters” Provide service to 17 area NICUs Send team of 2 each surgeons anesthesia providers (attending + CRNA) nurses Operate within 24 - 48 hours Monday – Friday No weekends Reimbursement exceeds other cardiac services Susan Nicholson and Gould DS et al: Pediatrics 2003 112:1298-1301

10. The Newborn Heart Foramen Ovale Functional closure first hours as LAP > RAP Probe-patent 50% of 5-year-olds 25% of 20-year-olds Paradoxical embolus

11. The Newborn Heart Ventricular tissue • Fewer myocytes • Greater proportion of connective tissue • Relative RVH So: • Decreased compliance • More sensitive to preload

12. The Newborn Heart • Near peak of Starling curve • Stroke volume relatively fixed • C.O. relatively heart rate dependent Normally near peak of Starling curve Stroke volume relatively fixed C.O. relatively heart rate dependent

13. The Newborn Heart Ca++ Newborn myocardium derives relatively high fraction of activator Ca from the extracellular pool, so Beware Ca channel blockers

14. The Preterm Infant Heart More sensitive to depressant effects of inhaled agents Decreased response to catecholamines Relatively high PVR persists Pulmonary vasculature more sensitive to vasoconstriction by: Hypoxia Acidosis Hypercarbia

15. CHD Pearl murmur in newborn = benign disease

16. Initial evaluation of child’s heart History: To determine • Level of function • CHF

17. Initial evaluation of child’s heart History - cyanosis • Turn blue? • At rest? • When crying? • Passes out? • Stops playing and squats

18. Initial evaluation of child’s heart History - CHF Run around like crazy? Like sibs? Or tends to be quiet, slow? Infant – feeding behavior: Slow to finish bottle? Sweats when nursing? Eyes puffy in the morning?

19. Initial evaluation of child’s heart Physical exam • Listen to heart first when/if infant quiet • (warm stethoscope) • First concentrate on S1 and especially S2 • Louder than normal? • Split normally? • Systolic murmur: • Starts after or obscures S1? • Diastolic murmur? • Widely radiating murmur? • Palpate liver • BP in arm and leg • Tongue - cyanosis

20. CHD Pearl Sudden CHF in ‘healthy’ 10-day-old = complicated coarct

21. General Approach to CHD Patient • Define cardiovascular pathology • Predict pathophysiology • Determine hemodynamic goals • Anticipate emergency treatments Cahalan MK. Anesthetic Management of Patients with Heart Disease. IARS 2003 Review Course Lectures

22. Don’t worry

23. Almost any anesthetic technic may be used in any CHD patient if • the anesthesiologist understands • the pathophysiology of the lesion and • the pharmacology of the drugs employed.

24. Normal Neonate 1 week SVC PV 60 99 LA RA m=2 m=4 65 RV LV 30/3 65 80/5 99 MPA 65 Ao 99 30/12 m=18 80/50

25. Some basic definitions physiologic L to R shunt = lungs to lungs shunt Blood that is returning to the heart from the lungs is recirculated back to the lungs without going out to the rest of the body.

26. Some basic definitions physiologic R to L shunt = body to body shunt Blood that is returning to the heart from the body is recirculated directly back to the body without going to the lungs to be oxygenated.

27. Some basic definitions effective pulmonary blood flow= body to lungs flow Blood that is returning to the heart from the body that is actually directed to the lungs to be oxygenated.

28. Some basic definitions Nonrestrictive VSD VSD large enough that pressure equalizes in the two ventricles (no pressure gradient can be maintained) LV pressure = RV pressure

29. Premature 1 week old PV SVC 28 weeks EGA RA LA 96 65 RV LV 65/10 65/12 65 96 Ao MPA PDA 65/30 65/25 80 92

30. to R arm & head To L arm MHMC PDA ligation

31. CHD Pearl blue newborn + no airway or breathing problem + quiet heart = decreased PBF lesion (TOF)

32. Tetralogy Of Fallot Most common cyanotic lesion NB: cyanosis plus quiet heart Diminished pulmonary blood flow Ao ejection click Hypercyanotic “tet” spells tachypnea, pallor, LOC, less murmur Tammy

35. 3 y/o with TOF s/pright BTS • Define cardiovascular pathology • Predict pathophysiology • Determine hemodynamic goals • Anticipate emergency treatments Tammy

36. Tetralogy Of Fallot • Essentially a duality: • severe RVOT obstruction plus • nonrestrictive VSD • With anatomic consequences: • RVH • Overriding aorta Tammy • And physiologic consequences • R to L shunt • Diminished pulmonary blood flow

38. Tetralogy of Fallot SVC 40 96 RA LA m=5 m=4 RV LV 85/6 85/5 40 85 MPA 50 Ao 40 15/10 85/45

39. Tetralogy Of Fallot s/pright BTS? Blalock-Taussig Shunt Tammy

40. Thomas-Blalock-Taussig Shunt Vivien Thomas Alfred Blalock Helen Taussig Vivien Thomas, Partners of the Heart, 1998 and Something the Lord Made - Best Made-for-TV Movie, 2004

41. November 29, 1944 Thomas-Blalock-Tuassig

42. Dr. Blalock does the Blalock (Johns Hopkins)

43. Systemic to Pulmonary Shunts

44. Tetralogy Of Fallot Maintain adequate tissue oxygenation • Avoid increasing O2 demand • Maintain SVR, systemic BP • Minimize PVR Avoid dehydration, especially if polycythemic Tammy Oral premed/induction midazolam + ketamine

45. Free written board answer: Speed of induction: • R->L shunt • Inhalational: slower • IV: faster • L->R shunt • Inhalational: maybe faster • IV: slower But probably not clinically important Tanner et al. Anesth Analg 64:101, 1985

46. Beware: blunted chemoreceptor response to hypoxemia Tammy

47. Beware: VD:VT may be 0.6 • And increase with • start of mechanical ventilation • too much PEEP • hypovolemia Tammy ETCO2 << PaCO2

48. Tetralogy Of Fallot Minimize R->L Shunt MAINTAINSVR • ketamine • phenylephrine Tammy

49. Tetralogy Of Fallot Minimize RVOT obst & PVR • oxygen • beta blocker ready • Maybe: • nitroglycerin • phentolamine • tolazoline • prostaglandin E1 • nitric oxide Tammy

50. Tetralogy Of Fallot And of course: • No Air in lines Maybe no N2O and infectious endocarditis prophylaxis Tammy