The Pediatric Cardiac Intensive Care Society, 10 th International Conference

1. The Pediatric Cardiac Intensive Care Society, 10th International Conference Challenging Case : Severe peri operative low cardiac output state (LCOS) in late primary arterial switch managed without mechanical circulatory support No disclosures Patient photographs shown with permission

2. Introduction • Late presentation of dTGA.IVS not uncommon in Asia • Surgical options include : Primary arterial switch, Two stage switch, Senning ( Atrial switch) • Our preference : Primary arterial switch in Infants upto 3 months of age • Invariably associated with transient and often severe post operative LCOS

3. Aim of presentation • Highlight a management challenge • Our Management protocol for severe LCOS without Extracorporeal life support (ECLS)

4. Baby AK – 50days , 2.9 Kg dTGA.IVS – Regressed LV • 50day old baby girl referred to us from another town • 32 days of age : Diagnosed to have dTGA.IVS At presentation : sick 40-45% satn, stabilized with PGE1 45days of age : Balloon atrial septostomy • Referred to our unit • O/E Mildly Tachypnoeic, Satn 70-75% • Lactate 2.5mmol/L • TSH 7.93 IU/mL – thyroxine commenced

5. Preoperative CXR

6. EchocardiographydTGA.IVS - ? Regressed LV • Situs solitus, Levocardia • 2 small ASD L→R shunt • AV concordance-VA discordance • Intact inter ventricular septum • Small PDA, left aortic arch • Coronary (Leiden 1L,2RCx) • No LSCVC • LVPW 2.4 mm, • LV mass 33 gm/M2

8. LVPWd: 2.4mm LV mass:33gm/m2 10

9. Baby AK – 50days, 2.9Kg Surgery-Uneventful • Primary arterial switch • CPB time : 110min Cross clamp time : 66min • Separation from CPB on dobutamine, milrinone, • Epicardial echo : LVEF50%, no residual defects • Stable hemodynamics – LaP ~5-7mm

10. Baby AK – 50days, 2.9Kg Surgery- Intraop Measures Anticipated LCOS, hemodynamic instability-fluid retention • Afterload reduction with Phenoxybenzamine • Siting of Peritoneal dialysis catheter • Deferred sternal closure

11. Baby AK –Arrival in PCICU On arrival – Stable hemodynamics • HR 160-180/min, MAP ~ high 50s, Lap 7-8mm, toe temp 320C • BE 14 mmol/L, Lactate 3.3mmol/L, SvO2 76% • Vasoactive support: Dobutamine, Milrinone, Phenoxybenzamine • 3hours : LaP 16 mmManual ventilation, Sedation, Muscle relaxation, NTG LaP 9mm Over the next few hours –Intermittent hypotension • ↓ BP MAP down to low 40s • SvO2 72%, lactate 0.9 mmol/L, ionic calcium- 0.9mmol/L • Gentle volume augmentation – target Lap 9-11mm • Calcium infusion as inotropy-target inonic Ca 1.1-1.3mmol/L [Schwartz, Crit Care Med 2001]

12. Baby AK –Subsequent course in PCICU 1st POD -Worsening hemodynamics • HR 160-180/min, • MAP <30mm, toe temp 34.50C, LaP ~5-9mm • Lactate 4.5mmol/L, SvO2 67% • What is happening ? • What should we do Next ??

13. What has happened CI : Neonates after Arterial Switch Dip in Cardiac Index many hours after surgery

16. MBP LAP HR ICU Course After Late Primary switch at 50 days Extubated to CPAP CPAP (POD – 7) POD – 2: LA 5 – 9 , MAP 40s Weaning started (POD – 6) Sternum closed (POD – 5) POD - 4 :Stable LA MAP ~50s LA surge: 16 mmHg (POD – 0) MAP ↓ 30 mmHg 1st POD

17. MBP LAP HR Arrived in ICU: Dobutamine Milrinone Phenoxybenz Extubated to N-CPAP POD 7 Unstable till 3rd POD- What we did.. Inj. Atracurium hypothermia Volume, Inj. Calcium Sternum closed (POD – 5) Stable LA: POD - 4 MAP ~50s LA surge: 16 mmHg (POD – 0)-NTG,sedation Nor epinephrine Steroids, Calcium

19. Subsequent course : Rapid recovery

20. 33 days post surgery Significantly Improved LV function

23. Discussion • Late primary arterial switch is associated with transient, often profound LCOS • “Early/Elective mechanical support” recommended Chaturvedi et al Heart 2004 Kang et al Circulation 2004 • Not feasible in busy programs in Asia with tight shoe string budget • What are the options ???

24. Improving cardiac outputPhysiologic Maneuvers (well described) Afterload reduction Preload optimization • Calcium infusion • Schwartz, Crit Care Med 2001 • Corticosteroid use • Shore S, Nelson DP, Pearl JM, et al : Am J Cardiol 2001 • Thyroxine supplementation for hypothyroidism • Nasopharyngeal CPAP for LV dysfunction • Bradley TD et al, Am Rev RespirDis 1992 Chang AC, Towbin JA, Heart Failure in children and young adults Saunders, Philadelphia, 2006

25. Ventilation,PEEP – powerful hemodynamic toolKnowledge translation

26. LCOS Management without ECLS: “Systematic approach”Diverse strategies, Basics refined Management without ECLS Surgical strategies Volume Adjustments Pharmacologic support Ventilation, PEEP Other strategies Reducing metabolic demands Analgesia, Sedation Muscle relaxation Hypothermia 1. Inotropes 2. Inodilators 3. Dilators 1. Ventilation 2. Pulmonary hypertension 3. Pacing 3. Hypothermia 4.Endocrine, Metabolic* Delayed** sternal closure Preload Creating R-L Shunts PAH Truncus Investigational 1. Steroids ** 2.Antiinflammatory measures Better management of Catecholamine resistant hypotension  Mechanical Support** Refractory LOW OUTPUT

27. Common pitfalls to be avoided • Large, rapid fluid blouses • High dose catecholamines • Chasing “low blood pressures” if well perfused

28. ICU Course After Late Primary switch at 50-100 days “Highly predictable” 0-2nd POD Unstable 3rd POD More stable POD 4-5 Sternum closed MAP 29mm POD 6-7 Extubate to CPAP La 18mm La 6-7mm

29. ICU Course After Late Primary switch at 50-100 days 0-2nd POD Unstable 3rd POD More stable 75 infants Median age 58 days 4/75 deaths Last 4years 0 deaths POD 4-5 Sternum closed MAP 29mm POD 6-7 Extubate to CPAP La 18mm La 6-7mm POD 15-21 LOS

30. World population density 1 million children born with CHD/year

31. 960,000 children born with CHD live in low income, lower middle income countries

32. Implications to clinical practice Tremendous, Global • Cost saving • Avoids potential complications of ECLS in units manned by inexperienced medical and nursing staff We live in a beautiful world .. Health care is inequitable … Potential in Humanitarian missions..