Practical Pediatric Cardiac Anesthesia

1. Practical Pediatric Cardiac Anesthesia Michael S. Mazurek, MD

2. Overview • Preoperative Workup • Pathophysiology • Induction • Pre-pump considerations • On-pump considerations • Post-pump considerations • ?Extubation

3. Preoperative Workup • Heart Center 4th floor • Medicines • Heart failure, arrythmias • Previous surgeries • Sternotomy, BT shunt • Recent echocardiogram • Pathophysiology, ventricular function

4. Preoperative Workup • Labs • Electrolytes, CBC, Coags • CXR • Cardiomegaly, pulmonary congestion • Physical exam • Failing to thrive, tachypneic, pulses, perfusion, rales, hepatomegaly • Consent • Caudal morphine • Intubated, sedated in ICU

5. Preoperative Workup Orders • NPO same as usual • Preop versed same as usual • Inotrope drip sheet order • Dopamine, dobutamine, epinephrine, nitroglycerine usually (discuss with staff) • Send to pharmacy night before • Give to nurses in heart center • Fax it to the pharmacy yourself

6. Pathophysiology • Understand the patient’s lesion (recent echo most helpful) • Cyanotic or acyanotic lesion (RA sats) • Ventricular function good or poor • Obstructive lesion? • Are there oxygenation and ventilation issues? • Are there line placement issues? • Postop pulmonary hypertension?

7. Room Setup • Normal setup plus: • Phenyephrine 100mics/cc • Epinephrine 10mics/cc • Have inotrope drips in the room • 2 or 3 IVs and A-line • Add several stopcocks to D5LR line • Hot line • Need blood available • Bair hugger (for post-pump use) • Cerebral oximeter

8. Induction • IV induction or inhalation induction • Again, know the pathophysiology • If ventricular function poor or LVOT obstructive lesion (critical AS), lean towards gentle IV induction (ketamine, narcotic, etomidate) • If ventricular function good, inhalation induction most likely well tolerated

9. Induction • Again consider oxygenation/ventilation issues • Again consider line placement issues • Caudal morphine 70-100mics/kg if plan on early extubation • Cefuroxime 25mg/kg if not allergic

10. Anesthesia Maintenance • Narcotic based • Remifentanil infusion • Fentanyl bolus • < 10mic/kg if plan on extubation • 50 – 100mic/kg as sole anesthetic for many neonatal pumps • Volatile anesthetic titration • Ketamine • Muscle relaxant (usually cisatra infusion) • Intermittent midazolam

11. Pre-Pump Considerations • Aprotinin? (Surgeon’s decision) • Dr. Brown • 3.5cc/kg IV shortly before cannulation (wait until pursestring sutures in) • 3.5cc/kg in pump per perfusionist • Dr. Turrentine • 2.5 + 2.5 + 2.5cc/kg • Heparin 400Units/kg given in RA • ACT 2mins after • Midazolam dose pre-cannulation

12. Pre-Pump Considerations • Cannulation • Aortic line first (trendelenburg position) • Look for bubbles • IVC and SVC cannulation • Valsalva 10-20 cm/H20 until pursestrings cinched • Potential for blood loss – watch field and ABP and have perfusionist give volume through aortic line if necessary

13. On-Pump Considerations • IVFs to keep open • Turn off humidifier • Monitor mean ABP • Monitor urine output • Get inotropes ready for post-pump • Dopamine, nitroglycerine

14. On-Pump Considerations • Nitroglycerine 0.25mcg/kg/min • Dr. Turrentine for whole case • Helps with rewarming • Dopamine 5mcg/kg/min ready to go • Call for echo and blood products 20 minutes before coming off pump • Repeat midazolam with rewarming • Set up RA, LA, PA lines

15. On-Pump Considerations • Start ventilating when patient starts ejecting • One of venous canulas out • Decompression line out • Re-expand lungs with large breath and hold

16. Off-Pump Considerations • Weaning off pump • Full ventilation 100% O2 • Bair hugger full warm • Hypotension? • What does echo show – volume and function • Hct, calcium • Consider small dose epi or phenylephrine • Consider inotropes • Modified Ultrafiltration (MUF)

17. Off-Pump Considerations • Protamine after MUF • Half dose at a time • Hypotension and pulmonary hypertension side effects • ACT and ABG 5 minutes after protamine • Start blood products if coagulopathy • Platelets first, then cryo • Rarely need FFP

18. Off-Pump Considerations • Coagulopathy Risk • < 8 kg • Cyanotic lesions • Long pump run • Redo sternotomy • Residual hypothermia • Keep calcium > 1.0 (20mg/kg/dose CaGluc) • NaHCO3 for metabolic acidosis: mEq dose= base deficit x wt. x 0.3

19. Extubation • Extubation criteria (case by case basis) • Non-neonate • Stable hemodynamics • Stable coagulopathy • Caudal helpful, not mandatory • Reasonable PaO2 on 40-50% O2

20. Transport to ICU • Emergency supplies (laryngoscope, ETT, drugs, etc.) • Oxygen (Jackson-Rees circuit or Ambu) • Discuss case with ICU resident and nurses • Return monitor and oxygen to workroom

21. Case Example • 5 year old boy who is otherwise healthy for repair of a secundum ASD.

22. 5 year old ASD • Preoperative workup • What’s important • Pathophysiology • Induction • Anesthesia maintenance • Aprotinin? • Coagulopathy? • Extubation?

23. Case Example • 3 day old with hypoplastic left heart syndrome for Norwood procedure.

24. 3 day old Norwood • Preoperative workup • Pathophysiology • Induction • Anesthesia maintenance • Aprotinin? • Coagulopathy? • Extubation?