Practical Pediatric Cardiac Anesthesia

Michael S. Mazurek, MD

Overview

Preoperative Workup Pathophysiology Induction Pre-pump considerations On-pump considerations Post-pump considerations ?Extubation

Preoperative Workup

Heart Center 4th floor Medicines

Heart failure, arrythmias Previous surgeries

Sternotomy, BT shunt Recent echocardiogram

Pathophysiology, ventricular function

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

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

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?

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

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

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

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

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

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

On-Pump Considerations

IVFs to keep open Turn off humidifier Monitor mean ABP Monitor urine output Get inotropes ready for post-pump

Dopamine, nitroglycerine

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

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

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)

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

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

Extubation

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

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

Case Example

5 year old boy who is otherwise healthy for repair of a secundum ASD.

5 year old ASD Preoperative workup

What’s important Pathophysiology Induction Anesthesia maintenance Aprotinin? Coagulopathy? Extubation?

Case Example

3 day old with hypoplastic left heart syndrome for Norwood procedure.

3 day old Norwood

Preoperative workup Pathophysiology Induction Anesthesia maintenance Aprotinin? Coagulopathy? Extubation?