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?