ECMO ECPR and Special Populations 5 — Questions and Answers
Question 1: Which neonatal cardiac diagnosis most commonly requires ECMO support in the immediate post-operative period?
- Atrial septal defect repair
- Hypoplastic left heart syndrome (HLHS) after Norwood procedure (Correct answer)
- Patent ductus arteriosus ligation
- Coarctation of the aorta repair
Correct answer: Hypoplastic left heart syndrome (HLHS) after Norwood procedure
HLHS after Norwood palliation carries the highest rate of post-operative ECMO requirement due to single-ventricle physiology and complex hemodynamics.
Question 2: A trauma patient on ECPR after traumatic cardiac arrest has ongoing abdominal hemorrhage. The most appropriate anticoagulation management is:
- Full systemic heparinization at 400 units/kg bolus
- Heparin-free ECMO circuit with careful monitoring (Correct answer)
- Enoxaparin subcutaneously every 12 hours
- Systemic thrombolytics to maintain circuit patency
Correct answer: Heparin-free ECMO circuit with careful monitoring
Heparin-free or minimally heparinized ECMO is used in active hemorrhage to balance circuit thrombosis risk against life-threatening bleeding.
Question 3: During ECPR for a patient in status asthmaticus cardiac arrest, which ventilator strategy is most appropriate once on ECMO?
- High RR with low tidal volume targeting normocapnia
- Permissive hypercapnia with prolonged expiratory time and low PEEP (Correct answer)
- Pressure control with high PEEP to recruit atelectasis
- Oscillatory ventilation at 300 Hz
Correct answer: Permissive hypercapnia with prolonged expiratory time and low PEEP
Status asthmaticus requires permissive hypercapnia, very low respiratory rates, and prolonged expiratory time to prevent dynamic hyperinflation; ECMO manages gas exchange.
Question 4: In ECPR for a patient with pulmonary embolism (PE), which additional therapeutic intervention has the strongest evidence as an adjunct to ECMO?
- IV thrombolytics
- Catheter-directed thrombolysis or surgical embolectomy (Correct answer)
- High-dose anticoagulation alone
- Inferior vena cava filter placement
Correct answer: Catheter-directed thrombolysis or surgical embolectomy
Surgical embolectomy or catheter-directed intervention definitively removes the clot burden and is preferred in massive PE on ECMO to restore right ventricular function.
Question 5: What is the recommended activated clotting time (ACT) target range for ECPR in a pediatric patient without active bleeding?
- 120–140 seconds
- 160–200 seconds (Correct answer)
- 220–280 seconds
- 300–350 seconds
Correct answer: 160–200 seconds
ACT targets of 160–200 seconds balance circuit thrombosis prevention with bleeding risk in pediatric ECMO patients without active hemorrhage.
Question 6: Which finding on cranial ultrasound in a neonate on ECMO is an absolute contraindication to continuing ECMO support?
- Grade I intraventricular hemorrhage
- Grade II intraventricular hemorrhage
- Grade III–IV intraventricular hemorrhage (Correct answer)
- Periventricular leukomalacia
Correct answer: Grade III–IV intraventricular hemorrhage
Grade III–IV IVH carries a very high risk of death or severe neurodevelopmental disability, and is an absolute contraindication due to anticoagulation requirements worsening hemorrhage.
Question 7: In post-cardiac surgery ECPR, the 'Berlin criteria' for ECMO candidacy emphasize which factor as most predictive of survival to discharge?
- Patient age under 50
- Lactate below 15 mmol/L at ECMO initiation (Correct answer)
- Absence of pre-operative renal failure
- Duration of CPR less than 30 minutes before ECMO
Correct answer: Lactate below 15 mmol/L at ECMO initiation
Lactate below 15 mmol/L at ECMO initiation is the strongest predictor of survival in post-cardiotomy ECMO patients, reflecting residual metabolic reserve.
ECMO ECPR and Special Populations 5
Which neonatal cardiac diagnosis most commonly requires ECMO support in the immediate post-operative period?