ECMO ECPR and Special Populations 2 — Questions and Answers
Question 1: What is the maximum recommended 'no-flow' time before ECPR initiation to expect meaningful neurological recovery?
- 2 minutes
- 5 minutes (Correct answer)
- 10 minutes
- 20 minutes
Correct answer: 5 minutes
Witnessed cardiac arrest with no-flow time under 5 minutes is associated with better neurological outcomes after ECPR.
Question 2: In pediatric ECPR, which circuit component is most commonly downsized compared to adult configurations?
- The oxygenator membrane surface area (Correct answer)
- The heat exchanger
- The centrifugal pump head size
- The sweep gas inlet
Correct answer: The oxygenator membrane surface area
Pediatric ECPR uses smaller oxygenator membrane surface areas to match the lower blood flow requirements and reduce prime volume.
Question 3: During ECPR for in-hospital cardiac arrest, chest compressions should be continued until ECMO flow reaches which threshold?
- 0.5 L/min
- 1.0 L/min
- 1.5 L/min
- Full target flow (Correct answer)
Correct answer: Full target flow
CPR should continue until ECMO reaches full target flow to ensure uninterrupted perfusion during cannulation and ramp-up.
Question 4: Which underlying rhythm is associated with the BEST outcomes in ECPR?
- Asystole
- PEA with narrow complex
- Ventricular fibrillation (Correct answer)
- Complete heart block
Correct answer: Ventricular fibrillation
Ventricular fibrillation as the initial arrest rhythm is associated with the best ECPR survival because myocardial viability is often preserved.
Question 5: A neonate on ECPR has an arterial PaO2 of 400 mmHg. What is the most appropriate adjustment?
- Increase sweep gas flow
- Reduce FiO2 in the sweep gas blender (Correct answer)
- Increase pump speed
- Add PEEP to the ventilator
Correct answer: Reduce FiO2 in the sweep gas blender
Hyperoxia in neonates is harmful; reducing sweep gas FiO2 via the blender lowers delivered oxygen concentration to the circuit.
Question 6: In ECPR for hypothermic cardiac arrest, rewarming should occur at a rate no faster than:
- 0.25°C per hour
- 0.5°C per hour
- 1–2°C per hour (Correct answer)
- 4°C per hour
Correct answer: 1–2°C per hour
Rewarming at 1–2°C per hour via the ECMO heat exchanger minimizes afterdrop and cardiovascular instability.
Question 7: Which cannulation strategy is preferred when ECPR is performed during active CPR in a pediatric patient under 10 kg?
- Femoral-femoral VA-ECMO
- Neck (carotid-jugular) cannulation (Correct answer)
- Subclavian artery cannulation
- Transcaval approach
Correct answer: Neck (carotid-jugular) cannulation
Carotid artery and internal jugular vein cannulation is the preferred approach in small pediatric patients due to vessel size limitations at the femoral site.
ECMO ECPR and Special Populations 2
What is the maximum recommended 'no-flow' time before ECPR initiation to expect meaningful neurological recovery?