ECMO ECPR and Special Populations 3 — Questions and Answers
Question 1: What term describes ECMO support initiated specifically to support a patient through a reversible cause of cardiac arrest when conventional CPR has failed?
- Bridge-to-recovery ECMO
- ECPR (Extracorporeal CPR) (Correct answer)
- LVAD bridging
- Resuscitative ECMO
Correct answer: ECPR (Extracorporeal CPR)
ECPR is the specific term for VA-ECMO deployed as an adjunct to conventional CPR for refractory cardiac arrest.
Question 2: In pregnant patients requiring ECMO, which hemodynamic position is recommended to optimize venous return?
- Supine with legs elevated
- Left lateral tilt of 15–30 degrees (Correct answer)
- Reverse Trendelenburg
- Right lateral decubitus
Correct answer: Left lateral tilt of 15–30 degrees
Left lateral tilt relieves aortocaval compression by the gravid uterus, improving venous return to the ECMO circuit.
Question 3: Which lab finding most strongly suggests successful ECPR resuscitation and adequate end-organ perfusion?
- Falling serum lactate over 4–6 hours (Correct answer)
- Rising white blood cell count
- Stable hematocrit
- Increasing creatinine
Correct answer: Falling serum lactate over 4–6 hours
A downward trend in serum lactate is the most reliable indicator of restored oxygen delivery and end-organ recovery after ECPR.
Question 4: A patient with morbid obesity (BMI 55) requires ECPR. What circuit modification is most commonly necessary?
- Larger cannula sizes with higher flow-rated tubing (Correct answer)
- Smaller oxygenator to reduce resistance
- Reduced heparin dosing
- Removal of the heat exchanger
Correct answer: Larger cannula sizes with higher flow-rated tubing
Morbidly obese patients require larger cannulas and higher flow-rated tubing to achieve adequate perfusion for their increased body mass.
Question 5: Which ethical principle is MOST relevant when deciding NOT to initiate ECPR after 60 minutes of conventional CPR without ROSC?
- Autonomy
- Beneficence
- Non-maleficence (Correct answer)
- Justice
Correct answer: Non-maleficence
Non-maleficence (do no harm) guides the decision to withhold futile ECPR when prolonged CPR indicates irreversible injury.
Question 6: In a patient with Down syndrome (Trisomy 21) on ECMO, which anatomical variant most increases cannulation risk?
- Atlantoaxial instability affecting neck vessels (Correct answer)
- Ventricular septal defect
- Macroglossia complicating airway
- Duodenal atresia
Correct answer: Atlantoaxial instability affecting neck vessels
Atlantoaxial instability in Trisomy 21 increases risk during neck manipulation needed for carotid or jugular cannulation.
Question 7: After ECPR for drug-induced cardiac arrest, weaning should be attempted when which criterion is met?
- 48 hours have elapsed since arrest
- The causative drug has been metabolized and cardiac function recovers (Correct answer)
- Lactate normalizes below 4 mmol/L
- Patient regains consciousness
Correct answer: The causative drug has been metabolized and cardiac function recovers
Weaning is appropriate once the toxic drug is metabolized and intrinsic cardiac function demonstrates recovery on echo.
ECMO ECPR and Special Populations 3
What term describes ECMO support initiated specifically to support a patient through a reversible cause of cardiac arrest when conventional CPR has failed?