ECMO Weaning and Decannulation 4

Question 1

In pediatric VA-ECMO for post-cardiac surgery myocardial stunning, which myocardial function marker on echocardiography is most commonly used to guide weaning readiness?

Accepted Answer

Left ventricular shortening fraction > 25–30%

Answer

An LV shortening fraction above 25–30% on echocardiography is a widely used pediatric benchmark indicating adequate myocardial recovery for VA-ECMO weaning.

Question 2

During a VV-ECMO weaning trial with sweep gas at zero, the patient's arterial blood gas shows pH 7.30, PaCO2 58 mmHg, PaO2 72 mmHg on FiO2 0.50. The correct interpretation is:

Accepted Answer

Oxygenation is marginal and CO2 retention is unacceptable; defer decannulation

Answer

Both significant hypercapnia (PaCO2 58) and borderline oxygenation with respiratory acidosis indicate the native lungs are not yet ready to sustain gas exchange independently.

Question 3

Which of the following correctly describes the 'bridge-to-decision' scenario in which ECMO decannulation is deferred pending further evaluation?

Accepted Answer

ECMO supports a patient awaiting heart transplant listing or durable LVAD implantation

Answer

Bridge-to-decision ECMO maintains perfusion while the team evaluates candidacy for definitive therapy such as transplant or durable mechanical support.

Question 4

When performing surgical decannulation of an arterial cannula in the femoral artery, the surgeon should routinely assess for:

Accepted Answer

Distal limb perfusion by checking pedal pulses or Doppler signals after repair

Answer

Arterial decannulation carries risk of distal ischemia or embolism; confirming pedal pulses or Doppler flow after repair is essential before closure.

Question 5

A patient fails multiple VA-ECMO weaning trials over 14 days. The ECMO team should next consider:

Accepted Answer

Evaluation for durable ventricular assist device implantation or heart transplantation

Answer

Repeated weaning failure after 2 weeks indicates the heart is unlikely to recover; escalation to a durable VAD or transplant evaluation is the appropriate next step.

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO Weaning and Decannulation 4