ECMO Patient Monitoring and Assessment 5

Question 1

Which ECMO parameter directly reflects the efficiency of the membrane oxygenator's gas exchange capacity?

Accepted Answer

Post-oxygenator PaO2 and PaCO2

Answer

Post-oxygenator blood gas values directly measure how effectively the membrane is transferring oxygen and removing CO2 from the blood passing through it.

Question 2

During ECMO weaning trials, which clinical parameter best confirms readiness to separate from VV-ECMO support?

Accepted Answer

SpO2 > 88% at ECMO flows of 1 L/min with FiO2 0.5 and moderate vent settings

Answer

Maintaining acceptable oxygenation at minimal ECMO flows (1 L/min) with reduced FiO2 and moderate ventilation confirms sufficient native lung recovery for safe decannulation.

Question 3

What is the target range for activated partial thromboplastin time (aPTT) in most adult ECMO protocols?

Accepted Answer

60-80 seconds

Answer

Most adult ECMO programs target an aPTT of 60-80 seconds to balance clot prevention within the circuit against systemic bleeding risk from anticoagulation.

Question 4

A patient on VA-ECMO develops low ECMO flows with high RPM, and the circuit pressure alarm activates. After ruling out hypovolemia, the next assessment should be:

Accepted Answer

Inspect for cannula kinking or positional obstruction

Answer

High RPM with low flows and elevated pressures despite adequate volume suggests mechanical obstruction such as cannula kinking, migration, or outflow obstruction requiring immediate inspection.

Question 5

Cerebral regional oxygen saturation (rSO2) measured by NIRS falls below 50% in an ECMO patient. The first intervention should be:

Accepted Answer

Assess and optimize ECMO flow, MAP, hemoglobin, and arterial CO2

Answer

A rSO2 below 50% signals cerebral oxygen debt; optimizing DO2 determinants — ECMO flow, mean arterial pressure, hemoglobin, and PaCO2 — is the first-line response.

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO Patient Monitoring and Assessment 5