ECMO Foundations of ECMO and ECMO Management 3

Question 1

A patient on VV-ECMO has a pre-oxygenator saturation of 75% and a post-oxygenator saturation of 99%. This indicates:

Accepted Answer

Adequate oxygenator function with normal circuit performance

Answer

A large step-up in saturation across the oxygenator (75% to 99%) confirms the membrane lung is functioning correctly and fully oxygenating the blood.

Question 2

Which anticoagulant is most commonly used to maintain circuit patency during ECMO?

Accepted Answer

Unfractionated heparin (UFH)

Answer

Unfractionated heparin is the most widely used anticoagulant in ECMO due to its titrability, reversibility with protamine, and availability of established monitoring assays.

Question 3

The ACT (activated clotting time) target range typically used for monitoring anticoagulation during ECMO is:

Accepted Answer

180–220 seconds

Answer

An ACT of 180–220 seconds is the most common target range for ECMO anticoagulation, balancing thrombosis prevention against bleeding risk.

Question 4

Plasma-free hemoglobin (pfHgb) elevation on ECMO is a marker of:

Accepted Answer

Circuit-induced hemolysis

Answer

Elevated plasma-free hemoglobin indicates red blood cell destruction within the circuit, signaling hemolysis that can cause renal injury and must be investigated.

Question 5

In ECMO management, 'chatter' of the venous drainage cannula or tubing typically indicates:

Accepted Answer

Hypovolemia or inadequate venous return to the circuit

Answer

Chatter (intermittent collapse) of the venous drainage line reflects inadequate preload or hypovolemia limiting the circuit's ability to maintain continuous blood flow.

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO Foundations of ECMO and ECMO Management 3