ECMO - Extracorporeal Membrane Oxygenation Circuit Components and Management Questions and Answers

Question 1

An adult patient on VA ECMO for cardiogenic shock has a progressively increasing pressure gradient across the oxygenator, now measured at 120 mmHg.
What is the most likely cause and appropriate initial action?

Accepted Answer

Oxygenator thrombus formation; prepare for an oxygenator change-out.

Answer

Kinked return cannula; reposition the patient's leg.

Answer

Hypovolemia; administer a fluid bolus.

Answer

Pump head malfunction; switch to the backup pump immediately.

Question 2

During routine monitoring of a patient on VV ECMO, you observe 'chatter' or visible shaking in the venous drainage line, and the ECMO flow has intermittently decreased. Which of the following is the LEAST likely cause of this issue?

Accepted Answer

Increased sweep gas flow

Answer

Excessive pump RPM settings

Answer

Hypovolemia or inadequate preload

Answer

Cannula migration against a vessel wall

Question 3

A centrifugal pump is the most common type used in adult ECMO circuits. A key characteristic of a centrifugal pump is that its flow is:

Accepted Answer

Preload dependent and afterload sensitive

Answer

Independent of afterload and preload

Answer

Insensitive to afterload but dependent on preload

Answer

Dependent on afterload but insensitive to preload

Question 4

The heat exchanger is an integral component of the ECMO circuit. What is its primary physiological purpose?

Accepted Answer

To maintain patient normothermia

Answer

To cool the blood to reduce metabolic demand

Answer

To prevent clot formation within the oxygenator

Answer

To facilitate carbon dioxide removal

Question 5

Which component of the ECMO circuit is directly responsible for both oxygenating the blood and removing carbon dioxide?

Accepted Answer

Membrane oxygenator

Answer

Centrifugal pump

Answer

Heat exchanger

Answer

Blender

Question 6

In the event of a complete ECMO console power failure and inability to immediately restore power, what is the most critical emergency intervention to maintain some level of circuit flow?

Accepted Answer

Connecting the pump head to the emergency hand crank.

Answer

Clamping the circuit and manually ventilating the patient.

Answer

Initiating cardiopulmonary resuscitation (CPR).

Answer

Administering a large bolus of intravenous fluids.