ECMO Complications and Troubleshooting 2

Question 1

A patient on VA-ECMO develops a sudden drop in arterial line pressure with unchanged ECMO flows. What is the most likely cause?

Accepted Answer

Cardiac tamponade

Answer

Cardiac tamponade reduces native cardiac output, causing a drop in arterial pulsatility and blood pressure despite maintained ECMO flow.

Question 2

During VV-ECMO, SpO2 remains persistently low at 78% despite flows at 5 L/min. The sweep gas is 10 L/min and FiO2 is 1.0. What should be evaluated first?

Accepted Answer

Recirculation fraction

Answer

High recirculation means oxygenated blood is re-entering the drainage cannula before reaching the patient, causing persistent hypoxemia despite adequate flows.

Question 3

A visible clot is noted in the ECMO tubing near the pump head. The appropriate immediate action is to:

Accepted Answer

Clamp the circuit and prepare for emergency circuit change

Answer

A visible thrombus in the circuit poses an immediate risk of systemic embolism or pump failure, requiring circuit change rather than acceleration.

Question 4

A patient on ECMO has a platelet count that drops from 180,000 to 30,000 over 48 hours. The MOST likely cause in this clinical context is:

Accepted Answer

ECMO circuit consumption

Answer

Platelet consumption due to contact activation within the ECMO circuit is the most common cause of thrombocytopenia in ECMO patients.

Question 5

The ECMO centrifugal pump is running at 3,000 RPM but flow has dropped from 4.5 to 2.0 L/min with no change in circuit resistance. What is the most concerning explanation?

Accepted Answer

Pump thrombus reducing pump efficiency

Answer

Pump thrombus increases internal resistance and reduces the pump's hydraulic efficiency, causing decreased flow at the same RPM.

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO Complications and Troubleshooting 2