ECMO Patient Monitoring and Assessment 2

Question 1

Which parameter most directly indicates adequate oxygen delivery during ECMO support?

Accepted Answer

Mixed venous oxygen saturation (SvO2) 65-75%

Answer

SvO2 of 65-75% reflects the balance between oxygen delivery and consumption, indicating adequate systemic perfusion during ECMO.

Question 2

During VV-ECMO, a patient's native SpO2 drops despite stable ECMO flow. What should the clinician assess first?

Accepted Answer

Recirculation fraction

Answer

Recirculation occurs when oxygenated blood is re-aspirated by the drainage cannula, reducing effective oxygen delivery and causing SpO2 to drop despite adequate flows.

Question 3

What is the significance of a widening arteriovenous CO2 difference (AVCO2 gap) in an ECMO patient?

Accepted Answer

Inadequate tissue perfusion and anaerobic metabolism

Answer

A widening AVCO2 gap (>6 mmHg) suggests poor cardiac output and tissue hypoperfusion with anaerobic CO2 production.

Question 4

In VA-ECMO, the 'north-south syndrome' or differential hypoxia is identified by comparing:

Accepted Answer

Right radial and femoral arterial blood gas values

Answer

Right radial (upper body, native heart output) vs. femoral (ECMO-oxygenated blood) ABG comparison identifies differential hypoxia when the failing heart ejects desaturated blood to the upper body.

Question 5

Which neurological monitoring tool is most commonly used at the bedside during neonatal ECMO?

Accepted Answer

Near-infrared spectroscopy (NIRS)

Answer

NIRS is widely used during neonatal ECMO to continuously monitor cerebral regional oxygen saturation (rSO2) and detect neurological compromise non-invasively.

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO - Extracorporeal Membrane Oxygenation Practice Test

ECMO Patient Monitoring and Assessment 2