CVP CVP ECMO and Mechanical Circulatory Support 2

Question 1

What is 'Harlequin syndrome' (North-South syndrome) in VA-ECMO?

Accepted Answer

Differential oxygenation between upper and lower body due to competing native cardiac output and ECMO return

Answer

Harlequin syndrome occurs when the recovering native heart ejects poorly oxygenated blood to the upper body while ECMO returns well-oxygenated blood to the lower body via the femoral artery.

Question 2

What is the primary function of the oxygenator membrane in an ECMO circuit?

Accepted Answer

To remove CO2 from and add O2 to blood across a hollow-fiber membrane

Answer

The hollow-fiber membrane oxygenator allows gas exchange across a semi-permeable membrane: O2 diffuses in and CO2 diffuses out driven by concentration gradients.

Question 3

What serious vascular complication is associated with femoral arterial VA-ECMO cannulation?

Accepted Answer

Limb ischemia distal to the arterial cannula

Answer

The large arterial cannula can obstruct femoral artery flow, causing acute limb ischemia distal to the insertion site, requiring vigilant monitoring and often a distal perfusion cannula.

Question 4

How is ECMO flow rate primarily managed by the perfusionist?

Accepted Answer

By adjusting pump speed (RPM) while monitoring flow, pressures, and patient hemodynamics

Answer

The perfusionist titrates pump RPM to achieve target flow (typically 60–80 mL/kg/min for VA-ECMO) while monitoring circuit pressures, arterial saturation, and clinical perfusion markers.

Question 5

What is the purpose of a distal perfusion cannula (DPC) placed in the superficial femoral artery during VA-ECMO?

Accepted Answer

To perfuse the limb distal to the arterial cannula and prevent ischemia

Answer

A DPC is a small-diameter side cannula placed distal to the main arterial cannula, connected to the ECMO circuit to maintain limb perfusion and prevent ischemic complications.

(CVP) Cardiovascular Perfusionist Practice Test

(CVP) Cardiovascular Perfusionist Practice Test

CVP CVP ECMO and Mechanical Circulatory Support 2