ECMO - Extracorporeal Membrane Oxygenation Cannulation Techniques and Strategies Questions and Answers

Question 1

A patient on Veno-Arterial (VA) ECMO with femoral artery cannulation develops signs of limb ischemia, including coolness and pallor in the cannulated leg.
Which of the following is the most appropriate immediate intervention?

Accepted Answer

Place a distal perfusion cannula (DPC) in the ipsilateral femoral artery.

Answer

Increase the ECMO pump flow to improve perfusion.

Answer

Administer a bolus of an anticoagulant.

Answer

Elevate the affected limb above the level of the heart.

Question 2

In a standard femoro-jugular Veno-Venous (VV) ECMO configuration, what is the primary purpose of ensuring adequate distance (e.g., >15 cm) between the tips of the drainage and reinfusion cannulas?

Accepted Answer

To minimize recirculation of oxygenated blood.

Answer

To prevent cannula migration and dislodgement.

Answer

To minimize the risk of right ventricular rupture.

Answer

To reduce the risk of venous thrombosis.

Question 3

Which of the following is a primary advantage of using a central cannulation strategy (e.g., aortic and right atrial cannulation) for VA ECMO compared to a peripheral (femoral) strategy?

Accepted Answer

It provides antegrade aortic flow, reducing the risk of differential hypoxia.

Answer

It can be performed more quickly at the bedside in an emergency.

Answer

It is associated with a lower risk of bleeding complications.

Answer

It carries a lower risk of stroke and neurological complications.

Question 4

A 35-year-old patient with severe ARDS is being cannulated for VV ECMO. The team opts for a dual-lumen single cannula to be inserted via the right internal jugular vein. Which imaging modality is crucial for confirming the optimal placement of this type of cannula?

Accepted Answer

Echocardiography (TEE or TTE)

Answer

Chest X-ray

Answer

Computed Tomography (CT) scan

Answer

Fluoroscopy

Question 5

When selecting cannula size for a patient requiring VA ECMO, the primary goal is to choose a size that allows for:

Accepted Answer

A target blood flow equivalent to a cardiac index of 2.2-2.5 L/min/m2 without causing excessive shear stress.

Answer

The easiest and quickest possible insertion.

Answer

The lowest possible prime volume for the circuit.

Answer

The longest duration of use without needing to be changed.

Question 6

A patient is placed on peripheral VA ECMO via the femoral artery and vein for cardiogenic shock. Which of the following cannulation-related complications is a direct consequence of the retrograde blood flow delivered by the arterial cannula?

Accepted Answer

Increased left ventricular afterload.

Answer

Limb ischemia in the cannulated leg.

Answer

Deep vein thrombosis in the non-cannulated leg.

Answer

Recirculation between the arterial and venous cannulas.