ECMO

Question 1

Difference between VV and VA ECMO

Answer 1

VV only bypasses the lungs - heart still working ok

VA bypasses both heart and lungs - careful because some native cardiac output is still present - differential hypoxia prior to site of mixing native and ECMO blood

Question 2

Why is ventilation important in VA ECMO?

Answer 2

The native blood flow from the residual cardiac output will be the one perfusing the proximal aorta and branches to the upper body. If this is poorly oxygenated from dysfusional lungs there is high risk of hypoxia of brain, heart and upper body
differential hypoxemia
Always have an arterial line in the right forelimb to monitor ventilation.