Femoral venoarterial extracorporeal membrane oxygenation

This image depicts typical circuitry of V-A ECMO. Blood is drained from a central vein (blue) with the tip of the cannula at or above the inferior vena cava-atrial junction. Blood is pumped through the oxygenator and reinfused into a central artery (red [eg, femoral artery as in this graphic]) or cardiac chamber, thereby providing both gas exchange and circulatory support. The blender mixes air and oxygen to set the fraction of delivered oxygen that reaches the membrane. Depending on native LV ejection, a mixing point can develop from competitive flow between the ECMO circuit and native cardiac output, creating dual circulations. This can lead to differential oxygenation and differential carbon dioxide tension in different parts of the body. Refer to UpToDate topics on extracorporeal membrane oxygenation.