Fig. 3.
Schematic view of the basic veno-venous extracorporeal membrane oxygenation circuit. Blood is drained from the vena cava (more often the inferior) and a centrifugal pump pushes it through an oxygenator. Inside the oxygenator, the blood is in contact with polymethypenthane hollow fibers, which are permeable only to gases. Gas flow, a mixture of medical air and oxygen (at a fraction decided by the clinician), flows into the hollow fibers, exchanging oxygen, which enters the blood, and carbon dioxide, which leaves the blood. The oxygenated and decarboxylated blood returns to the patient and, in absence of recirculation (see Recirculation section for more details), enters the right atrium and finally the systemic circulation.