Which statement best describes how ECMO works?

Which statement best describes how ECMO works?

• A. Blood pumped out of body and returned
• B. Oxygenated in natural lungs
• C. Blood pumped out of body, oxygenated in an artificial lung, then returned to the body
• D. Blood filtered only without oxygenation

Answer: (C)

ECMO works by taking blood from the body, routing it through an external pump and an artificial membrane lung where gas exchange occurs, and then returning the oxygenated blood back to the circulation. This external gas exchange bypasses the lungs (and can support the heart depending on the circuit used), providing oxygen to the blood and removing carbon dioxide while the patient’s lungs recover. Different configurations exist—for example, support focused on the lungs uses blood returned after oxygenation without arterial involvement, while combined heart-and-lung support uses an arterial return—but the key idea is the blood is oxygenated in an artificial lung outside the body before being returned. The other descriptions miss this essential outside-by-pass oxygenation or describe only filtration without oxygen exchange.

ECMO works by taking blood from the body, routing it through an external pump and an artificial membrane lung where gas exchange occurs, and then returning the oxygenated blood back to the circulation. This external gas exchange bypasses the lungs (and can support the heart depending on the circuit used), providing oxygen to the blood and removing carbon dioxide while the patient’s lungs recover. Different configurations exist—for example, support focused on the lungs uses blood returned after oxygenation without arterial involvement, while combined heart-and-lung support uses an arterial return—but the key idea is the blood is oxygenated in an artificial lung outside the body before being returned. The other descriptions miss this essential outside-by-pass oxygenation or describe only filtration without oxygen exchange.