Which ECMO configuration provides support for pulmonary gas exchange only?

Which ECMO configuration provides support for pulmonary gas exchange only?

• A. Veno-venous
• B. Veno-arterial
• C. Arterial-venous
• D. Cardiopulmonary bypass

Answer: (A)

When the lungs alone need support for gas exchange, the ECMO setup is arranged to bypass the lungs for oxygenation and CO2 removal while the heart continues to pump the blood to the body. This is achieved with veno-venous ECMO: blood is taken from a venous site, runs through an oxygenator where it is oxygenated and CO2 is removed, and then returned to the venous circulation so the native heart handles circulation to the systemic circuit. Because the blood is returned to the venous side, there’s no direct arterial flow to support blood pressure or systemic perfusion, so this configuration gives pulmonary gas-exchange support only and relies on the heart for circulation. In contrast, a veno-arterial setup drains venous blood but returns it to the arterial system, providing both heart and lung support by aiding systemic perfusion in addition to gas exchange. Cardiopulmonary bypass is a temporary intraoperative form of cardiopulmonary support, far less suited for prolonged, standalone respiratory support.

When the lungs alone need support for gas exchange, the ECMO setup is arranged to bypass the lungs for oxygenation and CO2 removal while the heart continues to pump the blood to the body. This is achieved with veno-venous ECMO: blood is taken from a venous site, runs through an oxygenator where it is oxygenated and CO2 is removed, and then returned to the venous circulation so the native heart handles circulation to the systemic circuit. Because the blood is returned to the venous side, there’s no direct arterial flow to support blood pressure or systemic perfusion, so this configuration gives pulmonary gas-exchange support only and relies on the heart for circulation.

In contrast, a veno-arterial setup drains venous blood but returns it to the arterial system, providing both heart and lung support by aiding systemic perfusion in addition to gas exchange. Cardiopulmonary bypass is a temporary intraoperative form of cardiopulmonary support, far less suited for prolonged, standalone respiratory support.