Which of the following best describes how ECMO supports gas exchange?

The correct answer is that ECMO acts similarly to an artificial lung. This is because ECMO functions to oxygenate blood and remove carbon dioxide outside of the patient's body, effectively taking over the role of the lungs. In patients with severe respiratory failure, traditional mechanical ventilation may not provide sufficient oxygenation or may cause further injury to the lungs. Therefore, ECMO bypasses the lungs entirely, allowing for gas exchange to occur in the artificial system instead.

This process involves drawing blood from the body, passing it through an oxygenator—where oxygen is added and carbon dioxide is removed—and then returning the treated blood back into circulation. This is crucial for critically ill patients in need of prolonged respiratory support.

In contrast, while mechanical ventilation assists with gas exchange, it relies on the lungs’ function and does not provide a complete substitute as ECMO does. Removing carbon dioxide is part of the process, but it is not the sole function of ECMO. It also does not directly address blood circulation issues related to the heart; instead, it focuses on external gas exchange. Thus, describing ECMO as an artificial lung encapsulates its primary role in supporting patients in respiratory distress.