Extracorporeal membrane oxygenation (ECMO) is a treatment sometimes used to help patients with urgent, severe heart or lung failure. In other cases, it’s used for patients whose lungs don’t work properly. ECMO is often used when treatments like mechanical breathing machines haven’t helped the patient.
These patients often need a lung or heart transplant. The ECMO machine replaces the breathing function of the heart and lungs while they wait for their new heart or lung. ECMO can provide a “bridge to transplant,” meaning it can help very ill patients remain stable until they receive a lung or heart-and-lung transplant.
How ECMO Works
ECMO is a complex treatment, as seen in the illustration below. Here’s a step-by-step review of what happens:
- A doctor inserts tubes, called cannulas, into blood vessels near the heart or in the leg.
- Blood is then pumped out of the body.
- The blood goes through an artificial lung.
- The artificial lung removes carbon dioxide from the blood and adds oxygen.
- In healthy lungs, this happens on the surfaces of the “alveoli,” which are tiny air sacs.
- In the artificial lung, the blood gets oxygen in a device called a “membrane oxygenator,” which exchanges gasses like they’re exchanged in the lungs.
- Finally, the oxygen-rich blood is pumped back into the body.