COVID-19 has caused more than 2 million deaths worldwide since the World Health Organization declared it a pandemic in March 2020. Patients with severe COVID-19 frequently experience respiratory distress and require assistance breathing. For patients whose lungs are so injured that even a ventilator is unable to deliver enough oxygen, extracorporeal membrane oxygenation (ECMO)—which does the work of the lungs by removing carbon dioxide and adding oxygen to blood outside the body—may improve the odds of survival for certain patients with severe COVID-19.