By Christopher Cheney
Seriously ill coronavirus patients placed on extracorporeal membrane oxygenation life support have a similar mortality rate as other patients placed on ECMO with acute respiratory distress syndrome (ARDS), a recent research article says.
ECMO is a form of life support that features a machine that performs essential functions of the heart and lungs. The ECMO machine is connected to a patient through plastic tubes that are placed in large veins and arteries in the legs, neck, or chest, according to the American Thoracic Society. Blood flows through the ECMO machine, which adds oxygen to the blood and removes carbon dioxide, then the blood is returned to the patient.
The co-authors of the recent research article wrote that the study provides “provisional support” for using ECMO to treat coronavirus patients with acute hypoxemic respiratory failure. “In ECMO-supported patients with COVID-19 and characterized as having ARDS, estimated in-hospital mortality 90 days after ECMO initiation was 38.0%, consistent with previous mortality rates in non-COVID-19 ECMO-supported patients with ARDS and acute respiratory failure.”
The recent journal article, which was published by The Lancet, features data collected from more than 1,000 ECMO patients at more than 200 hospitals. The study includes two key data points.
- COVID-19 patients with ARDS who received respiratory (venovenous) ECMO had a 38.0% estimated cumulative incidence of in-hospital mortality 90 days after ECMO began.
- COVID-19 patients with ARDS who received respiratory ECMO had a mortality rate similar to the mortality rate found in the largest randomized controlled trial of ECMO for ARDS patients without coronavirus—the ECMO to Rescue Lung Injury in Severe ARDS (EOLIA) trial. In the EOLIA trial, 60-day mortality for ECMO patients with ARDS was 35%.
Interpreting the data
The lead author of the study told HealthLeaders that the research is significant because it provides a generalizable estimate of mortality for ECMO-supported patients with COVID-19, and the estimate is similar to the reported mortality in other major studies of ECMO support for ARDS patients.
“If your center is experienced in providing ECMO support to patients with ARDS you might expect similar results when providing ECMO support to patients with COVID-19-related ARDS,” said Ryan Barbaro, MD, MS, an assistant professor at University of Michigan in Ann Arbor, Michigan.
Organ injury is a key factor for survival of coronavirus patients with ARDS who receive ECMO, he said.
“We found that patients had a higher risk of dying if they had worse lung disease, required circulatory support, had kidney injury, or experienced a cardiac arrest. Our study did not answer when is the best time to initiate ECMO support for patients with COVID-19. However, it does suggest that patients who initiated ECMO support with less organ injury had less risk of dying.”
Barbaro speculated that ECMO can be an effective treatment for coronavirus patients with ARDS because the technology avoids lung damage associated with mechanical ventilation and effectively oxygenates a patient’s blood.
“The World Health Organization recommends doctors consider ECMO support in patients who have failed lung protective ventilation. In theory, ECMO benefits patients because it avoids the accumulation of injury caused by high ventilator pressures or caused by the inability to provide enough oxygen to the patient. In these cases, ECMO support can do the work of the lung outside of the body—this is analogous to how dialysis can do the work of the kidney outside of the body.”
Christopher Cheney is the senior clinical care editor at HealthLeaders.