The life-support system called ECMO can rescue COVID-19 patients from the brink of death but not at the rates seen early in the pandemic, a new international study finds, according to a news release from Michigan Medicine.
Where once about 60% of such patients survived at least 90 days in spring 2020, by the end of the year just under half of COVID patients on ECMO survived that long.
The decreased survival over time might be due to a combination of factors, including which critically ill patients clinicians chose to place on ECMO as the pandemic went on, and the treatments the patients had received before they started on ECMO.
The new findings show how important it is for hospitals that offer ECMO to choose carefully which patients get access to this labor-intensive level of care, the authors say.
Hospitals should also make policies that can guide such choices when ECMO circuits are in high demand because of a pandemic surge, they advise.
The new findings are published in Lancet by an international team co-led by ECMO experts from the University of Michigan, Singapore, and Columbia University. The paper uses data from more than 4,800 patients over age 16 who were treated with ECMO for advanced COVID-19 in 41 countries during 2020.
ECMO, short for extracorporeal membrane oxygenation, has been used for decades in select hospitals to treat critically ill children and adults. It takes over for both the heart and lungs temporarily, circulating the blood outside the body under constant supervision of trained providers.
At the start of the pandemic, some experts had strong reservations about placing COVID-19 patients on ECMO, for fear of harming their lungs. As more centers began to try it, the survival rate mirrored that of ECMO’s use in other forms of acute lung failure, as the team behind the new paper reported a year ago.
But all the centers in that first study had begun offering ECMO before May of 2020, and most were highly experienced with providing ECMO in general, says Ryan Barbaro, MD, MS, Associate Professor at the U-M Medical School and Intensive Care Physician at Michigan Medicine, the University of Michigan’s academic medical center.
The new study breaks the patients into three groups: those treated before May 1, 2020, those treated in these “early adopter” hospitals after May 1, and those treated with ECMO in other hospitals from May 1 through the end of 2020. May 1 was chosen because the evidence for how best to treat critically ill COVID-19 patients had evolved considerably by then.
Within the “early adopter” centers, mortality rates increased from 37% in the months before May, to 52% after May. At the centers that didn’t start providing ECMO until at least May, 58% of the patients died within 90 days of being placed on an ECMO circuit.
Patients treated with ECMO later in the pandemic were more likely to have received medications such as remdesivir and dexamethasone, and to have received non-invasive ventilation before being intubated for total breathing support.