Use of ECMO, a machine that can take over the function of lungs, in patients with severely compromised lung function shows promise in treating COVID-19 patients.
The most common cause of mortality in COVID-19 patients is respiratory failure and to a lesser extent, cardiac failure. Being 65 years of age or older, obesity, pre-existing conditions such as diabetes, asthma, heart conditions such as coronary heart disease, are known risk factors for severe illness from COVID-19. As doctors around the world struggle with treating these patients with limited resources at hand, insights into the management of severely ill patients are valuable. A team of clinicians shared their findings from treatment of a small cohort of 32 COVID-19 patients with ECMO or extracorporeal membrane oxygenation machine. These 32 patients had severely reduced lung function that did not respond to conventional treatment. The findings were published in the ASAIO journal.
The ECMO machine carries out the function of the lungs. Blood from the patient is transferred to the ECMO machine where the blood receives oxygen and carbon dioxide is removed. The oxygenated blood is then pumped back into the patient. ECMO usage is meant to give the lungs time to heal and can help in situations where ventilators are not enough to keep a patient alive. Studies of the H1N1 pandemic in 2009-2010 showed that ECMO usage was associated with 79% survival of patients with severe respiratory failure.
A multi-institutional registry was created to allow the team of clinicians to gather data on COVID-19 patients supported by ECMO. At the time of publication of their findings, 68% or 22 patients had survived. The 10 patients who did not survive died prior to or shortly after being removed from the machine and the most common cause (6/10) of death was respiratory failure. Of the 22 patients, five patients were removed from ECMO while the remaining 17 were still on the machine. One of the five patients was discharged from the hospital.
The common characteristic of the patients who recovered after ECMO usage was that all of them received support for lung function but not for heart function. None of the patients who received both lung and heart function support had been successfully removed from ECMO. It is possible that the patients who received ECMO support for both lung and heart function had more compromised lung and heart function from the beginning of treatment.
Additionally, patients under 65 and with fewer pre-existing conditions did better on ECMO as compared to the other patients. As Dr. Jeremiah Hayanga, West Virginia University’s director of ECMO and member of the research team explained, “Our previously published research on national ECMO use has highlighted that patients over age 70 have drastically reduced survival.  Indeed, the Extracorporeal Life Support Organization that provides oversight for ECMO programs around the world considers age 65 as a relative contraindication. As such, patients with advanced age require careful evaluation to ensure the benefit outweighs the risk.”
Also, in contrast to reports from China that treatment with steroids was detrimental to patients with COVID-19, four of the five patients in this study who recovered after ECMO support were receiving steroids. Other medication given to the surviving patients included Remdesivir (3/5), Tocilizumab or Sarilumab that help to counteract the uncontrolled immune response seen in some COVID-19 cases (2/5), and hydroxychloroquine (1/5). As the number of patients in this study are low, more research is needed to understand the role of these medications in management of COVID-19. Dr. Jeffrey Jacobs, member of the research team and a non-faculty collaborator with WVU’s School of Medicine acknowledged, “It is a fact that any given treatment is a single instrument in an orchestra of other treatments. The role of multiple medications in the treatment of COVID-19 remains unclear [.] Ongoing research is necessary to determine the role of these medications in the treatment of patients with COVID-19, both in patients treated with ECMO and in patients not treated with ECMO.”
Nevertheless as Dr. Hayanga put it succinctly, insights like these help clinicians to “counsel patients and family members about the individualized risks and benefits of ECMO.”
Written by Bhavana Achary Ph.D
Reference: Jacobs JP, Stammers AH, St Louis J, et al. Extracorporeal Membrane Oxygenation in the Treatment of Severe Pulmonary and Cardiac Compromise in COVID-19: Experience with 32 patients [published online ahead of print, 2020 Apr 17]. ASAIO J. 2020;10.1097
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