Mortality on ECMO higher in second wave of patients with COVID-19
Mortality on extracorporeal membrane oxygenation was higher in the second wave of patients with COVID-19, despite improvements in treatment before ECMO initiation, according to data presented at the CHEST Annual Meeting.
“ECMO, which has been used as a rescue therapy in prior viral outbreaks, has been used to support certain patients with refractory acute respiratory distress syndrome from COVID-19, but evidence for its efficacy is limited,” Rohit Reddy, BS, second-year medical student at Thomas Jefferson University Hospital, Philadelphia, said during a virtual presentation of the data. “Respiratory failure remained a highly concerning complication in the second wave of the COVID-19 pandemic, but it's unclear how the evolution of the disease and pharmacologic therapy has affected the clinical utility of ECMO.”
Researchers identified 41 adults with ARDS due to COVID-19 who required venovenous ECMO at Thomas Jefferson University Hospital from April 2020 to March 2021. Patients were categorized by “wave” during the COVID-19 pandemic: first-wave patients (n = 28; median age, 52 years; 68% men) were initiated on ECMO from April to September 2020 and second-wave patients (n = 13; median age, 45 years; 69% men) were initiated on ECMO from November 2020 to March 2021.
Median ECMO duration was 16 days overall; patients in the first wave had a median duration of 14 days and those in the second wave had a median duration of 20 days (P = .72).
The researchers reported no significant differences in pre-ECMO vital signs or comorbidities between patients in the first and second waves.
Patients treated during the second wave were more likely to receive pre-ECMO immunomodulators, including steroids (100% vs. 54%; P = .003) and remdesivir (Veklury, Gilead Sciences; 85% vs. 39%; P = .007) compared with those treated in the first wave. Patients in the second wave were also more likely to be placed in the prone position before ECMO (85% vs. 11%; P < .001).
The rate of survival was 67% among patients treated in the second wave compared with 31% among those treated in the first wave (P = .03). Rates of 30-day survival were not significantly different between the groups. Sepsis and lung recovery failure were the most common causes of death while on ECMO, according to the results.
Compared with the first wave, patients treated in the second wave experienced higher rates of complications. The most common complications were hemorrhage (n = 25) and new infection (n = 22). The researchers noted no centrifugal pump thrombosis in these patients.
“Control of infection for the patient with COVID-19 on immunomodulation therapy is challenging, but necessary to improve outcomes,” Reddy said. “More research is required to develop stricter inclusion and exclusion criteria and to improve pre-ECMO management in order to improve outcomes.”
Data from the third wave, representing the Delta variant, were not included in this study, according to the researchers.