(727) Obesity is Associated with Improved Outcome of Extracorporeal Membrane Oxygenation for Severe Covid-19 Pneumonia

PURPOSE: Morbidly obese patients are considered to be poor candidates for extracorporeal membrane oxygenation (ECMO) in patients with respiratory failure due to COVID-19 pneumonia. A body mass index (BMI) greater than or equal to 40 is a relative contraindication to ECMO by the Extracorporeal Life Support Organization (ELSO) COVID-19 guidelines. This study seeks to determine the impact of obesity on survival of patients with COVID-19 on ECMO. METHODS: This project is a retrospective cohort study of a multicenter US healthcare system queried from January 2020 to December 2021. All patients aged 16 years and older with COVID-19 treated with ECMO support were included in the study. Patients with missing data on ECMO duration were excluded from secondary analyses. The primary outcome was in-hospital mortality in a time-to-event analysis after ECMO initiation, with a comparison between patient groups based on body mass index (BMI) categories. Secondary outcomes included ventilator days, intensive care days, complications, and discharge destination. RESULTS: We identified 335 patients for the primary analysis; 66 were removed from secondary analysis due to missing data for duration of ECMO. There were no baseline differences between obese and non-obese patients in terms of demographics, comorbidities, pre-ECMO treatments, or hospital length of stay. Obese patients were more likely to be younger (median age 41 vs 45; p = 0.016). Obesity (BMI ≥ 30) was associated with a decreased risk of mortality, odds ratio 0.620 (95% CI 0.399 - 0.964; p = 0.0338) after controlling for age. Severe obesity (BMI ≥ 40) was not associated with increased mortality compared to non-obese. Secondary analysis of 269 patients with complete data demonstrate overall in-hospital mortality of 34.3%. There was no difference in ECMO duration, ICU length of stay, rate of blood stream infection, stroke, or blood transfusion between BMI groups. CONCLUSION: Obesity is not associated with increased mortality on ECMO for COVID-19. Neither obesity nor severe obesity should be used to rule out candidacy for the use of ECMO in this population.