Extracorporeal Membrane Oxygenation (ECMO) is a critical support system for patients with acute and severe cardiac and respiratory failure. This study investigates the impact of different patient body weight categories on the mortality rates of patients undergoing ECMO support.

Using the Nationwide Sample (NIS) database and ICD-10 codes for 2016 to 2020 in adults over age 18, we evaluated total mortality based on weight categories compared to normal weights using univariate and multivariate analyses.

A total population of 47 990 patients underwent ECMO insertion with a mean age of 52.6 years. Total mortality was 45.7%. Patients with cachexia, overweight, and obesity had similar mortality to normal-weight patients. (Cachexia: 43.75%, normal weight: 46.30%, p = .60, OR = 0.90, 95% CI: 0.61-1.33, overweight 42.31%, p = .69, OR = 0.85, 95% CI: 0.38-1.89, and obesity 45.73%, p = .73, OR = 0.98, 95% CI: 0.85-1.12). However, morbid obesity had the lowest mortality in the univariate analysis (41.89%, p = .01, OR = 0.84, 95% CI: 0.73-0.96) but was not significant in the multivariate analysis (p = .66, OR: 0.97, CI: 0.83-1.12). Separating peripheral veno-arterial versus veno-venous ECMO showed similar results with similar mortalities based on weight categories.

Our data suggest that the ‘obesity paradox’ does not exist in ECMO-treated patients, with no effect of weight on total mortality . Further research is necessary to understand the underlying factors contributing to these outcomes.