Rationale: Patients with obesity are at increased risk for developing acute respiratory distress syndrome (ARDS). Some centers consider obesity a relative contraindication to receiving extracorporeal membrane oxygenation (ECMO) support, despite growing implementation of ECMO for ARDS in the general population.

Objectives: To investigate the association between obesity and mortality in patients with ARDS receiving ECMO.

Methods: In this large, international, multicenter, retrospective cohort study, we evaluated the association of obesity, defined as body mass index (BMI) ≥ 30 kg/m2, with intensive care unit (ICU) mortality in patients receiving ECMO for ARDS by performing adjusted multivariable logistic regression and propensity score matching.

Measurements and Main Results: Of 790 patients with ARDS receiving ECMO in our study, 320 had obesity. Of those, 24.1% died in the ICU, compared to 35.3% patients without obesity (p < 0.001). In adjusted models, obesity was associated with lower ICU mortality (OR 0.63 [95% CI 0.43-0.93], p = 0.018). Examined as a continuous variable, higher BMI was associated with decreased ICU mortality in multivariable regression (OR 0.97 [95% CI 0.95-1.00], p = 0.023). Propensity score matching 199 patients with obesity to 199 patients without, patients with obesity had a lower probability of ICU death than those without (22.6% versus 35.2%, p = 0.007).

Conclusions: Among patients receiving ECMO for ARDS, patients with obesity had lower ICU mortality than patients without obesity in multivariable and propensity score matching analyses. Our findings support the notion that obesity should not be considered a general contraindication to ECMO.