VV-ECMO in critical COVID-19 obese patients: a cohort study.

Background: Obesity causes significant difficulties in successful extracorporeal membrane oxygenation (ECMO) support and may interfere with patient outcomes. During the COVID-19 pandemic, we experienced an increased number of obese patients supported with ECMO in our intensive care unit due to severe illness in this population.

Methods: We designed a single-center retrospective study to identify prognostic factors for 180-day survival in obese critical COVID-19 patients receiving venovenous ECMO (VV-ECMO). We included adult critical COVID-19 patients on VV-ECMO, who were obese and overweight (according to the World Health Organization) and admitted to a tertiary hospital's intensive care unit from April 1, 2020, to May 31, 2022. Univariate logistic regression analysis was performed to assess differences in 180-day mortality.

Results: Forty-one patients were included. The median age was 55 (IQR 45-60) years, and 70.7% of the patients were male. The median body mass index (BMI) was 36 (IQR 31-42.5) kg/m²; 39% of patients had a BMI ≥ 40 kg/m². The participants had 3 (IQR 1.5-4) days of mechanical ventilation prior to ECMO, and 63.4% were weaned from VV-ECMO support after a median of 19 (IQR 10-34) days. The median ICU length of stay was 31.9 (IQR 17.5-44.5) days. The duration of mechanical ventilation was 30 (IQR 19-49.5) days. The 180-day mortality rate was 41.5%. Univariate logistic regression analysis revealed that a higher BMI was associated with greater 180-day survival (OR 1.157 [1.038-1.291], p = 0.009). Younger age, female sex, less invasive ventilation time before ECMO, and fewer complications at the time of ECMO cannulation were associated with greater 180-day survival [OR 0.858 (0.774-0.953), p 0.004; OR 0.074 (0.008-0.650), p 0.019; OR 0.612 (0.401-0.933), p 0.022; OR 0.13 (0.03-0.740), p 0.022), respectively].

Conclusion: In this retrospective cohort of critical COVID-19 obese adult patients supported by VV-ECMO, a higher BMI, younger age, and female sex were associated with greater 180-day survival. A shorter invasive ventilation time before ECMO and fewer complications at ECMO cannulation were also associated with increased survival.