Figure 2.

Patient selection CONSORT diagram. CONSORT diagram of patient selection process. Screening the institutional COVID-19 data registry, 61 179 patients were identified between March 3, 2020, and October 1, 2021. Patients not admitted to an ICU and those admitted for less than 24 h were excluded. Patients less than 3 years of age were excluded as their normal vital signs ranges are significantly different than adult patients, who constitute the majority of patients supported on ECMO, and because there have not been any local patients of this age group supported on ECMO for a primary COVID-19 pathology. Finally, following the institutional ECMO exclusion criteria, patients with BMI above 45 kg/m² and those above 70 years of age were excluded. The final included cohort was divided in 2, the development cohort from March 2020 to January 2021 for model development, training and testing, and the holdout cohort from January 2021 to October 2021 for model testing alone. BMI: body mass index; ECMO: extracorporeal membrane oxygenation; ICU: intensive care unit.