Fig. 1

Patient’s flow chart – in the nested study. Abbreviations: ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; OVATION-65, Optimal VAsopressor TitratION in patients 65 years and older. * These patients were fully eligible but not enrolled in OVATION-65 and were not included in the analyses because identifying data, including medical record number, were not available