Fig. 1

Patient population. ECMO, extracorporeal membrane oxygenation. Patients undergoing coronary artery bypass surgery without cardiopulmonary bypass at a single hospital were excluded from the exclusion criteria. ECMO Conversion was defined as patients who required extracorporeal circulation due to intraoperative hemodynamic instability. Eligible patients for analysis were classified according to the type of end-expiratory positive pressure used