ALB and chronic obstructive pulmonary disease: The SWSFS identified 13 important features associated with the development of ARDS, including six preoperative features [chronic obstructive pulmonary disease (COPD), preoperative albumin, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), preoperative white blood cell (WBC) count, preoperative neutrophil-to-lymphocyte ratio (NLR)] and five intraoperative features [CPB time, aortic cross-clamping (ACC) time, transfusion, central venous pressure (CVP)_T4, intraoperative urine output] (Fig. 2).