ALB and chronic obstructive pulmonary disease: The occurrence of POD in older patients after TKA was closely associated with age, educational level, history of sleep disturbance, living style, preoperative hospital stay, hospital stay, American Society of Anesthesiologists (ASA) grade, accompaniment of diabetes, coronary heart disease, cerebral stroke, and chronic obstructive pulmonary disease (COPD), postoperative hypoxemia, preoperative albumin level, blood transfusion, operation time, and postoperative pain (P < .05) (Table 1).