ALB and pneumonia: The most frequent postoperative complications were hypoproteinemia (albumin ≤ 30 g/L) (9.8%), followed by wound infection (3.7%), pneumonia (2.8%), urinary tract infection (2.3%), delirium (1.9%), transient arrhythmia (1.4%), pressure sores (1.4%), cerebral infarction (1.4%), myocardial infarction (1.4%), ileus (0.9%), gastrointestinal tract bleeding (0.9%), respiratory failure (0.9%), deep vein thrombosis (0.5%), cardiac failure (0.5%), and pulmonary embolus (0.5%).