A significant difference exists between the patients in delirious group or nondelirious group with respect to postoperative incision infection. The incidence of pulmonary infection or cardiovascular events after the surgery seemed significantly associated with the occurrence of POD. When we compared other postoperative complications, no significant differences were observed between groups with respect to the prevalence of urinary tract infection, bowel obstruction, anastomotic leakage, and postoperative bleeding.