OBJECTIVETo determine the incidence, risk factors and clinical outcomes of postoperative delirium in colorectal cancer patients over 60 years.

METHODSConsecutive 382 patients older than 60 years undergoing colorectal cancer surgery at Shenzhen Second People's Hospital from June 2013 to June 2016 were recruited prospectively in this study. These patients were evaluated daily after surgery for 7 days by confusion assessment method. Clinical outcomes were compared between patients with and without postoperative delirium, including postoperative complications, length of hospital stay, and mortality within 30 days. Logistic regression analysis was used to identify independent predictors of postoperative delirium.

RESULTSThere were 230 male and 152 female patients with median age of 67(range 60 to 92) years. Among them, 213 had colon cancer and 169 had rectal cancer. Postoperative delirium developed in 46(12.0%) patients, and most deliriums (78.3%) were diagnosed within 3 days after surgery. Patients with postoperative delirium had more complications [30.4%(14/46) vs. 17.3%(58/336), P=0.032], higher mortality [6.5%(3/46) vs. 1.8%(6/336), P=0.047], and longer postoperative hospital stay (median 14 days vs. 9 days, P=0.008). Univariate analysis revealed that advanced age, male, higher Charlson comorbidity index, higher American Society of Anesthesiologists Classification, lower preoperative blood albumin concentration, history of psychiatric disease, history of cerebrovascular disease, alcohol abuse, emergent operation, and perioperative blood transfusion were significantly related to the development of postoperative delirium. Logistic regression analysis identified that advanced age (OR=1.06, 95%CI: 1.01 to 1.13), history of psychiatric disease (OR=10.89, 95%CI: 2.73 to 41.59) and perioperative blood transfusion (OR=2.37, 95%CI: 1.11 to 7.32) were independent risk factors of postoperative delirium.

CONCLUSIONSPostoperative delirium is relatively common in elderly patients over 60 years undergoing colorectal cancer surgery. The high morbidity of postoperative complication and mortality associated with postoperative delirium warrant implementation of preoperative risk assessment and postoperative screening protocol for postoperative delirium. Comprehensively preventive strategies should be carried out for high-risk patients, e.g. advanced age, history of psychiatric disease, and perioperative blood transfusion.