Preoperative risk factors for postoperative delirium

The objective of this article was to estimate the incidence of delirium in a sample of patients undergoing elective surgery and to identify the preope rative factors most closely associated with developing this complication. C onsecutive patients (n=500) underwent a full preoperative medical evaluatio n including assessment of cognitive and functional status, Daily evaluation on postoperative days 1 through 4 included medical record review and direc t standardized patient interviews. logistic regression was used to explore the associations between preoperative factors and postoperative delirium. D elirium was detected in 57 (11.4%) patients. Univariate factors associated with delirium included age greater than or equal to 70 years (RR=3.1 [1.75, 5.55]), preexisting cognitive impairment (RR=3.1 [1.73, 5.43]). greater pre operative functional limitations (RR 1.57 [1.27, 1.94]), and a history of p rior delirium (RR 4.1 [1.98 to 8.27]. Adjusting for other factors, previous delirium (OR=4.08 [1.85, 9.0]). age greater than or equal to 70 years (OR= 3.2 [1.6, 6.0], and preexisting cognitive impairment [OR=2.16 [1,15, 4.0] r emained predictive of delirium. Patients' perceptions that alcohol had affe cted their health (OR=6.53 [1.58 to 28.1]) and use of narcotic analgesics j ust prior to admission (OR=2.7 [1.37 to 5.3]) were also significantly assoc iated with delirium postoperatively. Several easily obtained preoperative c linical factors can be used to identify patients at risk for postoperative delirium, This approach, when combined with specialized delirium teams usin g established guidelines, may be more. effective in targeting patients tit risk, thus reducing the number of episodes and days of delirium. (C) 2001 E lsevier Science Inc. All rights reserved.