Risk and Protective Factors Analysis for Postoperative Delirium in Elderly Critically Ill Patients: A Multicenter Retrospective Study

Abstract Objective: To study the incidence and risk factors of postoperative clinical delirium in critically ill elderly patients in order to devise strategies for prevention and treatment.Methods: We collected clinical data from 451 critically ill patients in the intensive care unit from four hospitals in Shanghai Pudong New Area. Postoperative delirium was measured using the Confusion Assessment Method for the ICU (CAM-ICU), and then the incidence of postoperative delirium was calculated. We used univariate analysis and multivariate logistic regression analysis to determine the risk factors associated with postoperative delirium in critically ill elderly patients.Results: Among the 451 critically ill patients, 56 had delirium after operation. The incidence of postoperative delirium was 12.4%. Univariate analysis showed that the incidence of postoperative delirium was significantly higher (P <0.05) in patients who had a past history of chronic obstructive pulmonary disease (COPD), underwent emergency surgery, were not administered intraoperative Propofol, had postoperative hypertension, were administered postoperative methylprednisolone, and did not have postoperative analgesia. Multivariate logistic regression analysis showed that age (OR=1.111, 95% CI, 1.056-1.168), surgical timing (OR=1.154, 95% CI, 1.058-7.200), and use of methylprednisolone postoperatively (OR=8.030, 95% CI, 1.050-61.408) were risk factors. Use of Propofol intraoperatively (OR=0.315, 95%CI, 0.124-0.800) was protective factors for postoperative delirium in elderly critically ill patients.Conclusion: Adavanced age, COPD history, emergency surgery, postoperative hypertension, use of methylprednisolone, and no postoperative analgesia are risk factors for postoperative delirium in critically ill elderly patients. Medical staff should be educated in evaluating delirium in postoperative patients and conducting risk assessment in order to prevent and treat the disease earlier, and reduce the incidence of delirium.