Risk factors for postoperative hyperactive-type delirium in elderly patients undergoing orthopedic surgery

Objective To determine the risk factors for postoperative hyperactive-type delirium (PHTD) in elderly patients undergoing orthopedic surgery. Methods A total of 7 171 elderly patients of both sexes, aged more than or equal to 65 yr, of American Society of Anesthesiologists physical status Ⅰ- Ⅳ, who underwent orthopedic surgery from January 2008 to December 2012 in Second Affiliated Hospital of Wenzhou Medical University, were retrospectively analyzed.Data such as gender, age, preoperative electrolytes, blood glucose, hemoglobin, albumin, senile dementia and use of benzodiazepines, type of operation, anesthesia methods, operation time, intraoperative use of anticholinergic agents and benzodiazepines and hypotension (decrease more than 20% of the baseline), and postoperative electrolyte, hemoglobin, albumin and hypotension were collected.The patients were divided into postoperative PHTD group (group PHTD) and postoperative non-PHTD group (group non-PHTD) according to whether PHTD developed within 7 days after operation.The risk factors of which P values were less than 0.05 would enter the multivariate logistic regression to stratify the risk factors for postoperative PHTD. Results Ninety-nine patients developed PHTD, and the incidence was 1.38%.The results of logistic regression analysis showed that age more than or equal to 80 yr, hip surgery and preoperative anemia were independent risk factors for postoperative PHTD (P<0.05). Conclusion Age more than or equal to 80 yr, hip surgery and preoperative anemia are independent risk factors for postoperative PHTD in elderly patients undergoing orthopedic surgery. Key words: Delirium; Aged; Risk factors; Orthopedic surgery