Associated factors for postoperative delirium following major abdominal surgery: A systematic review and meta‐analysis

OBJECTIVES: Postoperative delirium (POD) is a common postsurgical complication. The early identification of its risk factors is the first step toward reducing POD. The predictive factors for POD in patients after major abdominal surgery remain obscure. Therefore, this meta-analysis aimed to comprehensively summarize the risk factors of POD after major abdominal surgery. METHODS: POD studies published between January, 1900 and June 2022 were obtained by searching PubMed, Cochrane Library, Web of Science, Embase, and Medline. Two authors independently reviewed the studies to extract the risk factors and assessed the quality of related articles using the Newcastle-Ottawa Scale. Data were recorded, and a meta-analysis was performed using Review Manager version 5.4.1. RESULTS: Ten studies including total 2900 patients undergoing major abdominal surgery, were eligible for analysis, 608 of whom developed POD, for a cumulative incidence of 21%. This pooled analysis suggested the statistically significant risk factors for POD were age, higher American Society of Anesthesiologists grade, lower preoperative Mini-Mental State Examination score, cognitive impairment, preoperative Katz-ADL score <6, preoperative and postoperative hypoalbuminemia, lower preoperative insulin-like growth factor-1 levels, and longer duration of anesthesia. CONCLUSION: POD is common in patients undergoing major abdominal surgery. This meta-analysis identified risk factors that may aid the early detection of POD and play a prominent role in preventing POD.