Risk factors of delirium after gastrointestinal surgery: A meta‐analysis

Abstract Background Postoperative delirium is one of the common complications after any major surgery such as gastrointestinal surgery. And it is related to increased mortality and morbidity and other serious surgical outcomes. Aims This study aims to identify risk factors for postoperative delirium in patients undergoing gastrointestinal surgery. Materials and Methods Relevant studies published before August 2021 were searched on Pubmed, Embase and Medline. The risk of bias of included studies was assessed by Newcastle–Ottawa Scale (NOS). A random‐effects model of DerSimonian‐Laird was used to synthesise the overall ORs or RRs for all risk factors. MOOSE checklist was used to review this manuscript. Results A total of 21 studies including 6165 patients were finally included for quantitative analysis. The pooled incidence of postoperative delirium is 11% (95% CI: 9%‐15%). 16 risk factors were identified, in which age, sex, alcohol consumption, cerebrovascular diseases, cardiovascular diseases, use of sleeping pills, history of delirium, preoperative C‐reactive protein (CRP) levels, operation time, blood loss and perioperative blood transfusion were statistically significant while smoking, American Society of Anesthesiologists (ASA) score, performance status, diabetes and operation approach were insignificant. Discussion This meta‐analysis may provide tips for nursing staff and surgeons to design and implement prevention programmes to reduce the incidence of postoperative delirium. Conclusion Potential risk factors of delirium after gastrointestinal surgery are age, sex, alcohol consumption, cerebrovascular diseases, cardiovascular diseases, use of sleeping pills, history of delirium, preoperative CRP levels, operation time, blood loss and blood transfusion.