Risk Factors for Postanesthetic Emergence Delirium in Adults: A Systematic Review and Meta-analysis

Emergence delirium (ED) is delirium that occurs during or immediately after emergence from general anesthesia or sedation. Effective pharmacological treatments for ED are lacking, so preventive measures should be taken to minimize the risk of ED. However, the risk factors for ED in adults are unclear. In this systematic review and meta-analysis, we evaluated the evidence for risk factors for ED in adults. The PubMed, Scopus, Cochrane Library, Google Scholar, and Embase databases were searched for observational studies reporting the risk factors for ED in adults from inception to July 31, 2023. Twenty observational studies reporting 19,171 participants were included in this meta-analysis. Among the preoperative factors identified as risk factors for ED were age <40 or ≥65 years, male sex, smoking history, substance abuse, cognitive impairment, anxiety, and American Society of Anesthesiologists physical status score III or IV. Intraoperative risk factors for ED were the use of benzodiazepines, inhalational anesthetics, or etomidate, and surgical factors including abdominal surgery, frontal craniotomy (vs. other craniotomy approaches) for cerebral tumors, and the length of surgery. Postoperative risk factors were indwelling urinary catheters, the presence of a tracheal tube in the postanesthetic care unit or intensive care unit, the presence of a nasogastric tube, and pain. Knowledge of these risk factors may guide the implementation of stratified management and timely interventions for patients at high risk of ED. The majority of studies included in this review investigated only hyperactive ED and further research is required to determine risk factors for hypoactive and mixed ED types.