Risk factors for emergence agitation in adults after general anesthesia: A systematic review and meta-analysis

Background: Emergence agitation (EA) is an adverse post-operative complication that increases the risk for injury, self-extubation, hemorrhages, and prolonged hospitalization. This meta-analysis aims to define the risk factors for adult EA after general anesthesia and provide recommendations for clinical practice. Methods: Embase, PubMed, Medline, and the Cochrane Library databases were comprehensive retrieved. Observational studies that reported the risk factors for adult EA were enrolled. Review Manager 5.4 was used to analyze the extracted data. Results: Eighteen observational studies involving 16, 678 adult patients were enrolled in this study. Eighteen pre-operative and nineteen intraoperative factors with unadjusted data, and five pre-operative and five intraoperative factors with adjusted data were meta-analyzed separately. Among them, seven factors (age, male, smoking, history of substance misuse, inhalational anesthesia, urinary catheter, complain of pain, or need analgesic drug use in post-anesthetic care unit) were the risk factors no matter meta-analyzed by unadjusted data or adjusted data. Intraoperative use of benzodiazepines was the risk factor when meta-analyzed by adjusted data, but not unadjusted data. Moreover, age and inhalational anesthesia were not the risk factors when omitted one study for sensitivity analysis, and history of substance misuse could not do sensitivity analysis. Conclusion: Based on this meta-analysis, male, smoking, urinary catheter, and post-operative pain are the risk factors, while age, inhalational anesthesia, history of substance misuse, and intraoperative use of benzodiazepines are the possible risk factors for adult EA. Editorial Comment: This systematic review and meta-analysis identify risk factors associated with the occurrence of agitation during emergence from general anesthesia. As might be expected, the strongest factors are generally things which are irritating or painful for patients, but cannot necessarily be avoided.