Impact of intravenous dexmedetomidine on postoperative gastrointestinal function recovery: an updated meta-analysis

Background: Postoperative ileus (POI) is a complication that may occur after abdominal or nonabdominal surgery. Intravenous dexmedetomidine (Dex) has been reported to accelerate postoperative gastrointestinal function recovery; however, updated evidence is required to confirm its robustness. Methods: To identify randomized controlled trials examining the effects of perioperative intravenous Dex on gastrointestinal function recovery in patients undergoing noncardiac surgery, databases including MEDLINE, EMBASE, Google Scholar, and Cochrane Library were searched on August 2023. The primary outcome was time to first flatus. Secondary outcomes included time to oral intake and defecation as well as postoperative pain scores, postoperative nausea/vomiting (PONV), risk of hemodynamic instability, and length of hospital stay (LOS). To confirm its robustness, subgroup analyses and trial sequential analysis were performed. Results: The meta-analysis of 22 randomized controlled trials with 2566 patients showed that Dex significantly reduced the time to flatus [mean difference (MD):-7.19 h, P<0.00001), time to oral intake (MD: -6.44 h, P=0.001), time to defecation (MD:-13.84 h, P=0.008), LOS (MD:-1.08 days, P<0.0001), and PONV risk (risk ratio: 0.61, P<0.00001) without differences in hemodynamic stability and pain severity compared with the control group. Trial sequential analysis supported sufficient evidence favoring Dex for accelerating bowel function. Subgroup analyses confirmed the positive impact of Dex on the time to flatus across different surgical categories and sexes. However, this benefit has not been observed in studies conducted in regions outside China. Conclusions: Perioperative intravenous Dex may enhance postoperative gastrointestinal function recovery and reduce LOS, thereby validating its use in patients for whom postoperative ileus is a significant concern.