The Effect of Intravenous Dextrose Administration on Postoperative Nausea and Vomiting: Systematic Review and Meta-Analysis with Trial Sequential Analysis.

Background and Objectives: Intravenous dextrose administration is a potential nonpharmacological adjunct for preventing postoperative nausea and vomiting (PONV); however, its efficacy and optimal timing remain unclear. This systematic review and meta-analysis, including trial sequential analysis (TSA), evaluated the antiemetic effects of perioperative dextrose administration. Materials and Methods: Electronic databases were searched for randomized controlled trials (RCTs) comparing dextrose-containing fluids with dextrose-free solutions under general anesthesia. The primary outcomes were the incidence of postoperative nausea (PON) and vomiting (POV) and PONV during the early (0-6 h) and late (6-48 h) periods, as well as the overall period (defined as any assessment for which the included study did not report a specific time point). The secondary outcome was the use of rescue antiemetics. Subgroup analyses were performed according to the timing of administration (preoperative, combined preoperative-and-intraoperative, intraoperative, or postoperative). Results: Fourteen RCTs (n = 1455), predominantly derived from laparoscopic surgery, were identified as eligible for the systematic review; of these, 13 RCTs (15 sub-studies, 1334 patients) contributed to the quantitative synthesis, while one trial (Firouzian et al.) was included in the qualitative review and risk-of-bias assessment only, as it reported continuous outcome data incompatible with the binary-outcome meta-analysis. Overall, dextrose infusion significantly reduced PON (RR = 0.73; 95% CI: 0.62-0.87), early PON (RR = 0.73; 95% CI: 0.60-0.88), PONV (RR = 0.65; 95% CI: 0.51-0.86), and early PONV (RR = 0.66; 95% CI: 0.51-0.85). Dextrose also significantly reduced the overall use of rescue antiemetics (RR = 0.57; 95% CI: 0.37-0.87). Formal tests for subgroup interaction by administration timing were significant only for rescue antiemetic use (p = 0.044); interaction tests for all PON, POV, and PONV outcomes were not statistically significant (all p > 0.4), indicating that the timing-based subgroup findings for these outcomes should be considered exploratory. Conclusions: Perioperative intravenous dextrose is an effective nonpharmacological adjunct for PONV prevention, with efficacy that may vary according to the timing of administration; however, this timing-based pattern was formally supported by a significant subgroup interaction test only for the use of rescue antiemetics, not for PON, POV, or PONV, and should therefore be regarded as exploratory. In this analysis, postoperative administration was associated with reduced PON and PONV, and preoperative, combined preoperative-and-intraoperative, and postoperative administration were each associated with reduced use of rescue antiemetics, whereas intraoperative administration alone showed no significant benefit.