Effect of a preoperative single dose of intravenous dexamethasone on 24-hour postoperative nausea and vomiting in women undergoing laparoscopic gynecologic surgery: a randomized controlled trial

Abstract Background Postoperative nausea and vomiting (PONV) are frequent and distressing complications following laparoscopic gynecologic surgery, affecting up to 70–80% of high-risk women. Dexamethasone is a low-cost, well-tolerated corticosteroid with established antiemetic effects; however, data specific to gynecologic laparoscopy remain limited. This study evaluated the effect of preoperative intravenous dexamethasone on 24-h PONV and explored patient related factors associated with its occurrence. Methods In this single-blind randomized controlled trial, 120 women undergoing elective laparoscopic gynecologic surgery were randomized 1:1 to receive intravenous dexamethasone (5 mg) or placebo at anesthesia induction. The primary outcome was PONV within 24 h. Sensitivity analysis accounted for the baseline imbalance in previous PONV, and exploratory associations with PONV were assessed using multivariable logistic regression. Results PONV occurred in 26/60 (43.3%) patients receiving dexamethasone and 45/60 (75.0%) controls (RR 0.58, 95% CI 0.42–0.80). After adjustment for previous PONV, the treatment effect was attenuated (adjusted RR 0.66, 95% CI 0.42–1.04). No significant between-group differences were observed in exploratory secondary recovery outcomes. In multivariable analysis, higher BMI was associated with increased odds of PONV (adjusted OR 1.11 per kg/m², 95% CI 1.02–1.21). Conclusions A single preoperative 5-mg dose of intravenous dexamethasone was associated with a lower incidence of 24-h PONV following laparoscopic gynecologic surgery. However, the substantial baseline imbalance in history of PONV between treatment groups and the reduced effect estimate after statistical adjustment warrant cautious interpretation. Future adequately powered, prospectively registered, double-blind multicenter trials are needed to confirm the magnitude and generalizability of this effect. Trial registration The trial was retrospectively registered at ClinicalTrials.gov (NCT07421817) on 12 February 2026.