Efficacy of Combined Ramosetron and Dexamethasone on Postoperative Recovery in Patients Undergoing General Anesthesia: A Multicenter Randomized Controlled Trial

Background/Objectives: Postoperative nausea and vomiting (PONV) is a frequent complication following general anesthesia. Ramosetron is a standard prophylactic agent for PONV; the efficacy of adjunctive dexamethasone in this specific population is not well established. We aimed to evaluate whether adding dexamethasone to ramosetron enhances antiemetic efficacy across diverse surgical procedures. Methods: This prospective, randomized, double-blind, multicenter trial enrolled adults undergoing gynecological, orthopedic, otolaryngologic, general, or plastic surgery managed without postoperative patient-controlled analgesia. We randomized 385 patients into two groups. Group D received 5 mg of dexamethasone immediately after anesthesia induction and ramosetron (0.3 mg) at the end of surgery, whereas Group C received only ramosetron. We assessed the incidence and severity of nausea and vomiting, pain scores, rescue antiemetic and analgesic requirements, and adverse events immediately after surgery and at 6 and 24 h postoperatively. Results: At 6 h, the incidence of nausea was significantly lower in Group D than in Group C (41.7% vs. 58.3%; p = 0.047). Group D also exhibited lower pain scores (VAS: 3.0 ± 1.8 vs. 3.5 ± 1.7; p = 0.012) and reduced consumption of additional analgesics (44.1% vs. 55.9%; p = 0.028). At 24 h, there were no significant differences between the two groups in the incidence of nausea, pain scores, or consumption of additional analgesics. Multivariable logistic regression analysis identified dexamethasone administration as an independent predictor of reduced postoperative nausea at 6 h (odds ratio 0.575; 95% confidence interval 0.344–0.962; p = 0.035). Conclusions: Low-dose dexamethasone to ramosetron substantially reduced postoperative nausea and improved analgesic profiles at 6 h in patients managed without PCA. However, no significant between-group differences were observed at 24 h.