Dexamethasone and Ondansetron Combined Decreases Postoperative Nausea and Vomiting in Orthognathic Surgery Compared With Dexamethasone Alone: A Prospective Randomized Controlled Trial.

Objective: This study aimed to compare the efficacy of dexamethasone alone and dexamethasone-ondansetron combined for preventing postoperative nausea and vomiting (PONV) in patients undergoing orthognathic surgery. Methods: Patients scheduled to undergo mandibular orthognathic surgery who were 18 to 50 years of age and American Society of Anesthesiologists physical status I or II were enrolled. Dexamethasone 6.6 mg was administered after intubation, followed by either ondansetron 4 mg (group DO) or saline placebo (group D) 15 minutes before the end of surgery. Nausea severity was assessed at 3 times postoperatively (immediately after the end of anesthesia, 2 hours later, and 24 hours later) using a 11-point numeric rating scale (NRS). If a patient complained of postoperative nausea or vomited, the NRS score was reevaluated. If the NRS score was 3 or higher, intravenous metoclopramide 10 mg was administered for PONV rescue. Assessed data included nausea NRS scores, vomiting, metoclopramide use, and other patient demographics. Results: Mean nausea NRS scores at 2 hours were significantly lower in group DO vs group D (0.3 vs 2.1; P = .003), but differences in vomiting rates were not significant (P > .05). PONV rescue rates with metoclopramide were lower overall and at 2 hours later in group DO (P < .001). Conclusion: Dexamethasone combined with ondansetron was more effective in preventing early postoperative nausea and reducing need for PONV rescue than dexamethasone alone for patients undergoing orthognathic surgery.