A Double-Blinded Randomized Trial Comparing Dexamethasone to Ondansetron as the First-Line Antiemetic After Cesarean Delivery

BACKGROUND: Postoperative nausea and vomiting is a common adverse outcome after cesarean delivery. Both ondansetron and dexamethasone are effective prophylactic medications; however, dexamethasone has also been shown to decrease pain medication use after cesarean delivery. We hypothesize that dexamethasone may be preferred as the first-line agent due to the dual benefit of reduced nausea and opioid consumption. METHODS: Prospective randomized, double-blinded, controlled trial comparing dexamethasone 8 mg to ondansetron 4 mg. Patients received spinal anesthesia including morphine150 µg, and an enhanced recovery after cesarean protocol with scheduled nonopioid analgesic medications. The main outcome was the total number of medications for the treatment of any nausea and vomiting, pain, or pruritus in the first 24 hours following cesarean. RESULTS: One hundred patients were enrolled and 95 completed the trial. We found no difference in the mean (95% confidence interval of the mean) number of postoperative medications (ondansetron 0.23 [0.11–0.35], dexamethasone 0.40 [0.20–0.61] medications per patient per 24 hours; P = .337). Differences in the use of supplemental pain medications and pain scores were not statistically significant over the 24-hour period. Similarly, differences in nausea and pruritus scores were not statistically significant over 24 hours. CONCLUSIONS: We found no differences in the number of medications used to treat pain, nausea, or pruritus in the first 24 hours after cesarean delivery between women who received either ondansetron or dexamethasone. We also found no difference in pain despite prior research showing improvement with dexamethasone, which may be due to the low pain scores and rate of breakthrough postoperative pain in our study.