Despite the development of a new class of antiemetics, postoperative nausea and vomiting (PONV) still remains a frequent and distressing complication. We compared the prophylactic antiemetic effect of administering dexamethasone 5 mg as an adjunct to ramosetron and ondansetron in patients at high-risk for PONV following lumbar spinal surgery.

In this randomized, double-blind study, 120 female non-smoking patients with intravenous patient-controlled analgesia (PCA) received ramosetron 0.3 mg plus dexamethasone 5 mg (group R + D) or ondansetron 4 mg plus dexamethasone 5 mg (group O + D) intravenously. Fentanyl-based PCA was administered for 48 hr postoperatively; ramosetron 0.3 mg or ondansetron 12 mg was added to the PCA regimen according to the allocated group. The incidence of PONV and rescue antiemetic were assessed for 48 hr postoperatively at 0-6, 6-24, and 24-48 hr.

The overall incidence of PONV did not differ between the groups (50% vs. 60%, in groups R + D and O + D, respectively). The overall incidence of nausea was similar between groups (47% vs. 60%, in groups R + D and O + D, respectively). The overall frequency of vomiting was also similar between groups (8% vs. 12%, in groups R + D and O + D, respectively). The severity of nausea and the overall use of rescue antiemetic were not different between groups.

The antiemetic efficacy of ramosetron plus dexamethasone was similar to that of ondansetron plus dexamethasone on preventing PONV in high-risk patients undergoing lumbar spinal surgery.