Effect of ramosetron on patient-controlled analgesia related nausea and vomiting after spine surgery in highly susceptible patients: comparison with ondansetron.

Study Design: A prospective, randomized, double-blind clinical trial.

Objective: To compare the effect of ramosetron with that of ondansetron on opioid-based IV patient-controlled analgesia (PCA) related postoperative nausea and vomiting (PONV) in highly susceptible patients after lumbar spine surgery.

Summary Of Background Data: Optimal postoperative pain management is important to facilitate early mobilization after lumbar spine surgery. Opioid analgesia is associated with a high incidence of PONV. Among the currently available 5-hydroxytryptamine receptor 3 antagonists (5-HT3), ondansetron is being most widely used with unsatisfactory results regarding opioid-based IV PCA related PONV. Ramosetron is a newly developed 5-HT3 antagonist with higher receptor affinity and longer duration of action having theoretical advantage over ondansetron in this setting. However, data to support this view are lacking.

Methods: All 94 female nonsmoker patients (aged 18-65 years) were randomly allocated into either ondansetron group (group O, n = 47) or ramosetron group (group R, n = 47). Fentanyl-based IV PCA was administered for 48 hours after surgery. Overall incidence and severity of nausea and incidence of vomiting were assessed for 48 hours after surgery. Secondary measures included: pain intensity and total amount of administered rescue analgesic.

Results: Patients' characteristics were similar between the groups. Overall incidence of nausea was similar between the groups; however, moderate to severe degree of nausea was significantly more in the group O (34%) than in the group R (13%) 6 to 24 hours after surgery. Overall incidence of vomiting and use of rescue antiemetic 6 to 24 hours after surgery was significantly lower in the group R (30% vs. 11% and 28% vs. 11%, respectively). Pain scores at 24 to 48 hours after surgery were significantly lower in the group R (31 +/- 25 vs. 13 +/- 15).

Conclusion: Ramosetron was superior to ondansetron in terms of preventing vomiting and reducing the severity of nausea related to fentanyl-based IV PCA, with less adverse events, in patients with high susceptibility, undergoing lumbar spine surgery.