Effect of ramosetron plus dexamethasone versus ramosetron alone for preventing nausea and vomiting after spine surgery in highly susceptible patients

Abstract

Backgrounds : Opioid based patient-controlled analgesia (PCA) provides effective pain control after spine surgery, however is associated with a high incidence of postoperative nausea and vomiting (PONV). The antiemetic effect of 5-HT3 antagonists against PONV is enhanced when used in combination with dexamethasone. Although the combination of dexamethasone and ramosetron is theoretically more advantageous than ramosetron alone, there are not enough reports to support this theory. In this study, we investigated the effectiveness of ramosetron plus dexamethasone against ramosetron alone to prevent opioid-based IV PCA related PONV in highly susceptible patients after spinal surgery using inhalational anesthetics.Methods : Female nonsmoking patients (aged 18?65 years) were randomly allocated to ramosetron group (group R, n = 50) and ramosetron plus dexamethasone group (group RD, n = 50). Patients received normal saline 1ml (group R) or dexamethasone 5 mg (group RD) intravenously before induction. Anesthesia was maintained with remifentanil, rocuronium and sevoflurane. At the end of the surgery, ramosetron 0.3 mg was given to all patients and fentanyl-based IV PCA was continued for 48 hrs postoperatively. The incidence and severity of PONV, pain score, amount of rescue antiemetics were assessed for 48 hrs after surgery.Results : Patients’ characteristics were similar between the groups. Although the overall incidence of nausea and severity of nausea were similar between the groups, the number of patients with moderate to severe nausea was significantly lower in the RD group (P = 0.029). The overall incidence of vomiting was significantly lower in the group RD than in the group R (P = 0.037). The frequency in use of rescue antiemetic was lower in RD group but not statistically significant. Pain scores were similar between the groups throughout the study period. The number of patients who experienced adverse events during postoperative period was similar between the groups.Conclusions : Despite similar incidence of overall PONV, combination of ramosetron and dexamethasone significantly reduced the incidence of moderate to severe nausea and vomiting compared to ramosetron alone in highly susceptible patients for PONV using fentanly-based IV PCA and inhalation anesthetics.