Opioid based patient-controlled analgesia (PCA) effectively provides adequate pain control after spine surgery, often at the expense of high incidence of postoperative nausea and vomiting (PONV). This study was designed to compare the effect of ramosetron with ondansetron for preventing PONV in highly susceptible patients using PCA following spine surgery under general anesthesia.

Seventy female patients, aged 18 to 65, scheduled for elective lumbar spine surgery, were randomly allocated into either ondansetron group (Group O, n = 35) or ramosetron group (Group R, n = 35). In patients assigned to group O, ondansetron 4 mg was injected and 12 mg was added to the PCA regimen. In patients assigned to group R, ramosetron 0.3 mg was injected and 0.3 mg was added to the PCA regimen. The PCA regimen consisted of fentanyl 25 µg/kg (total volume including saline: 100 ml) and was programmed to deliver 2 ml/hr as background infusion and 0.5 ml per demand with a 15 min lockout. The incidence and severity of PONV, pain score, total amount of administered rescue analgesic and rescue antiemetic were assessed following 48 hrs after surgery.

The incidence of PONV showed no significant differences between groups during 48 hrs after surgery. There were no differences in the severity of nausea, pain score, total amount of administered rescue analgesic and rescue antiemetic between groups.

Ramosetron prophylaxis for preventing PONV is as effective as ondansetron in highly susceptible patients using fentanyl based PCA following spine surgery under general anesthesia.