Background: We made a comparative study on the antiemetic effect of midazolam and ondansetron added to intravenous patient-controlled analgesia (PCA) using fentanyl with gynecologic patients undergoing pelviscopic surgery.
Methods: The PCA using 20 µg/kg of fentanyl was started in all groups postoperatively. A dose of 16 mg of ondansetron was added to the PCA of group O (n = 30). A dose of 5 mg of midazolam was added to the PCA of group M (n = 30). While 16 mg of ondansetron and 5 mg of midazolam were added to the PCA of group MO (n = 30). Total volume of the PCA was 60 ml, and the PCA system was programmed to deliver 0.5 ml/h of continuous doses and a 0.5 ml bolus on demand, with a 15 minutes lockout interval. The incidence of postoperative nausea and vomiting (PONV), sedation score, visual analog scale (VAS) for pain, and rescue drug dose for PONV were investigated at the postanesthesia care unit (PACU), 6 hours, and 24 hours after recovery.
Results: The incidence of PONV in group MO was significantly lower than in group O at PACU, 24 hours after recovery (P < 0.05). The sedation score and VAS pain score showed no differences among all groups.
Conclusions: Midazolam added to PCA using fentanyl proved more effective than ondansetron in preventing PONV without adverse effects.
Keywords: Midazolam; Ondansetron; Patient-controlled analgesia; Postoperative nausea and vomiting.