Effects of adding intravenous midazolam to a dual postoperative nausea and vomiting regimen in patients undergoing breast surgery: A pragmatic randomized controlled trial.

Background: For high-risk patients, adding a third antiemetic drug to dual postoperative nausea and vomiting (PONV) prophylaxis is controversial. Given the established antiemetic properties of midazolam, this study compared the combination of low-dose dexamethasone-ondansetron and midazolam with high-dose dexamethasone-ondansetron.

Methods: A total of 300 female patients scheduled for breast surgery were recruited and randomly assigned to two groups. The DO group received dexamethasone 8 mg and ondansetron 4 mg, whereas the DOM group received dexamethasone 4 mg, ondansetron 4 mg, and midazolam 0.04 mg/kg. The primary outcome was the incidence of PONV within 24 h. Secondary outcomes were PONV severity, antiemetic requirement, blood glucose levels, satisfaction and sedation scores, time to eye opening and extubation, pain outcome, and sore throat.

Results: Primary outcome analysis included 298 patients. Incidence of PONV within the first 24 h after surgery occurred in 52 of 150 (35%) patients in the DO group and 33 of 148 (22%) patients in the DOM group (adjusted risk ratio, 0.63; 95% confidence interval, 0.45-0.88; P = 0.007). The antiemetic requirement was significantly greater in the DO group compared with the DOM group (P = 0.034). However, a significantly higher sedation level and longer time for eye-opening and extubation were observed in the DOM group (P < 0.05).

Conclusion: Compared to high-dose dexamethasone and ondansetron alone, midazolam combined with low-dose dexamethasone and ondansetron decreased the incidence of PONV in patients undergoing breast surgery; however, it increased the sedation level in the early postoperative period.