Background and Goal of Study: The combination of antiemetic drugs could be a solution to prevent severe postoperative nausea and vomiting (PONV) (1). Midazolam may effectively reduce the frequency of PONV following general anaesthesia (2). We compared the prophylactic antiemetic efficacy of combining dexamethasone with midazolam or ondansetron for patients at high risk of PONV.
Materials and Methods: A total of 135 non-smoking female patients with a history of PONV or motion sickness were included in this prospective, randomized, placebo-controlled study. The patients received dexamethasone 8 mg before induction of anaesthesia and received midazolam 0.04 mg/kg (D + M), ondansetron 4 mg (D + O) or saline (D + S) 30 min before the end of anaesthesia. Relevant endpoints were prevention of early (0-2 h), and overall (0-24 h) PONV, and side effects. Sample size calculation was performed before starting the trials by using a statistical power analysis (N = 45). Data were analyzed using Fisher's exact test, Chi square test with Yates' correction, Mantel-Haenszel test and Wilcoxon's ranked sum test as appropriate.
Results and Discussions: Data [mean(SD) or number(%)] and sedation score (0-2 h, 1 = awake/alert and 5 = deep sleep) are shown in the table:
Conclusion(s): There was no significant difference in antiemetic efficacy or side effects profile when dexamethasone was combined with either midazolam or ondansetron and that both combination regimens are significantly more effective than dexamethasone alone.
1 Heffernan AM, Rowbotham DJ. Br J Anaesth
2 Bauer KP, Dom PM, Ramirez AM, et al. J Clin Anesthesia