Comparing the preventive effect of midazolam and midazolam-dexamethasone on postoperative nausea and vomiting in elective middle ear surgery

BACKGROUND: Nausea and vomiting are common postoperative complications with incidence of 20-80% depends on the surgery type, anesthetic drugs, age, sex, etc. This complication may lead to patient discomfort, intraocular, and intracerebral pressures increase, sutures rupture, esophageal injury, and rarely death. Many studies reported that midazolam and dexamethasone alone can decrease postoperative nausea and vomiting (PONV), but their combination has never been studied yet. The aim of this study was to compare the effect of midazolam and midazolam-dexamethasone on PONV after middle ear surgery. MATERIALS AND METHODS: 66 ASA I and II patients aged 15-65 year scheduled for elective middle ear surgery under general anesthesia randomly divided into two groups. Immediately after induction of the anesthesia group one (M) received midazolam 0.075 mg/kg and group two (M+D) received combination of midazolam (0.075 mg/kg) plus dexamethasone (0.05 mg/kg). Then the severity of nausea was measured by visual analog scales 0-10 (VAS) in recovery room at 6, 12, and 24 h after surgery. Metoclopramid (0.1 mg/kg) was administrated I.V. slowly if nausea score was above 3 or patient had vomiting. The postoperative need for antiemetics and the duration of stay in recovery room were recorded. Values of P<0.05 were considered statistically significant. RESULTS: There were no significant differences in age, gender, and weight between the two groups. There was no significant difference in the mean nausea scores between two groups except after 12 h postoperatively (1.39 ± 3.19 in M group vs. 0.42 ± 1.71 in M+D group). The mean vomiting frequency was significantly less in midazolam-dexamethasone group in the recovery room (0.9 ± 0.29 vs. 0 ± 0) and at 6-12 h (1.09 ± 2.41 vs. 0.3 ± 0.8), and 12-24 h (0.42 ± 1.32 vs. 0.03 ± 0.17) postoperatively. During the first 24 h postoperatively, the metoclopramid consumption was significantly less in combination therapy (6.48 ± 9.54) than in the midazolam group (12.9 ± 23.44) (Value<0.5). CONCLUSION: The combination of midazolam-dexametazone is more effective than midazolam alone in prevention of postoperative vomiting after middle ear surgery. Therefore, we recommend combination therapy for patients who are prone to PONV.