Effects of Intravenous Midazolam Premedication on Postoperative Nausea and Vomiting after Cataract Surgery under General Anesthesia

Postoperative nausea and vomiting is still a common and major complication after general anesthesia, which may delay post-anesthetic care unit (PACU) discharge, prolong hospital stay and thus increase the cost of hospitalization. Several drugs and techniques have been shown to be effective in reducing postoperative nausea and vomiting. In this study the effects of premedication with Intra venus midazolam on the incidence and severity of postoperative nausea and vomiting was investigated in a sample of adult patients undergoing Extra Capsular Cataract Extraction under general anesthesia. One hundred adult patients undergoing general anesthesia for Cataract surgery were randomly divided into two groups to receive either midazolam (0.025mg/kg) or a same volume of normal saline intravenously two minutes prior to induction of anesthesia. Incidence and severity of Postoperative nausea and vomiting and the total amount of administered metoclopramide during the first postoperative day (24hours) were compared between the two groups. There were no differences between the two groups regarding the age, sex, body mass index, NPO time, preoperative anxiety, and severity of post operative pain. Severity of nausea and frequency of vomiting were significantly lower in midazolam group during the first 24 hours after surgery compared with placebo group (nausea: 1.14 ± 1.42 of a ten point visual analog scale vs. 3.18 ± 2.43 in placebo group, P<0.05), and (vomiting: 0.08 ± 0.340 vs. 0.8 ± 0.948 in placebo group, P<0.05). Midazolam group received a significantly less amount of metoclopramide during the first postoperative day (0.8 ± 2.7 mg vs. 2.2 ± 1.4 mg in placebo group P<0.05) but recovery time in midazolam group was slightly longer than placebo group (20.80 ± 4.88 minutes vs. 16.20 ± 3.43 P<0.05). The results of this study suggest the effectiveness of intravenous midazolam premedication to reduce the incidence and severity of postoperative nausea and vomiting.