During induction of general anesthesia, proper mask ventilation is crucial for supplying sufficient oxygen to unconscious patients. Midazolam has a relaxing effect on airway muscles. We hypothesized that sedative premedication with midazolam would facilitate mask ventilation during anesthetic induction.
Patients undergoing elective surgery under general anesthesia were randomized into 2 groups. The midazolam group received midazolam premedication at the reception area, 3 minutes before transfer to the operating room. Patients in the control group were treated with normal saline as a placebo. The primary outcome was difficulty of mask ventilation during induction, as evaluated using the Warters scales.
A total of 97 patients completed the analysis: 49 in the control group and 48 in the midazolam group. The patients in the midazolam group showed a significantly lower mask ventilation difficulty score on the Warters scale than that of the control group (mean [standard deviation], 0.92 [1.13] vs 0.19 [0.57]; estimated difference [95% confidence interval], 0.73 [0.37−1.09]; P < .001). The incidence of difficult mask ventilation (≥2 Warters scale) was significantly lower in the midazolam group than in the control group (risk ratio [95% confidence interval], 0.15 [0.03−0.72]; P = .015).
This randomized clinical trial demonstrated that midazolam premedication enhanced mask ventilation during induction of general anesthesia.
From the *Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
†Department of Anesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul, Korea.
Published ahead of print 3 July 2018.
Accepted for publication July 3, 2018.
The authors declare no conflicts of interest.
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Clinical trial number and registry URL: KCT0002323, https://cris.nih.go.kr.
Reprints will not be available from the authors.
Address correspondence to Jin-Hee Kim, MD, PhD, Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82 Gumi-ro, 173 Beon-gil, Bundang-gu, Seongnam, Gyeonggi-do, 13620, Republic of Korea. Address e-mail to firstname.lastname@example.org.