Effect of preoperative midazolam anxiolysis on anesthetic gas consumption: A randomized controlled trial

BACKGROUND: Adult patients often experience preoperative anxiety that can influence their anesthetic requirements. We investigated the effect of a preoperative midazolam anxiolytic dose on intraoperative sevoflurane consumption. METHODS: This prospective, randomized, double-blind, placebo-controlled study involved 80 patients undergoing elective surgery. Participants were randomized to receive either intravenous midazolam (0.04 mg/kg) or saline preoperatively. Preoperative anxiety assessment was conducted using the short version of the State-Trait Anxiety Inventory. The primary outcome was cumulative sevoflurane consumption within the first hour of surgery. Secondary outcomes included minimum alveolar concentration (MAC), MAC-hour, inspiratory and end-tidal sevoflurane concentrations, and hemodynamic variables. RESULTS: Sevoflurane consumption in 60 minutes was comparable between the midazolam (mean ± standard deviation: 24.2 ± 3.9 mL) and control (25.2 ± 4.1 mL) groups (P = .291). The study found no statistically significant difference in mean MAC-hour values between the groups administered midazolam (3.3 ± 0.7) and saline (3.4 ± 0.7; P = .612). Anxiety levels and sevoflurane consumption or MAC-hour values were not significantly correlated. Hemodynamic parameters remained stable and comparable between groups. CONCLUSION: Preoperative anxiolytic dose of midazolam administration did not significantly reduce intraoperative sevoflurane consumption, and preoperative anxiety levels were not associated with sevoflurane requirements.