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.