Anesthesia & Clinical Research
Open Access

Abstract

Optimal Concentration of Sevoflurane to Prevent Cardiovascular Depression after Induction of General Anesthesia with Remifentanil and Propofol

Naotaka Kishimoto, Shinichi Koyama, Noboru Nagata and Junichiro Kotani

Background: We examined the optimal concentration of sevoflurane to prevent cardiovascular depression after induction of general anesthesia with remifentanil and propofol.

Methods: Seventy-five adult patients were randomized to one of three groups (n = 25). Midazolam (0.025 mg/kg) and remifentanil (0.5 ?g/kg/min) were administered to all patients, followed by propofol (1.0 mg/kg) and rocuronium (0.6 mg/kg) after 2 min. The lungs were ventilated manually with sevoflurane and oxygen via a tightly fitted face mask. The trachea was intubated when end-tidal sevoflurane concentration reached 1%, 1.5%, and 2% in each group, respectively. Three min after the start of administration, remifentanil was decreased to 0.25 ?g/kg/min. The effect-site concentration of remifentanil was 6.0 ng/ml for 4 min after it was started. Hemodynamic variables were recorded from before induction of anesthesia to 15 min after tracheal intubation.

Results: There were no serious adverse events such as severe bradycardia or asystole. Relative change of mean arterial pressure after induction of general anesthesia in the end-tidal sevoflurane 1% group was smaller than that of the end-tidal sevoflurane 1.5% and end-tidal sevoflurane 2% groups.

Conclusion: An end-tidal sevoflurane concentration of 1% was sufficient when general anesthesia was induced with an effect-site concentration of remifentanil of 6.0 ng/mL and propofol of 1 mg/kg.