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

Naotaka Kishimoto,Shinichi Koyama,Noboru Nagata,Junichiro Kotani

doi:10.4172/2155-6148.1000149

Abstract

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.

Highlights

Remifentanil is widely used with midazolam [1], propofol [2,3,4,5,6], or sevoflurane [7,8,9] for induction of general anesthesia
The relative value of Mean arterial pressure (MAP) at T1 in the end-tidal sevoflurane (ETSevo) 1.5% (59.8 ± 9.9%; P < 0.01) and ETSevo 2% (56.3 ± 11.2%; P < 0.01) groups were lower than that in the ETSevo 1% group (68.4 ± 9.9%)
The results of this study demonstrated that the change in MAP from before induction of anesthesia was smaller in the ETSevo 1% group than in the ETSevo 1.5% and 2% groups

Summary

Introduction

Remifentanil is widely used with midazolam [1], propofol [2,3,4,5,6], or sevoflurane [7,8,9] for induction of general anesthesia. Previous studies have assessed the optimal concentrations for inducing loss of consciousness and calculation of the minimum alveolar concentration following administration of remifentanil in combination with sevoflurane or propofol at the induction of general anesthesia [7,9,10]. The optimal concentration of sevoflurane, which does not affect hemodynamics, has not yet been quantified in combination with remifentanil and propofol during induction of general anesthesia. The purpose of this study was to examine the optimal concentration of sevoflurane to prevent cardiovascular depression after induction of general anesthesia with remifentanil and propofol. We examined the optimal concentration of sevoflurane to prevent cardiovascular depression after induction of general anesthesia with remifentanil and propofol

Objectives

Methods

Results

Conclusion