Changes of Blood Pressure and Heart Rate According to the Effect-Site Concentrations of Alfentanil during Endotracheal Intubation with the Effect-Site Concentration of Propofol Fixed at 4microgram/ml / 대한마취과학회지

ABSTRACT

BACKGROUND: Propofol and alfentanil are frequently combined for general anesthesia. The purpose of this study was to characterize the appropriate effect-site concentration of alfentanil combined with an effect-site concentration of propofol of 4 microgram /ml during endotracheal intubation. METHODS: One hundred and thirty patients, aged 40-70 years and scheduled for abdominal surgery were randomly allocated to four groups according to the target effect-site concentrations of alfentanil: 0 ng/ml in the placebo group, 50 ng/ml in the P50 group, 75 ng/ml in the P75 group, and 100 ng/ml in the P100 group. All patients received a computer controlled infusion of propofol with an effect-site concentration of 4microgram/ml. After equilibration between plasma and effect-site was achieved, and the trachea of the patient was intubated. The assessments of hemodynamic changes were usually confined to the measurement of changes in systolic/diastolic blood pressure (SBP/DBP), mean arterial pressure (MAP), and heart rate (HR). Also, we checked the dose requirements of ephedrine and atropine used to correct hypotension and bradycardia. RESULTS: The use of alfentanil (especially 50 or 75 ng/ml) was effective at blunting the SBP increase during the few minutes after intubation. However, the dose requirements of ephedrine and atropine in the P100 group were significantly higher than those in other groups. CONCLUSIONS: The appropriate effect-site concentration of alfentanil combined with an effect-site concentration of propofol of 4microgram/ml during endotracheal intubation lies between 50 and 75 ng/ml.