The effect-site concentration of remifentanil for blunting hemodynamic responses: comparative study in single-lumen endotracheal and double-lumen endobronchial intubation

Abstract

Background:This study undertook to compare the effect-site concentration of remifentanil for prevention of hemodynamic responses to endotracheal intubation, employing the single-lumen tracheal tube and the double-lumen bronchial tube during total intravenous anesthesia. Methods: Based on the nature of the surgery, 38 patients undergoing general anesthesia were assigned either to the singlelumen tube group or the double-lumen tube group. Anesthesia was induced by a target controlled infusion of propofol, with an effect-site concentration of 4 g/ml. Remifentanil was then administered to the first patient in each group, with an effect-site concentration of 3.5 ng/ml. Subsequent concentration of remifentanil was determined by hemodynamic responses of the previous patient to intubation, based on the up-and-down method. Results: The effect-site concentrations of remifentanil for prevention of hemodynamic responses to endotracheal intubation in 50% of patients (EC50) were 2.8 ng/ml (95% CI, 2.0-3.7 ng/ml) in