Tracheal Intubating Conditions and Hemodynamic Change in Ambulatory Surgery: Propofol and Remifentanil Target Controlled Infusions with Low Dose Rocuronium

Background: This study evaluated the tracheal intubating conditions and hemodynamic changes in tracheal intubation according to the different effect-site concentrations of remifentanil combined with a target controlled infusion (TCI) of propofol using low dose rocuronium.Methods: Forty-five patients presenting for ambulatory surgery were randomly assigned to one of three groups according to the target effect-site concentration of remifentanil: 2.5 ng/ml (group R2.5), 3.0 ng/ml (group R3.0), 3.5 ng/ml (group R3.5).After midazolam administration, anesthesia was induced using a target effect-site controlled infusion of propofol 4.0μg/ml, which was then reduced to 2.5μg/ml.At the same time, a TCI of remifentanil was started.A neuromuscular blockade was produced by rocuronium 0.4 mg/kg.The trachea was intubated 4 min after induction.The tracheal intubation conditions were assessed using a standard scoring system.The noninvasive arterial blood pressure, heart rate (HR), and bispectral index were recorded at 1 min intervals from the start of induction to 5 min after intubation.Results: Intubation was successful in all patients except for one in the R2.5 group.The number of excellent intubating conditions was significantly higher in the R3.5 group (12/15) than in the R2.5 group (6/15) (P ＜ 0.05).The mean arterial pressure (MAP) in the R2.5 and R3.0 groups increased significantly at 1 min after intubation (P ＜ 0.05), but the MAP in the R3.5 group increased slightly at 1 min after intubation.Conclusions: The effect-site concentration of remifentanil 3.5 ng/ml combined with a TCI of propofol using rocuronium 0.4 mg/kg provides the most adequate intubating conditions and hemodynamic stability.(Korean J Anesthesiol 2006; 51: 535～40)