Effect of Remifentanil Concentration on Propofol Demand during Total Intravenous Anesthesia

Abstract

Objective: The purpose of this study was to investigate the effects of remifentanil concentration during total intravenous anesthesia changes on propofol requirements, vital signs, wake-up time, and postoperative pain.Methods: After induction of anesthesia, the concentration of remifentanil was divided into 2 ng/mL (R2 group) and 6 ng/mL (R6 group). In each group, the propofol concentration for maintaining a bispectral index (BIS) of 40–50, systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, time from drug discontinuation to eye opening, and pain score in the recovery room were all measured using the Student t-test. Differences between the two groups were verified for statistical significance.Results: The average BIS scores maintained during the time of measurement were 45.0±3.8 and 45.5±3.9 in the R2 and R6 groups, respectively. The effective concentrations of propofol to maintain these corresponding BIS scores were 3.0±0.6 mcg/mL and 2.4±0.7 mcg/mL in the R2 and R6 groups, respectively.Conclusion: On using propofol and remifentanil during total intravenous anesthesia, the R6 group showed a reduction in the amount of propofol required to maintain a constant BIS, as well as reduced intraoperative blood pressure and pulse compared to those in the R2 group. No significant effects were observed in the time taken for the patient to wake up postoperatively and in postoperative pain experienced by the patient.