Increased Effect-Site Concentration of Propofol Reduces ECâ‚…â‚€ of Remifentanil for Successful Intubation Using the Shikani Optical Stylet without Neuromuscular Blockade

Cho, Sang Yun; Lee, Chang Wook; Park, Hyung Joon; Park, Seong Ho; Jeon, Woo Jae

Abstract

OBJECTIVE
For short-duration surgery, propofol and remifentanil are the drugs of choice for intubation without neuromuscular blockade. The Shikani Optical Stylet (SOS) is a novel semi-rigid type fiberoptic laryngoscope. In this study, we determined the clinically required effect-site concentration of remifentanil for intubation using SOS without neuromuscular blockade depending on propofol effect-site concentration.
METHODS
We enrolled patients scheduled for elective surgery with general anesthesia, and assigned them into two groups by a randomized, double-blind method: concentration of propofol 3.5 µg/mL (group PRO 3.5) and 7.0 µg/mL (group PRO 7.0). Anesthesia was conducted with target-controlled infusion in predetermined target effect-site concentrations of propofol. The concentration of remifentanil for successful intubation using SOS in 50% of patients (ECâ‚…â‚€) was determined using a modified Dixon's up-and-down method.
RESULTS
The mean±standard deviation ECâ‚…â‚€ of remifentanil was 5.07±0.40 ng/mL in group PRO 3.5 and 1.79±0.44 ng/mL in group PRO 7.0. From probit analysis, ECâ‚…â‚€ and ECâ‚‰â‚… of remifentanil in group PRO 3.5 were 4.85 ng/mL (95% confidence interval [CI], 4.44-5.16 ng/mL) and 5.42 ng/mL (95% CI, 5.13-7.47 ng/mL) respectively, and ECâ‚…â‚€ and ECâ‚‰â‚… of remifentanil in group PRO 7.0 were 1.68 ng/mL (95% CI, 1.22-2.01 ng/mL) and 2.29 ng/mL (95% CI, 1.98-4.05 ng/mL), respectively.
CONCLUSION
Increased concentration of propofol reduced ECâ‚…â‚€ of remifentanil for successful intubation using SOS without neuromuscular blockade.