Journal of Anesthesia

, Volume 23, Issue 2, pp 203–208

Low dose of fentanyl reduces predicted effect-site concentration of propofol for flexible laryngeal mask airway insertion

  • Junko Yumura
  • Yoshihiko Koukita
  • Ken-ichi Fukuda
  • Yuzuru Kaneko
  • Tatsuya Ichinohe
Original Article

DOI: 10.1007/s00540-008-0728-x

Cite this article as:
Yumura, J., Koukita, Y., Fukuda, K. et al. J Anesth (2009) 23: 203. doi:10.1007/s00540-008-0728-x

Abstract

Purpose

In contrast to reports on the classical laryngeal mask airway (classical LMA; CLMA), no report has calculated the 50% and 95% effect-site concentrations (EC50 and EC95, respectively) of propofol required for flexible LMA (FLMA) insertion. This study was designed to determine the EC50 and EC95 of propofol for FLMA insertion, using probit analysis, and to investigate whether supplemental 0.25 μg·kg−1 fentanyl decreased these concentrations.

Methods

Fifty-nine unpremedicated patients who were scheduled for elective minor oral surgery were randomly allocated to a saline-propofol group (S-P group; n = 30) or a fentanyl-propofol group (F-P group; n = 29). Each group was further divided into four subgroups, in which the propofol EC for FLMA insertion was set at 2.5, 3.0, 3.5, and 4.0 μg·ml−1, respectively, in the S-P group and 1.8, 2.0, 2.5, and 3.0 μg·ml−1, respectively, in the F-P group,. The experiment was assessed as ”successful” when FLMA insertion within 1 min was possible.

Results

The EC50 and EC95 in the S-P group were 3.29 (95% confidence interval [CI], 2.83–3.93) and 4.73 (95% CI, 3.94–12.22) μg·ml−1, and those in the F-P group were 2.13 (95% CI, 1.42–2.60) and 3.54 95% CI, (2.78-34.78) μg·ml−1, respectively. The EC50 in the F-P group was significantly lower than that in the S-P group. There were no significant differences in bispectral index (BIS), hemodynamic variables, respiratory rate, and arterial oxygen saturation (\( Sp_{O_2 } \)) between the S-P and F-P groups.

Conclusion

The propofol EC50 for FLMA insertion was decreased by supplemental 0.25 μg·kg−1 fentanyl without BIS, hemodynamic, or respiratory depression.

Key words

Flexible laryngeal mask airwayPropofolFentanylBispectral index

Copyright information

© Japanese Society of Anesthesiologists 2009

Authors and Affiliations

  • Junko Yumura
    • 1
  • Yoshihiko Koukita
    • 2
  • Ken-ichi Fukuda
    • 2
  • Yuzuru Kaneko
    • 1
  • Tatsuya Ichinohe
    • 1
  1. 1.Department of Dental AnesthesiologyTokyo Dental CollegeChibaJapan
  2. 2.Department of Oral Health and Clinical Science, Division of Dental AnesthesiologyTokyo Dental CollegeTokyoJapan