Approximate entropy as the measurement of the electroencephalographic effect during sevoflurane induction.
10.4097/kjae.2008.55.4.404
- Author:
Byung Moon CHOI
1
;
Cheol Sueng YANG
;
Dong Hee WOO
;
Min Seok KOO
;
Sang Ho KIM
;
Myung Ae LEE
;
Ho Sung KWAK
;
Gyu Jeong NOH
Author Information
1. Department of Anesthesiology and Pain Medicine, National Medical Center, Seoul, Korea. rios76@nate.com
- Publication Type:Original Article
- Keywords:
approximate entropy;
electroencephalogram;
pharmacodynamics;
sevoflurane
- MeSH:
Anesthesia;
Anesthetics;
Colon, Sigmoid;
Electroencephalography;
Entropy;
Humans;
Methyl Ethers
- From:Korean Journal of Anesthesiology
2008;55(4):404-411
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: The processed electroencephalograms are useful surrogate measures of quantification of volatile anesthetics effect. We hypothesized that there is a certain relationship between the end-tidal concentration of sevoflurane and approximate entropy (ApEn). The aim of this study was to investigate the effect of sevoflurane on ApEn during induction. METHODS: Fourteen patients were enrolled. With recording of the electroencephalogram at the F3, F4, P3, and P4 montages, anesthesia was induced by increasing the vapor setting of sevoflurane by 1 vol% up to 8 vol% via a facemask. When the end-tidal concentration of sevoflurane did not show any further change, we increased vapor setting of sevoflurane by 1 vol%. When the end-tidal concentration of sevoflurane did not show any further change with 8 vol% of sevoflurane vapor setting, measurement of electroencephalogram was finished. The relation between end-tidal sevoflurane concentration and ApEn was tested by Spearman correlation. RESULTS: ApEn showed a significant correlation (R = -0.7551, P < 0.0001) with end-tidal sevoflurane concentration. The final pharmacodynamic parameters estimated by a sigmoid E(max) model were described as follows: E(0) = 0.91, E(max) = 0.28, C(e50) = 1.36 vol%, gamma = 1.27, kappa(e0) = 0.67 min(-1). CONCLUSIONS: Sevoflurane induction with gradual increase of end-tidal sevoflurane concentration increases the amount of regularity in approximate entropy.
