Korean J Anesthesiol Search


Korean J Anesthesiol > Volume 46(2); 2004 > Article
Korean Journal of Anesthesiology 2004;46(2):164-169.
DOI: https://doi.org/10.4097/kjae.2004.46.2.164   
Does Level of Sensory Block by Epidural Anesthesia Affect the Degree of Sedation?
Young Sun Seo, Hye Won Lee, Byung Cheol Shin, Hun Cho, Hae Ja Lim
Department of Anethesiology and Pain Medicine, College of Medicine, Korea University, Seoul, Korea.
Epidural anesthesia has been shown to have a direct sedative effect, and to markedly reduce the hypnotic requirement of intravenous anesthetics. The purpose of this study was to investigate whether the level of sensory block by epidural anesthesia is related with the degree of sedation, and to the hypnotic requirement of propofol. In addition, we tested whether bispectral index (BIS) monitoring can quantify the sedative effects of epidural anesthesia.
Thirty two patients scheduled for elective upper abdominal or lower extremity surgery were allocated into two groups. 2% lidocaine 15 ml was administered through an epidural catheter at the T9 T10 level (group T, n = 16) or at the L3-L4 level (group L, n = 16). Observer's assessment of alertness/sedation (OAA/S) and BIS were evaluated 20 min after the epidural injection. Hypnotic doses of propofol were then determined by evaluating the loss of open eyes in response to a verbal command as an end point while propofol was administered by target controlled infusion (target effect concentration 5microgram/ml, induction time 3 min). At the time of induction of hypnosis, the target effect concentration and BIS were recorded.
The average level of sensory block was up to T3 in group T, and up to T11 in group L. Compared with the group L, more decreases were noticed in group T in terms of the hypnotic dose of propofol (1.13+/-0.31 mg/kg vs. 1.67+/-0.36 mg/kg; P = 0.03). A decrease in the OAA/S scale from 5 to 4 was more frequently noticed in group T than in group L (93.7% vs. 12.5%, P < 0.05). BIS recorded at the time of induction of hypnosis was higher in group T than in group L (94.8+/-2.8 vs. 82.6+/-2.2; P < 0.001).
A higher sensory block observed in group T than in group L induced a more profound sedative effect and hypnotic induction with a lesser dose of propofol. These results support the condition that the level of sensory block by epidural anesthesia affects the degree of sedation. Moreover, BIS monitoring could not quantify the sedative effect induced by epidural anesthesia.
Key Words: epidural anesthesia; lidocaine; propofol; bispectral index; sedation
Share :
Facebook Twitter Linked In Line it
METRICS Graph View
  • 1 Crossref
  • 740 View
  • 1 Download


Browse all articles >

Editorial Office
101-3503, Lotte Castle President, 109 Mapo-daero, Mapo-gu, Seoul 04146, Korea
Tel: +82-2-792-5128    Fax: +82-2-792-4089    E-mail: journal@anesthesia.or.kr                

Copyright © 2022 by Korean Society of Anesthesiologists.

Developed in M2PI

Close layer
prev next