Intravenous anesthesia


Anesthesia and Pain Medicine. 2002 Mar. 6(1): 13-18
ⓒ Korean Society for Intravenous Anesthesia
The Age Related Changes of Effect Site Concentration of Propofol Equivalent to Bispectral Index (BIS)50
Hoon Park, Hyun-Hwa Lee, Ho-Yeong Kil, Dae-Woo Kim
Department of Anesthesiology, College of Medicine, Hallym University, Seoul, Korea.,Department of Anesthesiology, College of Medicine, The Catholic University of Korea, Seoul, Korea

BACKGROUND: Bispectral index (BIS) has been used to good guide for sedation or hypnosis because of high correlation with blood concentration of propofol. The aim of this study was to titrate the target concentration in each decade group by observation of BIS 50 when propofol used to sedation or hypnosis.
METHODS: One hundred and twenty unpremedicated ASA physical status I or II patients undergoing lower extremity surgery were randomly allocated to six groups (2 nd 7 th decade) according to decade. After sensory dermatome of spinal anesthesia was fixed, propofol was infused by 2 minutes mode, target concentration 1.0 microgram/ml using Master TCI until the target concentration equilibrated with the effect site concentration. The target concentration of propofol was stepwise increased at intervals of 0.5 microgram/ml until BIS reached 50. BIS, observer\'s assessment of alertness/sedation scale (OAA/S), vital signs and effect site concentration at BIS50 were checked. If SpO2 decreased below 90%, oxygen (3 L/min) was given via nasal cannula.
RESULTS: The effect site concentration of propofol at BIS50 was 2.57, 2.5, 2.41, 2.17, 2.09, 1.89 microgram/ml in 2nd, 3rd, 4th, 5th, 6th and 7th decade respectively. The rate less than 90% in SpO2 significantly increased over 50 years.
CONCLUSION: The effect site concentration of propofol at BIS50 was reduced with increasing ages. Thus, the target concentration should be titrated according to increased decade and oxygen must be given at propofol infusion.
Key words : Anesthetic equipment, bispectral index, Anesthetic technique, target controlled infusion, Pharmacology, effect site concentration
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