Document Detail

Time-frequency balanced spectral entropy as a measure of anesthetic drug effect in central nervous system during sevoflurane, propofol, and thiopental anesthesia.
MedLine Citation:
PMID:  14995935     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Time-frequency balanced spectral entropy of electroencephalogram (EEG) and frontal electromyogram (FEMG) is a novel measure of hypnosis during anesthesia. Two Entropy parameters are described: Response entropy (RE) is calculated from EEG and FEMG; and State Entropy (SE) is calculated mainly from EEG. This study was performed to validate their performance during transition from consciousness to unconsciousness under different anesthetic agents. METHODS: Response entropy, SE [S/5 Entropy Module, M-ENTROPY (later in text: Entropy), Datex-Ohmeda Division, Instrumentarium Corp., Helsinki, Finland] and BIS (BIS XP, A-2000, Aspect Medical Systems, Newton, MA) data were collected from 70 patients; 30 anesthetized with propofol 2 mg kg-1, 20 with sevoflurane inhalation, and 20 with thiopental 5 mg kg-1. Loss and regaining of consciousness (LOC, ROC) was tested every 10 s, and sensitivity, specificity, and prediction probability (Pk) were calculated. Behavior of the indices was studied. RESULTS: Sensitivity, specificity, and Pk values for consciousness were high and similar for all indices. During regaining of consciousness after propofol bolus, RE, SE, and BIS values recovered by 81 +/- 22%, 75 +/- 26%, and 59 +/- 18% (mean +/- SD), respectively, from the minimum relative to their baseline. After thiopental bolus, RE, SE, and BIS values recovered by 86+/-21%, 88 +/- 13%, and 63 +/- 14%, respectively. The relative rise was higher in RE and SE compared with BIS (P < 0.01). During deep levels of hypnosis, RE and SE decreased monotonously as a function of burst suppression ratio, while BIS showed biphasic behavior. On average, RE indicated emergence from anesthesia 11 s earlier than SE, and 12.4 s earlier than BIS. CONCLUSIONS: All indices, RE, SE, and BIS, distinguished excellently between conscious and unconscious states during propofol, sevoflurane, and thiopental anesthesia. During burst suppression, Entropy parameters RE and SE, but not BIS, behave monotonously. During regaining of consciousness after a thiopental or propofol bolus, RE and SE values recovered significantly closer to their baseline values than did BIS. Response entropy indicates emergence from anesthesia earlier than SE or BIS.
A Vakkuri; A Yli-Hankala; P Talja; S Mustola; H Tolvanen-Laakso; T Sampson; H Viertiö-Oja
Related Documents :
3664515 - Stability and pharmacokinetics of m-[131i]iodobenzylguanidine in patients.
24259935 - Effect of the foot placements on the latissmus dorsi and low back muscle activities dur...
23526925 - Increased expression of neurotrophin 4 following focal cerebral ischemia in adult rat b...
15385365 - A comparison of bispectral index and rapidly extracted auditory evoked potentials index...
15259355 - Transmural distribution of iron in the hypoxic and reoxygenated rabbit left ventricular...
3884775 - Post-exercise ketosis in post-prandial exercise: effect of glucose and alanine ingestio...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Acta anaesthesiologica Scandinavica     Volume:  48     ISSN:  0001-5172     ISO Abbreviation:  Acta Anaesthesiol Scand     Publication Date:  2004 Feb 
Date Detail:
Created Date:  2004-03-03     Completed Date:  2004-05-19     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  0370270     Medline TA:  Acta Anaesthesiol Scand     Country:  Denmark    
Other Details:
Languages:  eng     Pagination:  145-53     Citation Subset:  IM    
Department of Anesthesia, Surgical Hospital, Helsinki University Hospital, Kasarmikatu 11-13, PO Box 263, 00029 HUS, Helsinki, Finland.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Anesthetics / pharmacology*
Electroencephalography / drug effects*
Electromyography / drug effects
Methyl Ethers / pharmacology*
Middle Aged
Propofol / pharmacology*
Sensitivity and Specificity
Thiopental / pharmacology*
Time Factors
Reg. No./Substance:
0/Anesthetics; 0/Methyl Ethers; 2078-54-8/Propofol; 28523-86-6/sevoflurane; 76-75-5/Thiopental

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Medical and legal considerations of brain death.
Next Document:  Recovery characteristics and post-operative delirium after long-duration laparoscope-assisted surger...