Document Detail


Entropy of EEG during anaesthetic induction: a comparative study with propofol or nitrous oxide as sole agent.
MedLine Citation:
PMID:  14722164     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: The search continues for an anaesthetic monitor that can define the level of anaesthesia in an individual patient irrespective of anaesthetic agent(s) used. Studies of available monitors based on bispectral analysis or evoked auditory potentials show the complexity of the problem. We assessed a new monitor, based on the entropy of the EEG, during induction of anaesthesia with either propofol or nitrous oxide. METHODS: In an open, randomized study (two groups; n=10) of day surgical patients, we induced loss of response with incremental boluses of propofol. The other group was given propofol 30 mg and then increasing concentrations of nitrous oxide until loss of response. We measured entropy with the M-Entropy Module S/5 (Datex-Ohmeda) using forehead electrodes and recorded response entropy (RE; including frontal electromyogram) and state entropy (SE; only the cortical EEG). Values are median (range). RESULTS: Baseline values were RE 98 (96-100), SE 89 (87-91) and RE 98 (96-99), SE 89 (87-91) for the propofol and nitrous oxide patients, respectively. During propofol induction, both entropy indices decreased with increasing sedation, with RE 40 (23-76) and SE 34 (17-70) at loss of response. Neither RE nor SE decreased during nitrous oxide inhalation, and at loss of response using nitrous oxide, RE and SE were unchanged at 98 (96-100) and 88 (85-91) respectively. CONCLUSIONS: The entropy monitor of anaesthetic depth shows a successive decrease with propofol but loss of consciousness with nitrous oxide is not associated with change in entropy indices.
Authors:
R E Anderson; J G Jakobsson
Related Documents :
1898684 - Prolongation of the qt interval by enflurane, isoflurane, and halothane in humans.
2241014 - Management of tracheobronchial foreign bodies in children: an update.
24560714 - Acute exercise prevents the development of neuropathic pain and the sprouting of non-pe...
15155344 - A comparison of frontal and occipital bispectral index values obtained during neurosurg...
12580674 - Physiological profiles and performance predictors of a women's ncaa rowing team.
15470314 - Physiologic profile of recreational male and female novice and experienced tae kwon do ...
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  British journal of anaesthesia     Volume:  92     ISSN:  0007-0912     ISO Abbreviation:  Br J Anaesth     Publication Date:  2004 Feb 
Date Detail:
Created Date:  2004-01-14     Completed Date:  2004-02-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372541     Medline TA:  Br J Anaesth     Country:  England    
Other Details:
Languages:  eng     Pagination:  167-70     Citation Subset:  IM    
Affiliation:
Department of Cardiothoracic Anaesthetics and Intensive Care, Karolinska Hospital, Stockholm, Sweden.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Aged
Anesthesia*
Anesthetics, Inhalation / pharmacology*
Anesthetics, Intravenous / pharmacology
Dose-Response Relationship, Drug
Electroencephalography / drug effects*
Entropy*
Female
Humans
Male
Middle Aged
Monitoring, Intraoperative / methods*
Nitrous Oxide / pharmacology*
Propofol / pharmacology
Prospective Studies
Chemical
Reg. No./Substance:
0/Anesthetics, Inhalation; 0/Anesthetics, Intravenous; 10024-97-2/Nitrous Oxide; 2078-54-8/Propofol
Comments/Corrections
Comment In:
Br J Anaesth. 2004 Feb;92(2):159-61   [PMID:  14722161 ]

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


Previous Document:  Progress in defining the molecular basis of type 2 diabetes mellitus through susceptibility-gene ide...
Next Document:  Unconscious learning during surgery with propofol anaesthesia.