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Comparison of the Bispectral Index and the Entropy of the Electroencephalogram During Total Intravenous Anesthesia

This study has been completed.
Information provided by:
Hopital Foch Identifier:
First received: October 24, 2006
Last updated: January 14, 2009
Last verified: January 2009
To compare Bispectral index and entropy during maintenance of anesthesia

Condition Intervention
Anesthesia, General
Device: Bispectral index, Entropy

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Comparison of the Bispectral Index and the Entropy of the Electroencephalogram During Total Intravenous Anesthesia

Resource links provided by NLM:

Further study details as provided by Hopital Foch:

Estimated Enrollment: 84
Study Start Date: June 2006
Study Completion Date: April 2007
Detailed Description:

Several monitors are currently proposed to evaluate the depth of hypnosis. Among them, Bispectral Index (BIS) is a well known and widely used parameter derived from the patient's electroencephalograph (EEG). Spectral entropy relies on the extent of disorder in both EEG and electromyography (EMG) signals and returns 2 values: State Entropy (SE) and Response Entropy. SE is computed over the frequency range of 0.8-32 Hz and reflects the level of hypnosis while Response Entropy is computed over the frequency range of 0.8-47 Hz and reflects also EMG activity. BIS and SE are dimensionless numbers scaled from 100 to 0 for BIS and from 91 to 0 for SE.

The BIS and Entropy manufacturers claim that adequate level of anesthesia is defined by a BIS or SE value between 40 and 60. But some observations have shown that the monitors provided different information. These observations led us to carry out this prospective observational study designed to study the comparability between BIS and SE during the maintenance period of propofol-sufentanil anesthesia.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • age > 18 years,
  • American Society of Anesthesiologists physical status 1-3,
  • surgery under general anesthesia using propofol, sufentanil, and a relaxant agent,
  • surgery lasting more than one hour,
  • tracheal extubation planned at end of surgery

Exclusion Criteria:

  • pregnant women,
  • allergy to propofol,
  • neurological or muscular disorder,
  • treatment with opioids or any psychoactive medication,
  • cardiac surgery,
  • thyroid disorder,
  • emergency surgery,
  • prone or lateral decubitus position (difficulty to have a correct probe position)
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Please refer to this study by its identifier: NCT00391963

Dept of Anesthesia and Intensive Care, Hôpital Beaujon
Clichy, France, 92110
Dept of Anesthesiology, Hôpital Foch
Suresnes, France, 92150
Sponsors and Collaborators
Hopital Foch
Principal Investigator: Marc Fischler, MD Hôpital Foch