Intensive Care Medicine

, 35:2096 | Cite as

Frequency and clinical impact of preserved bispectral index activity during deep sedation in mechanically ventilated ICU patients

  • Pierre Trouiller
  • Pascal Fangio
  • Catherine Paugam-Burtz
  • Corinne Appéré-de-Vecchi
  • Paul Merckx
  • Nicolas Louvet
  • Sebastian Pease
  • Hervé Outin
  • Jean Mantz
  • Bernard De JongheEmail author



Despite an overall correlation between the bispectral index of the EEG (BIS) and clinical sedation assessment, unexpectedly high BIS values can be observed at deep sedation levels. We assessed the frequency, interindividual variability and clinical impact of high BIS values during clinically deep sedation.

Design and setting

Prospective observational study in two university-affiliated intensive care units.


Sixty-two mechanically ventilated patients requiring intravenous sedation and analgesia for ≥24 h.

Measurements and main results

Paired measurements of BIS and sedation measured on the adaptation to intensive care environment (ATICE) score were obtained every 3 h until awakening. A paired measurement with BIS >60 at deep sedation (ATICE Awakeness ≤2) was defined as discordant. Patients were considered discordant if their individual ratio of number of discordant measurements to number of total measurements during deep sedation was above the median discordance ratio of the overall cohort. At least one discordant assessment was observed in 52 patients (83.9%). Median individual discordance ratio was 32% (14.3–50.0%). Time from awakening to first T-piece trial [16 h (4–34) vs. 46 h (9–109), p = 0.01] and to extubation [35 h (23–89) vs. 88 h (46–152 h), p = 0.05] were significantly shorter in discordant compared to concordant patients. BIS-ATICE discordance was independently associated with successful extubation within 48 h after awakening (OR 6.7, CI 95% 1.8–25.0, p = 0.005). The rate of ICU recall was not different in BIS-ATICE discordant and concordant patients.


In mechanically ventilated ICU patients, discordance between high BIS values and deep clinical sedation is frequently observed and may suggest faster weaning from the ventilator.


Bispectral index Sedation Mechanical ventilation Weaning Post-ICU recall 



Only institutional funding supported this study.

Supplementary material

134_2009_1636_MOESM1_ESM.doc (91 kb)
Supplementary material 1 (DOC 91 kb)


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Copyright information

© Copyright jointly hold by Springer and ESICM 2009

Authors and Affiliations

  • Pierre Trouiller
    • 1
  • Pascal Fangio
    • 2
  • Catherine Paugam-Burtz
    • 1
  • Corinne Appéré-de-Vecchi
    • 2
  • Paul Merckx
    • 1
  • Nicolas Louvet
    • 1
  • Sebastian Pease
    • 1
  • Hervé Outin
    • 2
  • Jean Mantz
    • 1
  • Bernard De Jonghe
    • 2
    Email author
  1. 1.Department of Anaesthesiology and Critical CareBeaujon University HospitalClichyFrance
  2. 2.Critical Care UnitPoissy HospitalPoissyFrance

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