Intra- and inter-individual variation of BIS-index® and Entropy® during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers: An interventional study

Matthias Haenggi, Heidi Ypparila-Wolters, Kathrin Hauser, Claudio Caviezel, Jukka Takala, Ilkka Korhonen, Stephan M. Jakob (Corresponding Author)

Research output: Contribution to journalArticleScientificpeer-review

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Abstract

Introduction: We studied intra-individual and inter-individual variability of two online sedation monitors, BIS® and Entropy®, in volunteers under sedation.

Methods: Ten healthy volunteers were sedated in a stepwise manner with doses of either midazolam and remifentanil or dexmedetomidine and remifentanil. One week later the procedure was repeated with the remaining drug combination. The doses were adjusted to achieve three different sedation levels (Ramsay Scores 2, 3 and 4) and controlled by a computer-driven drug-delivery system to maintain stable plasma concentrations of the drugs. At each level of sedation, BIS® and Entropy® (response entropy and state entropy) values were recorded for 20 minutes. Baseline recordings were obtained before the sedative medications were administered.

Results: Both inter-individual and intra-individual variability increased as the sedation level deepened. Entropy® values showed greater variability than BIS® values, and the variability was greater during dexmedetomidine/remifentanil sedation than during midazolam/remifentanil sedation.

Conclusions: The large intra-individual and inter-individual variability of BIS® and Entropy® values in sedated volunteers makes the determination of sedation levels by processed electroencephalogram (EEG) variables impossible. Reports in the literature which draw conclusions based on processed EEG variables obtained from sedated intensive care unit (ICU) patients may be inaccurate due to this variability.
Original languageEnglish
Article numberR20
JournalCritical Care
Volume13
DOIs
Publication statusPublished - 2009
MoE publication typeA1 Journal article-refereed

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Dexmedetomidine
Midazolam
Entropy
Healthy Volunteers
Electroencephalography
Volunteers
Drug Combinations
Drug Delivery Systems
Hypnotics and Sedatives
Intensive Care Units
remifentanil
Pharmaceutical Preparations

Cite this

Haenggi, Matthias ; Ypparila-Wolters, Heidi ; Hauser, Kathrin ; Caviezel, Claudio ; Takala, Jukka ; Korhonen, Ilkka ; Jakob, Stephan M. / Intra- and inter-individual variation of BIS-index® and Entropy® during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers : An interventional study. In: Critical Care. 2009 ; Vol. 13.
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title = "Intra- and inter-individual variation of BIS-index{\circledR} and Entropy{\circledR} during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers: An interventional study",
abstract = "Introduction: We studied intra-individual and inter-individual variability of two online sedation monitors, BIS{\circledR} and Entropy{\circledR}, in volunteers under sedation.Methods: Ten healthy volunteers were sedated in a stepwise manner with doses of either midazolam and remifentanil or dexmedetomidine and remifentanil. One week later the procedure was repeated with the remaining drug combination. The doses were adjusted to achieve three different sedation levels (Ramsay Scores 2, 3 and 4) and controlled by a computer-driven drug-delivery system to maintain stable plasma concentrations of the drugs. At each level of sedation, BIS{\circledR} and Entropy{\circledR} (response entropy and state entropy) values were recorded for 20 minutes. Baseline recordings were obtained before the sedative medications were administered.Results: Both inter-individual and intra-individual variability increased as the sedation level deepened. Entropy{\circledR} values showed greater variability than BIS{\circledR} values, and the variability was greater during dexmedetomidine/remifentanil sedation than during midazolam/remifentanil sedation.Conclusions: The large intra-individual and inter-individual variability of BIS{\circledR} and Entropy{\circledR} values in sedated volunteers makes the determination of sedation levels by processed electroencephalogram (EEG) variables impossible. Reports in the literature which draw conclusions based on processed EEG variables obtained from sedated intensive care unit (ICU) patients may be inaccurate due to this variability.",
author = "Matthias Haenggi and Heidi Ypparila-Wolters and Kathrin Hauser and Claudio Caviezel and Jukka Takala and Ilkka Korhonen and Jakob, {Stephan M.}",
year = "2009",
doi = "10.1186/cc7723",
language = "English",
volume = "13",
journal = "Critical Care",
issn = "1364-8535",

}

Intra- and inter-individual variation of BIS-index® and Entropy® during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers : An interventional study. / Haenggi, Matthias; Ypparila-Wolters, Heidi; Hauser, Kathrin; Caviezel, Claudio; Takala, Jukka; Korhonen, Ilkka; Jakob, Stephan M. (Corresponding Author).

In: Critical Care, Vol. 13, R20, 2009.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Intra- and inter-individual variation of BIS-index® and Entropy® during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers

T2 - An interventional study

AU - Haenggi, Matthias

AU - Ypparila-Wolters, Heidi

AU - Hauser, Kathrin

AU - Caviezel, Claudio

AU - Takala, Jukka

AU - Korhonen, Ilkka

AU - Jakob, Stephan M.

PY - 2009

Y1 - 2009

N2 - Introduction: We studied intra-individual and inter-individual variability of two online sedation monitors, BIS® and Entropy®, in volunteers under sedation.Methods: Ten healthy volunteers were sedated in a stepwise manner with doses of either midazolam and remifentanil or dexmedetomidine and remifentanil. One week later the procedure was repeated with the remaining drug combination. The doses were adjusted to achieve three different sedation levels (Ramsay Scores 2, 3 and 4) and controlled by a computer-driven drug-delivery system to maintain stable plasma concentrations of the drugs. At each level of sedation, BIS® and Entropy® (response entropy and state entropy) values were recorded for 20 minutes. Baseline recordings were obtained before the sedative medications were administered.Results: Both inter-individual and intra-individual variability increased as the sedation level deepened. Entropy® values showed greater variability than BIS® values, and the variability was greater during dexmedetomidine/remifentanil sedation than during midazolam/remifentanil sedation.Conclusions: The large intra-individual and inter-individual variability of BIS® and Entropy® values in sedated volunteers makes the determination of sedation levels by processed electroencephalogram (EEG) variables impossible. Reports in the literature which draw conclusions based on processed EEG variables obtained from sedated intensive care unit (ICU) patients may be inaccurate due to this variability.

AB - Introduction: We studied intra-individual and inter-individual variability of two online sedation monitors, BIS® and Entropy®, in volunteers under sedation.Methods: Ten healthy volunteers were sedated in a stepwise manner with doses of either midazolam and remifentanil or dexmedetomidine and remifentanil. One week later the procedure was repeated with the remaining drug combination. The doses were adjusted to achieve three different sedation levels (Ramsay Scores 2, 3 and 4) and controlled by a computer-driven drug-delivery system to maintain stable plasma concentrations of the drugs. At each level of sedation, BIS® and Entropy® (response entropy and state entropy) values were recorded for 20 minutes. Baseline recordings were obtained before the sedative medications were administered.Results: Both inter-individual and intra-individual variability increased as the sedation level deepened. Entropy® values showed greater variability than BIS® values, and the variability was greater during dexmedetomidine/remifentanil sedation than during midazolam/remifentanil sedation.Conclusions: The large intra-individual and inter-individual variability of BIS® and Entropy® values in sedated volunteers makes the determination of sedation levels by processed electroencephalogram (EEG) variables impossible. Reports in the literature which draw conclusions based on processed EEG variables obtained from sedated intensive care unit (ICU) patients may be inaccurate due to this variability.

U2 - 10.1186/cc7723

DO - 10.1186/cc7723

M3 - Article

VL - 13

JO - Critical Care

JF - Critical Care

SN - 1364-8535

M1 - R20

ER -