The relationship of bispectral index values to conscious state: an analysis of two volunteer cohort studies.

Autor:	Wehrman JJ; Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia; Department of Anaesthetics, Royal Prince Alfred Hospital, Sydney Local Health District, Sydney, NSW, Australia. Electronic address: Jordan.Wehrman@sydney.edu.au., Schuller PJ; Cairns Hospital, Cairns, QLD, Australia; Department of Anaesthesia, James Cook University, Townsville, QLD, Australia., Casey CP; Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA., Scheinin A; Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland; Department of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, Turku, Finland., Kallionpää RE; Department of Psychology and Speech-Language Pathology, and Turku Brain and Mind Center, University of Turku, Turun yliopisto, Finland., Valli K; Department of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, Turku, Finland; Department of Psychology and Speech-Language Pathology, and Turku Brain and Mind Center, University of Turku, Turun yliopisto, Finland; Department of Cognitive Neuroscience and Philosophy, School of Bioscience, University of Skövde, Skövde, Sweden., Revonsuo A; Department of Psychology and Speech-Language Pathology, and Turku Brain and Mind Center, University of Turku, Turun yliopisto, Finland; Department of Cognitive Neuroscience and Philosophy, School of Bioscience, University of Skövde, Skövde, Sweden., Kantonen O; Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland; Department of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, Turku, Finland., Tanabe S; Department of Neuroscience, Canadian Centre for Behavioural Research, University of Lethbridge, Lethbridge, AB, Canada., Filbey W; Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA., Pearce RA; Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA., Sleigh JW; Department of Anaesthesia, Waikato Hospital, Hamilton, New Zealand; Department of Anaesthesiology, Waikato Clinical School, Waikato Clinical Campus, University of Auckland, New Zealand., Scheinin H; Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland; Department of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, Turku, Finland., Sanders RD; Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia; Department of Anaesthetics, Royal Prince Alfred Hospital, Sydney Local Health District, Sydney, NSW, Australia; Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney Local Health District, Sydney, NSW, Australia; NHMRC Clinical Trials Centre, The University of Sydney, Sydney, NSW, Australia.
Jazyk:	angličtina
Zdroj:	British journal of anaesthesia [Br J Anaesth] 2024 Dec 10. Date of Electronic Publication: 2024 Dec 10.
DOI:	10.1016/j.bja.2024.09.032
Abstrakt:	Background: The ability of current depth-of-anaesthesia monitors to differentiate subtle changes in the conscious state has not been well characterised. We examine the variability in bispectral index (BIS) scores associated with disconnected conscious and unconscious states as confirmed by a novel serial awakening paradigm. Methods: Seventy adult participants, given propofol or dexmedetomidine, had a cumulative 1381 electroencephalographic (EEG) recordings across two centres. Participants were awakened periodically, and their recent conscious experience interrogated by structured questioning. BIS were reconstructed from EEG using openibis, and the distribution of BIS scores were compared using linear mixed effects modelling. The predictive capacity of BIS across states of consciousness was also examined. Results: Reconstructed BIS scores correlated significantly with blood concentrations of propofol and dexmedetomidine (all P<0.001). However, while the average BIS was different between baseline wakefulness (mean BIS=95.1 [standard deviation=3.5]); connected consciousness with drug present (84.0 [10.9]); disconnected consciousness (70.0 [16.9]); and unconsciousness (68.1 [16.1]), the interquartile range of these states (3.6, 15.1, 23.3 and 26.8, respectively) indicated high degrees of overlap and individual variability. Connected consciousness could be differentiated from either disconnected consciousness or unconsciousness with 86% accuracy (i.e. 14% error rate), and disconnected consciousness differentiated from unconsciousness with 74% accuracy. Conclusions: These results agree with previous studies that BIS scores fail to reliably differentiate between states of consciousness, exacerbated by segregating connected, disconnected, and unconscious states. To develop a method that reliably identifies the conscious state of an individual (not an average), work is needed to establish the causal mechanisms of disconnection and unconsciousness. Competing Interests: Declaration of interest The authors declare that they have no conflicts of interest. (Copyright © 2024 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)
Databáze:	MEDLINE
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