Changes in information integration and brain networks during propofol-, dexmedetomidine-, and ketamine-induced unresponsiveness.
Zhenhu Liang, Yu Chang, Xiaoge Liu, Shumei Cao, Yali Chen, Tingting Wang, Jianghui Xu, Duan Li, Jun Zhang
British Journal of Anaesthesia March 1, 2024 DOI: 10.1016/j.bja.2023.11.033 (opens in new tab)
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Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 72 |
| Population | Participants receiving propofol, dexmedetomidine, or ketamine |
| Interventions | Propofol Dexmedetomidine Ketamine |
| Duration | Consciousness transition from eye-closed baseline to unresponsiveness state and then to recovery of responsiveness state |
| Topics | Ketamine Esketamine |
| Keywords | Brain network Dexmedetomidine Electroencephalography Propofol |
| Citations | 10 |
| Post-publication review | 1 comment on PubPeer (opens in new tab) · last active May 2026 |
| Key findings | Permutation cross mutual information and brain network measures showed state-related decreases in information integration and network efficiency during anaesthesia-induced unresponsiveness across three different drugs. |
Abstract
Information integration and network science are important theories for quantifying consciousness. However, whether these theories propose drug- or conscious state-related changes in EEG during anaesthesia-induced unresponsiveness remains unknown. A total of 72 participants were randomised to receive i.v. infusion of propofol, dexmedetomidine, or ketamine at a constant infusion rate until loss of responsiveness. High-density EEG was recorded during the consciousness transition from the eye-closed baseline to the unresponsiveness state and then to the recovery of the responsiveness state. Permutation cross mutual information (PCMI) and PCMI-based brain networks in broadband (0.1-45 Hz) and sub-band frequencies were used to analyse drug- and state-related EEG signature changes. PCMI and brain networks exhibited state-related changes in certain brain regions and frequency bands. The within-area PCMI of the frontal, parietal, and occipital regions, and the between-area PCMI of the parietal-occipital region (median [inter-quartile ranges]), baseline vs unresponsive were as follows: 0.54 (0.46-0.58) vs 0.46 (0.40-0.50), 0.58 (0.52-0.60) vs 0.48 (0.44-0.53), 0.54 (0.49-0.59) vs 0.47 (0.42-0.52) decreased during anaesthesia for three drugs (P<0.05). Alpha PCMI in the frontal region, and gamma PCMI in the posterior area significantly decreased in the unresponsive state (P<0.05). The frontal, parietal, and occipital nodal clustering coefficients and parietal nodal efficiency decreased in the unresponsive state (P<0.05). The increased normalised path length in delta, theta, and gamma bands indicated impaired global integration (P<0.05). The three anaesthetics caused changes in information integration patterns and network functions. Thus, it is possible to build a quantifying framework for anaesthesia-induced conscious state changes on the EEG scale using PCMI and network science.
Comparable studies
Other randomized controlled trials on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Subanesthetic Effects of the Noncompetitive NMDA Antagonist, Ketamine, in Humans Healthy human subjects recruited from the community | 1994 | Randomized controlled trial | n = 19 |
| Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial Patients with treatment-resistant major depression experiencing a major depressive episode | 2013 | Randomized controlled trial | n = 73 |
| Remifentanil-induced Postoperative Hyperalgesia and Its Prevention with Small-dose Ketamine Patients undergoing major abdominal surgery | 2005 | Randomized controlled trial | n = 75 |
| Efficacy of Intravenous Ketamine for Treatment of Chronic Posttraumatic Stress Disorder Patients with chronic PTSD related to a range of trauma exposures | 2014 | Randomized controlled trial | n = 41 |
| Ketamine-Induced Deficits in Auditory and Visual Context-Dependent Processing in Healthy Volunteers Healthy volunteers | 2000 | Single-blind placebo-controlled study | n = 20 |
Citations in the library
Cited by 3
- A methodological guideline for consciousness assessment via neural electrophysiological activity. Military Medical Research December 12, 2025
- A practical measure of integrated information reveals alpha-band activity and the posterior cortex as neural correlates of arousal. Neuroimage July 18, 2025
- Neurophysiological connectomic signatures of consciousness during propofol-induced general anesthesia. Cell Reports Medicine February 17, 2026
Cites 11
- Neural correlates of consciousness: progress and problems Nature Reviews Neuroscience April 20, 2016
- Theories of consciousness. Nature Reviews Neuroscience July 1, 2022
- Unresponsiveness ≠ Unconsciousness Anesthesiology February 7, 2012
- Reconfiguration of Network Hub Structure after Propofol-induced Unconsciousness Anesthesiology September 7, 2013
- Quantifying arousal and awareness in altered states of consciousness using interpretable deep learning Nature Communications February 25, 2022
and 6 more in the library