REcovery from DEXmedetomidine-Induced Unresponsiveness (REDEX): A Study Protocol for a Single Center, Parallel Arm,...

Area of Science:

• Neuroscience
• Anesthesiology
• Cognitive Science

Background:

• Dexmedetomidine (DEX) is a sedative inducing a sleep-like state, offering a model for studying consciousness transitions.
• The impact of repeated DEX exposure on recovery dynamics remains poorly understood.
• Understanding these effects is crucial for optimizing sedation protocols and neurological research.

Purpose of the Study:

• To investigate the effects of repeated dexmedetomidine (DEX) exposure on recovery from sedation.
• To explore transitions between states of consciousness using behavioral, EEG, and TMS-EEG measures.
• To assess the influence of biological sex and study arm on recovery and consciousness measures.

Main Methods:

• 12 healthy volunteers (6 female, 6 male) participated in a parallel-arm pilot study.
• Participants received DEX sedation twice, one week apart, with responsiveness monitored via a click-task.
• Electroencephalogram (EEG), physiological signals, cognition, vigilance, sleep quality, and TMS-evoked EEG responses were recorded.

Main Results:

• The study will report differences in time to return of responsiveness (ROR) between the first and second sedation.
• It will evaluate state transitions by comparing responsiveness, EEG signatures, and TMS-evoked EEG responses (Perturbational Complexity Index).
• Cognition, vigilance, sleep quality, and sleepiness will be assessed at various time points.

Conclusions:

• This pilot trial will provide insights into the effects of repeated DEX sedation on recovery.
• The findings will advance the understanding of altered states of consciousness and inform future DEX sedation study designs.
• The study will also report on the feasibility of TMS-EEG under DEX and the potential role of biological sex.