UNderstanding CONSciousness Connectedness and Intraoperative Unresponsiveness Study (UN-CONSCIOUS)
|The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.|
|ClinicalTrials.gov Identifier: NCT03284307|
Recruitment Status : Completed
First Posted : September 15, 2017
Last Update Posted : August 16, 2022
|Condition or disease||Intervention/treatment||Phase|
|Unconsciousness Consciousness||Drug: Dexmedetomidine Drug: Ketamine Drug: Propofol Drug: Midazolam||Phase 4|
* 20 subjects will be recruited per drug, and subjects can be recruited to undergo multiple sedation protocols.
Subjects will respond to the volunteer posts for the study by calling into a study specific phone number. They will complete a phone screening to determine basic eligibility for the study. At the beginning of the sedation session, participants will affirm that in the interval since their baseline visit, they have not acquired any of the cited exclusion criteria that would preclude participation. A review of these exclusion criteria will be completed by the Anesthesiologist. A standard pre-anesthetic assessment will be performed, including confirmation of NPO status, and documented using the standard Department of Anesthesiology pre-operative evaluation form.
The first sedative will be dexmedetomidine followed by ketamine, propofol and then midazolam (dependent on the availability of the drugs). Total enrollment in the study will be up to 80 subjects. Each sedation experiment will occur on separate days at least 28 days apart, if the subject chooses to participate in more than one session.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||30 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Official Title:||UNderstanding CONSciousness Connectedness and Intraoperative Unresponsiveness Study|
|Actual Study Start Date :||August 10, 2017|
|Actual Primary Completion Date :||March 12, 2020|
|Actual Study Completion Date :||March 12, 2020|
Experimental: Drug Administrated
Sedatives will be administered to participants while their brain activity is measured.
20 participants will be administered Dexmedetomidine.
20 participants will be administered Ketamine.
20 participants will be administered Propofol.
20 participants will be administered Midazolam.
- Spontaneous EEG slow wave activity [ Time Frame: Intraoperative (During sedation-- up to 8 hours) ]The difference in spontaneous EEG slow wave activity over posterior cortex between consciousness and unconsciousness is measured with high-density EEG equipment and reported in spectral power in the delta band at electrode Oz.
- Incidence of disconnected conscious experience (dreaming) vs connected conscious experience (awareness of external world). [ Time Frame: Intraoperative (During sedation-- up to 8 hours) ]The incidence of disconnected conscious experience (dreaming) versus connected conscious experience (awareness of the external world) during sedation is measured by subject self-report at the time of researcher initiated inquiry.
- Difference in high-density EEG responses assessed by calculation of the phase locking factor following auditory stimulation [ Time Frame: Intraoperative (During sedation-- up to 8 hours) ]Difference in high-density EEG responses assessed by calculation of the phase locking factor following auditory stimulation between conscious experience under sedation and lack of conscious experience. Phase locking factor is calculated by taking the Hilbert transform of the evoked response and quantifying the alignment of phases based on the imaginary component of the signal. Phase locking factor is quantified on a scale of 0 to 1, with 0 being no phase locking and 1 being maximal phase locking.
- Effect of study drug on percent difference in duration of phase locking factor [ Time Frame: Intraoperative (During sedation-- up to 8 hours) ]Phase locking factor will be calculated (as described previously) and compared between data collected at baseline and data collected after varying doses of drug have been administered. Effect size will be reported as a percentage of the reference group.
- Effect of consciousness on phase locking factor after auditory stimulation [ Time Frame: Intraoperative (During sedation-- up to 8 hours) ]Phase locking factor will be calculated (as described previously) and compared between data collected during different states of consciousness (as assessed by subject report). Effect size will be reported as a percentage of the reference group.
- Effect of study drug on ability to correctly identify shapes/images [ Time Frame: Intraoperative (During sedation-- up to 8 hours) ]The ability to identify shapes/images in visual illusions measured by the NIH Toolbox and match sounds and images measured by the predictive coding task. Will be reported by a percent correct from the predictive coding task and total score from NIH Toolbox.
- Effect of study drug on ability to form implicit memory [ Time Frame: Intraoperative (During sedation-- up to 8 hours) ]Subjects will have a list of words read to them while under sedation and their ability to hear these words and form implicit memories of them will be assessed using a two-alternative forced choice task. Results will be reported as the number correct responses out of sixteen.
- Incidence of EEG wave patterns during sedation vs natural sleep [ Time Frame: Intraoperative (During sedation and sleep visit-- up to 18 hours cumulative) ]Low frequency (<4 Hz) spectral power will be measured using high-density EEG acquired during natural sleep as well as during sedation. The magnitude of this spectral power will be compared across conditions and reported as a percentage relative to natural sleep.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03284307
|United States, Wisconsin|
|UW Hospital and Clinics|
|Madison, Wisconsin, United States, 53792|
|Principal Investigator:||Robert A Pearce, MD, PhD||Professor and chair of Anesthesiology at UW- Madison|