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UNderstanding CONSciousness Connectedness and Intraoperative Unresponsiveness Study (UN-CONSCIOUS)

Primary Purpose

Unconsciousness, Consciousness

Status

Completed

Phase

Phase 4

Locations

United States

Study Type

Interventional

Intervention

Dexmedetomidine

Ketamine

Propofol

Midazolam

About this trial

This is an interventional basic science trial for Unconsciousness focused on measuring Sedation, Propofol, Dexmedetomidine, Ketamine, Sevoflurane, Electroencephalogram

Eligibility Criteria

18 Years - 40 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

Age 18-40
In good health, determined by the PI on the basis of medical history and a standard assessment for anesthesia to be documented as part of the study record
Right handed, to standardize for asymmetry in brain functions

Exclusion Criteria:

Adults <18 years old or >40 years old
Pregnancy confirmed on pregnancy test on day of sedation
Contraindication to anesthesia or allergy to study drug
Difficult anesthesia: American Society of Anesthesiologists Physical Status greater than 1, per the discretion of the PI. Examples of ASA status include, but are not limited to:
- Any systemic disease present, such as diabetes, cardiac, pulmonary, or other acute or chronic disorder, or history of smoking
- Narrow angle glaucoma
- Abnormal airway examination
- Any abnormality on medical history and physical examination
- Snoring or sleep disorders including apnea
- Antecedent pulmonary aspiration risk (e.g., history GI reflux, heartburn, hiatal hernia)
- Adverse reaction or allergy with anesthesia or other sedatives
- Chronic medication use
- History of difficult anesthesia, laryngoscopy or intubation
- Family history of difficulty with anesthesia or sedation
- History of vertigo, nausea or vomiting after anesthesia
BMI > 35
Contraindication to HD-EEG, TMS or MRI for relative parts of the procedures. MRI exclusion criteria: presence of metallic or electronic implants; history of claustrophobia. TMS exclusion criteria: Presence or history of medical conditions that could increase the chance of seizures (e.g. - stroke, aneurysm, brain surgery, structural brain lesion) cranial metal implants; structural brain lesion; devices that may be affected by TMS (pacemaker, medication pump, cochlear implant, implanted brain stimulator); history of head trauma with loss of consciousness for greater than 5 minutes; family history of seizures; history of antecedent mood disorder.
Exclusion from Dexmedetomidine:
o Resting heart Rate<60 bpm
Exclusion from Propofol:
o Reported egg allergy
Exclusion from Ketamine:
- History of post-operative nausea and vomiting
- History of motion sickness

Additional exclusion criteria on the day of sedation:

Anything to eat or drink for the preceding 8 hours
Any use of over-the-counter or recreational drugs (including alcohol or tobacco) within the preceding 24 hours
Any use of sedative or sleep agents within the preceding 24 hours
Recent change in health, including cough, cold, or fever
Exposure to anesthesia or sedation in the last 6 days

Sites / Locations

UW Hospital and Clinics

Arms of the Study

Arm 1

Arm Type

Experimental

Arm Label

Drug Administrated

Arm Description

Sedatives will be administered to participants while their brain activity is measured.

Outcomes

Primary Outcome Measures

Occipital Delta Power Spectral Density by Conscious State and Study Group.

The difference in spontaneous EEG slow wave activity over posterior cortex between states of consciousness measured with high-density EEG equipment and reported in spectral power in the delta band (1-4 Hz) at electrode Oz. Disconnected conscious experience (dreaming), connected conscious experience (awareness of the external world), and unconsciousness (no report) was assessed when participants were roused from sedation or sleep.

Secondary Outcome Measures

Number of Instances of Disconnected Conscious Experience (Dreaming) vs Connected Conscious Experience (Awareness of External World).

The number of instances 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.

Effect of Study Drug on Ability to Correctly Identify Shapes/Images

The ability to identify shapes/images in visual illusions measured by the NIH Toolbox. Will be reported by a computed score from NIH Toolbox for the Dimensional Change Card Sort Test (DCCS) and the Flanker Inhibitory Control & Attention Test (Flanker). Both Flanker and DCCS use a 2-vector scoring method that takes accuracy and reaction time (if accuracy >=80%) into account, resulting in a computed score that can range in value from 0-10. A higher score indicates better performance on the test.

Effect of Study Drug on Ability to Correctly Identify Images

The ability to match sounds and images measured by the predictive coding task. Will be reported by a proportion correct as a decimal.

Effect of Study Drug on Ability to Form Implicit Memory

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 average number of correct responses out of sixteen.

Full Information

NCT ID

NCT03284307

First Posted

August 22, 2017

Last Updated

April 10, 2023

Sponsor

University of Wisconsin, Madison

1. Study Identification

Unique Protocol Identification Number

NCT03284307

Brief Title

UNderstanding CONSciousness Connectedness and Intraoperative Unresponsiveness Study

Acronym

UN-CONSCIOUS

Official Title

UNderstanding CONSciousness Connectedness and Intraoperative Unresponsiveness Study

Study Type

Interventional

2. Study Status

Record Verification Date

April 2023

Overall Recruitment Status

Completed

Study Start Date

August 10, 2017 (Actual)

Primary Completion Date

March 12, 2020 (Actual)

Study Completion Date

March 12, 2020 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title

Sponsor

Name of the Sponsor

University of Wisconsin, Madison

4. Oversight

Studies a U.S. FDA-regulated Drug Product

Yes

Studies a U.S. FDA-regulated Device Product

Product Manufactured in and Exported from the U.S.

Yes

Data Monitoring Committee

Yes

5. Study Description

Brief Summary

This study will be a single-site, controlled, unblinded study at the University of Wisconsin to examine changes in the electroencephalogram during anesthesia and waking.

Detailed Description

* 20 subjects will be recruited per drug, and subjects can be recruited to undergo multiple sedation protocols. Screening: 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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study

Unconsciousness, Consciousness

Keywords

Sedation, Propofol, Dexmedetomidine, Ketamine, Sevoflurane, Electroencephalogram

7. Study Design

Primary Purpose

Basic Science

Study Phase

Phase 4

Interventional Study Model

Single Group Assignment

Masking

None (Open Label)

Allocation

N/A

Enrollment

35 (Actual)

8. Arms, Groups, and Interventions

Arm Title

Drug Administrated

Arm Type

Experimental

Arm Description

Sedatives will be administered to participants while their brain activity is measured.

Intervention Type

Drug

Intervention Name(s)

Dexmedetomidine

Intervention Description

20 participants will be administered Dexmedetomidine.

Intervention Type

Drug

Intervention Name(s)

Ketamine

Intervention Description

20 participants will be administered Ketamine.

Intervention Type

Drug

Intervention Name(s)

Propofol

Intervention Description

20 participants will be administered Propofol.

Intervention Type

Drug

Intervention Name(s)

Midazolam

Intervention Description

20 participants will be administered Midazolam.

Primary Outcome Measure Information:

Title

Occipital Delta Power Spectral Density by Conscious State and Study Group.

Description

Time Frame