UNderstanding CONSciousness Connectedness and Intraoperative Unresponsiveness Study
Condition: Unconsciousness; Consciousness
MeSH terms: Unconsciousness
Intervention: Dexmedetomidine; Ketamine; Propofol; Midazolam
Intervention description: 20 participants will be administered Dexmedetomidine.; 20 participants will be administered Ketamine.; 20 participants will be administered Propofol.; 20 participants will be administered Midazolam.
Intervention MeSH terms: Midazolam; Dexmedetomidine; Ketamine; Propofol
Phase: Phase 4
Study type: Interventional
Primary purpose: Basic Science
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 35.0
Sex: All
Minimum age: 18 Years
Maximum age: 40 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Sedation; Propofol; Dexmedetomidine; Ketamine; Sevoflurane; Electroencephalogram

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.
    

Eligibility criteria:

        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