REcovery From DEXmedetomidine-induced Unconsciousness (REDEX)

This pilot study in healthy volunteers aims to determine if biological sex has an impact on recovery from dexmedetomidine-induced unconsciousness, and if transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) can be used to measure brain complexity during dexmedetomidine sedation without arousing study participants.

Study Overview

• Status: Recruiting
• Conditions: Healthy; Anesthesia; Consciousness, Level Altered
• Intervention / Treatment: Device: Transcranial Magnetic Stimulation-Electroencephalography

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: David Schreier, MD, PhD; Email: dschreier@mgh.harvard.edu
• Study Contact Backup: Name: Emery N Brown, MD, PhD; Phone Number: +1 617-324-1879; Email: ebrown@mgh.harvard.edu

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Recruiting
      • Massachusetts General Hospital
      • Contact: David Schreier, MD, PhD; Email: dschreier@mgh.harvard.edu
      • Contact: Emery N Brown, MD, PhD; Phone Number: 617-324-1879; Email: ebrown@mgh.harvard.edu
      • Principal Investigator: Emery N Brown, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Between the ages of 18 to 65
• Normal body weight and habitus, body mass index (BMI) 18 to 30 kg/m2
• Non-smoker
• No history of taking stimulants or substance abuse
• For women: either use of hormonal contraception, or > 45 years old and last menstrual period > 12 months ago in the absence of any contraceptives.
• American Society of Anesthesiologists (ASA) physical status classification 1 (ASA 1)
• Fluent in English (sufficient to communicate with the study team and understand the consent form)

Exclusion Criteria:

• Neurologic: epilepsy or positive history of a seizure, stroke, central disorders of hypersomnolence, neuroimmunological disorder (e.g. multiple sclerosis), Meniere's disease, Parkinson's disease, peripheral neuropathy, no significant visual or hearing impairments, findings in the clinical examination suggesting a neurologic disorder
• Psychiatric: history or treatment for an active psychiatric problem (including Attention-Deficit / Hyperactivity Disorder (ADHD) and anxiety disorder)
• Cardiovascular: hypertension, symptomatic hypotension or bradycardia, myocardial infarction, coronary artery disease, peripheral vascular disease, dysrhythmias, congestive heart failure, cardiomyopathy, valvular disease, familial history of sudden cardiac death
• Respiratory: bronchitis, asthma, chronic obstructive pulmonary disease, smoking, shortness of breath, sleep apnea
• Gastrointestinal: esophageal reflux, hiatal hernia, ulcer
• Hepatic: hepatitis, jaundice, ascites
• Renal: acute or chronic severe renal insufficiency
• Reproductive: pregnancy, breast-feeding
• Endocrine: diabetes, thyroid disease, adrenal gland disease
• Hematologic: blood dyscrasias, anemia, coagulopathies
• Musculoskeletal: prior surgery or trauma to head neck or face, arthritis, personal or family history of malignant hyperthermia
• Medications: regular use of prescription and non-prescription medications expected to affect central nervous function, anticoagulant or thrombocyte-aggregation inhibiting therapy; exception: oral hormonal contraception
• Allergies: dexmedetomidine, phenylephrine, betablockers (including labetalol and esmolol), hydralazine, glycopyrrolate

Potential participants will not be enrolled in our study if they fail to pass a standard drug screening test (toxicology).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: TMS-EEG Arm; This arm will undergo TMS-EEG during the study.	Device: Transcranial Magnetic Stimulation-Electroencephalography; Transcranial magnetic stimulation of the cerebral cortex and measurement of TMS-evoked potentials in the EEG.; Other Names: TMS-EEG
No Intervention: Non-TMS-EEG Arm; This arm will not undergo TMS-EEG during the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to return of responsiveness	The time to return of responsiveness will be measured in minutes and from the moment of dexmedetomidine discontinuation to the return of clicking a button in response to auditory stimulation.	Up to 120 minutes

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Investigators: Principal Investigator: Emery N Brown, MD, PhD, Massachusetts General Hospital

Publications and helpful links

General Publications

• Vincent KF, Mallari OG, Dillon EJ, Stewart VG, Cho AJ, Dong Y, Edlow AG, Ichinose F, Xie Z, Solt K. Oestrous cycle affects emergence from anaesthesia with dexmedetomidine, but not propofol, isoflurane, or sevoflurane, in female rats. Br J Anaesth. 2023 Jul;131(1):67-78. doi: 10.1016/j.bja.2023.03.025. Epub 2023 May 2.
• Kato R, Zhang ER, Mallari OG, Moody OA, Vincent KF, Melonakos ED, Siegmann MJ, Nehs CJ, Houle TT, Akeju O, Solt K. D-Amphetamine Rapidly Reverses Dexmedetomidine-Induced Unconsciousness in Rats. Front Pharmacol. 2021 May 18;12:668285. doi: 10.3389/fphar.2021.668285. eCollection 2021.

Study record dates

Study Major Dates

• Study Start (Actual): November 15, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: August 10, 2023
• First Submitted That Met QC Criteria: August 18, 2023
• First Posted (Actual): August 21, 2023

Study Record Updates

• Last Update Posted (Actual): January 22, 2026
• Last Update Submitted That Met QC Criteria: January 20, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Cognition; Transcranial magnetic stimulation; EEG; Dexmedetomidine
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Neurobehavioral Manifestations; Neurocognitive Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Consciousness Disorders
• Other Study ID Numbers: 2023P001821

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No