Investigating Near-Threshold Perception During Anesthetic Sedation

NCT06403852 | Completed Phase 2 FDA Drug

• 2 other identifiers: HUM00251768R01GM103894
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

The researchers expect to gain a deeper understanding of mental function during different levels of anesthesia, and to evaluate if the use of ultrasonic brain stimulation accelerates return to consciousness. Propofol is FDA approved for use in patients undergoing an anesthetic for medical treatment but is not approved for use in healthy volunteers.

Conditions

Propofol; Anesthesia; fMRI

Keywords

Hypnotics and Sedatives; Central Nervous System Depressants; Physiological Effects of Drugs; Anesthetics, Intravenous; Anesthetics, General; Anesthetics; Propofol

Outcome Measures

Primary Outcomes (1)

• Blood Oxygen Level Dependent (BOLD) response to visual stimuli

  Visual stimuli evoked activity was quantified by measurements of the fMRI BOLD signal. Neural response to a natural visual stimulus will be assessed during both conscious and anesthetized states.

  Up to 90 minutes

Secondary Outcomes (2)

• Perceptual criterion (c) derived from the Signal Detection Theory (SDT)

  Up to 90 minutes

• Sensitivity (d') criterion derived from the Signal Detection Theory (SDT)

  Up to 90 minutes

Study Arms (1)

Image recognition task

EXPERIMENTAL

The stimulus set will include real and scrambled images, where the scrambled images will be created by phase-shuffling a randomly chosen real image from each category to preserve category specific low-level image features. Each object category will include four unique real images and one scrambled image. Each image will be repeated 10 times (i.e., trials) for each 16-min session. The pre-stimulus interval will vary randomly from trial to trial between 4 and 8 seconds to prevent stimulus timing predictability. The stimuli will be presented in a randomized order to prevent category predictability.

Combination Product: Functional Magnetic Resonance Imaging (fMRI) with propofol

Interventions

Functional Magnetic Resonance Imaging (fMRI) with propofol COMBINATION_PRODUCT

Three 16-min sessions in wakeful baseline, light sedation, and recovery will be conducted (Fig. 2). Light sedation will be achieved by IV infusion of propofol to achieve effect-site concentrations of 1.0 μg/ml. Infusion rate will be manually controlled. An initial bolus dose (525 µg/kg) and subsequent infusion rate (82 µg/kg/min) for each participant

Image recognition task

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy study subjects with American Society of Anesthesiologists (ASA)-1 status.
• Right-handed
• Body mass index (BMI) less than 30.
• All subjects will be English speakers.

You may not qualify if:

• Medical contraindication to magnetic resonance imaging (MRI) scanning; are unable to undergo MRI scanning because of possible pregnancy or currently breastfeeding, BMI\>30, metallic substances in the body, claustrophobia, anxiety, or cardiopulmonary disease; or have an intracranial structural abnormality on T1-weighted MRI scans.
• History of allergy to propofol, eggs or egg products, soybean or soybean products, neurological, cardiovascular, or pulmonary illness; significant head injury with loss of consciousness; learning disability or other developmental disorder; sleep apnea or any severe snoring history; gastroesophageal reflux disease (GERD) or heartburn; pancreatitis or a history of pancreatitis, or sensory/motor loss sufficient to interfere with performance of the study.
• Tattoos in the head or neck region will be excluded from study; other tattoos are subject to determination by investigators based on their assessment regarding participant safety. To eliminate aspiration risk subjects will also be excluded if they have had recent food or liquid intake (within 8 hours).
• History of drug use, have a positive drug screen, are unwilling to abstain from alcohol for 24 hours prior to dosing, or have a current history of nicotine use.
• Pregnancy

Sponsors & Collaborators

• University of Michigan: lead
• National Institute of General Medical Sciences (NIGMS): collaborator

Study Sites (1)

University of Michigan

Ann Arbor, Michigan, 48109, United States

Location

Study Officials

• Zirui Huang

  University of Michigan

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Assistant Professor, Anesthesiology and Research Fellow

Study Record Dates

• First Submitted: May 3, 2024
• First Posted: May 8, 2024
• Study Start: May 10, 2024
• Primary Completion: October 3, 2025
• Study Completion: October 3, 2025
• Last Updated: November 13, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)