NCT06403852

Investigating Near-Threshold Perception During Anesthetic Sedation

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 36 (actual)
• Sponsor: University of Michigan · Academic / Other
• Sex: All
• Age: 18 Years – 40 Years
• Healthy volunteers: Accepted

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.

Detailed description

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. Because scrambled images do not include an object stimulus, the images are used as "catch trials" to determine the subjects' baseline tendency to give positive responses to a question about the subjects' recognition experience. 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.

Conditions

• Propofol
• Anesthesia
• fMRI

Interventions

Type	Name	Description
COMBINATION_PRODUCT	Functional Magnetic Resonance Imaging (fMRI) with propofol	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

Timeline

• Start date: 2024-05-10
• Primary completion: 2025-10-03
• Completion: 2025-10-03
• First posted: 2024-05-08
• Last updated: 2025-11-13

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study