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Assessing Covert Consciousness During Dexmedetomidine and Ketamine Sedation: An fMRI Study

10. juli 2026 opdateret af: Zirui Huang, University of Michigan
This research is studying whether mental functions take place during different levels of anesthesia, using a commonly used drug (either dexmedetomidine [with propofol in some participants] or ketamine), which shows areas in the brain involved in thinking at different depths of anesthesia. As a result of this study, the researchers expect to gain a deeper understanding of mental function during different levels of anesthesia.

Studieoversigt

Status

Ikke rekrutterer endnu

Betingelser

Intervention / Behandling

Detaljeret beskrivelse

Dexmedetomidine is an FDA-approved sedative agent and is used off-label in this study for controlled experimental modulation of consciousness under direct anesthesiology supervision. Ketamine is a FDA-approved anesthetic and analgesic agent and is used off-label in this study for controlled experimental modulation of consciousness under direct anesthesiology supervision.

Using fMRI and established cognitive paradigms, the proposed study will directly examine residual conscious processing under dexmedetomidine and ketamine and compare these findings with our existing propofol dataset from NCT03361605.

Undersøgelsestype

Interventionel

Tilmelding (Anslået)

60

Fase

  • Fase 2

Kontakter og lokationer

Dette afsnit indeholder kontaktoplysninger for dem, der udfører undersøgelsen, og oplysninger om, hvor denne undersøgelse udføres.

Studiekontakt

Studiesteder

  • Forenede Stater
    • Michigan
      • Ann Arbor, Michigan, Forenede Stater, 48109
        • University of Michigan
        • Kontakt:
        • Ledende efterforsker:
          • Zirui Huang, Ph.D.

Deltagelseskriterier

Forskere leder efter personer, der passer til en bestemt beskrivelse, kaldet berettigelseskriterier. Nogle eksempler på disse kriterier er en persons generelle helbredstilstand eller tidligere behandlinger.

Berettigelseskriterier

Aldre berettiget til at studere

  • Voksen

Tager imod sunde frivillige

Ja

Beskrivelse

Inclusion Criteria:

  • Healthy study subjects with American Society of Anesthesiologists (ASA)-1 status
  • Right-handed
  • Body mass index (BMI) less than 30
  • Participants will have the experience of playing tennis (or other racquet sport) at least 30 times in their lifetime
  • English speaking

Exclusion Criteria:

  • Medical contraindication to MRI scanning; are unable to undergo MRI scanning because of possible pregnancy or currently breastfeeding
  • BMI greater than or equal to 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 dexmedetomidine, ketamine, propofol, or any components of these medications, 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,
  • sensory/motor loss sufficient to interfere with performance of the study
  • epilepsy/seizure disorder (including a history of seizures) or stroke (including a history of stroke).
  • history of schizophrenia spectrum disorder, bipolar disorder, other psychotic disorder, or any prior adverse psychiatric reaction to ketamine or similar drugs
  • Participants taking medications that, in the judgment of the investigators or attending anesthesiologist, may interact with the study drugs or increase the risk of participation will also be excluded
  • participants with hypertension or diabetes mellitus
  • 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
  • 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.
  • Potential participants who have participated in a clinical trial using an investigational drug or device within 30 days will be considered for enrollment after 30 days.
  • History of a difficult airway with a previous anesthetic

Studieplan

Dette afsnit indeholder detaljer om studieplanen, herunder hvordan undersøgelsen er designet, og hvad undersøgelsen måler.

Hvordan er undersøgelsen tilrettelagt?

Design detaljer

  • Primært formål: Grundvidenskab
  • Tildeling: Randomiseret
  • Interventionel model: Parallel tildeling
  • Maskning: Enkelt

Våben og indgreb

Deltagergruppe / Arm
Intervention / Behandling
Eksperimentel: Dexmedetomidine during fMRI
About 30 healthy participants will be randomized to this arm.
Medicin: Dexmedetomidine (+propofol as indicated)
Dexmedetomidine dosing will follow FDA-labeled parameters for procedural sedation, with a loading dose of 1 mcg/kg administered intravenously over 10 minutes, followed by maintenance infusion within the range of 0.2 to 1.0 mcg/kg/hr, titrated to clinical effect under anesthesiologist supervision. Sedation depth will be assessed behaviorally using standardized squeeze-response testing to determine lost responsiveness (LOR). If LOR is not achieved within labeled dexmedetomidine dosing limits, low-dose propofol will be conditionally added using a target-controlled infusion at an effect-site concentration of 0.5-1.5 μg/ml, which is below typical induction levels and intended to provide supplemental sedation while preserving spontaneous ventilation. Once LOR is achieved, sedation will be maintained within the approved dexmedetomidine range, with adjunct propofol continued only as clinically indicated.
Eksperimentel: Ketamine during fMRI
About 30 healthy participants will be randomized to this arm.
Medicin: Ketamine
participants will first receive a subanesthetic ketamine infusion of 0.5 mg/kg administered intravenously over 40 minutes. After that, 1.5 mg/kg ketamine will be administered slowly as a bolus over 60 seconds. Based on prior experience with this paradigm, most subjects who lose responsiveness do so for approximately 10 minutes following the bolus dose. For a 70 kg healthy subject, the total ketamine dose in this paradigm is approximately 140 mg. This dosing remains within the range of standard anesthetic induction dosing, which is typically 1.5 to 2 mg/kg in clinical practice.

Hvad måler undersøgelsen?

Primære resultatmål

Resultatmål
Foranstaltningsbeskrivelse
Tidsramme
Blood Oxygen Level Dependent (BOLD) response to mental imagery tasks
Tidsramme: Up to approximately 130 minutes
Three mental imagery tasks will be used: tennis imagery, navigation imagery, and hand-squeeze imagery
Up to approximately 130 minutes

Sekundære resultatmål

Resultatmål
Tidsramme
Grip force (in mmHg) of participants' hand squeezing on a rubber ball in response to squeeze instructions
Tidsramme: Up to approximately 130 minutes
Up to approximately 130 minutes

Samarbejdspartnere og efterforskere

Det er her, du vil finde personer og organisationer, der er involveret i denne undersøgelse.

Sponsor

University of Michigan

Samarbejdspartnere

National Institute of General Medical Sciences (NIGMS)

Efterforskere

  • Ledende efterforsker: Zirui Huang, PhD, University of Michigan

Datoer for undersøgelser

Disse datoer sporer fremskridtene for indsendelser af undersøgelsesrekord og resumeresultater til ClinicalTrials.gov. Studieregistreringer og rapporterede resultater gennemgås af National Library of Medicine (NLM) for at sikre, at de opfylder specifikke kvalitetskontrolstandarder, før de offentliggøres på den offentlige hjemmeside.

Studer store datoer

Studiestart (Anslået)

1. juli 2026

Primær færdiggørelse (Anslået)

1. januar 2028

Studieafslutning (Anslået)

1. januar 2028

Datoer for studieregistrering

Først indsendt

10. juli 2026

Først indsendt, der opfyldte QC-kriterier

10. juli 2026

Først opslået (Faktiske)

15. juli 2026

Opdateringer af undersøgelsesjournaler

Sidste opdatering sendt (Faktiske)

15. juli 2026

Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier

10. juli 2026

Sidst verificeret

1. juli 2026

Mere information

Begreber relateret til denne undersøgelse

Nøgleord

Yderligere relevante MeSH-vilkår

Andre undersøgelses-id-numre

  • HUM00285398
  • R01GM103894 (U.S. NIH-bevilling/kontrakt)

Plan for individuelle deltagerdata (IPD)

Planlægger du at dele individuelle deltagerdata (IPD)?

JA

IPD-planbeskrivelse

Data collected in the proposed experiments will be shared at the OpenNeuro. Preprocessed, curated, artifact-free data will be preserved and shared. Detailed documentation for reproducing the specific analyses will be provided in publications and in open sharing. In addition to the fMRI imaging data, task related paradigm designs and experiment definitions will be shared in OpenNeuro.

IPD-delingstidsramme

The data will be deposited after the after the analysis have been completed and accepted for scientific publication. Access to the data deposited to OpenNeuro will not be controlled. Data will remain accessible as long as OpenNeuro hosts the data.

IPD-delingsadgangskriterier

All research participants will be consented for sharing their de-identified data.

IPD-deling Understøttende informationstype

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE

Lægemiddel- og udstyrsoplysninger, undersøgelsesdokumenter

Studerer et amerikansk FDA-reguleret lægemiddelprodukt

Ja

Studerer et amerikansk FDA-reguleret enhedsprodukt

Ingen

produkt fremstillet i og eksporteret fra U.S.A.

Ingen

Disse oplysninger blev hentet direkte fra webstedet clinicaltrials.gov uden ændringer. Hvis du har nogen anmodninger om at ændre, fjerne eller opdatere dine undersøgelsesoplysninger, bedes du kontakte register@clinicaltrials.gov. Så snart en ændring er implementeret på clinicaltrials.gov, vil denne også blive opdateret automatisk på vores hjemmeside .

Kliniske forsøg med Dexmedetomidine (+propofol as indicated)

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Kosttilskud

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