Assessing Covert Consciousness During Dexmedetomidine and Ketamine Sedation: An fMRI Study
10 augustus 2026 bijgewerkt door: 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.
Studie Overzicht
Toestand
Aanmelden op uitnodiging
Conditie
Interventie / Behandeling
Gedetailleerde beschrijving
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.
Studietype
Ingrijpend
Inschrijving (Geschat)
60
Fase
- Fase 2
Contacten en locaties
In dit gedeelte vindt u de contactgegevens van degenen die het onderzoek uitvoeren en informatie over waar dit onderzoek wordt uitgevoerd.
Studie Locaties
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Michigan
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Ann Arbor, Michigan, Verenigde Staten, 48109
- University of Michigan
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Deelname Criteria
Onderzoekers zoeken naar mensen die aan een bepaalde beschrijving voldoen, de zogenaamde geschiktheidscriteria. Enkele voorbeelden van deze criteria zijn iemands algemene gezondheidstoestand of eerdere behandelingen.
Geschiktheidscriteria
Leeftijden die in aanmerking komen voor studie
- Volwassen
Accepteert gezonde vrijwilligers
Ja
Beschrijving
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
Studie plan
Dit gedeelte bevat details van het studieplan, inclusief hoe de studie is opgezet en wat de studie meet.
Hoe is de studie opgezet?
Ontwerpdetails
- Primair doel: Fundamentele wetenschap
- Toewijzing: Gerandomiseerd
- Interventioneel model: Parallelle opdracht
- Masker: Enkel
Wapens en interventies
Deelnemersgroep / Arm |
Interventie / Behandeling |
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Experimenteel: Dexmedetomidine during fMRI
About 30 healthy participants will be randomized to this arm.
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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.
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Experimenteel: Ketamine during fMRI
About 30 healthy participants will be randomized to this arm.
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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.
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Wat meet het onderzoek?
Primaire uitkomstmaten
Uitkomstmaat |
Maatregel Beschrijving |
Tijdsspanne |
|---|---|---|
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Blood Oxygen Level Dependent (BOLD) response to mental imagery tasks
Tijdsspanne: Up to approximately 130 minutes
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Three mental imagery tasks will be used: tennis imagery, navigation imagery, and hand-squeeze imagery
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Up to approximately 130 minutes
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Secundaire uitkomstmaten
Uitkomstmaat |
Tijdsspanne |
|---|---|
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Grip force (in mmHg) of participants' hand squeezing on a rubber ball in response to squeeze instructions
Tijdsspanne: Up to approximately 130 minutes
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Up to approximately 130 minutes
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Medewerkers en onderzoekers
Hier vindt u mensen en organisaties die betrokken zijn bij dit onderzoek.
Sponsor
Onderzoekers
- Hoofdonderzoeker: Zirui Huang, PhD, University of Michigan
Studie record data
Deze datums volgen de voortgang van het onderzoeksdossier en de samenvatting van de ingediende resultaten bij ClinicalTrials.gov. Studieverslagen en gerapporteerde resultaten worden beoordeeld door de National Library of Medicine (NLM) om er zeker van te zijn dat ze voldoen aan specifieke kwaliteitscontrolenormen voordat ze op de openbare website worden geplaatst.
Bestudeer belangrijke data
Studie start (Werkelijk)
7 augustus 2026
Primaire voltooiing (Geschat)
1 januari 2028
Studie voltooiing (Geschat)
1 januari 2028
Studieregistratiedata
Eerst ingediend
10 juli 2026
Eerst ingediend dat voldeed aan de QC-criteria
10 juli 2026
Eerst geplaatst (Werkelijk)
15 juli 2026
Updates van studierecords
Laatste update geplaatst (Werkelijk)
11 augustus 2026
Laatste update ingediend die voldeed aan QC-criteria
10 augustus 2026
Laatst geverifieerd
1 augustus 2026
Meer informatie
Termen gerelateerd aan deze studie
Aanvullende relevante MeSH-voorwaarden
Andere studie-ID-nummers
- HUM00285398
- R01GM103894 (Subsidie/contract van de Amerikaanse NIH)
Plan Individuele Deelnemersgegevens (IPD)
Bent u van plan om gegevens van individuele deelnemers (IPD) te delen?
JA
Beschrijving IPD-plan
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-tijdsbestek voor delen
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-toegangscriteria voor delen
All research participants will be consented for sharing their de-identified data.
IPD delen Ondersteunend informatietype
- LEERPROTOCOOL
- SAP
- ICF
- ANALYTIC_CODE
Informatie over medicijnen en apparaten, studiedocumenten
Bestudeert een door de Amerikaanse FDA gereguleerd geneesmiddel
Ja
Bestudeert een door de Amerikaanse FDA gereguleerd apparaatproduct
Nee
product vervaardigd in en geëxporteerd uit de V.S.
Nee
Deze informatie is zonder wijzigingen rechtstreeks van de website clinicaltrials.gov gehaald. Als u verzoeken heeft om uw onderzoeksgegevens te wijzigen, te verwijderen of bij te werken, neem dan contact op met register@clinicaltrials.gov. Zodra er een wijziging wordt doorgevoerd op clinicaltrials.gov, wordt deze ook automatisch bijgewerkt op onze website .