Assessing Covert Consciousness During Dexmedetomidine and Ketamine Sedation: An fMRI Study
10 augusti 2026 uppdaterad av: 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.
Studieöversikt
Status
Anmälan via inbjudan
Betingelser
Intervention / Behandling
Detaljerad beskrivning
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.
Studietyp
Interventionell
Inskrivning (Beräknad)
60
Fas
- Fas 2
Kontakter och platser
Det här avsnittet innehåller kontaktuppgifter för dem som genomför studien och information om var denna studie genomförs.
Studieorter
-
-
Michigan
-
Ann Arbor, Michigan, Förenta staterna, 48109
- University of Michigan
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Deltagandekriterier
Forskare letar efter personer som passar en viss beskrivning, så kallade behörighetskriterier. Några exempel på dessa kriterier är en persons allmänna hälsotillstånd eller tidigare behandlingar.
Urvalskriterier
Åldrar som är berättigade till studier
- Vuxen
Tar emot friska volontärer
Ja
Beskrivning
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
Det här avsnittet ger detaljer om studieplanen, inklusive hur studien är utformad och vad studien mäter.
Hur är studien utformad?
Designdetaljer
- Primärt syfte: Grundläggande vetenskap
- Tilldelning: Randomiserad
- Interventionsmodell: Parallellt uppdrag
- Maskning: Enda
Vapen och interventioner
Deltagargrupp / Arm |
Intervention / Behandling |
|---|---|
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Experimentell: 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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Experimentell: Ketamine during fMRI
About 30 healthy participants will be randomized to this arm.
|
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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Vad mäter studien?
Primära resultatmått
Resultatmått |
Åtgärdsbeskrivning |
Tidsram |
|---|---|---|
|
Blood Oxygen Level Dependent (BOLD) response to mental imagery tasks
Tidsram: Up to approximately 130 minutes
|
Three mental imagery tasks will be used: tennis imagery, navigation imagery, and hand-squeeze imagery
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Up to approximately 130 minutes
|
Sekundära resultatmått
Resultatmått |
Tidsram |
|---|---|
|
Grip force (in mmHg) of participants' hand squeezing on a rubber ball in response to squeeze instructions
Tidsram: Up to approximately 130 minutes
|
Up to approximately 130 minutes
|
Samarbetspartners och utredare
Det är här du hittar personer och organisationer som är involverade i denna studie.
Sponsor
Samarbetspartners
Utredare
- Huvudutredare: Zirui Huang, PhD, University of Michigan
Studieavstämningsdatum
Dessa datum spårar framstegen för inlämningar av studieposter och sammanfattande resultat till ClinicalTrials.gov. Studieposter och rapporterade resultat granskas av National Library of Medicine (NLM) för att säkerställa att de uppfyller specifika kvalitetskontrollstandarder innan de publiceras på den offentliga webbplatsen.
Studera stora datum
Studiestart (Faktisk)
7 augusti 2026
Primärt slutförande (Beräknad)
1 januari 2028
Avslutad studie (Beräknad)
1 januari 2028
Studieregistreringsdatum
Först inskickad
10 juli 2026
Först inskickad som uppfyllde QC-kriterierna
10 juli 2026
Första postat (Faktisk)
15 juli 2026
Uppdateringar av studier
Senaste uppdatering publicerad (Faktisk)
11 augusti 2026
Senaste inskickade uppdateringen som uppfyllde QC-kriterierna
10 augusti 2026
Senast verifierad
1 augusti 2026
Mer information
Termer relaterade till denna studie
Ytterligare relevanta MeSH-villkor
Andra studie-ID-nummer
- HUM00285398
- R01GM103894 (U.S.S. NIH-anslag/kontrakt)
Plan för individuella deltagardata (IPD)
Planerar du att dela individuella deltagardata (IPD)?
JA
IPD-planbeskrivning
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.
Tidsram för IPD-delning
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.
Kriterier för IPD Sharing Access
All research participants will be consented for sharing their de-identified data.
IPD-delning som stöder informationstyp
- STUDY_PROTOCOL
- SAV
- ICF
- ANALYTIC_CODE
Läkemedels- och apparatinformation, studiedokument
Studerar en amerikansk FDA-reglerad läkemedelsprodukt
Ja
Studerar en amerikansk FDA-reglerad produktprodukt
Nej
produkt tillverkad i och exporterad från U.S.A.
Nej
Denna information hämtades direkt från webbplatsen clinicaltrials.gov utan några ändringar. Om du har några önskemål om att ändra, ta bort eller uppdatera dina studieuppgifter, vänligen kontakta register@clinicaltrials.gov. Så snart en ändring har implementerats på clinicaltrials.gov, kommer denna att uppdateras automatiskt även på vår webbplats .