Assessing Covert Consciousness During Dexmedetomidine and Ketamine Sedation: An fMRI Study
10. august 2026 oppdatert 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.
Studieoversikt
Status
Påmelding etter invitasjon
Forhold
Intervensjon / Behandling
Detaljert 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.
Studietype
Intervensjonell
Registrering (Antatt)
60
Fase
- Fase 2
Kontakter og plasseringer
Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.
Studiesteder
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Michigan
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Ann Arbor, Michigan, Forente stater, 48109
- University of Michigan
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Deltakelseskriterier
Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.
Kvalifikasjonskriterier
Alder som er kvalifisert for studier
- Voksen
Tar imot friske 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
Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.
Hvordan er studiet utformet?
Designdetaljer
- Primært formål: Grunnvitenskap
- Tildeling: Randomisert
- Intervensjonsmodell: Parallell tildeling
- Masking: Enkelt
Våpen og intervensjoner
Deltakergruppe / Arm |
Intervensjon / Behandling |
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Eksperimentell: 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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Eksperimentell: 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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Hva måler studien?
Primære resultatmål
Resultatmål |
Tiltaksbeskrivelse |
Tidsramme |
|---|---|---|
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Blood Oxygen Level Dependent (BOLD) response to mental imagery tasks
Tidsramme: 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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Sekundære resultatmål
Resultatmål |
Tidsramme |
|---|---|
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Grip force (in mmHg) of participants' hand squeezing on a rubber ball in response to squeeze instructions
Tidsramme: Up to approximately 130 minutes
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Up to approximately 130 minutes
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Samarbeidspartnere og etterforskere
Det er her du vil finne personer og organisasjoner som er involvert i denne studien.
Sponsor
Samarbeidspartnere
Etterforskere
- Hovedetterforsker: Zirui Huang, PhD, University of Michigan
Studierekorddatoer
Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.
Studer hoveddatoer
Studiestart (Faktiske)
7. august 2026
Primær fullføring (Antatt)
1. januar 2028
Studiet fullført (Antatt)
1. januar 2028
Datoer for studieregistrering
Først innsendt
10. juli 2026
Først innsendt som oppfylte QC-kriteriene
10. juli 2026
Først lagt ut (Faktiske)
15. juli 2026
Oppdateringer av studieposter
Sist oppdatering lagt ut (Faktiske)
11. august 2026
Siste oppdatering sendt inn som oppfylte QC-kriteriene
10. august 2026
Sist bekreftet
1. august 2026
Mer informasjon
Begreper knyttet til denne studien
Ytterligere relevante MeSH-vilkår
Andre studie-ID-numre
- HUM00285398
- R01GM103894 (U.S. NIH-stipend/kontrakt)
Plan for individuelle deltakerdata (IPD)
Planlegger du å dele individuelle deltakerdata (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.
Tilgangskriterier for IPD-deling
All research participants will be consented for sharing their de-identified data.
IPD-deling Støtteinformasjonstype
- STUDY_PROTOCOL
- SEVJE
- ICF
- ANALYTIC_CODE
Legemiddel- og utstyrsinformasjon, studiedokumenter
Studerer et amerikansk FDA-regulert medikamentprodukt
Ja
Studerer et amerikansk FDA-regulert enhetsprodukt
Nei
produkt produsert i og eksportert fra USA
Nei
Denne informasjonen ble hentet direkte fra nettstedet clinicaltrials.gov uten noen endringer. Hvis du har noen forespørsler om å endre, fjerne eller oppdatere studiedetaljene dine, vennligst kontakt register@clinicaltrials.gov. Så snart en endring er implementert på clinicaltrials.gov, vil denne også bli oppdatert automatisk på nettstedet vårt. .