Assessing Covert Consciousness During Dexmedetomidine and Ketamine Sedation: An fMRI Study
10 de agosto de 2026 actualizado por: 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.
Descripción general del estudio
Estado
Inscripción por invitación
Condiciones
Intervención / Tratamiento
Descripción detallada
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.
Tipo de estudio
Intervencionista
Inscripción (Estimado)
60
Fase
- Fase 2
Contactos y Ubicaciones
Esta sección proporciona los datos de contacto de quienes realizan el estudio e información sobre dónde se lleva a cabo este estudio.
Ubicaciones de estudio
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Michigan
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Ann Arbor, Michigan, Estados Unidos, 48109
- University of Michigan
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Criterios de participación
Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.
Criterio de elegibilidad
Edades elegibles para estudiar
- Adulto
Acepta Voluntarios Saludables
Sí
Descripción
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
Plan de estudios
Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.
¿Cómo está diseñado el estudio?
Detalles de diseño
- Propósito principal: Ciencia básica
- Asignación: Aleatorizado
- Modelo Intervencionista: Asignación paralela
- Enmascaramiento: Único
Armas e Intervenciones
Grupo de participantes/brazo |
Intervención / Tratamiento |
|---|---|
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Experimental: 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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Experimental: 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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¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
|---|---|---|
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Blood Oxygen Level Dependent (BOLD) response to mental imagery tasks
Periodo de tiempo: 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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Medidas de resultado secundarias
Medida de resultado |
Periodo de tiempo |
|---|---|
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Grip force (in mmHg) of participants' hand squeezing on a rubber ball in response to squeeze instructions
Periodo de tiempo: Up to approximately 130 minutes
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Up to approximately 130 minutes
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Colaboradores e Investigadores
Aquí es donde encontrará personas y organizaciones involucradas en este estudio.
Patrocinador
Colaboradores
Investigadores
- Investigador principal: Zirui Huang, PhD, University of Michigan
Fechas de registro del estudio
Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.
Fechas importantes del estudio
Inicio del estudio (Actual)
7 de agosto de 2026
Finalización primaria (Estimado)
1 de enero de 2028
Finalización del estudio (Estimado)
1 de enero de 2028
Fechas de registro del estudio
Enviado por primera vez
10 de julio de 2026
Primero enviado que cumplió con los criterios de control de calidad
10 de julio de 2026
Publicado por primera vez (Actual)
15 de julio de 2026
Actualizaciones de registros de estudio
Última actualización publicada (Actual)
11 de agosto de 2026
Última actualización enviada que cumplió con los criterios de control de calidad
10 de agosto de 2026
Última verificación
1 de agosto de 2026
Más información
Términos relacionados con este estudio
Palabras clave
Términos MeSH relevantes adicionales
Otros números de identificación del estudio
- HUM00285398
- R01GM103894 (Subvención/contrato del NIH de EE. UU.)
Plan de datos de participantes individuales (IPD)
¿Planea compartir datos de participantes individuales (IPD)?
SÍ
Descripción del plan IPD
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.
Marco de tiempo para compartir IPD
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.
Criterios de acceso compartido de IPD
All research participants will be consented for sharing their de-identified data.
Tipo de información de apoyo para compartir IPD
- PROTOCOLO DE ESTUDIO
- SAVIA
- CIF
- CÓDIGO_ANALÍTICO
Información sobre medicamentos y dispositivos, documentos del estudio
Estudia un producto farmacéutico regulado por la FDA de EE. UU.
Sí
Estudia un producto de dispositivo regulado por la FDA de EE. UU.
No
producto fabricado y exportado desde los EE. UU.
No
Esta información se obtuvo directamente del sitio web clinicaltrials.gov sin cambios. Si tiene alguna solicitud para cambiar, eliminar o actualizar los detalles de su estudio, comuníquese con register@clinicaltrials.gov. Tan pronto como se implemente un cambio en clinicaltrials.gov, también se actualizará automáticamente en nuestro sitio web. .