Assessing Covert Consciousness During Dexmedetomidine and Ketamine Sedation: An fMRI Study
2026年8月10日 更新者：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.
研究概览
详细说明
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.
研究类型
介入性
注册 (估计的)
60
阶段
- 阶段2
联系人和位置
本节提供了进行研究的人员的详细联系信息，以及有关进行该研究的地点的信息。
学习地点
-
-
Michigan
-
Ann Arbor、Michigan、美国、48109
- University of Michigan
-
-
参与标准
研究人员寻找符合特定描述的人，称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。
资格标准
适合学习的年龄
- 成人
接受健康志愿者
是的
描述
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
学习计划
本节提供研究计划的详细信息，包括研究的设计方式和研究的衡量标准。
研究是如何设计的？
设计细节
- 主要用途：基础科学
- 分配：随机化
- 介入模型：并行分配
- 屏蔽：单身的
武器和干预
参与者组/臂 |
干预/治疗 |
|---|---|
|
实验性的：Dexmedetomidine during fMRI
About 30 healthy participants will be randomized to this arm.
|
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.
|
|
实验性的：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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研究衡量的是什么？
主要结果指标
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
|
Blood Oxygen Level Dependent (BOLD) response to mental imagery tasks
大体时间：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
|
次要结果测量
结果测量 |
大体时间 |
|---|---|
|
Grip force (in mmHg) of participants' hand squeezing on a rubber ball in response to squeeze instructions
大体时间：Up to approximately 130 minutes
|
Up to approximately 130 minutes
|
合作者和调查者
在这里您可以找到参与这项研究的人员和组织。
调查人员
- 首席研究员：Zirui Huang, PhD、University of Michigan
研究记录日期
这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查，以确保它们在发布到公共网站之前符合特定的质量控制标准。
研究主要日期
学习开始 (实际的)
2026年8月7日
初级完成 (估计的)
2028年1月1日
研究完成 (估计的)
2028年1月1日
研究注册日期
首次提交
2026年7月10日
首先提交符合 QC 标准的
2026年7月10日
首次发布 (实际的)
2026年7月15日
研究记录更新
最后更新发布 (实际的)
2026年8月11日
上次提交的符合 QC 标准的更新
2026年8月10日
最后验证
2026年8月1日
更多信息
与本研究相关的术语
关键字
其他相关的 MeSH 术语
其他研究编号
- HUM00285398
- R01GM103894 (美国 NIH 拨款/合同)
计划个人参与者数据 (IPD)
计划共享个人参与者数据 (IPD)？
是的
IPD 计划说明
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 共享时间框架
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 共享访问标准
All research participants will be consented for sharing their de-identified data.
IPD 共享支持信息类型
- 研究方案
- 树液
- 国际碳纤维联合会
- 分析代码
药物和器械信息、研究文件
研究美国 FDA 监管的药品
是的
研究美国 FDA 监管的设备产品
不
在美国制造并从美国出口的产品
不
此信息直接从 clinicaltrials.gov 网站检索，没有任何更改。如果您有任何更改、删除或更新研究详细信息的请求，请联系 register@clinicaltrials.gov. clinicaltrials.gov 上实施更改，我们的网站上也会自动更新.