Characterizing the Neuropharmacology of Dexmedetomidine Through Trimodal Imaging
Overview
- Phase
- Early Phase 1
- Intervention
- Dexmedetomidine
- Conditions
- Anesthesia
- Sponsor
- Massachusetts General Hospital
- Enrollment
- 30
- Locations
- 1
- Primary Endpoint
- Functional magnetic resonance imaging (fMRI) signals.
- Last Updated
- 3 years ago
Overview
Brief Summary
The investigators will be studying the sedative drug dexmedetomidine using hybrid PET/fMRI/EEG imaging to better understand the neuropharmacology of anesthesia/artificially induced sleep.
Detailed Description
A group of healthy volunteers will undergo simultaneous PET/fMRI/EEG imaging under two different conditions: while being administered a sedative (dexmedetomidine), and while being administered a normal saline infusion, as a control. The order of these two scans will be randomized, and the study design is open label (ie subjects and investigators know which session will be the control scan and which one will be the sedative scan). Investigators hope that by comparing the results of the sedative and control scans, the different neuromodulatory states involved in the transition from wakefulness to medically induced vs naturally occurring sleep can be better understood.
Investigators
Christin Y. Sander, PhD
Dr Christin Sander, Assistant Professor
Massachusetts General Hospital
Eligibility Criteria
Inclusion Criteria
- •Adults aged 18-
- •No contraindications to MRI or PET scanning.
Exclusion Criteria
- •Contraindications to fMRI scanning and PET scanning (including presence of a cardiac pacemaker or pacemaker wires, metallic particles in the body, vascular clips in the head or previous neurosurgery, prosthetic heart valves, claustrophobia);
- •Pregnancy or breast feeding;
- •Current or past history of major medical, neurological, or psychiatric condition;
- •History of major head trauma;
- •Any cardiovascular disorders, including heart disorders or high blood pressure \[\>155/95\];
- •Breathing problems such as severe asthma;
- •Bleeding disorder, or use of anticoagulants;
- •Bladder obstruction, urinary problems, or history of impaired elimination;
- •Known kidney or liver problems;
- •Intestinal blockage;
Arms & Interventions
Dexmedetomidine
During the imaging scan subjects will receive an initial 1µg/kg bolus of dexmedetomidine up to a maximum dose of 80 µg, infused through IV over 10 minutes. After the bolus has been administered, a constant infusion of up to 0.6 µg/kg/hr (0.01 µg/kg/min) of dexmedetomidine will be maintained for the remainder of the scan (about 60 minutes).
Intervention: Dexmedetomidine
Saline
A saline infusion will be used as a placebo comparator for the dexmedetomidine infusion. It will be administered in the same manner and dosages as the dexmedetomidine.
Intervention: Saline
Outcomes
Primary Outcomes
Functional magnetic resonance imaging (fMRI) signals.
Time Frame: 2 hours
fMRI measures of hemodynamic responses.
Differences in electroencephalography (EEG) measures between arousal and anesthesia.
Time Frame: 2 hours
Arousal states will be characterized from changes in the EEG power spectrum.
Brain positron emission tomography (PET) imaging signals.
Time Frame: 2 hours
Changes in dopamine receptor availability will be quantified from brain PET images.
Secondary Outcomes
- Respiratory physiology(2 hours)
- Heart rate(2 hours)
- Pulse oximetry(2 hours)