Neuroimaging of Anesthetic Modulation of Human Consciousness
Overview
- Phase
- Phase 4
- Intervention
- Propofol
- Conditions
- Healthy
- Sponsor
- University of Michigan
- Enrollment
- 30
- Locations
- 1
- Primary Endpoint
- Change From Baseline in Blood Oxygen Level Dependent (BOLD) Response to Sensory Stimuli During Sedation
- Status
- Completed
- Last Updated
- 5 years ago
Overview
Brief Summary
This study's purpose is to see if mental functions take place during different levels of anesthesia, using a commonly used drug (Propofol). fMRI (functional Magnetic Resonance Imaging, or "brain imaging") shows areas in the brain involved in thinking at different depths of anesthesia.
Detailed Description
Administering anesthetic drugs to suppress consciousness is an imperatively important step in major surgical operations. Yet the neurobiological mechanisms that underlie loss of consciousness under general anesthesia remain elusive. Despite advancements in understanding the molecular, synaptic, and cellular effects of anesthetics, the large-scale, systems-level modulation of neuronal processes that support conscious cognitive functions is incompletely understood. While profound decreases in global and regional brain metabolism, blood flow, and functional connectivity have been reported, these changes often fail to correlate with the loss and return of consciousness. To date, there is no "consciousness meter" or "gold standard" to objectively assess and monitor the level of consciousness under general anesthesia. Several studies suggest that residual cognitive functions may not completely vanish under general anesthesia; however, the level and complexity of residual information processing in the anesthetized brain remains unknown. Finally, the neurobiological mechanisms that govern anesthesia induction and emergence appear to be partially different, but the relevance of these differences to the modulation of the state of consciousness is unclear.
Investigators
Anthony G Hudetz
Professor of Anesthesiology
University of Michigan
Eligibility Criteria
Inclusion Criteria
- •Must have a body mass index (BMI) less than
- •Must be right handed
- •Must be English speaking
- •Must be capable of giving written informed consent.
- •Must have history of playing tennis (or any type of racquet sport) at least 30 times over lifetime.
Exclusion Criteria
- •History of obstructive sleep apnea;
- •History of a difficult airway with a previous anesthetic;
- •History of neurological disorders;
- •Hypertension or other cardiovascular abnormalities;
- •Pulmonary hypertension or other pulmonary abnormalities;
- •Gastroesophageal reflux disease (GERD) or heartburn;
- •History of significant head injury with loss of consciousness;
- •Learning disability or other developmental disorder;
- •Allergic reactions to eggs;
- •Pregnant or nursing mothers;
Arms & Interventions
Propofol Administration
Intervention: Propofol
Outcomes
Primary Outcomes
Change From Baseline in Blood Oxygen Level Dependent (BOLD) Response to Sensory Stimuli During Sedation
Time Frame: Baseline to 90 minutes
Change = BOLD Response During Sedation - BOLD Response During Baseline
Secondary Outcomes
- Change From Baseline in Squeeze Pressure(Baseline to 90 minutes)