Mechanisms of Pharyngeal Collapse in Sleep Apnea, Study B
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Brigham and Women's Hospital
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Difference in peak inspiratory flow
Study Overview
Brief Summary
In obstructive sleep apnea (OSA), the upper airway recurrently closes during sleep. The mechanisms that lead to airway closure are not completely understood. Some studies have shown that there is progressive narrowing of the pharyngeal airway across breaths during expiration (Progressive Expiratory Narrowing, PEN) preceding an obstructive apnea. The cause of PEN is unknown. The investigators will test if lung volumes and low respiratory drive play a role in PEN.
Detailed Description
The mechanisms that lead to airway closure in OSA are not completely understood. Some studies have shown that there is progressive narrowing of the pharyngeal airway across breaths during expiration (Progressive Expiratory Narrowing, PEN) preceding an obstructive apnea.
The investigators will test if lung volumes and low respiratory drive play a role in PEN. To this end, the investigators will visualize the pharynx of sleep apnea patients during sleep using a thin endoscope during sleep while simultaneously measuring lung volumes, genioglossus electromyogram, and pharyngeal pressure during flow-limited breaths. Flow limitation will be induced by sustained reductions of continuous positive airway pressure (CPAP).
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Primary Purpose
- Other
- Masking
- None
Eligibility Criteria
- Ages
- 21 Years to 65 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Normal subjects or patients with OSA
Exclusion Criteria
- •Any unstable cardiac condition (other than well controlled hypertension) or pulmonary problems.
- •Any medication known to influence breathing, sleep/arousal or muscle physiology
- •Concurrent sleep disorders (insomnia, narcolepsy, central sleep apnea or parasomnia)
- •Claustrophobia
- •Inability to sleep supine
- •Allergy to lidocaine or oxymetazoline hydroclhoride
- •For women: Pregnancy
Arms & Interventions
Induction of flow limitation
Flow limitation will be induced by sustained reductions in continuous positive airway pressure during sleep
Intervention: Induction of flow limitation (Other)
Outcomes
Primary Outcomes
Difference in peak inspiratory flow
Time Frame: 3 minutes
Measured peak inspiratory flow will be compared to predicted peak inspiratory flow during flow restricted breaths. The time frame for the outcome will be the duration of induced flow limitation (3 minutes each) . Flow limitation will be induced several times during the night. Flow limited breaths will be averaged.
Secondary Outcomes
No secondary outcomes reported
Investigators
David Andrew Wellman
Principal Investigator
Brigham and Women's Hospital