Sleep Apnea
Conditions
Keywords
Sleep Apnea, Pathophysiology
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).
Interventions
OTHERInduction of flow limitation
Sponsors
National Heart, Lung, and Blood Institute (NHLBI)
Brigham and Women's Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 65 Years
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in peak inspiratory flow | 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. |
Countries
United States
Outcome results
None listed