Mechanisms of Pharyngeal Collapse in Sleep Apnea, Study B

Not Applicable

Completed

• Conditions: Sleep Apnea
• Interventions: Other: Induction of flow limitation

• Registration Number: NCT01738009
• Lead Sponsor: Brigham and Women's Hospital

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 Timeline

• Study First Submitted: 2012-11-14
• Study First Submitted QC: 2012-11-28
• Study First Posted: 2012-11-30
• Study Start: 2012-12-08
• Primary Completion: 2016-06
• Study Completion: 2016-10
• Status Verified: 2022-02
• Last Update Submitted: 2022-02-23
• Last Update Posted: 2022-03-09

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 40

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Induction of flow limitation	Induction of flow limitation	Flow limitation will be induced by sustained reductions in continuous positive airway pressure during sleep

Primary Outcome Measures

Name	Time	Method
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.

Trial Locations

Locations (1)

Brigham and Women's Hospital; 🇺🇸 Boston, Massachusetts, United States