Mechanisms of Pharyngeal Collapse in Sleep Apnea, Study C

Mass General Brigham

Status: Withdrawn

Conditions: Sleep Apnea

Treatments: Other: Administration of gas mixtures

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT01738022

2012P000957C

1R01HL102321-01A1 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

In obstructive sleep apnea (OSA), the upper airway recurrently closes during sleep. The mechanisms that lead to airway closure are not completely understood. Models to study mechanisms of airway collapse have been proposed. However, these models have not been tested in the human upper airway. Gas density and viscosity are different gas properties that influence upper airway collapse and are variables of different models. In this study, subjects will breathe gas mixtures of different densities and viscosities for brief periods of time in order to test those models.

Full description

Models to study mechanisms of airway collapse have been proposed. However, these models have not been tested in the human upper airway. Gas density and viscosity are different gas properties that influence upper airway collapse and are variables of different models.

In this study, subjects will breathe gas mixtures of different densities (helium and sulfur-hexafluoride) or viscosity (neon) for brief periods of time during flow-limited breaths. Flow limitation will be induced by sustained reductions of continuous positive airway pressure (CPAP). The investigators will test some models of upper airway collapse by observing if flow while breathing different gas mixtures scales according to the differences in density and viscosity.

Sex: All

Ages: 21 to 65 years old

Volunteers: Accepts Healthy Volunteers

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 hydrochloride
• For women: Pregnancy

Trial design

Primary purpose: Other

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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0 participants in 1 patient group

Gas mixture administration

Experimental group

Description:

Subjects will breathe different gas mixtures with different densities and viscosity for brief periods in order to promote changes in peak inspiratory flow

Treatment:

Other: Administration of gas mixtures