Mechanisms of Pharyngeal Collapse in Sleep Apnea, Study C

July 9, 2019 updated by: David Andrew Wellman, Brigham and Women's Hospital
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.

Study Overview

Status

Withdrawn

Conditions

Intervention / Treatment

Detailed 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.

Study Type

Interventional

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Brigham and Women's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Gas mixture administration
Subjects will breathe different gas mixtures with different densities and viscosity for brief periods in order to promote changes in peak inspiratory flow
Other: Administration of gas mixtures
Other Names:
  • Heliox
  • Sulfur-hexafluoride
  • Neon

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference in peak inspiratory flow
Time Frame: 10 - 15 seconds

Observed peak inspiratory flow while breathing different gas mixtures will be compared to model predicted flows.

Subjects will breathe different gas mixtures for 2 consecutive breaths only. Therefore the time frame is equal to one breath before gas mixture administration and two breaths after (usually 10-15 seconds).
10 - 15 seconds

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Brigham and Women's Hospital

Collaborators

National Heart, Lung, and Blood Institute (NHLBI)

Investigators

  • Principal Investigator: David A Wellman, MD, Brigham and Women's Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 8, 2012

Primary Completion (Actual)

February 7, 2017

Study Completion (Actual)

February 7, 2017

Study Registration Dates

First Submitted

November 14, 2012

First Submitted That Met QC Criteria

November 28, 2012

First Posted (Estimate)

November 30, 2012

Study Record Updates

Last Update Posted (Actual)

July 11, 2019

Last Update Submitted That Met QC Criteria

July 9, 2019

Last Verified

July 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2012P000957C
  • 1R01HL102321-01A1 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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