Mechanisms of Pharyngeal Collapse in Sleep Apnea, Study C

This study is currently recruiting participants. (see Contacts and Locations)
Verified September 2013 by Brigham and Women's Hospital
Sponsor:
Collaborator:
Information provided by (Responsible Party):
David Andrew Wellman, Brigham and Women's Hospital
ClinicalTrials.gov Identifier:
NCT01738022
First received: November 14, 2012
Last updated: September 25, 2013
Last verified: September 2013
  Purpose

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.


Condition Intervention
Sleep Apnea
Other: Administration of gas mixtures

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Official Title: Mechanisms of Pharyngeal Collapse in Sleep Apnea, Study C

Resource links provided by NLM:


Further study details as provided by Brigham and Women's Hospital:

Primary Outcome Measures:
  • Difference in peak inspiratory flow [ Time Frame: 10 - 15 seconds ] [ Designated as safety issue: No ]

    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).



Estimated Enrollment: 20
Study Start Date: December 2012
Estimated Study Completion Date: December 2014
Estimated Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

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.

  Eligibility

Ages Eligible for Study:   21 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01738022

Contacts
Contact: Pedro R Genta, MD (617) 732-6541 pgenta@partners.org
Contact: Lauren B Hess, BS (617) 732-8976 lhess1@partners.org

Locations
United States, Massachusetts
Brigham and Women's Hospital Recruiting
Boston, Massachusetts, United States, 02115
Sub-Investigator: Pedro R Genta, MD         
Sponsors and Collaborators
Brigham and Women's Hospital
Investigators
Principal Investigator: David A Wellman, MD Brigham and Women's Hospital
  More Information

No publications provided

Responsible Party: David Andrew Wellman, Principal Investigator, Brigham and Women's Hospital
ClinicalTrials.gov Identifier: NCT01738022     History of Changes
Other Study ID Numbers: 2012P000957C, 1R01HL102321-01A1
Study First Received: November 14, 2012
Last Updated: September 25, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Brigham and Women's Hospital:
Sleep apnea
Pathophysiology

Additional relevant MeSH terms:
Apnea
Sleep Apnea Syndromes
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Dyssomnias
Sleep Disorders
Nervous System Diseases

ClinicalTrials.gov processed this record on September 14, 2014