Mechanisms of Pharyngeal Collapse in Sleep Apnea, Study A

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

Mechanisms of Pharyngeal Collapse in Sleep Apnea

In obstructive sleep apnea, the upper airway recurrently closes during sleep. The mechanisms that lead to airway closure are not completely understood. While the airway of some people narrows and airflow decreases during inspiration due to increasing inspiratory effort, others maintain constant airflow throughout inspiration. Airway neuromuscular reflexes may protect against airway narrowing that occurs due to increasing inspiratory effort. To test this hypothesis, the investigators will initially measure airway neuromuscular reflex and inspiratory flow and then attenuate neuromuscular reflex through topical pharyngeal anesthesia to observe the effects on inspiratory flow.

Study Overview

Status

Completed

Detailed Description

The mechanisms that lead to airway closure are not completely understood. While the airway of some people narrows and airflow decreases during inspiration due to increasing inspiratory effort, others maintain constant airflow throughout inspiration (negative effort dependence, NED). The investigators hypothesize that upper airway neuromuscular reflexes may protect against narrowing that occurs due to increasing inspiratory effort. Topical oropharyngeal anesthesia has been shown to reduce neuromuscular reflexes. Thus, the investigators also hypothesize that patients with stable inspiratory flow will develop NED once the reflexes have been impaired with topical anesthetic. The investigators plan to:

  1. measure upper airway muscle EMG to assess how it corresponds to the presence or absence of NED. This aim will allow us to test the hypothesis that robust upper airway muscle reflexes can protect against NED.
  2. reduce upper airway muscle activity and reflexes by topical oropharyngeal anesthesia. This will allow us to test the hypothesis that attenuated upper airway muscle activity induced by topical anesthesia can induce NED.

Study Type

Interventional

Enrollment (Actual)

26

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

    • 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 HCl
  • 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: Pharyngeal topical anesthesia
Pharyngeal topical anesthesia will be performed using 4% lidocaine spray
Pharyngeal topical anesthesia will be performed using 4% lidocaine spray

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Negative effort dependence variation
Time Frame: After pharyngeal topical anesthesia
The magnitude of negative effort dependence will be expressed as the percent decrease in inspiratory flow from Vmax. NED will be compared before and after topical upper airway anesthesia
After pharyngeal topical anesthesia

Collaborators and Investigators

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

Investigators

  • Principal Investigator: David A Wellman, 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)

December 26, 2018

Study Completion (Actual)

December 26, 2018

Study Registration Dates

First Submitted

November 14, 2012

First Submitted That Met QC Criteria

November 19, 2012

First Posted (Estimate)

November 20, 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

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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