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Gas Supply, Demand and Middle Ear Gas Balance: Specific Aim 3c

This study has been completed.
National Institute on Deafness and Other Communication Disorders (NIDCD)
Information provided by:
Children's Hospital of Pittsburgh Identifier:
First received: January 12, 2007
Last updated: September 8, 2010
Last verified: September 2010
This study will determine if gas can pass between the environment and the middle ear by way of the eardrum. This route of gas exchange was observed in animals but has not been studied in humans. If gas exchange across the eardrum is documented and the rate is sufficiently high, this can help explain certain past observations such as why middle ear pressure does not change very much in some children and adults when they have a cold or flu. The investigators also expect that the rate of gas exchange across the eardrum will depend on whether or not the eardrum has scarred or abnormally thin regions.


Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Gas Supply, Demand and Middle Ear Gas Balance: Specific Aim 3c

Further study details as provided by Children's Hospital of Pittsburgh:

Estimated Enrollment: 45
Study Start Date: June 2007
Study Completion Date: February 2009
Normal tympanic membrane
dimeric (atrophic)

Detailed Description:
Middle-ear (ME) pressure is a measure of the number of contained gas moles, and processes that addd or remove gas moles from the relatively fixed volume ME cavity change its pressure. Experimental results from animal studies document significant gas exchange across the tympanic membrane and if confirmed for humans may explain some of the paradoxical findings for children with poor Eustachian tube function such as the preservation of an aerated ME when the normal routes of gas supply are disrupted. This study measures the rates of reactive and inert gas exchange across the adult tympanic membrane with and without structural abnormalities and determines if these transfers are purely diffusive phenomena. The resulting data will be used to develop species-specific rate-constants that will be used as parameters in modeling ME pressure regulation.

Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
Adults 18-50 years old with at least one intact and effusion-free middle ear

Inclusion Criteria:

  • 18-50 years old
  • at least one intact and effusion-free middle ear

Exclusion Criteria:

  • bilateral otitis media
  • unable to remain relaxed and quiet for up to 2 hours
  Contacts and Locations
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Please refer to this study by its identifier: NCT00422851

United States, Pennsylvania
ENT Research Center Children's Hospital of Pittsburgh
Pittsburgh, Pennsylvania, United States, 15213
Sponsors and Collaborators
Children's Hospital of Pittsburgh
National Institute on Deafness and Other Communication Disorders (NIDCD)
Principal Investigator: William Doyle, PhD Children's Hospital of Pittsburgh
Study Director: J. Douglas Swarts, PhD Children's Hospital of Pittsburgh
  More Information

Responsible Party: William J. Doyle, PhD, University of Pittsburgh School of Medicine Identifier: NCT00422851     History of Changes
Other Study ID Numbers: 0609093
NIH P50DC007667
Study First Received: January 12, 2007
Last Updated: September 8, 2010

Keywords provided by Children's Hospital of Pittsburgh:
gas diffusion
Eustachian tube
tympanic membrane processed this record on April 27, 2017