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Serial Exhaled Breath pH Monitoring

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified March 2011 by University of Virginia.
Recruitment status was:  Recruiting
Information provided by:
University of Virginia Identifier:
First received: May 26, 2006
Last updated: March 4, 2011
Last verified: March 2011

This study will seek to determine the amount of acids a person with a chronic cough that is suspected to be related to acid reflux breathes out after coughing. The study will also seek to determine if this measurement can predict the best treatment for the cough.

Subjects with a chronic cough which is suspected to be related to acid reflux for which their doctor has prescribed a proton pump inhibitor medication will be enrolled in this study.

Condition Intervention
Gastroesophageal Reflux Procedure: Serial exhaled breath collections

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Serial Exhaled Breath pH Monitoring

Resource links provided by NLM:

Further study details as provided by University of Virginia:

Primary Outcome Measures:
  • pH of cough samples [ Time Frame: 1 month ]
  • change in Leicester Cough Questionnaire (LCQ) total score [ Time Frame: 1 month ]

Secondary Outcome Measures:
  • proton pump inhibitor dosing [ Time Frame: 1 month ]

Estimated Enrollment: 99
Study Start Date: April 2006
Estimated Study Completion Date: December 2011
Estimated Primary Completion Date: December 2011 (Final data collection date for primary outcome measure)
Intervention Details:
    Procedure: Serial exhaled breath collections
    collect breath for 5 minutes on 8 occasions
Detailed Description:

Acid reflux has been considered to be a key contributor to cough, particularly in patients with obstructive lung diseases. However, diagnosis has relied upon either responsiveness to high dose twice daily administration of proton pump inhibitor therapy or by 24 hour esophageal pH probes. This study is designed to provide information for the development of a clinically useful diagnostic (exhaled breath condensate pH) to identify the contribution of acid reflux to cough.

Exhaled breath condensate (EBC) pH has been well documented to reflect airway acidification. Acid reflux to the level of the hypopharynx, which is a key common trigger of acid reflux induced cough, acidifies the airway sufficiently to be identified with EBC pH assays. The association of low EBC pH with an immediately preceding cough strongly suggests an association of the cough with an airway acid event, and even if the acidity is not prolonged, acid reflux becomes highly suspect.

This study will examine the ability of EBC pH measurements to prognose the likelihood of a positive response to acid blockade with proton pump inhibitor therapy in subjects with chronic cough.


Ages Eligible for Study:   5 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
patients with chronic cough for whom their doctor is planning to begin an empiric trial of proton pump inhibitor as a diagnostic trial of therapy.

Inclusion Criteria:

  • Outpatient
  • 5 years of age and older
  • Cough lasting a minimum of 3 weeks
  • Has been prescribed a proton pump inhibitor as a single therapeutic and diagnostic effort to control the cough

Exclusion Criteria:

  • Inability to perform serial exhaled breath condensate collections at home
  • Unwillingness to initiate proton pump inhibitor therapy as prescribed by physician
  • Other changes planned in therapy, such as initiating or discontinuing cough suppressant therapy, initiating or augmenting antibiotic therapy, initiating or augmenting anti-inflammatory therapy
  • Previous treatment of respiratory symptoms with proton pump inhibitor therapy
  • Current treatment with angiotensin converting enzyme inhibitor medication or H2 antagonists
  • Regular exposure to an environmental irritant
  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 identifier: NCT00330603

Contact: John Hunt, MD 434-243-9324

United States, Virginia
University of Virginia Recruiting
Charlottesville, Virginia, United States, 22908
Contact: John Hunt, MD    434-243-9916   
Principal Investigator: John Hunt, MD         
Sponsors and Collaborators
University of Virginia
Principal Investigator: John Hunt, MD University of Virginia
  More Information

Responsible Party: John Hunt, MD, University of Virginia, Pediatrics Identifier: NCT00330603     History of Changes
Other Study ID Numbers: 12302
Study First Received: May 26, 2006
Last Updated: March 4, 2011

Keywords provided by University of Virginia:
Gastroesophageal Reflux

Additional relevant MeSH terms:
Gastroesophageal Reflux
Esophageal Motility Disorders
Deglutition Disorders
Esophageal Diseases
Gastrointestinal Diseases
Digestive System Diseases processed this record on August 18, 2017