Esophageal Motility in Reflux Induced Cough

Study Overview
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Brief Summary
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To determine whether contraction abnormalities in the esophagus plays a role in gastroesophageal reflux induced cough, and thus cough severity in patients with chronic cough.

Official Title
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Chronic Cough and Reflux: Is Esophageal Motility the Key?

Conditions
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Cough

Intervention / Treatment
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* Other: Citric Acid


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Adult patients (ages 18-75 years old) Cough for more than 8 weeks Additional clinical evaluation of cough including a complete pulmonary function test with methacholine challenge and a high resolution CT scan of the chest. Ability to understand the purpose and nature of the study Willingness to participate and provide consent form Exclusion criteria: Actively smoke in the preceding 6 months. Recent respiratory tract infection (<4 weeks). Drink above the recommended safe alcohol limit (21 units per week). History of respiratory or gastrointestinal malignancies. Previous gastrointestinal surgery (excluding minor surgeries, such as cholecystectomy, appendectomy). Subjects with established and significant cardiac, pulmonary, or neurological disorders as deemed by the clinician or study personnel Use of angiotensin converting enzyme inhibitors Use of H2 blockers or proton pump inhibitors in the seven days prior to reflux testing (impedance/pH), or inability to withhold such medications for the duration of the study Women of childbearing potential, using adequate birth control. Adequate birth control includes: (i) hormonal methods, such as birth control pills, patches, injections, vaginal ring, or implants; (ii) barrier methods (such as, a condom or diaphragm) used with a spermicide (a foam, cream, or gel that kills sperm); (iii) intrauterine device (IUD); or (iv) abstinence (no sex). Adequate birth control must be maintained for the duration of the study. Women not using adequate birth control will be excluded from the study, as funding for the pregnancy tests was not included in the small grant awarded for this study. Nursing mothers will be excluded. Persons with allergies to citrus will be excluded. Inability to understand the purpose and nature of the study Unwillingness to participate and provide consent form

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Chronic Cough<br>Subjects with chronic cough will undergo cough reflex sensitivity testing to citric acid. The dose, starting at 0.03 mol/L citric acid will be administered as single breath inhalations using flow-limited calibrated pots and a dosimeter with 3 placebo inhalations of normal saline randomly interspersed. Following each inhalation, the number of coughs in the subsequent 15 seconds will be counted and recorded. The challenge will be terminated once the citric acid has induced 5 or more coughs. | Other: Citric Acid<br>* Subjects will undergo cough reflex sensitivity testing to citric acid.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of subjects with reflux related cough |  | 24 hrs | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic Cough, Gastroesophageal Reflux, Esophageal Motility, Cough Sensitivity