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Completed

NCT Number: NCT03172130

Sham CPAP vs. Straight CPAP for Chronic Cough

Chronic cough is an important clinical problem in primary care and sub-specialty practice. Besides the distress experienced by patients with chronic cough, significant healthcare resources are expended to understand the role of gastroesophageal reflux, asthma and post-nasal drip in understanding their contribution to cough.

Obstructive sleep apnea (OSA) is common in patients with chronic cough. More importantly, treatment of OSA with continuous positive airway pressure (CPAP) has led to improvement in cough for chronic cough patients. Mechanisms by which OSA therapy with CPAP can improve cough includes beneficial effects on reflux and airway inflammation.

The aim of this study is to definitively establish that CPAP therapy for treatment of OSA in chronic cough patients improves cough. While these patients with chronic cough are not routinely screened and treated for OSA, this study aims to evaluate these chronic cough patients with screening questionnaires for OSA and if necessary with polysomnography and randomize them to either CPAP or sham CPAP for 6 weeks.

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Key information

Conditions

Chronic Cough Apnea Cough Dyssomnias Nervous System Diseases OSA Pathological Conditions, Signs and Symptoms Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory Sleep Apnea Syndromes Sleep Apnea, Obstructive Sleep Disorders, Intrinsic Sleep Wake Disorders

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Utah

Salt Lake City, Utah, 84132, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Cough of more than 2 month duration
  • Not active smoker with history of stoppage of smoking for more than 6 months
  • Evaluation and treatment by other providers for suspected gastroesophageal reflux disease (GERD), upper airway cough syndrome (UACS), or cough-variant asthma (CVA) for at least 1 month
  • Normal chest radiography or computed tomography (CT) scans (patients with up to 2 lung nodules less than 3 mm will be allowed if there is no history of malignancy elsewhere)
  • Normal spirometry with predicted diffusing capacity of the lung for carbon dioxide (DLCO) more than 50% predicted. Pulmonary Function Test criteria: no evidence of airflow limitation (FEV1/FVC > 0.7) or significant chest restriction (FVC > 70% predicted) with predicted DLCO more than 50% predicted

Exclusion criteria

  • Pregnancy
  • Recent pneumonia (less than 6 months)
  • Congestive heart failure, acute or chronic renal disease, jaundice or chronic liver disease, pulmonary embolism, stroke or neurodegenerative disease, malignancy
  • Use of supplemental oxygen or positive airway pressure therapy (if patients have been diagnosed with obstructive sleep apnea in the past but were non-compliant with positive airway pressure therapy, they will not be excluded)
  • Use of opiates for cough suppression (opiate use for pain suppression can be included)
  • Alcoholism, drug dependence (including chewing tobacco) or illicit drug use
  • Esophageal cancer or laryngeal surgery
  • Craniofacial abnormalities that preclude CPAP placement

Treatment and study plan

Straight CPAP

Device

Sham CPAP

Device

Primary outcomes

  1. Change in Leicester Cough Questionnaire Score

    Time frame: Baseline and 6 weeks

    Subjects will complete the Leicester Cough Questionnaire at the baseline and 6-week visits. The Leicester Cough Questionnaire comprises 19 items, which assess symptoms, or the impact of symptoms, over the last 2 weeks on a seven-point Likert scale. Scores in three domains (physical, psychological and social) are calculated as a mean for each domain (range 1 to 7). A total score (range 3 to 21) is also calculated by adding the domain scores together. Higher scores indicate better quality of life. The change in Leicester Cough Questionnaire score will be compared between the Straight CPAP and Sham CPAP groups

Secondary outcomes

  1. Change in Cough Frequency

    Time frame: Baseline and 6 weeks

    Subjects will wear a Leicester cough monitor for 24 hours at the baseline and 6-week visits, which will record cough frequency during that period. The change in cough frequency from baseline to 6 weeks will be compared between the Straight CPAP and SHAM CPAP groups

  2. 8 Isoprostane Level in Exhaled Breath Condensate

    Time frame: Baseline and 6 weeks

    Samples of breath condensate will be collected from study subjects at the baseline and 6-week visits. The 8 isoprostane level from baseline to 6-weeks will be compared between the Straight CPAP and Sham CPAP groups

  3. Interleukin-8 (IL-8) Level in Exhaled Breath Condensate

    Time frame: Baseline and 6 weeks

    Samples of breath condensate will be collected from study subjects at the baseline and 6-week visits. IL-6 level from baseline to 6-weeks will be compared between the Straight CPAP and Sham CPAP groups

  4. Nitrite/Nitrate (NOX) Level in Exhaled Breath Condensate

    Time frame: Baseline and 6 weeks

    Samples of breath condensate will be collected from study subjects at the baseline and 6-week visits. NOX level from baseline to 6-weeks will be compared between the Straight CPAP and Sham CPAP groups.

  5. Hydrogen Peroxide (H2O2) Level in Exhaled Breath Condensate

    Time frame: Baseline and 6 weeks

    Samples of breath condensate will be collected from study subjects at the baseline and 6-week visits. H2O2 level from baseline to 6-weeks will be compared between the Straight CPAP and Sham CPAP groups

  6. Change in Leukotriene B4 (LTB4) Level in Exhaled Breath Condensate

    Time frame: Baseline and 6 weeks

    Samples of breath condensate will be collected from study subjects at the baseline and 6-week visits. The change in LTB4 level from baseline to 6-weeks will be compared between the Straight CPAP and Sham CPAP groups

  7. Change in Gastroesophageal Reflux Disease Quality of Life (GERD-QoL) Questionnaire Score

    Time frame: Baseline and 6 weeks

    Subjects will complete the GERD-QoL questionnaire at the baseline and 6-week visits. The GERD-QoL comprises 15 items on a five-point Likert scale; lowest possible score (0) = no symptoms, greatest possible score (75) = worst symptoms. The change in GERD-QoL score will be compared between the Straight CPAP and Sham CPAP groups

Sponsors and collaborators

Lead sponsor

Krishna M. Sundar

Other

Registry information

Official study title

Prospective Study of Efficacy of Sham CPAP vs. Straight CPAP on Cough Intensity in Patients With Chronic Cough

Important dates

Study start
2014
Primary completion
2019
Study completion
2019
First posted
Jun 1, 2017
Registry last updated
Jun 18, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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