Sham CPAP vs. Straight CPAP for Chronic Cough

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

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03172130

Enrollment

Registered

2017-06-01

Start date

2014-10-13

Completion date

2019-11-25

Last updated

2020-06-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chronic Cough, OSA

Keywords

Obstructive Sleep Apnea, CPAP

Brief summary

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.

Interventions

DEVICEStraight CPAP

DEVICESham CPAP

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

ALL

Age

18 Years to 80 Years

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame	Description
Change in Leicester Cough Questionnaire Score	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

Measure	Time frame	Description
8 Isoprostane Level in Exhaled Breath Condensate	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
Interleukin-8 (IL-8) Level in Exhaled Breath Condensate	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
Nitrite/Nitrate (NOX) Level in Exhaled Breath Condensate	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.
Change in Cough Frequency	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
Change in Leukotriene B4 (LTB4) Level in Exhaled Breath Condensate	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
Change in Gastroesophageal Reflux Disease Quality of Life (GERD-QoL) Questionnaire Score	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
Hydrogen Peroxide (H2O2) Level in Exhaled Breath Condensate	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

Countries

United States

Participant flow

Participants by arm

Arm	Count
Straight CPAP Patients randomized to straight CPAP will receive 10 cm of air pressure, or as determined by the results of polysomnography, for 6 weeks. Following the 6-week visit, patients will be placed on straight CPAP with equipment approved by insurance for an additional 6 weeks. Straight CPAP	9
Sham CPAP Patients randomized to sham CPAP will receive 1-2 cm of air pressure for 6 weeks. Following the 6-week visit, patients will be placed on straight CPAP with equipment approved by insurance for an additional 6 weeks. Sham CPAP	9
Total	18

Withdrawals & dropouts

Period	Reason	FG000	FG001
Overall Study	Failure to tolerate CPAP/Sham CPAP	3	1

Baseline characteristics

Characteristic	Straight CPAP	Sham CPAP	Total	—
Age, Categorical <=18 years	0 Participants	0 Participants	0 Participants	—
Age, Categorical >=65 years	2 Participants	2 Participants	4 Participants	—
Age, Categorical Between 18 and 65 years	7 Participants	7 Participants	14 Participants	—
Age, Continuous	52.4 years STANDARD_DEVIATION 10.9	62.7 years STANDARD_DEVIATION 6.3	57.2 years STANDARD_DEVIATION 10.27	—
Ethnicity (NIH/OMB) Hispanic or Latino	—	—	0 Participants	—
Ethnicity (NIH/OMB) Not Hispanic or Latino	—	—	0 Participants	—
Ethnicity (NIH/OMB) Unknown or Not Reported	—	—	0 Participants	—
Race (NIH/OMB) American Indian or Alaska Native	—	—	0 Participants	—
Race (NIH/OMB) Asian	—	—	0 Participants	—
Race (NIH/OMB) Black or African American	—	—	0 Participants	—
Race (NIH/OMB) More than one race	—	—	0 Participants	—
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	—	—	0 Participants	—
Race (NIH/OMB) Unknown or Not Reported	—	—	0 Participants	—
Race (NIH/OMB) White	—	—	0 Participants	—
Region of Enrollment United States	—	—	—	— participants
Sex: Female, Male Female	7 Participants	4 Participants	11 Participants	—
Sex: Female, Male Male	2 Participants	5 Participants	7 Participants	—

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	0 / 9	0 / 9
other Total, other adverse events	0 / 9	0 / 9
serious Total, serious adverse events	0 / 9	0 / 9

Outcome results

Primary

Change in Leicester Cough Questionnaire Score

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