Evaluating Sensations of Breathlessness in Patients With Cystic Fibrosis (CF_Dyspnea)
Shortness of breath (dyspnea) during exercise is a major source of distress and is a commonly reported symptom in patients with cystic fibrosis (CF). Due to the investigators' poor understanding of how dyspnea develops, there are no treatments that consistently reduce dyspnea in this population. The investigators aim to acquire a more comprehensive understanding of the physiological mechanisms of exertional dyspnea in CF patients. This study will likely identify an important physiological mechanism of dyspnea in CF and may contribute to the development and use of effective treatments to reduce dyspnea in this population.
The central hypothesis is that the impaired tidal volume (VT) response during exercise in CF, in the setting of increased ventilatory demand will give rise to different qualitative descriptions of exertional dyspnea compared with healthy age and sex-matched controls. Specifically, CF patients will select "increased work and effort" as their dominant descriptor of dyspnea up to the VT inflection/plateau. Beyond this point, CF patient's dominant descriptor will become "unsatisfied inspiration." In contrast, healthy control participants will report "increased work and effort" throughout all phases of exercise and will not report "unsatisfied inspiration", even after the VT inflection/plateau.
|Lung; Disease Cystic Fibrosis Healthy|
|Study Design:||Observational Model: Case Control|
|Official Title:||Qualitative Descriptors of Dyspnea During Exercise in Cystic Fibrosis|
- To determine if dyspnea is qualitatively and quantitatively different in patients with cystic fibrosis compared with age and sex-matched healthy controls during exercise [ Time Frame: Parameters will be measured during the 1 visit. ]Included will be 20 patients with cystic fibrosis (CF) who have no other pulmonary or extra-pulmonary limitation to exercise, as well as 20 healthy age and sex-matched control participants. All participants (CF and control) will perform an incremental symptom-limited cardio-pulmonary exercise test while detailed cardio-respiratory responses, dyspnea responses, muscle oxygenation and muscle hemodynamic data are measured.
- To determine if the dyspnea responses can be explained by differences in the ventilatory response to exercise. [ Time Frame: Parameters will be measured during the 1 visit. ]Included will be 20 patients with cystic fibrosis (CF) who have no other pulmonary or extra-pulmonary limitation to exercise, as well as 20 healthy age and sex-matched control participants. All participants (CF and control) will perform an incremental symptom-limited cardio-pulmonary exercise test while detailed cardio-respiratory responses, dyspnea responses, muscle oxygenation and muscle hemodynamic data are measured. The point at which the tidal volume deviates from linearity and begins to plateau will be defined as the inflection point of the tidal volume and minute ventilation relationship. Two different observers will determine the inflection point for each participant during the incremental exercise test by examining individual Hey plots.
|Study Start Date:||June 2013|
|Study Completion Date:||December 2014|
|Primary Completion Date:||December 2014 (Final data collection date for primary outcome measure)|
Cystic Fibrosis Patients
Participants with Cystic Fibrosis
Participants who do not have cystic fibrosis and are otherwise healthy.
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01799642
|Canada, British Columbia|
|UBC James Hogg Research Centre, St. Paul's Hospital|
|Vancouver, British Columbia, Canada, V6Z1Y6|
|Principal Investigator:||Jordan A Guenette, PhD||UBC James Hogg Research Centre|