Qualitative dimensions of exertional dyspnea in adults with cystic fibrosis.
No studies of cystic fibrosis (CF) have systematically characterized the evolution of the qualitative dimensions of exertional dyspnea. Adults with CF (n = 25) and control individuals matched for sex, age, and body mass index (n = 25) underwent cardiopulmonary cycle exercise testing with a detailed evaluation of ventilatory and dyspnea responses. The qualitative dimensions of dyspnea were examined during each exercise stage by having subjects select phrases that best described their breathing (i.e., "work/effort," "unsatisfied inspiration," and "unsatisfied expiration"). Subjects also selected phrases that described the quality of their breathing at peak exercise using an established 15-item questionnaire, which was then clustered into different categories. Subjects with CF had greater ventilatory requirements, higher end-inspiratory and end-expiratory lung volumes (% total lung capacity), and an earlier inflection/plateau in tidal volume during exercise compared with control subjects. Increased work/effort was the dominant qualitative descriptor in both groups throughout exercise. Unsatisfied inspiration was selected by 48% of subjects with CF and 40% of controls at some point during exercise. The onset of unsatisfied inspiration in these subjects occurred at a significantly lower relative exercise intensity in subjects with CF vs. controls (72 ± 21 vs. 94 ± 11% Wmax, P < 0.01). Chest tightness was the only qualitative descriptor cluster that was selected more frequently by subjects with CF vs. controls (36 vs. 0%, respectively, P < 0.05) at peak exercise. Therapeutic interventions that reduce ventilatory requirements and improve lung volumes may delay the onset of distressing sensations such as unsatisfied inspiration and chest tightness in adults with CF.
Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada;
Bradley S
BS
Quon
Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada;
Sabrina S
SS
Wilkie
Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada; Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada; and.
Andrew H
AH
Ramsook
Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada; Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada; and.
Michele R
MR
Schaeffer
Centre for Health Evaluation & Outcome Sciences, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada.
Joseph H
JH
Puyat
Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada;
Pearce G
PG
Wilcox
Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada; Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada; and.
Jordan A
JA
Guenette
D000328:Adult; D003550:Cystic Fibrosis / Q000150:complications / Q000503:physiopathology*; D004417:Dyspnea / Q000209:etiology / Q000503:physiopathology*; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D015656:Respiratory Mechanics; D013990:Tidal Volume
breathlessness; dynamic hyperinflation; exercise physiology; ventilation