Qualitative dimensions of exertional dyspnea in adults with cystic fibrosis

No studies in cystic fibrosis (CF) have systematically characterized the evolution of the qualitative dimensions of exertional dyspnea. Adults with CF (n=25) and sex-, age-, and body mass index-matched controls (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 increased ventilatory requirements, higher end-inspiratory and end-expiratory lung volumes (% total lung capacity), and an earlier inflection/plateau in tidal volume during exercise compared to controls. Increased "work/effort" was the dominant qualitative descriptor in both groups throughout exercise. "Unsatisfied inspiration" was selected in 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 in CF vs. controls at peak exercise (36 vs. 0%subjects, p<0.05). 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.

from Physiology via xlomafota13 on Inoreader http://ift.tt/1US8DZe
via IFTTT