Dyspnea perception in cystic fibrosis patients

We evaluated dyspnea perception in cystic fibrosis patients compared with normal subjects, during an inspiratory resistive loading test and 6-min walk test. We also evaluated the correlation between dyspnea scores induced by resistive loads and by the 6-min walk test. In this prospective, cross-sectional study, 31 patients with cystic fibrosis (≥15 years of age) and 31 age-, gender-, and ethnicity-matched healthy volunteers (20 females and 11 males per group) underwent inspiratory resistive loading, spirometry, and the 6-min walk test. As the magnitude of the inspiratory loads increased, dyspnea scores increased (P<0.001), but there was no difference between groups in dyspnea score (P=0.654). Twenty-six (84%) normal subjects completed all the resistive loads, compared with only 12 (39%) cystic fibrosis patients (P<0.001). Dyspnea scores were higher after the 6-min walk test than at rest (P<0.001), but did not differ between groups (P=0.080). Post-6-min walk test dyspnea scores correlated significantly with dyspnea scores induced by resistive loads. We conclude that dyspnea perception induced in cystic fibrosis patients by inspiratory resistive loading and by 6-min walk test did not differ from that induced in normal subjects. However, cystic fibrosis patients discontinued inspiratory resistive loading more frequently. There were significant correlations between dyspnea perception scores induced by inspiratory resistance loading and by the 6-min walk test. This study should alert clinicians to the fact that some cystic fibrosis patients fail to discriminate dyspnea perception and could be at risk for delay in seeking medical care.

B lunted dyspnea perception in severe asthmatics / 천식및알레르기

BACKGROUND: Blunted perception of dyspnea, which may be related to the increased mortality, has been demonstrated in patients with a history of near-fatal asthma and in the elderly. OBJECTIVE: The purpose of this study was to evaluate the relationship between the perception of dyspnea and the severity of asthma. METHOD: Baseline spirometry and Borg score change(A Borg score) during breathing through an inspiratory muscle trainer were measured in 27 consecutive asthma patients and 11 normal subjects. RESULTS: The baseline Borg score was negatively related to FEV1 A Borg score was significantly lower in asthmatics than in controls at high level of loads. A Borg score was lower in severe asthma than in mild asthma. A Borg score was positively related to the baseline FEV1. Seventy-five percent of severe asthma, 62.5% of moderate one, and 9.1% of mild one showed impaired dyspnea perception. Dyspnea perception was related to age(r, = -0.49, p<0.001). CONCLUSION: Three quarters of patients with severe asthma showed impaired dyspnea perception to inspiratory resistive load. Dyspnea perception was related to asthma severity and age.