Relationship between dyspnoea, pulmonry function and exercise capacity in patients with cystic fibrosis

Abstract

The median age of survival in patients with cystic fibrosis (CF) has improved considerably. Despite this improvement, deterioration of pulmonary function and decrease in exercise capacity are still the main problems for many patients. Although dyspnoea is a common complaint in CF patients, relatively little regard has been paid to this symptom. This study examined the relationship between dyspnoea, bicycle exercise capacity and pulmonary function in patients with CF. In 14 patients in a stable clinical condition, pulmonary function [forced expiratory volume in 1 s (FEV1), inspiratory vital capacity (IVC)], bicycle exercise capacity [maximum exercise capacity (Wmax)], subjective degree of dyspnoea during daily living [Medical Research Council (MRC) dyspnoea scale], and during exercise (Borg scale) were assessed. The mean (SD) age of the patients was 25 (6.8) years, FEV1 was 41 (19)% predicted, IVC was 63 (17)% predicted and FEV1/IVC ratio was 47 (10)%; median (range) Wmax was 55 (0-79)% predicted. Bicycle exercise test performance appeared to be mainly determined by pulmonary function and MRC dyspnoea grade; multiple regression equation containing FEV1 and dyspnoea accounted for 76% of the variance in Wmax (% predicted) (Wmax = -7.9 dysp + 1.1 FEV1, +24). Exercise dyspnoea, assessed by the Borg scale, showed a significant linear correlation with minute ventilation. (VE), maximal voluntary ventilation (MVV) (%) (r = 0.76; P < 0.001). Medical Research Council dyspnoea score correlated relatively poorly with FEV1 (% predicted) (r = -0.17; n.s.) and IVC (% predicted) (r = -0.48; n.s.). Borg score at maximal exercise did not correlate with MRC dyspnoea score (r = -0.07). Borg50% score correlated significantly with MRC dyspnoea score (r = 0.61; P < 0.05). These results show that dyspnoea has an influence on exercise capacity. Dyspnoea score showed a large inter-individual variation, not strongly related to pulmonary function. It is concluded that dyspnoea deserves more attention in CF patients and needs to be assessed in rehabilitation programmes and other intervention studies in these patients.

Use of exercise testing in the evaluation of interventional efficacy: an official ERS statement

“…Two different approaches are used to measure dyspnoea: ratings based on daily living activities and ratings during specific exercise tasks. The information obtained by these two methods is different [151,152]. As the task force focused on exercise testing, the latter are discussed here.…”

Relationship Between Anxiety, Depression, and Quality of Life in Adult Patients With Cystic Fibrosis

“…9 The self-completed CF-QOL consists of 52 items across 9 domains of functioning: physical functioning, social functioning, treatment issues, chest symptoms, emotional functioning, concerns for the future, interpersonal relationships, body image, and future/career concerns. Each item is scored on a 6 point Likert scale (1)(2)(3)(4)(5)(6), and each domain is scored out of 100, with a higher score of each domain reflecting a better quality of life. The CF-QOL is a validated diseasespecific measure in adults and adolescents with CF.…”

“…3 Recent advances in the detection and management of CF have led to an increase in the number of individuals surviving into adulthood, and as a result, patients with CF are living with a chronic illness with a substantial psychological and social challenge. 4,5 A few studies have examined the prevalence of anxiety and depression in subjects with CF. Havermans and colleagues 6 reported normal scores for anxiety and depression using the Hospital Anxiety and Depression Scale (HADS) among 57 adult CF subjects.…”

Patient-reported Outcomes in Cystic Fibrosis

“…It has been used extensively in COPD. In a recent study in CF, the MRC correlated poorly with FEV 1 percent predicted (n ϭ 14) and showed large interindividual variation, but was associated with maximal work achieved on bicycle exercise capacity testing (78). The MRC was used to assess the subjective degree of dyspnea during daily living.…”

“…The instrument has been shown to have acceptable content and criterion validity and test-retest reliability, and discriminates well, but only assesses a limited number of symptoms. The Borg scale has been used in three different studies of patients with CF and is one of the most widely used scales to quantify perceived dyspnea (73,74,78).…”