Breathing Pattern Adopted by Children with Cystic Fibrosis with Mild to Moderate Pulmonary Impairment during Exercise

Abstract

Background: It is well known that severe lung impairment in cystic fibrosis (CF) may compromise respiratory muscle function at rest. Even though patients with CF and severe obstructive lung disease exhibit an abnormal breathing pattern during exercise (due to expiratory flow limitation), patients with CF and normal lung function reportedly have a normal breathing pattern. Objectives: The aim of the study was to assess the precise characteristics of the ventilatory pattern adopted during exercise by children with CF and mild to moderate lung disease. Methods: Nine children diagnosed as having mild to moderate CF and 9 healthy children with a similar age distribution participated in this study. Both groups performed a continuous incremental cycling protocol. Breathing and timing components were assessed during exercise. Results: Differences in the breathing pattern between children with CF and controls during exercise are illustrated in Hey plot which described a rapid shallow breathing pattern in children with CF. During exercise, children with CF showed a significantly lower mean inspiratory flow than healthy children (p < 0.001), whereas the mean expiratory flow was higher (p < 0.001). Children with CF also showed a significant increase in the end-tidal carbon dioxide pressure, which may indicate the emergence of hypercapnia. Conclusions: During exercise, children with CF (even those not suffering from advanced disease) showed signs of rapid, shallow breathing and an increase in the ventilatory response. This was essentially due to an increase in the mean inspiratory flow, which in turn suggests an expiratory flow limitation. The children were also predisposed to hypercapnia.

Breathing pattern and chest wall volumes during exercise in patients with cystic fibrosis, pulmonary fibrosis and COPD before and after lung transplantation

“…During exercise, these patients are able to increase tidal volume slightly (p<0.01) mainly by increasing abdominal displacement. These data are in agreement with those of Keochkerian et al ,30 who reported that during exercise, children with CF, even those not suffering from advanced disease, showed signs of rapid and shallow breathing and an increase in the ventilatory response. This was essentially due to an increase in the mean inspiratory flow, which in turn suggests an expiratory flow limitation 31.…”

Statement on Exercise Testing in Cystic Fibrosis

“…Exercise may be associated with adverse events which may be detected during an exercise test, such as hypoxemia [2,41,42], hypercapnia [43] and cardiac dysrhythmias [2]. These cannot be predicted from measurements at rest [2] and thus require exercise testing.…”

Head-Out Spirometry Accurately Monitors the Course of <i>Pseudomonas aeruginosa</i> Lung Infection in Mice

“…Spirometry is an established and extensively used method to assess pulmonary status in humans with lung pathologies like cystic fibrosis, asthma or COPD [1,2,3,4]. In cystic fibrosis and COPD, it is a valuable tool for the diagnosis of an acute exacerbation [5,6,7].…”