Restricted Pulmonary Function in Cystic Fibrosis: Outcome

In this study, we proposed that restriction would be due to scarring and infiltration of the pulmonary parenchyma and, therefore, expected to find differences between the radiographic and gas volumes in the restricted patients. Although these differences did exist and, on average, were in the expected direction, there was considerable variability within groups, and the differences did not reach statistical significance. We also expected to find that the radiographic-gas volume differences in the restricted patients would correlate with radiographic grades of pulmonary parenchymal lesions (air-space or nodular cystic lesions) as a reflection of severity Surprisingly, the radio-graphic-gas volume differences were highly correlated only with radiographic ratings of air trapping (hyperinflation) and bronchial markings. These findings suggest that the mechanism of restriction in these patients with cystic fibrosis is not related directly to the extent of air-space-filling lesions and raises the interesting possibility that the restriction may be related more to airway disease. The fact that maximum inspiratory pressure was not different between groups indicates that inspiratory muscle weakness was also not a cause of restriction. read only

The primary pulmonary lesion is cystic fibrosis is obstruction of the small airways by inflammation and mucous plugging. Restrictive changes have been observed occasionally in patients with other airway diseases, including asthma and bronchiolitis obliterans and may be related to diffuse inflammatory obstruction of small airways. A similar mechanism in cystic fibrosis might explain the significant correlations observed between radiographic-gas volume differences and bronchial marking grades on the chest roentgenograms reflecting generalized airway inflammation.

Category: Pulmonary Function

Tags: airway, cystic fibrosis, Pulmonary Function