[Pulmonary physiopathology in scleroderma: study of respiratory function in 86 patients]

To contribute to an early diagnosis of pulmonary involvement in scleroderma by evaluating the correlation between respiratory symptoms and functional respiratory data observed.

86 patients affected by scleroderma, 76 women and 10 men, age 14-75, underwent lung function tests, blood gas sample, CO diffusing capacity in setting and supine position, respiratory drive measurement through P0.1 and evaluation of the respiratory muscles efficiency with Maximum Inspiratory Pressure (MIP).

Data obtained suggested us to divide our patients in four different groups: first group where both spirometric data and pulmonary diffusion were normal; a second group with a clear reduction of pulmonary diffusion likely due to the reduction of vascular bed; a third group where we observed a restrictive ventilatory impairment due to the reduction of the compliance and a reduction of the pulmonary diffusion likely related to interstitial damage; finally, a fourth group where beside a restricted spirometric outline we have detected a more accentuated reduction of pulmonary diffusion likely due to pulmonary hypertension. Moreover, our study has highlighted a progressive decrease of MIP and Maximum Voluntary Ventilation (MVV) shifting from the first to the fourth group, suggesting reduction of the muscular efficiency with an increase of P0.1 index of activity in the respiratory drive.

The results could explain the dyspnea often reported by the patients affected by scleroderma even without spirometric alteration.