[Respiratory mechanics in patients with stage III pulmonary sarcoidosis and idiopathic fibrosing alveolitis: similarities and differences].

Impaired function of the lung was studied in 28 patients with Stage 111 pulmonary sarcoidosis and 17 patients with idiopathic fibrosing alveolitis (IFA). The study involved spirography, body plethysmography, and esophageal probing of respiratory mechanics. In patients with Stage III pulmonary sarcoidosis, the mechanics of respiration has the following similarities: restrictive ventilation disorder is revealed in IFA; the functional syndrome with a predominance of restriction is also detectable in some patients with Stage III sarcoidosis; significant differences are found in patients with IFA and Stage III pulmonary sarcoidosis: there is no marked impaired patency of peripheral bronchi in IFA; and all the functional changes found suggest that there is an increase in lung tissue rigidity and a decrease in the capacity of the lung to straighten; in Stage III sarcoidosis, of great importance is a marked impairment of patency of peripherally located bronchi, which is associated with the increase of this or that degree of lung compliance and in the retraction index.