An informative value of impulse oscillometry for diagnosis of ventilation abnormalities in patients with newly diagnosed pulmonary sarcoidosis

Abstract

The aim of this study was to analysis the total respiratory impedance and its components and to evaluate the informative value of impulse oscillometry in comparison with conventional methods of lung function testing in patients with pulmonary sarcoidosis. Methods . The study involved 50 patients (88% of males; mean age, 31 ± 9 years) with newly diagnosed pulmonary sarcoidosis. The diagnosis of sarcoidosis was confirmed by lung biopsy. Spirometry, body plethysmography, and impulse oscillometry were used in all patients; the lung diffusing capacity was measured. Results . Abnormalities of the respiratory mechanics were found using the conventional diagnostic methods in 34% of the patients, including obstructive disorders in 18% and restrictive disorders in 16%; all were mild to moderate. Parameters of impulse oscillometry were abnormal only in 10% of the patients. Conclusion . The impulse oscillometry has a low sensitivity to detect mild functional respiratory abnormalities in patients with newly diagnosed pulmonary sarcoidosis.