The place of impulse oscillometry system in the diagnosis of early obstructive disorders associated with asthma

Asthma is one of the most common and socially significant human diseases. To date, spirometry is included in most recommendations as the gold standard for the diagnosis of obstructive disorders. However, in real clinical practice, this procedure does not always reveal signs of bronchial obstruction, not only in the early stages of the disease but also in more severe controlled bronchial asthma. Tests of oscillatory mechanics are increasingly being used to detect early violations of the pulmonary ventilation function. These tests are based on the forced oscillation technique, and the latest modification is impulse oscillometry system. Theaimof this study was to investigate the capabilities of impulse oscillometry in diagnosing early changes in the function of the respiratory system in patients with asthma and identifying the most informative parameters of the method.Methods. A total of 146 patients with an established diagnosis of mild and moderate asthma were examined during remission. The patients were divided into 2 groups by the severity of asthma. The comparison group included 40 people with no signs of lung abnormalities.Results. Disorders of the pulmonary ventilation function were found in 23% of patients with asthma by spirometry, in 42% by bodypletismography in 42%, and in 72% of patients by impulse oscillometry. Impulse oscillometry system revealed obstructive changes localized in the central respiratory tract in 11% of patients, and obstruction of mixed localization was found in 6% of respondents. Peripheral respiratory tract disorders were diagnosed in 56 % of patients. Most respiratory tract lesions were located in the small bronchi in both groups. The obstructive disorders in large bronchi and generalized obstruction were observed more often in the 2ndgroup. Among impulse oscillometry parameters, the increase in Delta (Rrs5– Rrs20) was most often recorded in both examined groups of patients with asthma.Conclusion. Compared to standard methods, impulse oscillometry system is more sensitive. Therefore, it has advantages in diagnosing respiratory system dysfunctions both in the early stages of asthma and in more severe cases during remission.