[Analysis of external respiratory function disturbances in combined pulmonary fibrosis and emphysema]

To analyze the features of indicators of the external respiration function and their dynamics in patients with a combined pulmonary fibrosis and emphysema (CPFE).

The results of studies of 44 patients with a confirmed diagnosis of CPFE are presented. As a control group, the results of a study of respiratory function of 41 patients with idiopathic pulmonary fibrosis (IPF) were analyzed. The study of respiratory function included the measurement of static lung volumes and capacities, speed indicators, airway response to inhalation of a bronchodilator drug, diffusive capacity of the lungs and gas exchange parameters.

Spirometry indicators, such as vital capacity (p = 0.003), forced vital capacity - FVC (p = 0.003), forced expiratory volume in the first second - FEV₁ (p = 0.02), were significantly higher in CPFE. The same differences were observed in the group of patients with severe dyspnea (p = 0.029, p = 0.019, p = 0.032, respectively). The FEV₁/FVC ratio in CPFE was significantly lower (p = 0.013). The study of lung volumes and capacities by body plethysmography reveals higher values of total lung capacity (p = 0.002) and functional residual capacity of the lungs (p = 0.01) in CPFE. Alveolar volume was higher in CPFE (p = 0.046) and the DL_CO/VA ratio was higher in IPF (p = 0.013). Diffusion capacity of the lungs was equally low in the group of patients with severe dyspnea and correlated with the severity of dyspnea. There were no statistically significant differences between the rate of decrease in FVC, DL_CO, and other parameters.

In CPFE, the results of spirometry and bodyplethysmography do not reflect the degree of functional impairment and may make it difficult to assess the severity of the disease. Measurement of the diffusing capacity of the lungs and its components is an important method for determining the severity of functional disorders in patients with CPFE.