Analise da mecânica respiratória em indíviduos com sarcoidose através de modelos de ordem inteira e fracionária

Abstract

Sarcoidosis is a multisystemic syndrome of uncertain etiology with abnormal respiratory findings in approximately 90% of cases, with the central focus being the accumulation of non-infectious granulomas, causing changes in the lung structure. Spirometry is the most common lung function test and is used to assess lung function in diagnosis and monitoring lung health. Respiratory oscillometry allows the analysis of respiratory impedance and its components. Respiratory oscillometry (FOT) allows you to analyze respiratory impedance and its components. Integer order (eRIC) and fractional order (FrOr) modeling have been increasingly used to interpret measurements obtained through FOT. These models have the potential to improve the clinical understanding of lung diseases, offering accurate models for analyzing ventilatory mechanics. Models can provide a detailed description of the respiratory system, contributing to a greater understanding of the changes resulting from the disease. In this context, in order to contribute to the understanding of respiratory pathophysiology in sarcoidosis, the present work has the following objectives: Improve knowledge about pathophysiological changes in the respiratory system of patients with sarcoidosis; Analyze the evolution of sarcoidosis in individuals without changes in spirometry; Evaluate changes in respiratory mechanics in patients with sarcoidosis using eRIC and FrOr fractional order modeling; Analyze the correlation between the aforementioned modeling and spirometry; Analyze the diagnostic accuracy of these models in the groups studied. In the eRIC model, R and Rt showed a significant increase in the groups with normal sarcoidosis on examination (NE) and with alterations (SALT) compared to the control group (CG). There was a reduction in compliance in the SALT sacidosis group compared to the CG (p<0.001) and an increase in Rp in the same group (p<0.001). There was no statistical difference in inertance between the groups studied. In the FrOr model, G and hysteresivity increased in the diseased groups compared to the CG, while H decreased in the NE sarcoidosis group (p<0.05). In the correlation analysis between spirometry parameters and the eRIC and FrOr models in the NE and altered sarcoidosis groups, the greatest relationships were between Rt and FEV1 (r:-0.600 and p:0.0001). The diagnostic accuracy in patients with NE sarcoidosis and with changes showed that Rt and hysteresivity obtained the highest values, reaching an AUC: 0.986 and AUC: 0.938 in the NE and changes groups, respectively. The model offered a deeper understanding of changes in lung mechanics in sarcoidosis. The results suggest that the parameters obtained through this model can improve the assessment and enable better management of these patients. Specifically, the parameters of total resistance and hysteresivity demonstrated diagnostic potential, which may be beneficial for early identification of individuals with sarcoidosis, even when spirometry results are within normal limits.