Efeito do Tempo de Doença na Biomecânica Respiratória de Pacientes Portadores de Artrite Reumatóide

Abstract

Rheumatoid arthritis (RA) is a rheumatic disease that primarily affects peripheral joints, but its mortality is directly related to pulmonary involvement. Some results have shown that spirometric exams are often normal in these individuals. Recently, a prototype of an instrument implementing the Forced Oscillation Technique (FOT) was used in the analysis of these patients, showing significant adverse modifications in biomechanics. This study evaluates the effect of the duration of the disease on respiratory function by spirometry and FOT. For this purpose, the study involved 11 normal subjects and 38 patients that were classified into four groups according to disease duration. There was no change in the values of spirometric parameters with disease duration. On the other hand, the FOT resistive parameters R0 and Rm increased significantly (p<0.0001, p<0.00001), while the dynamic compliance (Cdyn,rs) decreased significantly (p<0.00001), with disease duration. The correlations confirm these results, demonstrating r² values of 0.11 for R0 and 0.24 for Cdyn,rs. We conclude that there are significant changes in the biomechanical properties of the respiratory system of individuals with RA that are associated with disease duration and that this early changes may be detected by the FOT.