Validação da técnica de oscilações forçadas no diagnóstico das alterações respiratórias em pacientes com silicose

Abstract

Silicosis is a typical occupational respiratory disease characterized by irreversible alterations throughout the alveolar and interstitial structure. The objectives of this study were: (1) investigate the potential of the Forced Oscillation Technique (FOT) in the analysis of the patients with silicosis, (2) evaluate the ability of FOT to identify early alterations in the respiratory mechanics of these patients and (3) identify the best parameter(s) of FOT for the diagnosis of silicosis. 67 volunteers were studied: 21 healthy subjects and 46 with silicosis and these were divided into 3 groups according to the spirometric classification: normal spirometry results (n=12), mild obstruction (n=22), moderate and severe obstruction (n=12). A significant (p<0.0002) increase in respiratory resistance at 4 Hz (Rsr4) and module of respiratory system impedance (|Z4Hz|) were observed, as well as a decrease in the slope of the resistance (S, p<0.0004). Rsr4 and |Z4Hz| obtained adequate values of accuracy (>80%). FOT parameters adequately describe pathophysiological changes associated with silicosis and showed adequate accuracy for clinical use, indicating that this technique may represent an alternative for the evaluation of respiratory mechanics in patients with silicosis. © 2013 Springer.