Impulse oscillometry system: association with pulmonary function in patients with COPD and healthy subjects

Resumo

Background: Spirometry is the gold-standard diagnosis test for COPD. However, the impulse oscillometry system (IOS) has proven to be effective for early detection of COPD and little is known about the association between the two techniques in the presence or absence of pulmonary disease. Objective: To investigate the association between lung function and lung mechanics using the IOS in patients with COPD and healthy subjects. Methodology: Eighteen patients with COPD and 18 healthy individuals performed spirometry and the IOS. Results: FEV1 and FEF25-75% correlated with X5Hz (r=0.74; r=0.63), and with R5Hz-R20Hz (r=-0.67; r=-0.51), and FVC moderately correlated with most of the oscillometric parameters (R5Hz, Z5Hz, R5Hz – R20Hz, X5Hz and Fres) in the COPD group. Conclusions: Reactance is related to pulmonary airflow obstruction and peripheral resistance is associated with mean forced expiratory flow. Thus, IOS is a method that can complement spirometric findings in patients with COPD.