RESUMO
Objective To explore the diagnostic value of impulse oscillometry(IOS) in the patients with COPD. Methods The IOS parameters of 142 cases of COPD (COPD group) were measured and compared with those of 160 normal eases (control group). Linear correlation analysis was done between the IOS parameters and the conventional pulmonary function indexes such as FEV1 / Pred and FEV1/FVC, and the diagnostic value of the IOS parameters in COPD was discussed. Results Compared with those of the control group, respiratory impedance (Zrs),resistance at 5 Hz and 20 Hz (R5,R<<20>) and their difference (R5-R20), central resistance (Re) and peripheral resistance (Rp), resonance frequency (Fres)in the COPD group increased significantly, while reactance at 5 Hz (X5) decreased obviously (P< 0.01 ). In the COPD group, Zrs, Fres, R5, R20, R5-R20 and Rp were all correlated negatively with FEV1 / Pred, but X5 was correlated positively with FEV1/Pred. And the most strong correlation was found between Fres and FEV1/Pred. Fres, R5, R5-R20, Rp were correlated negatively with FEV1/FVC( P all < 0.05). Conclusions IOS is suitable for the diagnosis of COPD,and can be used to evaluate the severity of COPD. The application perspective is very extensive.