RESUMEN
OBJECTIVE: To investigate the value of impulse oscillometry(IOS) technique in the assessment of silicosis. METHODS: A judgment sampling method was used to select 90 patients with silicosis as the silicosis group, which includes 30 cases in each stage of silicosis(stage 1-3). Thirty workers with no exposure history to free silica dust were selected as the control group. All subjects underwent routine pulmonary function and IOS test. RESULTS: The total respiratory impedanceat at 5 Hz(Z5), reactance at 5 Hz(X5), airway resistance at 5 Hz(R5), airway resistance at 20 Hz(R20), difference of R5 and R20(R5-R20), low frequency reactance area(AX) and resonance frequency(Fres) were higher in silicosis group than those in control group(P<0.05). The above IOS indicators showed an upward trend with the higher stages of silicosis(P<0.05). X5 was positively correlated with forced vital capacity(FVC), one-second expiratory capacity(FEV_1), FEV_1/FVC(P<0.05). Z5, R5, R50-R20 and Fres were negatively correlated with FVC, FEV_1 and FEV_1/FVC(P<0.05). CONCLUSION: IOS detection is highly sensitive for early diagnosis of silicosis. The parameters of airway resistance in IOS is correlated with the parameters of ventilatory dysfunction in routine pulmonary function test, which is of great value for the evaluation of silicosis.