Pulse Oscillation Clinical Application Of Pulmonary Function Test Of Chronic Obstructive Pulmonary Disease And Respiratory Impedance

Objective To explore the clinical application value of IOS by testing respiratory resistance of patients with COPD and comparing the indexes with that tested by routine pulmonary functions testing.Methods The IOS and routine pulmonary functions parameters of 172 patients with COPD were measured and compared with that of 60 healthy people.Results Compared with that of the control group,respiratory impedance(Z₅), respiratory resistance at 5Hz(R₅),R₅-R₂₀,and peripheral resistance(R_p) in patients of COPD group increased significantly.And with the state of an illness being aggravated,Fres,Z₅,R₅,R₅-R₂₀,R_p are increased gradually.R₅-R₂₀ have significant difference among COPD groups.Compared with that of the control group,X₅ decreased significantly in COPD groups,and the difference is significant,IOS output figures have significant characteristic.Fres have most significant correlation with FEV₁/pre%,FEV₁/FVC%and the correlation coefficient are -0.65 and -0.64 respectively.The positive rate of diagnosed COPD by Fres,Z₅,R₅,X₅ increase with the state of an illness being aggravated.Among these indexes,Fres had highest specificity,diagnose coincidence and positive predictive value.Conclusion IOS testing could not only reflect the airway obstruction degree,but also be used to evaluate the airway obstruction location and severity degree.In combination with routine pulmonary functions testing,lOS testing could present strong evidence for diagnosis of COPD.IOS testing had higher clinical application value.Fres is a sensitive index for diagnosis of COPD and X₅ is also used to evaluate the severity of COPD.