Diagnostic value of the forced oscillation test in detection of bronchial obstruction

: Clinical testing of the forced oscillation test (FOT) yielded criteria for bronchial obstruction: an increase in viscous respiratory resistance (VRR) (Rfo, Rin, Rex); the frequency dependence of VRR; and a decrease in a phase angle. The study of VRR promoted detection of bronchial malpatency in additional 20.7% of the individuals who had no bronchial obstruction, as evidenced by spirography (SG) and forced expiration volume-current curve (FEV-CC) recording. To improve the diagnosis of bronchial patency impairments, it is expedient to use FOT of VRR along with the routine methods (SG and FEV-CC recording). A relationship has been established between the values of VRR and the clinical signs of chronic bronchitis and the degree of bronchial obstruction.