[Oscillometric differentiation of lung fibrosis and lung emphysema]

In three groups of healthy subjects and patients with pulmonary fibrosis or pulmonary emphysema, the secondary periodical oscillatory phenomena observed under conditions of normal breathing and a slow VC manoeuvre on the Siregnost FD 5 were broken down into a volume- and a flow-synchronous component, as also a third component with no correlation with either volume or flow, and which can be observed in the primary parameters Ros and psi, as also the secondary parameters Rre and phi. While both fibrotic patients and healthy subjects revealed a volume-inverse phase behaviour, patients with pulmonary emphysema revealed a volume-proportional phase behaviour. This difference in volume dependence is explained by the difference in elastic recoil in patients with fibrosis as compared with those suffering from emphysema, and the associated different influence on the filling of the lungs with air and blood.