[Modification of inspiratory phase angle behavior in oscilloresistometry].

The diagnosis of pulmonary emphysema and fibrosis is possible by measuring the inspiratory behaviour of phase angle PSI of oscillation method. In addition to the different lung compliance as the main reason an influence of the shifting intrathoracical blood volume as the result of the pressure change is discussed especially for the appearing secondary PSI-periodic. Because a direct experimental evidence is not present in this study it was attempted to describe qualitatively the blood volume shift. Thoracic electrical impedance plethysmography and methods of nuclear medicine were used as methodological base. Although impedance plethysmography appears theoretical suitable and there are references, that alterations being independent from the heart rhythm may be detected, the originally aim of the study was not reached by the used method. The registration of radioactive labeled blood over the thoracical region by means of methods of nuclear medicine was applied as an alternative method. In contrast to the theoretical concept of a suction effect of the decreasing pressure during inspiration a decrease of the impulse rate and an increase of the latter during expiration was found. The reason could be the isolated registration of changes in the alveolar vessels. Possible secondary oscillations, which could be in relation with findings of lung mechanics, were not observed.