Valutazione del rapporto ventilazione/perfusione polmonare nelle broncopneumopatie croniche ostruttive (*).

The multiple inert gases technique based on the measurement of different solubility of inert gases by chromatography has been applied in 6 patients suffering of stable and severe chronic obstructive pulmonary disease (COPD) to estimate the distribution of lung ventilation (V) and perfusion (Q) as a function of their ratio V/Q. The recovered distributions of V and Q respect to V/Q ratio were then compared with the alveolar-arterial differences in oxygen and carbon dioxide, diffusion capacity for carbon monoxide and with the images of regional radioactivity distribution of ventilation and perfusion scanso In one patient measurements after therapy were repeated. All patients showed a broad distribution of V and Q respect lo V/Q and this finding was compatible with the detected regional alterations of ventilation and perfusion scan and pulmonary function parameters impairment. The analysis of the distribution data from inert gases technique confirmed that the presence of ventilation-perfusion heterogeneity was