[Value of the measurement of ventilatory and circulatory components in CO2 ductance].

Authors bring forth the results of the determination of CO2 ductances in 28 patients : 14 cases of pulmonary arterial thrombosis, 7 cases of diffuse interstitial fibrosis recognizing various etiologies, 4 cases of endothoracic sarcoidosis and 3 cases of pure restrictive syndrome due to functional amputation of some territories. The global CO2 ductance is lowered in 24 cases. In each one of these cases the PACO2 determination makes possible to decompose the global ductance into a ventilatory ductance and a circulatory ductance. The circulatory ductance is lowered in the case of pulmonary arterial thrombosis; the ventilatory component is lowered in the case of restrictive syndromes and in the case of diffuse interstitial fibrosis. For what concerns the pulmonary arterial thrombosis, authors discuss then the value of the information contained in the expression of the CO2 arterial-alveolar gradient on the one hand, and in the circulatory component of the ductance on the other hand. At last, the determination of the ductances appears interesting in the supervision of the course of various diseases.