[Pulmonary hypertension in patients with emphysema]

Fifty-three patients with chronic and stabilized emphysema, mostly of the panlobular type, and without any associated disease likely to interfere with the cardio-pulmonary function, were used to analyze the physiological factors responsible for their pulmonary hypertension, moderate at rest but marked at exercise. The study showed that the main responsibility for pulmonary hypertension, both at rest and during exercise, lay on mechanical respiratory factors and on passive regulation of the lesser circulation. It also showed that the predictive value of SaO2 was higher than that of PaO2 but lower than that of CvO2 which depends on a relative tissue hypoxia of cardiovascular origin responsible for vasoconstrictive acidosis at exercise. In this study, destruction of the pulmonary capillary bed, often different from destruction of the alveolar surface, had a predictive value for PAP higher than that of hypoxia. In these cases of pure, stabilized chronic emphysema hypoxia does not have the preponderant hypertensive role for which it is blamed in the literature in all circumstances.