Overperfusion of poorly ventilated alveoli in patients with severe airways obstruction

The volume and ventilation of the poorly ventilated alveoli were measured in five patients with severe chronic airways obstruction by the open circuit helium method. Distribution of blood perfusion to these alveoli was estimated from these data and from oxygen uptake and arterial oxygen saturation. These patients differed from others studied in the same way in that the fractional perfusion of the poorly ventilated alveoli in relation to their volume was equal to or greater than unity. There seemed to be a relationship between the patient's prognosis and the degree of overperfusion of the poorly ventilated alveoli.