Abstract

Blood volume measurements were made on forty-five patients with chronic obstructive non-specific lung disease. Thirty patients were considered to have the features of predominant emphysema, and fifteen had more bronchitic characteristics. Mean red cell volume was 100·8% of the predicted normal volume in the emphysematous group, whereas that of the bronchitic patients was 121·8% predicted. The emphysematous patients were not on average polycythaemic, because they were both less hypoxic and also had a subnormal polycythaemic response to hypoxia; in constrast a quantitatively normal response occurred in the more bronchitic subjects. The pathogenesis of the subnormal response occurring in the emphysema group is discussed. Mean plasma volume was similar but slightly reduced in both groups, being 92·1% predicted in the emphysema patients and 95·7% predicted in the remainder.