PULMONARY FUNCTION IN BRONCHIAL ASTHMA

Nine asthmatic patients, five of the extrinsic and four of the intrinsic type, were studied on repeated occasions. Measurements of their total lung capacity and carbon monoxide transfer showed no difference between the two groups. Carbon monoxide transfer factor remained normal despite wide variation in the asthmatic state as assessed by the F.E.V.I. Helium dilution underestimated the total lung capacity in severe asthma, and its measurement by whole body plethysmograpdy showed it to be greater than the predicted normal, in both mild and severe asthma. Arterial oxygen tension war. reduced in proportion to the severity of the airways obstruction and rose after bronchodilatation with orciprenaline. Carbon dioxide tension was normal or low in all these patients, but was persistently higher in the intrinsic than in the extrinsic group. © 1968, British Medical Journal Publishing Group. All rights reserved.