Patterns of Response to Bronchodilator in Young Patients With Asthma

SUMMARY Measurement of vital capacity (V.C.) and forced expiratory volume over one second (F.E.V.1·0) was performed daily on four young patients with asthma, and the response to isoprenaline (1%) administered from a hand nebulizer was determined. The present group of patients did not follow the bronchodilator response pattern reported by some other authors. The acute improvement following bronchodilator depended, not only on the initial F.E.V.1·0, but also on the path of improvement or deterioration by which the initial F.E.V.1·0 was reached. This represents yet a further factor to be taken into account in assessing the efficacy of a bronchodilator. Two well‐known clinical observations were confirmed quantitatively: that the greatest response to therapy is obtained early in an episode of asthma; and that admission to hospital without specific therapy may lead to steady improvement.