Contribution to the treatment of so-called “true asthma”: Dudan, A.: Schweiz. med. Wchnschr. 61: 137, 1931

Abstract

1.1. Time and volume measurements of ventilatory function have been obtained on 211 subjects, utilizing Gaensler's apparatus and graphic tracings of forced maximal expiration and inspiration by means of a Benedict-Roth spirometer and rapidly moving kymograph with timer. These determinations were obtained before and twenty minutes after the subcutaneous injection of epinephrine.2.2. A comparison of the ventilatory function of normal, symptom-free asthmatic, and active asthmatic subjects is given by relating the values for the mean determined vital capacity, the mean first one-second volume, and the mean rate of flow to the mean predicted vital capacity of each group, and by relating these expressions of the predicted vital capacity of the symptom-free group and active asthma group to that of the normal group. The results of these comparisons suggest that the relationship of the forced maximal vital capacity and time of performance of the expiratory ventilatory effort, as expressed by the mean rate of flow, is a more complete reflection of the ventilatory state than either vital capacity or the first one-second volume measurement, especially in the group of men and women over 40 years of age. The mean rate of flow, expressed as per cent of mean predicted vital capacity, was 5.9 per cent for forced inspiration and 4.12 per cent for forced expiration in the group of normal subjects. In the symptom-free asthmatic group, it was 6.4 per cent for forced inspiration and 2.46 per cent for forced expiration. In the active asthmatic group, it was 5.1 per cent for forced inspiration and 1.27 per cent for forced expiration.A comparison of similar studies of the inspiratory phase of forced respiration, utilizing volume, total time, and mean rate of flow measurements, reveals too little variation in observations between groups for statistical significance.