The Ventilatory Effect of Isoprenaline in Bronchial Asthma in Attack Free Intervals

¹ Associate Professor of Internal Medicine

The effect of isoprenaline inhalation on the ventilation capacity was studied in 112 patients with bronchial asthma. Comparisons were made between different tests of ventilation capacity and an attempt to determine by which test or tests this effect could best be shown. It was found that the effect was best noted on determination of the maximal expiratory flow with the peak flow meter.

The two groups of patients in whom the initial value for the ventilation capacity was less than 40 per cent and above 80 per cent of the predicted normal value, respectively, exhibited on the average a less marked isoprenaline effect than the group in whom this value lay between 40 per cent and 80 per cent.

Correlation calculations were performed between, on the one hand, the effect of isoprenaline and, on the other, both the degree of hyperinflation and different case-history factors representing the assessed degree of severity of the asthma, but—except age—no significant correlation could be demonstrated.