Change of regional ventilation after β2 stimulant inhalation in the asthmatics. A study with krypton-81m

This study was carried out in order to describe changes of the local ventilation after inhalation of β2 stimulant in 10 patients with bronchial asthma, and to assess the effect of β2 stimulant on each lung field. 81mKr gas was inhaled in tidal breathing at rest with constant concentration. 81mKr counts in the total lung field were significantly increased to 111.5% after inhalation of 400 μg of β2 stimulant and continued to 11 minutes. 81mKr counts were increased in the upper and middle lung fields immediately after inhalation and then decreased gradually. In the lower lung field, 81mKr counts were kept in increased condition after inhalation of β2 stimulant. The forced expiratory volume in 1 second was significantly increased to 110% after 20 minutes. It was demonstrated by 81mKr ventilation study that the effect of inhaled β2 stimulant is uneven in the lung field. (author)