specific airway conductance ( sgaw ) , peak expiratory flow , the sum of the absolute volume of isoflow and residual volume as a percentage of total lung capacity ( capacity of isoflow ) and the ratio of maximal expiratory flow at 50 per cent of vital capacity breathing 80 per cent helium-20 per cent oxygen to that breathing air ( ratio vmax50 ) were determined before and after the administration of aerosolized terbutaline ( 0.5 mg ) , subcutaneous terbutaline ( 0.5 mg ) or placebo .
C0024109
lung
C0035203
breathing