Abstract
This study was designed to compare the effect between low concentration-continuous inhalation and high concentration-intermi-ttent inhalation of isoproterenol. Changes of pulmonary function and heart rate were evaluated by cross over design in high concentration short-term inhalation (HCSTI) and low concentration long-term inhalation (LCLTI) in 9 children with acute asthma attack. The total dose given and inhalation equipment used were the same in the two inhalation methods. %FEV1.0 increased quickly after HCSTI, but decreased to the preinhalation level 60 minutes later. On the other hand, %FEV1.0 increased continuously during LCLTI. Although the maximal %FEV1.0 at 5 minutes after HCSTI was higher than that at 30 minutes during LCLTI, it was not statistically different from %FEV1.0 at 60 minutes. Heart rate increased after HCSTI, but did not change during LCLTI. Low concentration-continuous inhalation did not have an immediate effect, but gave continuous improvement in pulmonary function without rise of heart rate.
