Abstract

A randomised double blind, two period cross over study was designed to compare the ability of 51 hospitalised asthmatics with acute exacerbations to use each of two inhalers. The inhalers compared were a new breath actuated metered dose inhaler, the Autohaler inhalation device, and a dry powder device, the Rotahaler. Preassessment data included the measurement of peak inspiratory flow rate (PIFR), peak expiratory flow rate (PEFR), pulse rate, and oxygen saturation. Therapeutic response to each inhaler was compared by measurement of PEFR, oxygen saturation, and pulse rate. PIFR was sufficient in all children to fire the Autohaler, including the youngest. No significant difference was found between the two inhalers as assessed by PEFR. However the Autohaler inhalation device could be actuated 99/100 times successfully compared with 74 for the Rotahaler. There was a consistent, but clinically insignificant, increase in pulse rate after use of the Rotahaler compared with the Autohaler. All 11 patients under 6 years of age failed to empty the Rotahaler but five of these patients received a significant benefit from using the Autohaler compared with after the Rotahaler. A significant drop in oxygen saturation was observed 15 minutes after use of either inhaler. This may at times reach levels of clinical importance.