In a group of 56 asthmatic children and adolescents (age: 8 - 19 years, mean: 12.7 years, height: 129 - 181 cm, mean: 155.4 cm, in the symptom-free period) the degree of bronchodilation was studied following 2 puffs of „Berodual“ aerosol (Boehringer, Ingl., BRD) delivered from a pressurized metered dose inhaler (MDI) by both modes, with a spacer (Volumatic, Glaxo) and without spacer during 2 hours. Both modes of i nhalation in the same patients were done by a physician within a time interval of 6 - 7 days. The evaluation of the effect was focused on the peripheral airway obstruction. Bronchodilation was assessed from the changes of functional parameters measured from the maximum expiratory flow-volume curve (Spirometer ZAN100, FRG). Functional parameters before „Berodual“ inhalation by both modes revealed mainly the peripheral airway obstruction (MEF25 and MEF50 were reduced more than 2SD from the predicted value or were close to the lower limits). Following inhalation of Berodual aerosol delivered from MDI with a spacer as well as without a spacer the degree of bronchodilation was the same during 2 hours observation. All studied lung function par ameters became normal and the peripheral airway obstruction disappeared after both modes of delivery of „Berodual“ aerosol. In conclusion, the aerosol delivered by both modes from MDI either with a spacer or without a spacer to our asthmatics contained a similar spectrum and amount of particles which penetrated into the peripheral airways and elicited the same degree of bronchodilation. Therefore, the bronchodilating effect of aerosol given from MDI without a spacer by a physician (nurse) or in cooperating children is comparable with that delivered from MDI with a spacer.

        Key words: inhalation, asthmatic children, metered dose inhalers, spacer, bronchodilation, „Berodual“