[Definition of limits of bronchial reactivity with aid of bodyplethysmography (author's transl)].

Investigations for dose-effect relationship of acetylcholine-ultrasonic-aerosols (apparatus "TUR" USI3, duration of inhalation three minutes, control of the ventilation parameters five minutes after termination of inhalation) led to the result that the delimination of the bronchial hyperreactivity is already possible by application of a 0.01% test-concentration. In this way the ultrasonic-aerosol-method also leads to results which are comparable with the nozzle-aerosol-method used in GDR (0.5% test-concentration, duration of inhalation one minute). As a limiting criteria for the evaluation of a bronchial hyperreactivity analogous to the decrease in the FEV1 of greater than or equal to 15% in comparison with the starting position for the bodyplethysmography yield an increase of the resistance totalis of greater than or equal to 3.0 cm H2O/1/s.