A set-up for bronchial provocation by continuously generated aerosols.

Bronchial provocation tests have become a standard procedure to establish the diagnosis of asthma when symptoms are current but spirometry is normal. A simple, reproducible and widely used method for measuring airway responsiveness is continuous aerosol generation and tidal breathing inhalation. This paper presents the method, the apparatus built-up in our lung function office, reproducibility of aerosol production, and expression of results. With our set-up we are able to perform technically well regulated challenge. It has the advantages of relative simplicity in terms of equipment needed, short distance and no obstacles between nebulizer and mouthpiece. Our specially conceived computer programme is easy to handle, allows comparison and recalculation of data. Variations of nebulizers' output needs a carefully individual evaluation before use to allow reproducibility.