[Cold air provocation as a methods of differential diagnosis of bronchial asthma and chronic bronchitis].

To assess the usefulness of cold air hyperventilation challenge for the diagnosis of bronchial asthma (B. a.) and chronic bronchitis (c. B.) we studied 25 children with B. a. and 11 children with c. B. between 7 and 14 years. After baseline pulmonary function studies in a whole-body-plethysmograph and spirometry cold air challenge was done by 3 minutes hyperventilation of dry subfreezing (-15 degrees C) air in stepwise increasing doses of 20, 40 and 60% of maximum breathing capacity (MVV). Target size was specific airways resistance (sRaw). Its increase by 100% was considered a positive reaction. Thoracic gas volume (ITGV), airways resistance (Raw) and forced expiratory volume in one second (FEV1) were measured as well. The moment of maximum airway reaction and the time course of the recovery period were also studied. 18 children with B. a. and 1 patient with c. B. reacted significantly with sRaw. We neither found a reaction plateau nor a consistent moment of maximum reaction. Children with B. a. reacted especially with ITGV.