[Modifications of respiratory mechanics of asthmatics challenged with cholinergics and allergens]

Modifications of the mechanical ventilatory function in 18 atopic asthmatic patients challenged with carbachol and mites are studied. The patients were chosen according to clinical and immunoallergiological criteria. All patients reacted to carbachol and only 11 of them to mites. In addition to classical changes in total pulmonary resistance and forced expiration parameters, we observed modifications in lung elastic properties, with an impairment of the P/V curves. Ventilatory data after mite extract aerosols were heterogeneous. Bronchial infection seemed to facilitate central bronchoconstriction to allergens with a large increase of Rtot from 0.425 to 2.226 kPa . liter-1 . s (3.19-16.70 mm Hg . liters-1 . s). The delay between mite challenge and bronchoconstriction was longer when peripheral obstruction occurred without a significant increase in Rtot.