BRONCHIAL PROVOCATION TESTS - COMPARISON OF 2 INHALATION METHODS

This study was performed to compare two methods of aerosols delivery a nd inhalation in a bronchial provocation test with carbachol : the sto cked method (S) where the aerosol is previously stocked in a spiromete r bell before inhalation and the dosimeter method (D) where the aeroso l is directly inhaled after nebulization. Fourteen subjects (seven nor mal and seven asthmatic) underwent bronchial challenges with the two t echniques. Bronchial sensitivity was calculated on SRaw-dose response curves to carbachol. SGaw-dose response curves were also constructed a nd the slopes of these curves were used to measure bronchial reactivit y. Within subjects sensitivity values were lower with the D method tha n with the S method (40 +/- 5 mug (S E) versus 450 +/- 50 mug respecti vely in asthmatics, 340 +/- 30 mug versus 2350 +/-130 mug respectively in healthy subjects). Reactivity values were higher with the dosimete r method (2,7 +/- 0,7 x 10(-5) versus 27 +/- 4 x 10(-5) in healthy and 10 +/-1 X 10(-5) versus 106 +/- 16 x 10(-5) in asthmatics). The dosim eter method had greater efficacy, was less time consuming and appeared to be a useful method for carrying out standardised non-specific bron choprovocation test.