[Behavior of various spirometry parameters during bronchial provocation tests with D. pteronyssinus in patients with asthma, sensitized to housedust mites].

Abstract

Changes in particular spirometry parameters during specific bronchial provocation test (BPT) with an allergen in asthmatics sensitized to house dust mites were evaluated. Studies were carried out on 130 patients. Specific BPT with D. pteronyssinus was performed according to the Ryan's method using a jet De Villbiss 646 nebuliser powered by compressed air and connected to the French Rosenthal dosimeter. The spirometry was measured using Pneumoscreen II (Jaeger - Germany). The provocation was terminated when a value of FEV1 fell at least 20% from baseline and then the spirometry parameters were measured hourly for a period 8 hours. Early and late asthmatic responses were founded. Results were expressed as a percentage of the maximum decrease from the baseline in particular parameters. To the statistical calculations only positive sBPT results founded in 96 patients were selected. The mean values of the decreases during of the EAR were as follow: FEV1 = 30.6 +/- 9.9%, FVC = 18.9 +/- 9.9%, FEV/FVC = 14.6 +/- 9.2%, FEV25-27 = 41.5 +/- 15.7%, PEF = 30.8 +/- 15.7%. The correlation coefficients were between FEV1 and FVC -0.57, FEV1 and FEV1/FVC -0.56, FEV1 and FEF25.75 -0.65, FEV1 and PEF -0.6. The results were statistically significant. Decreases in FEV1 and PEF were very similar each other. The greatest changes were observed in FEF25.75. The curves of the FEV1 and PEF averages observed during LAR were quite close to each other and almost parallel. The usefulness of the both parameters seems to be equal.