[The effect of sputum induction on spirometry parameters in patients with bronchial asthma]

Evaluation of differential cell count and biochemical parameters in sputum seems to be a valuable method in asthma studies. The purpose of the paper was to evaluate the effects of sputum induction alone and after fenoterol and salmeterol premedication, on spirometry in asthma patients. The another aim of the study was to observe the correlation between bronchial hyperreactivity and decreases in FEV1 and MEF50 in asthmatics during sputum induction. The studies were carried out on 20 mild to moderate asthma patients (FEV1 baseline 79 +/- 16% of the predicted values) who inhaled an increasing concentration of hypertonic saline (3%, 4% and 5%), using an ultrasonic nebuliser. The forced expiratory volume in one second and MEF50, as the good indicators of bronchial obturation, were evaluated. During the sputum induction significant decreases in FEV1 and MEF50 were observed, which were proportional to the concentration of NaCl. After inhalation of 3% of NaCl the mean of FEV1 was 87.2 +/- 12.7% of the baseline, after 4%--84.3 +/- 16.9% and 5%--77.4 +/- 19.8%. No significant correlation between bronchial hyperreactivity and the induced decreases in FEV1 and MEF50 were found. Fenoterol and salmeterol fully prevented bronchial obturation during sputum induction.