Response to inhaled bronchodilators and nonspecific airway hyperreactivity in children with cystic fibrosis

摘要

AbstractWe tested the hypothesis that children with CF who have a significant response to bronchodilator (ED) would respond positively to standard methacholine (Mch) challenge. Our objective was to correlate the response to BD with the concentration that produced a 20 fall (PC20) in forced expiratory volume in 1 second (FEV1). We studied 22 patients (12 males), aged 10.5 ± 0.7 years (mean ± SE), with a Shwachman‐Kulczycki score 82 ± 2.6 and baseline FEV11 of 80 ± 4.5 predicted. Baseline expiratory flows, static lung volumes, and airway resistance were measured before and 30 min after inhaled salbutamol. On a separate day, within 2 weeks, a Mch challenge was given, with doubling concentrations from 0.03 to 8.0 mg/mL. A positive challenge was defined as a PC20≦ 2.0 mg/mL, and a positive response to BD as a>60 of FEV1increase. Mch challenge yielded 17 responders (R) with a PC20of 0.5 ± 0.1 mg/mL, and 5 nonresponders (NR) with a PC20of 8.8 of 2.9 mg/mL. Baseline FEV11 was 77 ± 5.3 predicted in R compared to 89 ± 6.3 in NR (P =6 increase in FEV11 was seen in 14/17 R (83 sensitivity) and in none of the 5 NR (100 specificity). In R, 8/17 patients had baseline FEV116 from baseline after bronchodilator in children with CF suggests nonspecific airway hyperreactivity. © 1992 Wi