Premium
Effects of a single dose inhaled corticosteroid on the dynamics of airway obstruction after exercise
Author(s) -
Driessen J.M.M.,
Nieland H.,
van der Palen J.A.M.,
van Aalderen W.M.C.,
Thio B.J.,
de Jongh F.H.C.
Publication year - 2011
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.21447
Subject(s) - medicine , bronchoconstriction , fluticasone propionate , spirometry , placebo , inhalation , asthma , anesthesia , airway obstruction , airway resistance , cardiology , airway , alternative medicine , pathology
Rationale Exercise‐induced bronchoconstriction (EIB) is defined as a transient narrowing of the airways induced by exercise. Repetitive measurements of spirometric parameters, such as FEV 1 and expiratory flows, and forced oscillation technique (FOT) measurements can be used to analyze the dynamics of EIB. A single high dose of fluticasone propionate (FP) protects against EIB. The aim of the study was to analyze the effect of FP on the dynamics of exercise‐induced airway narrowing as measured with FOT and spirometry. Methods Twelve children performed an exercise challenge on 2 separate days, 4 hr after inhalation of 1 mg FP (pressurized metered dose inhaler) or a placebo. Before and after the exercise flow‐volume loops as well as the FOT (frequency range: 4–32 Hz) were measured. Results The FEV 1 , and FEF 50 fell significantly after exercise within groups; the peak fall in FEV 1 after FP was significantly smaller than after placebo (respectively, 19.3 ± 14.6% and 29.2 ± 14.8%, P = 0.03, 95% CI: 0.9–18.8%). The fall in FEV 1 and FEF 50 peaked 3 min after exercise and showed a subsequent partial recovery. The fall in the FEV 1 /FVC ratio showed a later peak fall (12 min after exercise). The resistance increased while the reactance decreased significantly after exercise. FP significantly decreased the maximal increase in Rrs 6 when compared to the placebo (respectively 176.5 ± 59.1% and 201.0 ± 63.8%, P = 0.05, 95% CI: 0.5–48.7%). The maximal decrease in Xrs 6 was not significantly affected by FP ( P = 0.06). Conclusion Repetitive spirometric and FOT measurements after exercise show a rapid narrowing and steady recovery of the patency of the conducting airways, and indicate a delayed and prolonged recovery of the smaller airways. A single high dose of inhaled FP seems to employ its effect mainly in the conducting airways. Pediatr. Pulmonol. 2011; 46:849–856. © 2011 Wiley‐Liss, Inc.