RT Journal Article
SR Electronic
T1 Airway resistance variability and response to bronchodilator in children with asthma
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 260
OP 268
DO 10.1183/09031936.00064006
VO 30
IS 2
A1 C. A. Lall
A1 N. Cheng
A1 P. Hernandez
A1 P. T. Pianosi
A1 Z. Dali
A1 A. Abouzied
A1 G. N. Maksym
YR 2007
UL http://erj.ersjournals.com/content/30/2/260.abstract
AB Variability of airway function is a feature of asthma, spanning timescales from months to seconds. Short-term variation in airway resistance (Rrs) is elevated in asthma and is thought to be due to increased variation in the contractile activation of airway smooth muscle. If true, then variation in Rrs should decrease in response to bronchodilators, but this has not been investigated. Using the forced oscillation technique, Rrs and the variation in Rrs from 4–34 Hz were measured in 39 children with well-controlled mild-to-moderate asthma and 31 healthy controls (7–13 yrs) before and after an inhaled bronchodilator (200 µg salbutamol) or placebo. In agreement with other findings, baseline Rrs at all frequencies and the sd of Rrs (Rrs sd) below 14 Hz were found to be elevated in asthma while neither forced expiratory volume in one second nor the mean forced expiratory flow between 25 and 75% of forced vital capacity were different compared with controls. The present authors found that Rrs sd changed the most of any measurement in asthma, and this was the only measurement that changed significantly more in children with asthma following bronchodilator administration. The present results show that like airway narrowing, short-term airway variability of resistance may be a characteristic feature of asthma that may be useful for monitoring response to therapy.