The utility of the forced oscillation technique in assessing bronchodilator responsiveness in patients with asthma

• Published in: Respiratory medicine 2007-05, Vol.101 (5), p.995-1000
• Main Authors: Yaegashi, Makito, Yalamanchili, Venkata A.K, Kaza, Vaidehi, Weedon, Jeremy, Heurich, Albert E, Akerman, Michael J
• Format: Article
• Language: English
• Subjects: Adult; Airway management; Airway obstruction; Airway Resistance; Anthropometry; Asthma; Asthma - drug therapy; Asthma - physiopathology; Bronchodilator; Bronchodilator Agents - therapeutic use; Ethanolamines - therapeutic use; Female; Forced Expiratory Volume - drug effects; Forced oscillation; Humans; Impulse oscillometry system (IOS); Male; Middle Aged; Oscillometry - methods; Pulmonary/Respiratory; Respiratory Function Tests - methods; Retrospective Studies; Standard deviation; Studies; Treatment Outcome
• ISSN: 0954-6111; 1532-3064
• DOI: 10.1016/j.rmed.2006.09.001

Summary Objective : To address the utility of the forced oscillation technique (FOT) in assessing bronchodilator responsiveness compared with forced expiratory volume in 1 s (FEV1 ). Methods : This is a retrospective analysis of consecutive 126 patients with a clinical history of asthma without any other lung diseases at a pulmonary function testing laboratory. The following measurements were obtained three times each, before and after two doses of pirbuterol 0.2 mg inhalation: the respiratory resistance at 5 Hz ( R rs5), the mean respiratory resistance between 5 and 20 Hz ( R rs5–20), and the mean respiratory conductance (Grs5–20) by FOT and the FEV1 by spirometer. These measurements were transformed into dimensionless subject-specific effect-size “ d -scores” by dividing them by the estimated pooled within-subject standard deviation. Results : Descriptive statistics for each value were the following [mean baseline value (± sd ), Δ value (pre- minus post value), and d -score ( P value compared to FEV1 )]: Grs5–20 (L s−1 kPa−1 ) [1.79±0.53, Δ =+0.39, d =2.64 ( P