Details

Autor(en) / Beteiligte

• GELB, Arthur F
• FLYNN TAYLOR, Colleen
• KRISHNAN, Anita
• FRASER, Christine
• SHINAR, Chris M
• SCHEIN, Mark J
• OSANN, Kathryn

Titel

Central and Peripheral Airway Sites of Nitric Oxide Gas Exchange in COPD

Ist Teil von

• Chest, 2010-03, Vol.137 (3), p.575-584

Ort / Verlag

Northbrook, IL: American College of Chest Physicians

Erscheinungsjahr

2010

Quelle

MEDLINE

Beschreibungen/Notizen

• Background: This study investigated sites of nitric oxide (NO) gas exchange and response to inhaled corticosteroids (ICS) in patients with COPD and varying extents of emphysema. Methods: This was a prospective, randomized, single-blind, crossover study in treated, stable, ex-smoking patients with COPD who were ICS and leukotriene receptor antagonists naive. Lung function, high-resolution thin-section CT scan of the lung, and exhaled NO were measured at 50, 100, 150, and 200 mL/s. Airway NO was adjusted for NO axial backdiffusion. Results: In 39 (18 women), clinically stable ex-smokers with COPD aged 73 ± 9 years (mean ± SD) on salmeterol 50 μg (S50) bid, after 180 μg aerosolized albuterol, FEV 1 (L) was 52% ± 12% predicted and FEV 1 /FVC was 55% ± 6%. Compared with 20 (12 men) age-matched controls, 39 patients with COPD had normal large airway NO flux and small airway/alveolar NO. Subsequently, 19 patients with COPD (Group A) were randomized and continued on S50, and 20 (Group B) were randomized to fluticasone propionate 250 μg (F250)/S50 bid for 86 ± 16 days. Group A (S50) patients were then switched to F250/S50, and 12 of 19 completed 77 ± 15 days; there was significant ( P < .001) reduction only in the exhaled fraction of NO (F E NO) at 50 mL/s and large airway NO flux. In 20 patients with COPD initially randomized to F250/S50 (Group B), after 57 ± 22 days of S50 in 16 of 20 patients there was a significant ( P = .04) increase only in (F E NO) at 50 mL/s and large airway NO flux, which was not reduced after 60 ± 23 days of fluticasone propionate 100 μg (F100)/S50( P = .07). There was no correlation between NO gas exchange and CT-scored emphysema. Conclusions: In COPD, there was normal NO gas exchange in both large and small airways/alveoli and only large airway NO flux was suppressed with F250/S50 but not F100/S50, despite varying extents of emphysema. Peripheral NO must be corrected for axial NO backdiffusion to avoid spurious conclusions. Trial registration: NCT #00568347.