| Title | CENTRAL AND PERIPHERAL AIRWAY SITES OF NITRIC OXIDE GAS EXCHANGE IN COPD. | | Author(s) | Gelb AF, Flynn Taylor C, Krishnan A, Fraser C, Shinar CM, Schein MJ, Osann K | | Institution | From Pulmonary Division, Department of Medicine, Lakewood Regional Medical Center, Lakewood, Calif. and University of California at Los Angeles, Geffen School of Medicine (AFG); and Department of Radiology (MJS), Lakewood Regional Medical Center; Department of Performance Improvement and Patient Safety, Orange Coast Memorial Medical Center, Fountain Valley, CA (CMS); and Department of Medicine, University of California at Irvine, School of Medicine(KO). CFT, AK, and CF are independent research contractors. | | Source | Chest 2009 Oct 9. | | Abstract | BACKGROUND: This study investigated sites of NO gas exchange and response to inhaled corticosteroid (ICS) in COPD patients with varying extent of emphysema.
METHODS: This was a prospective, randomized, single blind, crossover study in treated, stable, ex-smoking COPD patients, who were ICS and LTRA naïve. Lung function, HRCT lung, and exhaled NO was measured at 50, 100, 150 and 200 mL/s. Airway NO was adjusted for NO axial backdiffusion.
RESULTS: In 39(18F), clinically stable COPD ex-smokers, age 73+/-9 yr (mean+/-SD), on salmeterol (S) 50mug bid, post 180mug aerosolized albuterol, FEV1 (L) was 52+/-12% predicted and FEV1/FVC was 55+/-6%. Compared to 20(12M) age matched, controls, 39 COPD patients had normal large airway NO flux and small airway/alveolar NO. Subsequently, 19 COPD patients (Group A) were randomized and continued on S50 and 20 (Group B) randomized to fluticasone propionate (F) 250mug/S50 bid for 86+/-16 days. Group A (S50) patients were then switched to F250/S50 and 12 of 19 completed 77+/-15 days and there was significant (p<0.001) reduction only in F(E)NO@50mL/s and large airway NO flux . In 20 COPD patients initially randomized to F250/S50 (GroupB), post 57+/-22 days of S50 in 16 of 20 there was a significant (p=0.04) increase only in F(E)NO@50mL/s and large airway NO flux which was not reduced post 60+/-23 days of F100/S50(p=0.07). There was no correlation between NO gas exchange and CT scored emphysema.
CONCLUSION: 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 extent of emphysema. Peripheral NO must be corrected for axial NO backdiffusion to avoid spurious conclusions. NCT#00568347. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19820080 |
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