COPD patients with peripheral airway obstruction reversibility identified by exhaled nitric oxide
Abstract
Besides its role as an inflammatory marker in asthma, fractional exhaled nitric oxide (FENO) provides information on the extent of the airway obstruction process through evaluating its change after bronchodilation. To investigate whether FENO change after bronchodilation can identify different sites of airway obstruction in COPD patients. FENO, FEV1 and the slopes (S) of the alveolar plateau of the single breath washout test (SBWT) were measured in 61 stable COPD patients (FEV1 34.5% predicted) before and after the inhalation of 400 μg salbutamol. SBWT used Helium (He), and sulfur-hexafluoride (SF6). Obstruction relief occurring in pre-acinar and intra-acinar small airways is expected to decrease SHe and SSF6, respectively. Indices changes (Δ) after bronchodilation were expressed as a percentage of pre-bronchodilation values. FENO stability (∣ΔFENO∣ ≤ 11%) was observed in 19 patients [-2.7(6.7)%] [mean (SD)] (NO = group); ΔFENO > 11% [+37.4(27.7)%] in 20 patients (NO+ group) and ΔFENO < -11% in 22 patients [-31.2(9.8)%] (NO- group). A similar ΔFEV1 (p = 0.583; [+9.4(9.6)%]) was found in the three groups. In NO = and NO+ groups, neither SHe nor SSF6 changed; in NO- both SHe [-12.4(27.5)%, p = 0.007] and SSF6 [-20.2(20.4)%, p < 0...Continue Reading
References
The current single exhalation method of measuring exhales nitric oxide is affected by airway calibre
Relationship between exhaled nitric oxide and treatment response in COPD patients with exacerbations
Correlation between fractional exhaled nitric oxide and sputum eosinophilia in exacerbations of COPD
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