Abstract
Exhaled nitric oxide (NO) remains a promising noninvasive index for monitoring inflammatory lung diseases; however, the plateau concentration (CNo,plat) is nonspecific and requires a constant exhalation flow rate. We utilized a new technique that employs a variable flow rate to estimate key flow-independent parameters characteristic of NO exchange in a group (n = 9) of 10 to 14 yr-old healthy children and children with cystic fibrosis (CF). maximum flux of NO from the airways (JNo,max, pl s-1), diffusing capacity of NO in the airways (DNo,air, pl s-1 ppb-1), steady-state alveolar concentration (Calv,ss, ppb), and mean tissue concentration of NO in the airways (Ctiss,air, ppb). We determined the following mean (± SD) values in the healthy children and patients with CF for JNo,max, DNo,air, C̄alv,ss, and C̄tiss,air, respectively; 784 ± 465 and 607 ± 648 pl s-1; 4.82 ± 3.07 and 17.6 ± 12.1 pl s-1 ppb-1; 4.63 ± 3.59 and 1.96 ± 1.18 ppb; and 198 ± 131 and 38 ± 25 ppb. DNo,air is elevated (p = 0.007), and both Calv,ss and C̄tiss,air are reduced (p = 0.05 and 0.002, respectively) in CF. In contrast, CNO,plat for healthy control subjects and patients with CF are not statistically different at both exhalation flow rates of 50 ml/s (17.5 ± 11.5 and 11.5 ± 8.97) and at 250 ml/s (7.11 ± 5.36 and 4.28 ± 3.43). We conclude that DNo,air, C̄tiss,air, and Calv,ss may be useful noninvasive markers of CF.
Original language | English (US) |
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Pages (from-to) | 349-357 |
Number of pages | 9 |
Journal | American Journal of Respiratory and Critical Care Medicine |
Volume | 165 |
Issue number | 3 |
DOIs | |
State | Published - Feb 1 2002 |
Keywords
- Airways
- Healthy children
- Inflammation
- Nitric oxide
- Parameter estimation
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine