Exhaled nitric oxide reflects asthma severity and asthma control


    loading  Checking for direct PDF access through Ovid

Abstract

IntroductionThis study was undertaken to a) evaluate whether exhaled nitric oxide (fraction of exhaled nitric oxide [Feno]) levels are reflective of asthma severity in concordance with the National Asthma Education and Prevention Program categorization and b) determine the usefulness of Feno using the single-breath exhalation technique for monitoring asthma control and compliance with steroid treatment.MethodsThirty patients with asthma (7–17 yrs old; 14 males and 16 females) that was mild (n = 8), moderate (n = 17), or severe (n = 5) were included in the study. Fifteen patients were seen on more than one occasion for a total of 53 visits. Information obtained at each visit included asthma symptoms, β-agonists and corticosteroids use, compliance to steroids, and forced expiratory volume in 1 sec (Fev1) and Feno measurements. Asthma control was judged by a pulmonologist based on overall evaluation of symptoms, Fev1 measurements, and the frequency of β-agonists use at each visit.ResultsThe mean ± sd Feno was significantly different in the mild, moderate, and severe asthma categories (30 ± 12, 65 ± 48, 104 ± 68, respectively; F2,52 = 6.02 p = .005). Feno was significantly correlated with asthma severity (r = .44, p = .001), compliance (r = −.75, p = .001), and control (r = −.51, p = .001). There were no statistically significant differences between asthma severity and compliance or Fev1.DiscussionOur data suggest that a) Feno may be a practical tool to evaluate asthma severity and asthma control over time and b) Feno may be used as a marker of compliance with steroids even when Fev1 has not decreased significantly.

    loading  Loading Related Articles