Edited by: Bodo Niggemann
Daily exhaled nitric oxide measurements and asthma exacerbations in children
Article first published online: 17 OCT 2011
© 2011 John Wiley & Sons A/S
Volume 67, Issue 2, pages 265–271, February 2012
How to Cite
van der Valk, R. J. P., Baraldi, E., Stern, G., Frey, U. and de Jongste, J. C. (2012), Daily exhaled nitric oxide measurements and asthma exacerbations in children. Allergy, 67: 265–271. doi: 10.1111/j.1398-9995.2011.02734.x
- Issue published online: 11 JAN 2012
- Article first published online: 17 OCT 2011
- Accepted for publication 19 September 2011
- exhaled nitric oxide;
To cite this article: van der Valk RJP, Baraldi E, Stern G, Frey U, de Jongste JC. Daily exhaled nitric oxide measurements and asthma exacerbations in children. Allergy 2012; 67: 265–271.
Background: Fractional exhaled Nitric Oxide (FeNO) is a biomarker for eosinophilic airway inflammation and can be measured at home on a daily basis. A short-term increase in FeNO may indicate a higher risk of future asthma exacerbations.
Objective: To assess changes in FeNO before and after asthma exacerbations compared to a stable control period.
Methods: A post hoc analysis was performed on daily FeNO measurements over 30 weeks in children with asthma (n = 77). Moderate exacerbations were defined by an increase in symptom scores and severe exacerbations by prescription of prednisone. Individual mean and maximum FeNO, the variability of FeNO assessed by the coefficient of variation (CV), and slopes of FeNO in time were all quantified in 3-week blocks. Cross-correlation of FeNO with symptoms and autocorrelation of FeNO were assessed in relation to exacerbations and examined as predictors for exacerbations compared to reference periods using logistic regression.
Results: Fractional exhaled nitric oxide could be assessed in relation to 25 moderate and 12 severe exacerbations. The CV, slope, cross-correlation, and autocorrelation of daily FeNO increased before moderate exacerbations. Increases in slope were also randomly seen in 19% of 2-week blocks of children without exacerbations. At least 3–5 FeNO measurements in the 3 weeks before an exacerbation were needed to calculate a slope that could predict moderate exacerbations. No specific pattern of FeNO was seen before severe exacerbations.
Conclusion: Fractional exhaled nitric oxide monitoring revealed changes in FeNO prior to moderate exacerbations. Whether this can be used to prevent loss of asthma control should be further explored.