The Value of Exhaled Nitric Oxide in Predicting Bronchial Hyperresponsiveness in Children

Abstract

Reduced attention span and motor skills in children limit the practicability of bronchial provocation tests. To assess exhaled nitric oxide (FeNO) as a surrogate for bronchial hyperresponsiveness (BHR) in children with possible reactive airway disease, FeNO was measured using the single-breath method in 169 successive outpatients 11 ± 5 years of age before lung function testing and subsequent bronchial provocation by exercise (n = 165) and methacholine (n = 134). Baseline forced expiratory volume in 1 second (FEV₁) less than 80% of predicted and/or BHR were seen in 59%. FeNO correlated weakly with PD₂₀ to methacholine (r = −0.24, p < 0.05), but not with the change in FEV₁ due to exercise-induced bronchoconstriction (EIB) (r = 0.1, p > 0.05). The negative predictive value of FeNO less than 10 ppb for EIB was 94%, but overall accuracy for predicting BHR was low. Measurement of FeNO is not a substitute for bronchial provocation in children.

Keywords:

• bronchial hyperresponsiveness
• exhaled nitric oxide
• FeNO
• lung function
• methacholine