The clinical use of exhaled nitric oxide in wheezing children.

The body of published work on the role of exhaled nitric oxide (FENO) in the study of bronchial inflammation allows it to be classed as a simple, non-invasive measurement that is very useful in evaluating asthmatic patients. During a prospective study into the effects of air pollution on the health of the population of Viseu (Saud'AR Project), children with a clinical history of wheezing were identified through using the International Study of Asthma and Allergy in Childhood (ISAAC) questionnaire. Children later filled in a new standardised questionnaire and underwent skin-prick-tests, spirometry and FENO measurement. Their mean age was 7.8+/-1.1 years. Comparing those who wheezed in the 6 months before evaluation (n=27) with those who didn't, statistical differences for DeltaFEV1 (8% median versus 4.5%, p=0.0399) and for FENO (23 ppb median versus 12 ppb, p=0.0195, respectively) were observed. Concerning children who needed a bronchodilator in the six previous months (n=19) and those who didn't, there was also a statistically significant difference in FENO: 27 ppb median versus 11 ppb median, respectively; p<0.0001. When comparing children who needed an unscheduled medical appointment in the six months previous to the evaluation (n=9) and those who didn't, there was also significant differences for FE NO: 28 ppb median versus 13 ppb median, p=0.0029. In conclusion, the existence of symptoms seems to be better related to FE NO than spirometry.