[Off-line exhaled nitric oxide measurement in children]. / Mesure de la fraction expirée de NO chez l'enfant par une analyse extemporanée.

ABSTRACT

INTRODUCTION: The objective is to test the validity of a tool allowing an offline measurement of the fraction of expired nitric oxide (FENO). The device is a T-tube on which a pressure gauge allows the control of the expiratory flow and whose two side branches have a gauge such as the bags assembled on each one of them fill successively. METHODS: The first phase aims to check that the sample collected in the second bag answers the criteria of analysis of NO during a single expiration and that this measurement can be delayed. The second phase aims to test the feasibility and the repeatability of the offline analysis in children. RESULTS: The device makes it possible to stabilize the expiratory flow at 100 ml/s. The NO concentration in the second bag is stable during 6 hours. The intra measurement coefficient of variation of delayed FENO 0.1 is 7% (N = 19). CONCLUSION: A off line measurement of the exhaled nitric oxide is reliable in asthmatic children.