Exhaled nitric oxide in infants--what is a nice test like FENO doing in a place like this?

• Published in: Seminars in respiratory and critical care medicine Vol. 28; no. 3; p. 264
• Main Authors: van Mastrigt, Esther, Gabriele, Carmelo, de Jongste, J C
• Format: Journal Article
• Language: English
• Published: United States 01.06.2007
• Subjects: Age Factors; Asthma - diagnosis; Biomarkers - metabolism; Breath Tests - methods; Bronchopulmonary Dysplasia - diagnosis; Child, Preschool; Ciliary Motility Disorders - diagnosis; Cystic Fibrosis - diagnosis; Humans; Infant; Infant, Newborn; Nitric Oxide - metabolism; Pulmonary Eosinophilia - diagnosis; Reproducibility of Results; Respiratory Sounds - diagnosis
• ISSN: 1069-3424
• DOI: 10.1055/s-2007-981647

In adults and older children the measurement of fractional exhaled nitric oxide (FENO) has been shown to be useful as a tool to diagnose and monitor eosinophilic airway inflammation. However, the recommended method to measure FENO in school-age children is not suited for use in preschool children and infants. This article reviews the data on FENO measurements in infants. In the first year of life, measurement of FENO can be done during tidal breathing or during a single forced passive expiration. Several technical factors, including contamination with nasal and ambient NO, and the influence of expiratory flow influence FENO levels in infants. Because asthma is uncommon in infants and wheezing is often related to viral infections, considerable differences in clinical utility of FENO between older children and infants could be expected. From the available data FENO could potentially be useful to identify early-onset asthma, to diagnose primary ciliary dyskinesia (PCD), and to monitor the effect of various treatments. In conclusion, there is still much uncertainty about the potential clinical utility of FENO in infants. There is a need for clinical studies showing the merits and limitations of different methodologies, to standardize FENO measurements in infants, and to obtain normal reference values for this age group.