Utility of exhaled nitric oxide in the diagnosis and management of asthma.
OBJECTIVE
The fraction of nitric oxide in exhaled air (FeNO) is elevated in the presence of airway inflammation, and it may be a useful biomarker in asthma. The purpose of the present review is to highlight the current literature investigating the use of exhaled nitric oxide in the diagnosis and management of asthma.


RESULTS
The measurement of exhaled nitric oxide has been studied in normal populations and in asthmatics. FeNO appears to be a useful screening tool for asthma, although nondisease factors may confound the interpretation of an elevated FeNO level. Clinical trials investigating the use of FeNO measurements in predicting asthma exacerbation and tailoring maintenance therapy have had varying success. Further studies incorporating individualized FeNO profiles into treatment algorithms are needed.


CONCLUSIONS
FeNO shows promise as a tool in the diagnosis and treatment of asthma. However, further studies are needed to address outstanding questions about its exact role in guiding asthma management.
Section of Pulmonary Critical Care and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
Hashir
H
Majid
Christina
C
Kao
D000465:Algorithms; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism*
D018927:Anti-Asthmatic Agents; D015415:Biomarkers; D009569:Nitric Oxide