Measurement of FeNO with a portable, electrochemical analyzer using a 6-second exhalation time in 7–10-year-old children with asthma: comparison to a 10-second exhalation

Abstract

Objective: Fractional exhaled nitric oxide (FeNO) is a valuable tool for assessing Th2 inflammation in children with asthma. Exhalation times of 6 and 10 s meet the current recommendations for assessing FeNO. The 6-s exhalation provides an alternative for 7–10 year olds not able to complete the 10-s exhalation. Methods: We performed a sub-analysis on data from 7–10-year-old children who participated in a previous study which evaluated the agreement of the 6 and 10-s exhalation times in 6–10 year olds with asthma. Agreement between observed FeNO results obtained by both modes was assessed by weighted Deming regression analysis and Bland-Altman plots. Repeatability was also assessed. Results: Repeatability and agreement of the 6 and 10-s exhalations was demonstrated in 7–10 year olds with two measurements in each mode. Mean observed FeNO measurements were 33.59 ppb (SD = 25.804) for 6 s and 32.46 ppb (SD = 25.302) for 10-s exhalation. Paired differences were centered close to 0 ppb (median = 0.50). Conclusions: Children aged 7–10 years can successfully perform FeNO measurements using a portable, electrochemical FeNO analyzer. Measurements from the 6 and 10-s exhalations were repeatable and consistent with a high degree of agreement between one another. Thus, in young children successful FeNO measurements can be obtained in either the 6-s or 10-s mode, providing physicians valuable information on airway inflammation to aid in the diagnosis and treatment of asthma.

Keywords:

• Biomarkers
• diagnostics
• pediatrics
• treatment

Acknowledgements

All named authors meet the criteria for authorship set forth by the International Committee for Medical Journal Editors; take responsibility for the integrity of the work as a whole and have given final approval to the version to be published. All authors were involved in the acquisition, analysis of data, drafting, critical revision of the manuscript and the final approval of the proof to be published.

Declaration of interest

Dr Kathy Rickard and Margot MacDonald-Berko are employees of Circassia Pharmaceuticals, Inc. and have no conflicts of interest. Dr Neal Jain received a research grant from Circassia Pharmaceuticals, Inc. for the conduct of this study and has received a speaker honorarium from Circassia Pharmaceuticals, Inc. All authors had full access to all of the data in this study and take complete responsibility for the integrity of the data and accuracy of the data analysis.

Additional information

Funding

This study was funded by Circassia Pharmaceuticals, Inc (formerly Aerocrine, Inc.).