Repeatability of standardised nasal nitric oxide measurements in healthy and asthmatic adults and children

SummarySeveral nasal nitric oxide (NO) measurement techniques have been described, but there is not a widespread measurement technique for measurement of nasal NO. In this study we evaluated the repeatability of one technique of nasal NO measurements using the nasal application of the NIOX® system.MethodsThree nasal NO measurements (NIOX® Nitric Oxide Monitoring System, Aerocrine, Sweden) were made on a single occasion in 22 healthy subjects and 27 patients with asthma, aged 5–69 years. Nasal NO was sampled during breath hold from one nostril at a flow rate of 5ml/s.ResultsThe repeatability of nasal NO assessed by the coefficient of variation (CV) was 12.5% (95% Confidence interval (CI) 11.0–14.7%) for the total population. Healthy adults had a significantly better repeatability than healthy children (P