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Background: Exhaled nitric oxide (FeNO) measurements and eucapnic voluntary hyperventilation (EVH) tests have been used as diagnostic tools for asthma. Data on the impact of hyperventilation on the level of FeNO are limited., Aim: We aimed to evaluate whether EVH tests affect the level of FeNO in children aged 10-16 years., Methods: A total of 234 children aged 10-16 years had a 6-min EVH test performed. In total, FeNO values for 153 of 234 children were measured before the test and within 15 min after the test. According to a baseline FeNO level of 20 ppb, children were divided into two groups: those with low values (FeNO < 20 ppb) and those with high values (FeNO ≥ 20 ppb)., Results: The median age of the children was 13.4 years (interquartile range 12.3-15.3 years); 58% were boys and 42% were girls. Of these children, 51% were sensitized to aeroallergens. In 101 of 153 children (66%), the FeNO values decreased after the EVH test. In children with low and high baseline levels, the median level of FeNO decreased after the EVH test: 10.5 ppb before versus 9.5 ppb after (p < .011), and 31.0 ppb before versus 28.0 ppb after (p < .011), respectively. The decrease in FeNO after EVH test was not associated with induced bronchoconstriction expressed as a change in FEV1 (R s  = .19)., Conclusions: The EVH test decreases FeNO levels. Therefore, FeNO should be measured before an EVH test is performed., (© 2020 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.)

Spirometry and exhaled nitric oxide are two important complimentary tools to identify and assess asthma control in children. We aimed to determine the ability of a new suggested spirometry-adjusted fraction of exhaled nitric oxide (NO) index in doing that. A random sample of 1602 schoolchildren were screened by a health questionnaire, skin prick tests, spirometry with bronchodilation and exhaled NO. A total of 662 children were included with median (IQR) exhaled NO 11(14) ppb. Receiver operating characteristic (ROC) curves using exhaled NO equations from Malmberg, Kovesi and Buchvald, and spirometry-adjusted fraction of exhaled NO values were applied to identify asthmatic children and uncontrolled asthma. Receiver operating characteristic (ROC) curves failed to identify asthmatic children (all AUC < 0.700). Spirometry-adjusted fraction of exhaled NO/FEV 1 (AUC = 0.712; P = .010) and NO/FEF 25%-75% (AUC = 0.735 P = .004) had a fair and increased ability to identify uncontrolled disease compared with exhaled NO (AUC = 0.707; P = .011) or the Malmberg equation (AUC = 0.701; P = .014). Sensitivity and specificity identifying non-controlled asthma were 59% and 81%, respectively, for the cut-off value of 9.7 ppb/L for exhaled NO/FEV 1 , and 40% and 100% for 15.7 ppb/L/s for exhaled NO/FEF 25%-75% . Exhaled NO did not allow to identify childhood asthma. Spirometry-adjusted fraction of exhaled NO performed better-assessing asthma control in children. Thus, although more validation studies are needed, we suggest its use in epidemiological studies to assess asthma control., (© 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Objective: Management of asthma could be improved by measuring exhaled nitric oxide (FENO). Portable hand-held FENO analyzer (NIOX MINO) is practical and small and could be used also in the primary care office. It has demonstrated good repeatability and correlation with stationary device (NIOX) in adults and school aged children, but so far there have been no reports on young children. The aim of this study was to compare conventional chemiluminescence device (NIOX) with a hand-held electrochemical device (NIOX MINO) in young children., Design: Paired measurements of FENO were performed with the stationary chemiluminescence-based analyzer (NIOX) and with portable electrochemical device (NIOX MINO) in children with asthmatic symptoms and age-matched controls., Results: Fifty-five children with mean (range) age of 5.7 (3.9-8.5) years were evaluated with both devices. Measurements were successful with both devices in 40 out of 57 children. NIOX MINO was more difficult to use than NIOX in this age group, success rates being 73% and 93%, respectively (P = 0.004). The reproducibility was similar and there was a close correlation between FENO measured by the two devices (r = 0.97, P < 0.001). However, Bland-Altman plot demonstrated limits of agreement that were relatively wide compared to low levels of FENO in the sample. Both devices were sensitive enough to distinguish higher FENO levels in children with asthmatic symptoms, compared to healthy controls., Conclusions: We conclude that NIOX MINO can be used as a screening tool for the assessment of airway inflammation in children from the age of 4 years, but its applicability is limited by lower measurement success rate and relatively poor accuracy and detection limit at low levels of FENO., (Copyright © 2011 Wiley-Liss, Inc.)

Early treatment of new-born high-risk children with certain probiotic strains has reduced the risk of atopic eczema. Whether probiotics reduce risk for airway inflammation in long term is not known. We aimed at studying the effect of probiotic treatment during the six first months of life on airway inflammation at age 5 yr. In a randomized double-blind allergy prevention trial between 2000 and 2007 in Helsinki, Finland, we gave a probiotic combination, plus pre-biotics, or placebo, to 1018 children during 6 months from birth. At age 5, we measured exhaled nitric oxide (FE(NO) ) in a randomized sub-population of 160 children. Allergic diseases and IgE-sensitization were assessed in all infants. FE(NO) did not differ between probiotic and placebo groups, median (interquartile range, IQR) 5.45 (4.3-7.3) vs. 5.70 (3.9-6.8) ppb, p = 0.22. FE(NO) was elevated among those suffering from asthma during the first 5 yr than in healthy non-sensitized children (p = 0.009). FE(NO) correlated positively with serum total and allergen-specific IgE concentrations. Early intervention with probiotics and pre-biotics does not affect airway inflammation later in childhood., (© 2011 John Wiley & Sons A/S.)