Exhaled Nitric Oxide In Children Research Articles

Defining the normal range of fractional exhaled nitric oxide in children: one size does not fit all.

BackgroundThe normal range of fractional exhaled nitric oxide (FENO) is influenced by demographic factors. However, single, fixed cut-off values are used for clinical interpretation in children despite rapid growth. We aimed to define the normal range of FENO during childhood and evaluate its utility in a diagnostic setting.MethodFENO percentile charts were developed using data from nonasthmatic children in a population-based birth cohort (Manchester Asthma and Allergy Study). Children were skin prick tested, FENO measured at the ages of 8, 11, 13–16 and 18 years and clinical information collected. This chart was externally validated in the Study of Eczema and Asthma to Observe the Influence of Nutrition (SEATON) cohort before being prospectively tested in symptomatic, treatment-naïve patients with suspected asthma in a diagnostic setting (Rapid Access Diagnostics for Asthma study).ResultsHeight, weight, body mass index and age were predictive of FENO in univariate analysis using 1220 FENO measurements. Only height remained significant after adjustment in the overall, nonatopic and atopic populations, and was included in the predictive equations for 50th, 75th 90th and 98th percentiles. The proposed percentile lines corresponded to the 57th (95% CI 53rd–61st), 80th (76th–83rd), 90th (87th–92nd) and 98th (96th–99th) percentiles in the SEATON cohort (660 measurements). When tested in 73 symptomatic treatment-naïve children and young adults (median (interquartile range) age: 11 (8–14) years), an FENO >90th percentile gave a 96% specificity and positive predictive value of 97%, identifying 59% of children who were subsequently diagnosed with asthma after extensive testing.ConclusionWe developed a height-based FENO percentile chart which quantifies the probability of asthma in symptomatic children and merits further validation towards clinical implementation.

Cough reflex sensitivity and fractional exhaled nitric oxide in children with asthma.

Individual studies have suggested the utility of fractional exhaled nitric oxide (FeNO) measurement in detecting cough-variant asthma and eosinophilic bronchitis in patients with chronic cough. The aim of this study was to clarify a correlation of cough reflex sensitivity and fractional exhaled nitric oxide in asthmatic children. 25 children with asthma and 15 controls were submitted to cough reflex sensitivity measurement - capsaicin aerosol in doubling concentrations (from 0.61 to 1250 micromol/l) was inhaled by a single breath method. Concentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Fractional exhaled nitric oxide (FeNO) measurement was included. Asthmatic children' (11 boys and 14 girls, mean age 9+/-1 years) and control group (unconfirmed diagnosis of asthma) (6 boys and 9 girls, mean age 8+/-1 years) were included into the study. FeNO vs. C2 in asthma (Spearman´s rank correlation: -0.146, p=0.49); FENO vs. C5 in asthma (Spearman´s rank correlation: -0.777, p=0.71). We found that there is no correlation between cough reflex sensitivity and fractional exhaled nitric oxide either in children with asthma or in the control group.

Genetic effects of allergen-specific IgE levels on exhaled nitric oxide in schoolchildren with asthma: The STOPPA twin study.

BackgroundExhaled nitric oxide and blood eosinophils are clinical asthma T‐helper type 2 markers in use. Immunoglobulin E (IgE) is often involved in the inflammation associated with atopic asthma. The effect of both blood eosinophils and allergen‐specific IgE on exhaled nitric oxide levels is not completely understood. Twin‐design studies can improve understanding of the underlying contribution of genetically and/or environmentally driven inflammation markers in asthma. Our aim was to disentangle the covariance between asthma and exhaled nitric oxide into genetic and environmental contributions that can account for inflammation markers in a paediatric population.MethodsThis population‐based, cross‐sectional twin study enrolled 612 monozygotic (MZ) and same‐sex dizygotic (DZ) schoolchildren. Multivariate structural equation modelling was utilized to separate the covariance between asthma and exhaled nitric oxide into genetic and/or environmental effects, taking allergen‐specific IgE level and blood eosinophil count into account while controlling for confounding factors.ResultsThe cross‐twin/cross‐trait correlations had a higher magnitude in the MZ twins than in the DZ twins, indicating that genes affect the association. The likelihood ratio test for model fitting resulted in the AE model (ie additive genetic effects, A, and non‐shared environmental effects, E) as the most parsimonious. A majority, 73%, of the phenotypic correlation between asthma and exhaled nitric oxide, r = .19 (0.05‐0.33), was attributable to genetic effects which mainly was due to the allergen‐specific IgE level.ConclusionsThis study indicates that the association between asthma and exhaled nitric oxide in children is to a large extent explained by genetics via allergen‐specific IgE level and not blood eosinophils. This might partly explain the clinical heterogeneity in this group. A next step could be to include allergen‐specific IgE level in multivariate omic studies.

Effects of the salbutamol bronchodilator response on measurements of fractional exhaled nitric oxide in children with asthma: a prospective, observational study.

Salbutamol bronchodilator response (BDR) test and fractional exhaled nitric oxide (FeNO) have been recommended for the diagnosis of asthma in children, but FeNO levels is affected by many factors. Nonetheless, data of the effect on the FeNO values throughout the bronchodilator test and the differences in FeNO values between BDR positive (BDR+) and negative (BDR-) children with asthma are still limited. We aimed to evaluate the effect of the BDR test on FeNO and the differences in FeNO levels between BDR+ and BDR- children with asthma. This was a prospective, observational study performed over a 5-month period (December 2018 to April 2019) and involved 57 children with asthma. The FeNO levels at pre-spirometry, post-spirometry, and post-salbutamol BDR testing were estimated. Finally, the children were divided into two groups i.e., BDR+ and BDR-, and differences in the FeNO levels were compared between the two groups. The spirometry results were normal in 2 patients (3.5%). There were 53 (93%) patients with obstructive lung disease, including 40 (70.2%), 11 (19.3%), and 2 (3.5%) patients with mild, moderate, and severe obstruction, respectively. The remaining two patients had mixed lesions (3.5%), none of which were restrictive. The baseline median FeNO levels were significantly higher in the BDR+ group than in the BDR- group [33.00 (23.78, 46.73) vs. 23.00 (9.80, 37.80), (P=0.048)]. Following spirometry, there was a statistically significant decrease in median FeNO levels from baseline to post-spirometry (P=0.002). However, there was no significant difference between the median FeNO levels at baseline and following the BDR test (P=0.976). The impact of spirometry on FeNO was not statistically different in BDR+ versus BDR- children (Z=-0.186, P=0.853); however, the impact of bronchodilators on FeNO exhibited a statistically significant difference between the two groups (Z=3.160, P=0.002). This study revealed dynamic changes in the FeNO levels during the BDR test. The use of a bronchodilator results in a statistically significant difference in FeNO levels between BDR+ and BDR- children with asthma. Moreover, spirometry leads to a marked decrease in the FeNO levels. Our results will allow clinicians to better interpret FeNO, BDR and pulmonary function outcomes and better develop clinical protocols.

Morning Fractional Exhaled Nitric Oxide in Children with Recurrent Desaturation During Sleep

The aim was to assess the relationship between morning fractional exhaled NO (FeNO) and nocturnal oxygen desaturation in children. Design: prospective study. Setting: The study was conducted from January 2012 to January 2018, in the division of pediatric at tertiary-care hospital.

Electrochemical Detection of the Exhaled Nitric Oxide in Children

Dosage of gaseous inflammatory markers is a promising method of evaluating various types of pediatric pathologies and not only. The fraction of exhaled nitric oxide (FeNO) can be quantified by electrochemical detection using a portable analyzer that delivers fast, reproducible, and widely available results. The objectives of our study were to evaluate the accessibility of the pediatric dosing method and the utility of FeNO for the diagnosis of atopic pathology in hospitalized children. We conducted a retrospective study that included children aged over 6 years admitted to the Pediatric Department of the Municipal Hospital Filantropia in Craiova who were evaluated according to the type of training performed for the determination of FeNO and according to the diagnosis of admission. Results. Using a human model was more effective in obtaining a valid result compared to the use of the demo provided by the manufacturer, especially at younger age (p = 0.05 and respectively, 0.04 - Student t test). Among the various allergic pathologies studied, children with asthma were the ones who recorded the highest levels of nitric oxide, even when compared to the rest of atopic children (p = 0.01 - t test). Moreover, the proportion of cases with positive values was increased in asthmatic children compared to the rest of the type of allergic pathology, but these values were at the limit of statistical significance (p = 0.08 - chi square and Mid-P exact test). The conclusion of our study was that it is possible to improve compliance with FeNO assessment especially at younger age, and the utility of the method is still limited, especially in asthma cases.

Bronchial Responsiveness 5-Class Model and Its Association with Baseline Spirometry and Fractional Exhaled Nitric Oxide in Children

Bronchial Responsiveness 5-Class Model and Its Association with Baseline Spirometry and Fractional Exhaled Nitric Oxide in Children

Factors associated with exhaled nitric oxide in children with asthma and allergic rhinitis.

Factors attributable to the level offraction of exhaled nitric oxide (FeNO) in different age groups of asthmatic children are still lack of report. To evaluate factors associated with FeNO and the response of FeNO to inhaled steroid in different age groups of asthmatic children with allergic rhinitis. Asthmatic children aged 5 to 12years were recruited. FeNO, lung function and bronchial hyperresponsiveness (BHR) to methacholine, skin prick testing to a panel of aeroallergens, total immunoglobulin E (T-IgE) in serum and eosinophils in blood were tested. Correlations between FeNO and the measured parameters were assessed. FeNO was measured again after the treatment of combined inhaled corticosteroid and long-acting beta-agonist (ICS/LABA) for 4weeks. Changes in FeNO between different age groups were compared. A total of 121 eligible subjects were enrolled in and completed this study. Asthmatic children aged 10 to 12years old had significantly higher FeNO than those between 8 and 9years and 5 to 7years of children (both P<0.01). Greater height/age (P<0.01) and higher level of total allergen IgE (P<0.01) are associated with a higher value of FeNO. After 4weeks of treatment with ICS/LABA, asthma control test scores were significantly increased in all age groups (P<0.01), while the level of FeNO significantly decreased in the elder age group only (P<0.01). Height and T-IgE are well correlated with FeNO in asthmatic children aged 5 to 12years. Measurement of FeNO is more suitable for evaluating the efficacy of ICS/LABA in elder asthmatic children.

Clinical application of exhaled nitric oxide in children with upper airway diseases

The exhaled air of healthy people contains nitric oxide.Under the physiological condition, nasal nitric oxide(NNO) comes primarily from the sinuses, a little is produced in the nasal mucosa.Fractional exhaled nitric oxide is mainly from the trachea and bronchus.When airway diseases occur, it can influence the concentration of exhaled nitric oxide.Therefore, with the continuous improvement of technology in recent years, the measurement of NNO has been widely used in upper airway diseases of children.It is characteristics of quantitative, non-invasive, simple and safe.This article reviews the measurement methods of NNO and its clinical application in children upper airway diseases such as rhinitis, sinusitis, nasal polyps and adenoid hypertrophy. Key words: Exhaled nitric oxide; Upper airway disease; Child

Levels of fractional exhaled nitric oxide in children in relation to air pollution in Chinese day care centres.

To study fractional exhaled nitric oxide (FeNO) levels among pre-school children in day care centres (DCCs) in relation to indoor and outdoor air pollution in northern China. This was a cross-sectional study among children aged 5 years from 34 classrooms at 10 randomly selected DCCs in Taiyuan, China. A total of 507 (99%) children participated. Air pollution and carbon dioxide (CO2) levels were measured in the classroom and outside the school. Linear mixed models were applied for statistical analysis. The geometric mean FeNO was 9.1 ± 1.5 parts per billion; 11.6% of children had wheeze, 6.0% had dry cough, 26.4% rhinitis symptoms, 1.6% ever physician-diagnosed asthma and 29.2% ever physician-diagnosed pneumonia. FeNO levels were associated with current wheeze (P = 0.04) and ever physician-diagnosed pneumonia (P = 0.05). The mean indoor concentrations were particulate matter with a diameter of <2.5 μm (PM2.5) 268 μg/m3, sulfur dioxide (SO2) 40.5 μg/m3, nitrogen dioxide (NO2) 43.0 μg/m3 and CO2 827 parts per million. Outdoor concentrations were PM2.5 244 μg/m3, SO2 106.6 μg/m3 and NO2 40.9 μg/m3. PM2.5 levels inside (P = 0.002) and outside DCCs (P = 0.05) were associated with FeNO levels. PM2.5 levels inside and outside DCCs in China can contribute to airway inflammation in pre-school children. Children with current wheeze and ever physician-diagnosed pneumonia may have higher FeNO levels.

Agreement Between the 6 Seconds and 10 Seconds Exhalation Modes When Measuring Fractional Exhaled Nitric Oxide in Children Aged 4-6 Years With the NIOX VERO Device

SESSION TITLE: Pediatrics SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: NIOX VERO has the capability to measure fractional exhaled nitric oxide (FeNO) using both the 6 second (6s) and the 10 second (10s) exhalation modes. ATS/ERS 2005 guidelines for measurement of FeNO in children require exhalation of at least 4 seconds for children <12 years of age and >6 seconds for children >12 years of age. This study was undertaken to compare results of FeNO measurements performed using the 6s and 10s exhalation modes in children 4-6 years of age. METHODS: This was a randomized, multi-center, single-visit study with healthy and asthmatic children 4 to 6 years of age. Subjects were randomized to perform FeNO measurements starting with either the 6s or 10s exhalation mode. Data are presented in which the degree of agreement of FeNO measurements using the 6s and the 10s exhalation modes was assessed by weighted Deming regression analysis. RESULTS: The total population (n=247) consisted of 137 (55.5%) males, had a mean height of 112.8 cm, and was composed of 73 four year olds (4yo), 87 five year olds (5yo) and 87 six year olds (6yo). 105 subjects completed one FeNO measurement in either mode (20 4yo, 40 5yo, 45 6yo). An additional 88 subjects completed one FeNO measurement in either mode but were discontinued because enrollment into the low FeNO group (<20 ppb) was met (25 4yo, 30 5yo, 33 6yo). 54 subjects were unable to complete any FeNO measurements (28 4yo, 17 5yo, 9 6yo). There were 83 subjects that completed one FeNO measurement in both modes. Average FeNO values for the 6s (21.3 ppb) and the 10s (21.0 ppb) modes were comparable and paired differences between the replicates centered around zero for each age group. The 4yo mean paired difference was -0.3 (n=13, SD=1.58, median=0.0). The 5yo mean paired difference was 0.5 (n=31, SD=3.61, median=0.5). The 6yo mean paired difference was 0.4 (n=39, SD=3.70, median=0.5). Of the 83 subjects, 68 completed two FeNO measurements in both modes. Average FeNO values for the 6s (21.1 ppb) and the 10s (20.7 ppb) modes were comparable and paired differences between the replicates centered around zero for each age group. The 4yo mean paired difference was 0.4 (n=9, SD=0.74, median=0.0). The 5yo mean paired difference was 0.6 (n=27, SD=3.28, median=0.5). The 6yo mean paired difference was 0.1 (n=32, SD=3.99, median=0.3). The estimated intercept and slope from the weighted Deming regression modeling 6s mode FeNO results as a function of the 10s mode FeNO results were not significantly different from 0 and 1.0, respectively. Average bias in the predicted 6s mode FeNO results expressed as a percent of the 10s mode FeNO result was low (1.03%), and the bias at the 35 ppb cut-off value (0.391) was significantly less than 7 ppb (20% of 35 ppb; p<0.0001). FeNO values were within the tolerance limits at the 35 ppb cut-off value for 65/68 subjects (95.6%). There were no reported adverse events or serious injuries. CONCLUSIONS: The results of this study demonstrate that the degree of agreement between the 6s and 10s modes was high and that the NIOX VERO was safe in children 4-6 years of age. CLINICAL IMPLICATIONS: Performing FeNO measurements to assess TH2 inflammation in the airway using the 6s mode is a feasible option and can provide valuable information in the management of asthma in children 4-6 years of age. DISCLOSURE: Kathy Rickard: Employee: salary Margot MacDonald-Berko: Employee: salary Robert Anolik: Grant monies (from industry related sources): contract for study-related tasks Neal Jain: Grant monies (from industry related sources): contract for study-related tasks, Consultant fee, speaker bureau, advisory committee, etc.: contract for advisory board and speaker fees Craig La Force: Grant monies (from industry related sources): contract for study-related tasks, Consultant fee, speaker bureau, advisory committee, etc.: contract for speaker fees Richard Wasserman: Grant monies (from industry related sources): contract for study-related tasks The use of the NIOX VERO 6s exhalation mode and the use of the NIOX VERO in children younger than 7 years of age are uses not yet cleared by the FDA. However, the results of this study have been submitted to the FDA for 510k and clearances may be obtained prior to the CHEST meeting.

Obesity disproportionately impacts lung volumes, airflow and exhaled nitric oxide in children.

BackgroundThe current literature focusing on the effect of obesity and overweight on lung function and fraction of exhaled nitric oxide (FeNO) in children, particularly among healthy children of non-European descent, remains controversial. Furthermore, whether the relationship of obesity and overweight with lung function and FeNO in children is modified by atopy is unclear. The objective of this study was to examine the effect of excess weight on lung function parameters and FeNO among Asian children, with a particular focus on exploring the potential effect modification by atopy.MethodsWe investigated the effect of excess weight on lung function and FeNO in a population sample of 1,717 children aged 5 to 18 years and explored the potential modifying effect of atopy.ResultsThere were positive associations of body mass index (BMI) z-score with forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), and forced expiratory flow at 25–75% (FEF25-75) (all P<0.001), after controlling for confounders. The beta coefficient for FEV1 (0.084) was smaller than that for FVC (0.111). In contrast, a negative association was found between BMI z-score and FEV1/FVC ratio (P<0.001) and FeNO (P = 0.03). A consistent pattern of association for lung function variables was observed when stratifying by atopy. There was a negative association of BMI z-score with FeNO in atopic subjects (P = 0.006), but not in non-atopic subjects (P = 0.46).ConclusionsExcess weight disproportionately impacts lung volumes and airflow in children from the general population, independent of atopic status. Excess weight inversely affects FeNO in atopic but not in non-atopic children.

Airway hyperresponsiveness to mannitol and methacholine and exhaled nitric oxide in children with asthma

ABSTRACTObjective: Asthma is characterized by airway hyperresponsiveness (AHR), inflammation, and obstruction. AHR to stimuli that indirectly cause bronchial smooth muscle (BSM) contractions via release of endogenous mediators is thought to better reflect airway inflammation than AHR to stimuli that act directly on BSM. Fractional exhaled nitric oxide (FeNO) is a useful parameter for noninvasive clinical airway inflammation assessments. Accordingly, this study aimed to examine the relationships of mannitol and methacholine challenge test outcomes with FeNO and the influence of inhaled corticosteroid treatment in children with asthma. Methods: One hundred thirty-four asthmatic children (89 males; ages: 5–17 years, median: 9 years) underwent spirometry, FeNO measurement, serum total/specific IgE testing, and blood eosinophil count. All subjects were challenged with mannitol dry powder (MDP; AridolH, Pharmaxis, Australia) and methacholine at 7-day intervals. Data of steroid-treated and steroid-naïve children were compared. Results: Positive responses to MDP and methacholine challenge tests were observed in 74.6% and 67.2% of total subject group, respectively, and 72 children had positive response to both challenge tests. The median FeNO level, response-dose ratio (RDR) of PC20 methacholine, and RDR of PD15 MDP were significantly higher in the steroid-treated group than in the steroid-naïve group (p < 0.001, 0.226, and 0.004, respectively). FeNO levels associated significantly with PD15 MDP and RDR PD15 MDP in total subject populations (p = 0.016 and 0.003, respectively); however, a significant correlation between FeNO and RDR PD15 MDP was observed only in the steroid-naïve group. Conclusions: Compared with AHR to methacholine, AHR to MDP more closely reflected the level of FeNO in steroid-naïve asthmatic children.

Clinical application of exhaled nitric oxide in children

Exhaled nitric oxide fraction(FeNO)reflects eosinophilic bronchial inflammation, and has been widely used to assist in the diagnosis of asthma, to monitor the airway inflammation and the responce to treatment effects of asthma in recent years.FeNO as a noninvasive examination, obtains a high degree of cooperation in adults and children over 5 years of age, but there are a lot of problems in children under 5 years of age.At present, there is still a lack of normal values and large sample-sized studies of FeNO in infants and neonates in China.The principle and method, normal reference value, influencing factors, clinical application and so on of exhaled nitric oxide detection are reviewed in this paper. Key words: Exhaled nitric oxide fraction; Children; Bronchial inflammation; Influencing factor

Ocena stężenia tlenku azotu w powietrzu wydychanym u dzieci z alergicznym nieżytem nosa

Ocena stężenia tlenku azotu w powietrzu wydychanym u dzieci z alergicznym nieżytem nosa

Particulate Oxidative Burden as a Predictor of Exhaled Nitric Oxide in Children with Asthma.

Background:Epidemiological studies have provided strong evidence that fine particulate matter (PM2.5; aerodynamic diameter ≤ 2.5 μm) can exacerbate asthmatic symptoms in children. Pro-oxidant components of PM2.5 are capable of directly generating reactive oxygen species. Oxidative burden is used to describe the capacity of PM2.5 to generate reactive oxygen species in the lung.Objective:In this study we investigated the association between airway inflammation in asthmatic children and oxidative burden of PM2.5 personal exposure.Methods:Daily PM2.5 personal exposure samples (n = 249) of 62 asthmatic school-aged children in Montreal were collected over 10 consecutive days. The oxidative burden of PM2.5 samples was determined in vitro as the depletion of low-molecular-weight antioxidants (ascorbate and glutathione) from a synthetic model of the fluid lining the respiratory tract. Airway inflammation was measured daily as fractional exhaled nitric oxide (FeNO).Results:A positive association was identified between FeNO and glutathione-related oxidative burden exposure in the previous 24 hr (6.0% increase per interquartile range change in glutathione). Glutathione-related oxidative burden was further found to be positively associated with FeNO over 1-day lag and 2-day lag periods. Results further demonstrate that corticosteroid use may reduce the FeNO response to elevated glutathione-related oxidative burden exposure (no use, 15.8%; irregular use, 3.8%), whereas mold (22.1%), dust (10.6%), or fur (13.1%) allergies may increase FeNO in children with versus children without these allergies (11.5%). No association was found between PM2.5 mass or ascorbate-related oxidative burden and FeNO levels.Conclusions:Exposure to PM2.5 with elevated glutathione-related oxidative burden was associated with increased FeNO.Citation:Maikawa CL, Weichenthal S, Wheeler AJ, Dobbin NA, Smargiassi A, Evans G, Liu L, Goldberg MS, Godri Pollitt KJ. 2016. Particulate oxidative burden as a predictor of exhaled nitric oxide in children with asthma. Environ Health Perspect 124:1616–1622; http://dx.doi.org/10.1289/EHP175

Antioxidant supplementation and exhaled nitric oxide in children with asthma.

The effect of allergen avoidance on airway inflammation is similar to that observed with treatment with inhaled steroids, whereas inhaled steroids have no effect on oxidative stress-induced inflammation. The aim of this study was to retrospectively evaluate the potential effect of an antioxidant dietary supplement on exhaled nitric oxide over a month in pediatric patients on stable antiasthma treatment. Forty-seven children with moderate-to-severe asthma were retrospectively evaluated. All the patients were sensitive to Dermatophagoides pteronyssinus and Dermatophagoides farinae, and they were receiving the minimum inhaled corticosteroid dosage required to maintain adequate control. Within a few weeks of admission at Misurina Hospital in the Alps, the regular treatment was gradually reduced, then some children who were receiving a daily dose of inhaled corticosteroids, ≤200 mcg of fluticasone propionate, were prescribed a nutraceutical dietary supplement for at least 4 weeks. Lung function and fractional exhaled nitric oxide (FeNO) measurements were recorded at the beginning and after 1 month of the dietary supplementation. Baseline lung function and FeNO values did not differ between the two groups of patients. After 4 weeks of nutraceutical supplementation, FeNO values decreased, from 19.00 ppb (interquartile range, 14-31 ppb) to 11.00 ppb (interquartile range, 6-23 ppb) (p = 0.03). No significant reduction was observed in the group that did not receive the supplementation, and no significant difference between groups was observed, both at baseline and after 4 weeks of nutraceutical supplementation. Supplementation with a nutraceutical of antioxidants and anti-inflammatory compounds, such as curcumin, resveratrol, soy phospholipids, zinc, selenium, and vitamin D, may be associated with reduced airway inflammation, as documented by a fall in FeNO.

Measurement of nasal and fractional exhaled nitric oxide in children with upper airway inflammatory disease: Preliminary results

ObjectivesTo assess the clinical significance of nasal nitric oxide (nNO) and fractional exhaled nitric oxide (FeNO) concentrations in children with upper airway inflammatory disease. MethodsFifteen healthy children, 30 with allergic rhinitis (AR), 10 with non-allergic rhinitis (NAR), and 30 with sleep disordered breathing (SDB) were enrolled. The FeNO and nNO concentrations were measured non-invasively using a NIOX MINO system. ResultsBoth nNO and FeNO were significantly higher in children with AR than in healthy children (P=0.000 and P=0.000, respectively). Compared to healthy children, nNO was also significant higher in children with NAR (P=0.011) or SDB (P=0.027). In contrast, FeNO did not differ from controls in children with NAR or SDB. ConclusionsOur data suggest that nNO has potential value for diagnosing upper airway inflammation. Moreover, elevated FeNO distinguishes allergic from non-allergic rhinitis.

Use of exhaled nitric oxide in children with bronchial asthma

BackgroundInflammation is an important aspect of the pathophysiology of bronchial asthma and measurement of inflammatory markers of airways can aid in management. Nitric oxide measurement in exhaled breath is a non-invasive method of determining airway inflammation which can be used in assessing severity and response to treatment in children with bronchial asthma. MethodsThirty children in the age group 6–14 years with previously or newly diagnosed bronchial asthma reporting for the first time to a tertiary care hospital constituted the study group. Assessment was done by history, clinical examination, spirometry and measurement of fractional excretion of nitric oxide (FeNO) before commencement of treatment as per standard guidelines and on follow up at 2 to 4 weeks intervals for a minimum of three times. ResultsThere was significant correlation between FeNO values, spirometry parameters and clinical profile in the first visit before the initiation of therapy. Children with higher FeNO in the first visit responded better to Inhaled Corticosteroids (ICS) with good clinical and spirometry responses and fall in FeNO on second visit. However, in subsequent visits no significant correlation was observed between clinical control, FeNO levels and spirometry. ConclusionHigh FeNO values at first presentation could give us a clue as to whether or not a child would respond to ICS but FeNO monitoring may not be helpful in long term follow up as various other factors can affect its value.

Association between allergic sensitization and exhaled nitric oxide in children in the School Inner-City Asthma Study

Association between allergic sensitization and exhaled nitric oxide in children in the School Inner-City Asthma Study