Exhaled nitric oxide measurements in childhood asthma: Techniques and interpretation

Kissoon, Niranjan; Duckworth, Laurie; Blake, Kathryn; Murphy, Suzanne P.; Silkoff, Philip E.

doi:10.1002/(sici)1099-0496(199910)28:4<282::aid-ppul8>3.3.co;2-u

Cited by 17 publications

(26 citation statements)

References 111 publications

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“…As asthma is an airway disease, low flows may be more discriminative between subjects and more sensitive to temporal changes. From a practical standpoint in children, fast exhalations cause a rapid decline in lung volume and difficulty in sustaining exhalations long enough for NO values to plateau [61]. At the other end of the spectrum, expiratory flows v30 mL?s -1 result in an excessively long time before NO plateaus, making the test impossible for some subjects and certainly for young children [62].…”

Section: Single-breath On-line Measurementmentioning

confidence: 99%

“…The problems of applying the single-breath on-line method to preschool children Given the aforementioned reasons which led to the adoption of the on-line method as the gold standard, there are considerable difficulties in applying this method to young children [61]. BARALDI et al [64] found that 50% of children aged 4-8 yrs could not perform the SBOL method adequately.…”

Section: Single-breath On-line Measurementmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of exhaled nitric oxide in children, 2001: E. Baraldi and J.C. de Jongste on behalf of the Task Force

Baraldi¹,

Jongste²,

Gaston³

et al. 2002

European Respiratory Journal

288

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Section: Single-breath On-line Measurementmentioning

confidence: 99%

Section: Single-breath On-line Measurementmentioning

confidence: 99%

Measurement of exhaled nitric oxide in children, 2001: E. Baraldi and J.C. de Jongste on behalf of the Task Force

Baraldi¹,

Jongste²,

Gaston³

et al. 2002

European Respiratory Journal

288

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“…First, exhaled NO measurement directly measures a surrogate for airway inflammation, which conventional pulmonary function testing, peak flow measurement, or symptom diaries do not [70,71]. Perhaps more importantly from a practical point of view, exhaled NO measurements are non-invasive and can be made much more reproducibly than pulmonary function testing in children and infants [72,73]. Because nasopharynx and paranasal sinuses account for a large portion of exhaled NO [49], it is important to use standardised techniques when collecting the samples.…”

Section: Breath Nomentioning

confidence: 99%

Measurement of nitric oxide, nitrite and nitrate using a chemiluminescence assay:an update for the year 2000

McMurtry¹,

Kim²,

Dinh-Xuan³

et al. 2000

Analusis

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This review deals with the measurement of nitric oxide (NO) using the chemiluminescence assay. A preliminary discussion is offered to explain the chemical basis for this assay and emphasize the importance of measuring NO. After reviewing some practical aspects and caveats of the chemiluminescence assay, we review its application in a variety of research and clinical settings, such as measurement of breath NO and serum nitrates. The importance of avoiding confounding effects of dietary nitrates when assessing the NO system in humans is discussed and new data are provided on the confounding effects of atmospheric NO on measurement of breath NO. The utility and ease of the chemiluminescence assay for these applications is contrasted with the challenge of using chemiluminescence for correlation of vascular tone and NO production, studies in which real-time measurements are required. Although the chemiluminescence assay is one of the most reliable, rapid and reproducible assays available, it is optimal for gas phase measurements and may be suboptimal for measurement under certain circumstances. This chapter complements several more general reviews of the methodology for measuring NO.Article available at http://analusis.edpsciences.org or http://dx.doi.org/10.1051/analusis:2000280455 Need for measuring NOIt is clear that NO is essential in a significant number of normal physiological processes. However, the scope of its importance also spans pathophysiology of disease, such as in cardiogenic shock [14,15]. Inhaled NO is used for diagnostic purposes, and has therapeutic value, in diseases such as pulmonary hypertension [16][17][18], asthma and chronic obstructive lung diseases [12,[19][20][21]. NO may even promote regression of diseases, such as atherosclerosis [22,23].In view of the broad biological importance of this molecule, it is not surprising that basic and clinical research pertaining to NO has been so prolific. However, a computerised search of the past five years' literature found NO measurements reported in only 1089 of 26123 articles dealing with NO. Since many scientists don't measure NO, perhaps we should make the case for measurement explicit.There are four major reasons why one should consider measuring NO: Non specificity of NO inhibitorsPharmacological experiments are useful in studying NO and its effects. Nevertheless, the non-specificity of NO inhibitors [24][25][26] impairs one's ability to draw sound mechanistic conclusions. For instance, N G -monomethyl-L-arginine (L-NMMA), a NOS antagonist, displays hemodynamic effects that are not solely mediated by its ability to inhibit NO synthesis [27]. L-NMMA can also be metabolized to yield NO. Furthermore, even high doses of NOS inhibitors do not completely prevent NO synthesis [28]. Without measuring NO one cannot be assured that the observed effects resulting from administration of a NOS inhibitor reflect the complete loss of NO, nor can one exclude non-specific effects of these inhibitors. The existence of multiple endothelium-derived vasodilatorsIt i...

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“…Accurate and reliable determination of NO synthesis in vivo is essential to understand the pathophysiologic and therapeutic roles of this biologic pathway. Direct measurement of exhaled NO is a noninvasive and practical approach for assessing airway inflammation in children (14). Indeed, exhaled NO has been proposed as a tool for screening and monitoring airway inflammation and titration of anti-inflammatory therapy in asthmatic children (15).…”

mentioning

confidence: 99%

A Noninvasive, Sensitive, Specific, and Reliable Approach to Assess Whole-Body Nitric Oxide Synthesis in Children

2006

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Determination of nitric oxide (NO) synthesis in vivo is essential to understand the pathophysiologic role and therapeutic implications of the L-arginine/NO pathway in pediatric diseases. The aim of this study was to establish a noninvasive, sensitive, specific, and reliable approach to determine whole-body NO synthesis in healthy children. Seventeen healthy children (eight boys/nine girls, 4 -16 y) were studied twice, and six of them on three occasions. Fasting children received a single oral dose of nonradioactive T he L-arginine/NO pathway has been an exciting research area for the past two decades. NO is endogenously synthesized from the amino acid L-arginine by NO synthase (NOS) in numerous cells, including platelets, neurons, macrophages, and endothelial cells (1). Three isoforms of human NOS have been cloned: neuronal, endothelial, and inducible (2). Both the neuronal NOS and endothelial NOS are constitutively expressed in cells and produce picomolar amounts of NO. By contrast, the inducible isoform produces high and sustained levels of NO and is usually expressed in macrophages and vascular smooth muscle cells following the exposure to cytokines and lipopolysaccharide (3). The physiologic importance of the L-arginine/NO pathway has been extensively studied in humans. It is known to play a major role in controlling vascular tone, platelet function, neurotransmission, and bronchial airway reactivity (1,4).Basic research on NO derived from in vitro and in vivo experimental models has started to have an impact on pediatrics. Accumulating evidence suggest that the NO signaling pathway is abnormal in a number of pediatric conditions including primary pulmonary hypertension (5), childhood essential hypertension (6), and cerebral malaria (7) and markedly increased in others such as septic shock (8), gastroenteritis (9,10), bronchial asthma (11), type 1 diabetes mellitus (12), and autoimmune and inflammatory diseases (13). Accurate and reliable determination of NO synthesis in vivo is essential to understand the pathophysiologic and therapeutic roles of this biologic pathway. Direct measurement of exhaled NO is a noninvasive and practical approach for assessing airway inflammation in children (14). Indeed, exhaled NO has been proposed as a tool for screening and monitoring airway inflammation and titration of anti-inflammatory therapy in asthmatic children (15). On the other hand, determination of systemic NO synthesis has been proved difficult because of NO's short plasma half-life (3-5 s) (16). This limitation has led to the development of functional and chemical markers to determine NO bioactivity. Biomarkers such as cyclic guanosine monophosphate, L-citrulline, and nitrate concentrations in plasma and urine have been used in clinical studies to assess systemic NO synthesis. However, these metabolites are not specific for the L-arginine/NO pathway (17). An approach to assess whole-body NO synthesis in critically ill children (i.e. septic shock) consists of a primed, 5-8-h constant i.

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Exhaled nitric oxide measurements in childhood asthma: Techniques and interpretation

Cited by 17 publications

References 111 publications

Measurement of exhaled nitric oxide in children, 2001: E. Baraldi and J.C. de Jongste on behalf of the Task Force

Measurement of exhaled nitric oxide in children, 2001: E. Baraldi and J.C. de Jongste on behalf of the Task Force

Measurement of nitric oxide, nitrite and nitrate using a chemiluminescence assay:an update for the year 2000

A Noninvasive, Sensitive, Specific, and Reliable Approach to Assess Whole-Body Nitric Oxide Synthesis in Children

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