Off-line sampling of exhaled air for nitric oxide measurement in children: methodological aspects

Measurement of nitric oxide in exhaled air is a noninvasive method to assess airway inflammation in asthma. This study was undertaken to establish the reference range of exhaled NO in healthy school-aged children and to determine the influence of ambient NO, noseclip and breath-holding on exhaled NO, using an off-line balloon sampling method. All children attending a primary school (age range 8-13 yrs) underwent NO measurements on two occasions with high and low ambient NO. Each time, the children performed four expiratory manoeuvres into NO-impermeable balloons, with and without 10 s of breath-holding and with and without wearing a noseclip. Exhalation flow and pressure were not controlled. NO was measured within 4 h after collection, by means of chemiluminescence. All children completed a questionnaire on respiratory and allergic disorders, and performed flow/volume spirometry. With low ambient NO, the mean exhaled NO value of 72 healthy children with negative questionnaires and normal lung function was 5.1 +/- 0.2 parts per billion (ppb) versus a mean of 6.8 +/- 0.3 ppb in the remaining 49 children with positive questionnaires for asthma and allergy, and/or recent symptoms of cold (p=0.001). Exhaled and ambient NO were significantly related, especially with ambient NO > 10 ppb (r = 0.86, p=0.0001 versus r=0.34, p=0.004 for ambient values <10 ppb). The use of a noseclip, with low ambient NO and without breath-holding, caused a small decrease in exhaled NO values (p=0.001). The effect of breath-holding on exhaled NO depended on ambient NO. With ambient NO > 10 ppb, exhaled NO decreased, whereas with ambient NO < 10 ppb, exhaled NO increased after 10 s breath-hold. It is concluded that off-line sampling in balloons is a simple and, hence, attractive method for exhaled nitric oxide measurements in children which differentiates between groups with and without self-reported asthma, allergy and colds, when ambient nitric oxide is < 10 parts per billion. Wearing a noseclip and breath-holding affected measured values and should, therefore be standardized or, preferably, avoided

Hydrogen peroxide in exhaled air of healthy children: reference values

An increased content of hydrogen peroxide (H2O2), a marker of inflammation, has been described in the condensate of exhaled air from adults and children with inflammatory lung disorders, including asthma. However, the normal range of [H2O2] in the exhaled air condensate from healthy children has not been established. Therefore, the aim of this study was to determine the reference range of exhaled [H2O2] in healthy school-aged children. Ninety-three healthy nonsmoking children (48 female and 45 male, mean age 10 yrs, range 8-13 yrs), with a negative history for allergy, eczema or respiratory disease and with a normal lung function, participated. Exhaled air condensate was examined fluorimetrically for the presence of H2O2. In addition, the reproducibility of [H2O2] within subjects and between days and the stability of [H2O2] during storage at -20 degrees C were assessed. The median [H2O2] in the exhaled air condensate of all children was 0.13 microM, with a 2.5-97.5% reference range of <0.01-0.48 microM. No significant difference existed between males and females. There was no correlation between exhaled [H2O2] and age or lung function. Repeated [H2O2] measurements on 2 consecutive days showed satisfactory within-subject reproducibility and [H2O2] in stored samples remained stable for at least 1 month at -20 degrees C. In conclusion, this study provides reference data for exhaled hydrogen peroxide in a large group of healthy children. The observed levels were lower than those reported previously for healthy adults and were independent of age, sex and lung function

The perception of substance use disorder among clinicians, caregivers and family members of individuals with intellectual and developmental disabilities

Introduction: Substance use disorders (SUD) are common among individuals with intellectual and developmental disorders (IDD). The quality of care individuals with these conditions receive can be affected by perceptions and attributions of SUD among clinicians, professional caregivers, and family members. The aim of this study was to explore such perceptions and attributions. Method: We conducted a web-based survey using snowball sampling. The Illness Perception Questionnaire Revised (IPQ-R) was used to assess SUD perceptions and attributions. Our sample consisted of 88 clinicians (53.3%), 58 caregivers (35.2%), and 19 adult family members (11.5%), mostly from the United States (73.3%). Results: Respondents - especially clinicians - indicated having a clear concept of the nature of SUD. They recognize that SUD has major consequences for the client, but are positive about the influence both the client and treatment can have on its course and outcome. SUD is attributed to psychological factors (especially so by clinicians and professional caregivers), including stress and worries, and personality, as well as to general risk factors, including hereditary and behavioral factors. Conclusion: According to our respondents, SUD is a serious condition with major consequences, and a variety of potential causes. Given the high prevalence of substance use in the ID population, this calls for more attention for identification, prevention, and treatment of SUD. This includes improving access to SUD treatment adapted to the needs of individuals with IDD, improving coping and emotional skills, and promoting a fulfilling life with adequate social support

Modeling and simulation of crack propagation in mixed-modes interlaminar fracture specimens

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