Experimental data for total deposition in the respiratory tract of children

Schiller-Scotland, Ch.F.; Hlawa, R.; Gebhart, J.

doi:10.1016/0378-4274(94)90020-5

Cited by 33 publications

(21 citation statements)

References 2 publications

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“…Extremely low birth weight newborn infants have very thin skin which does not provide an effective barrier [16] placing these infants at risk of adverse effects from topical exposures [18]. Rectal [19], pulmonary [20], sublingual [21] and buccal [22] administration are not well studied in neonates and although potentially appealing from an administration perspective are likely to lead to unpredictable absorption via these routes.…”

Section: Absorptionmentioning

confidence: 99%

Pharmacokinetics in neonatal prescribing: evidence base, paradigms and the future

O’Hara

Wright

Schneider

et al. 2015

Brit J Clinical Pharma

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Paediatric patients, particularly preterm neonates, present many pharmacological challenges. Due to the difficulty in conducting clinical trials in these populations dosing information is often extrapolated from adult populations. As the processes of absorption, distribution, metabolism and excretion of drugs change throughout growth and development extrapolation presents risk of over or underestimating the doses required. Information about the development these processes, particularly drug metabolism pathways, is still limited with weight based dose adjustment presenting the best method of estimating pharmacokinetic changes due to growth and development. New innovations in pharmacokinetic research, such as population pharmacokinetic modelling, present unique opportunities to conduct clinical trials in these populations improving the safety and effectiveness of the drugs used. More research is required into this area to ensure the best outcomes for our most vulnerable patients.

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Section: Absorptionmentioning

confidence: 99%

Pharmacokinetics in neonatal prescribing: evidence base, paradigms and the future

O’Hara

Wright

Schneider

et al. 2015

Brit J Clinical Pharma

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“…In the study by Bennett and Zeman (1998), controlled relaxed breathing was used while SchillerScotland et al (1994) used spontaneous relaxed breathing. Bennett and Zeman (1998) explained the large difference observed between the two groups by Schiller-Scotland et al (1994) as an effect of the mouthpiece, resulting in the children increasing their tidal volume compared to normal relaxed breathing. The set-up in our study was similar to that of Schiller-Scotland et al (1994) in the sense that our experiments were performed during spontaneous relaxed breathing through a mouthpiece.…”

Section: Lung Deposition Fractionmentioning

confidence: 99%

“…Neither was any statistically significant correlation observed between age and DF from the bivariate analysis of the adult group, even if other lung variables, such as FEV1 and RV, did correlate with age. In two earlier studies, the DF of children and adults were studied and compared (Schiller-Scotland et al, 1994;Bennett and Zeman, 1998). In the Schiller-Scotland et al (1994) study, the measured DF of the children was 50% higher compared to the adults, while Bennett and Zeman did not observe any significant differences in DF between children and adults.…”

Section: Lung Deposition Fractionmentioning

confidence: 99%

“…In two earlier studies, the DF of children and adults were studied and compared (Schiller-Scotland et al, 1994;Bennett and Zeman, 1998). In the Schiller-Scotland et al (1994) study, the measured DF of the children was 50% higher compared to the adults, while Bennett and Zeman did not observe any significant differences in DF between children and adults. In the study by Bennett and Zeman (1998), controlled relaxed breathing was used while SchillerScotland et al (1994) used spontaneous relaxed breathing.…”

Section: Lung Deposition Fractionmentioning

confidence: 99%

“…Most measurements of the deposition of inhaled particles have been carried out on healthy (male) adults, but some also include children (Becquemin et al, 1991;Schiller et al, 1992;Schiller-Scotland et al, 1994;Bennett and Zeman, 1998;Smith et al, 2001;Bennett and Zeman, 2004;Isaacs and Martonen, 2005;Olvera et al, 2012), elderly people (Kim et al, 1988;Bennett et al, 1996;Kim and Jaques, 2005), and patients with airway diseases (e.g., Kim et al, 1988;Schiller-Scotland et al, 1996;Bennett et al, 1997;Brown et al, 2002;Chalupa et al, 2004;Möller et al, 2008;Löndahl et al, 2012). The studies are not fully conclusive, but several of them report an increased respiratory tract deposition for patients with lung diseases and for children.…”

Section: Introductionmentioning

confidence: 99%

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A Set-up for Respiratory Tract Deposition Efficiency Measurements (15-5000 nm) and First Results for a Group of Children and Adults

Rissler

Nicklasson

Gudmundsson³

et al. 2017

Aerosol Air Qual. Res.

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Exposure to airborne particulate matter is associated with a number of negative health effects ranging from respiratory diseases to systemic effects and cancer. One important factor for understanding the health effects is the individual variation in the respiratory tract deposition of inhaled particles. In this study, we describe an experimental set-up for size-resolved measurements of the lung deposited fraction of airborne particles, covering the diameter range from 15 to 5000 nm. The set-up includes a system for generating a stable aerosol with a sufficiently broad size distribution. We used a scanning mobility particle sizer and an aerodynamic particle sizer to determine particle number and size. The set-up was used to investigate individual differences in the deposition fraction (DF) of particles in the respiratory tract for a group of 67 subjects of both sexes aged 7-70 years. The measured DF was applied to two model aerosols, one representing an urban environment and one a rural environment, and the particle deposition rates were derived (i.e., the deposited amount of particles per unit time). Furthermore, the deposition rates were normalized to lung surface area and body mass -two dose measures that are considered relevant for the health effects of airborne particles. In addition to validation of the set-up, we show that there is a large individual variation in DF, with some subjects having a DF that is more than twice as high as that of others. Although we observe differences in the DF between different subgroups, most individual variation was explained neither by age nor by gender. When normalizing the deposition rates to lung surface area or body mass, the deposition rates of children become significantly higher than those of adults. Furthermore, the individual variability is larger for the lung surface area or body mass normalized deposition rates than for DF.

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Effects of breathing variables on modelled particle lung deposition at physical activity for children and adults

Linell,

Isaxon,

Olsson

et al. 2023

Air Qual Atmos Health

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The respiratory tract deposited fraction (DF) is the link between exposure and health effects of airborne particles. Here, we investigate how breathing pattern alterations at increasing physical activity affect DF in different regions of the respiratory tract and compare DF between adults and children (5 and 10 years old). We performed a literature review on the alteration of tidal volume with minute ventilation at increasing physical activity and used the results to model the size resolved (0.001–10 µm) DF, primarily using the deposition models from NCRP and Yeh and Schum (1980), but also MPPD. We found a shift in the deposited size distribution with increasing physical activity—DF of ultrafine particles increased in the alveolar region and decreased in the other regions, while DF of coarser particles decreased in the alveolar region and increased in the extra-thoracic region. Children had a 10–20% higher DF of ultrafine particles in the alveolar region compared to adults. We also present parametrizations of the daily average size resolved (0.005–5 µm) DF, accounting for varying physical activity throughout the day and oral/nasal breathing. These can be applied to any size distribution to estimate deposited doses. We found that deposited mass and number doses were more than twice as high for 5-year-olds compared to adults when normalized for body weight, primarily caused by their higher weight normalized minute ventilation. This demonstrates the importance of studying children’s exposure to air pollution and not only rely on data from adults.

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Experimental data for total deposition in the respiratory tract of children

Cited by 33 publications

References 2 publications

Pharmacokinetics in neonatal prescribing: evidence base, paradigms and the future

Pharmacokinetics in neonatal prescribing: evidence base, paradigms and the future

A Set-up for Respiratory Tract Deposition Efficiency Measurements (15-5000 nm) and First Results for a Group of Children and Adults

Effects of breathing variables on modelled particle lung deposition at physical activity for children and adults

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