Total deposition of aerosol particles in the respiratory tract of children during spontaneous and controlled mouth breathing

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

doi:10.1016/0021-8502(92)90448-5

Cited by 35 publications

(16 citation statements)

References 2 publications

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“…The problem may be more present in children, in whom aerosol deposition shows more variability and is less well studied than in adults. 27,28 Our study has several limitations. First, iloprost was always given after iNO because of its longer half-life; iloprost has a documented hemodynamic effect of Ϸ1 to 2 hours, 9,13 which would have excluded a 2-group study protocol with a randomized drug allocation.…”

Section: Discussionmentioning

confidence: 94%

Inhaled Nitric Oxide Versus Aerosolized Iloprost in Secondary Pulmonary Hypertension in Children With Congenital Heart Disease

Rimensberger

Spahr-Schopfer²,

Berner³

et al. 2001

Circulation

170

116

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Background-Inhaled nitric oxide (iNO) has been used to assess the vasodilator capacity of the pulmonary vascular bed in children with congenital heart disease and elevated pulmonary vascular resistance. Inhaled iloprost is a pulmonary vasodilator for the long-term treatment of pulmonary hypertension (PHT). Because these 2 vasodilators act through different pathways (release of cGMP or cAMP, respectively), we compared the pulmonary vasodilator capacity of each. Methods and Results-A total of 15 children with congenital heart disease and PHT who had elevated pulmonary vascular resistance (preoperative, nϭ10; immediately postoperative, nϭ5) were first given 20 ppm of iNO for 10 minutes; then, after baseline values were reached again, they were given aerosolized iloprost at 25 ng ⅐ kg Ϫ1 ⅐ min Ϫ1 for another 10 minutes. Finally, iNO and iloprost were given simultaneously for 10 minutes. With iNO, the pulmonary vascular resistance and systemic vascular resistance ratio decreased from 0.48Ϯ0.38 to 0.27Ϯ0.16 (PϽ0.001). Similarly, iloprost decreased the ratio from 0.49Ϯ0.38 to 0.26Ϯ0.11 (PϽ0.05). The combination had no additional effect on the resistance ratio. Plasma cGMP increased from 17.6Ϯ11.9 to 34.7Ϯ21.4 nmol/L during iNO (PϽ0.01), and plasma cAMP increased from 55.7Ϯ22.9 to 65.1Ϯ21.2 nmol/L during iloprost inhalation (PϽ0.05). Conclusions-In children with PHT and congenital heart disease, both iNO and aerosolized iloprost are equally effective in selectively lowering pulmonary vascular resistance through an increase in cGMP or cAMP, respectively. However, the combination of both vasodilators failed to prove more potent than either substance alone. Aerosolized iloprost might be an alternative to iNO for early testing of vascular reactivity and for the postoperative treatment of acute PHT.

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Section: Discussionmentioning

confidence: 94%

Inhaled Nitric Oxide Versus Aerosolized Iloprost in Secondary Pulmonary Hypertension in Children With Congenital Heart Disease

Rimensberger

Spahr-Schopfer²,

Berner³

et al. 2001

Circulation

170

116

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“…3. Comparison of theoretical total deposition efficiency for an 8.2-year old (solid line) using the theory of Martonen and Zhang (1993), and experimental data from Roy et al (1986) (a group of eight children of 7.4 years average age and a group of nine children of 11.3 years average age, solid circles and squares, respectively) and Schiller-Scotland et al (1992) (a group of six children of 5.3 years average age and a group of 23 children of 10.6 years average age, open circles and squares, respectively). Although the model does not use the same ages as did the experimental investigations, the average ages match relatively well.…”

Section: Resultsmentioning

confidence: 98%

“…The agreement is good for group averages, but individual differences are large (Bennett and Smaldone, 1987). For children, very few clinical aerosol deposition measurements have been performed (Roy et al, 1986;Schiller-Scotland et al, 1992;Bennett et al, 1996). These clinical measurements can be compared to theoretical computations on a similarage case by Martonen and Zhang (1993).…”

Section: Discussionmentioning

confidence: 97%

Methods for modeling particle deposition as a function of age

Phalen

Oldham

2001

Respiration Physiology

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The purpose of this paper is to review the application of mathematical models of inhaled particle deposition to people of various ages. The basic considerations of aerosol physics, biological characteristics and model structure are presented along with limitations inherent in modern modeling techniques. Application of the models to children and senescent adults has been largely based on extrapolating anatomical and physiological data from young adults to match the changes observed during growth and aging. Sample results are included for total particle deposition and deposition in the bronchial and pulmonary regions. The models proposed provide particle deposition predictions that are consistent with the scant measurements available. The models discussed appear to be on firm theoretical grounds, but they are largely limited in application to simple aerosols and average individuals. Also, additional validation of the computational predictions is needed.

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“…Such measurements can be made rapidly with trace amounts of non-toxic materials and hence total deposition has been determined as functions of particle size and various breathing parameters. Some data are even available for children (Becquemin et al, 1991;Schiller-Scotland et al, 1992;. These measurements are reviewed in Annex D of ICRP Publication 66, which in turn refers to a series of reviews of total and regional respiratory tract deposition in the literature.…”

Section: Total Depositionmentioning

confidence: 99%

“…It seems from many data shown in this report that dispersion increases with aerosol size and that a 15% for 0.1 pm particles to 35% for 10 pm particles could be adopted. Becquemin et al (1991) and Schiller-Scotland et al (1992) have measured the total respiratory tract deposition in children. These references are the basis of this estimation with a dispersion of 20% around the central value.…”

Section: Question 2 Rationalementioning

confidence: 99%

Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices

Goossens¹,

Kraan²,

Cooke

et al. 1998

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LEGALNOTICENeither the European Commission nor any person acting on behalf of the Commission is responsible for the use that might be made of the information in this volume. NUREGlCR-6571 ii DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document. AbstractThe development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990.These codes estimate the risk presented by nuclear installations based on postulated frequencies and magnitudes of potential accidents. In 1991, the US Nuclear Regulatory Commission (NRC) and the European Commission (EC) began a joint uncertainty analysis of the two codes. The ultimate objective was to develop credible and traceable uncertainty distributions for the input variables of the codes.The study was formulated jointly and was limited to the current code models and to physical quantities that could be measured in experiments. An elicitation procedure was devised from previous US and EC studies with refinements based on recent experience. Elicitation questions were developed, tested, and clarified. Internationally recognized experts were selected using a common set of criteria. Probability training exercises were conducted to establish ground rules and set the initial and boundary conditions. Experts developed their distributions independently.Aft& the first feasibility study on atmospheric dispersion and deposition parameters, a second expert judgment exercise was carried out on food chain and external dose (calculation) parameters. A third expert judgment exercise has been carried out on early and late health effects and internal dosimetry parameters. The goal again was to develop a library of uncertainty distributions for the selected consequence parameters. Nine experts from five countries were selected for an expert panel on internal dosimetry. Their results were processed with an equal-weighting aggregation method, and the aggregated distributions will be used to determine distributions on the code input parameters of the dose per unit intake (DUPI) models used in COSYMA and for MACCS. PrefaceThis volume is the second of a two-volume document that summarizes a joint project conducted by the US Nuclear Regulatory Commission and the European Commission to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These codes were developed primarily for estimating the risks presented by nuclear reactors based on postulated frequencies and magnitudes of potential accidents. This document reports on an ongoing project to assess uncertainty in the MACCS and COSYMA calculations for the offsite consequences of radionuclide releases by hypothetical nuclear power plant accidents. A panel of nine experts was formed to compile credible and traceable uncertainty distributions for internal dosimetry input variables that affect calculations of offsite consequences. The expert judgment elicitation procedure and its outcomes are described in...

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Total deposition of aerosol particles in the respiratory tract of children during spontaneous and controlled mouth breathing

Cited by 35 publications

References 2 publications

Inhaled Nitric Oxide Versus Aerosolized Iloprost in Secondary Pulmonary Hypertension in Children With Congenital Heart Disease

Inhaled Nitric Oxide Versus Aerosolized Iloprost in Secondary Pulmonary Hypertension in Children With Congenital Heart Disease

Methods for modeling particle deposition as a function of age

Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices

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