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A mathematical model of aerosol holding chambers

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A mathematical model of aerosol holding chambers. / Zak, M; Madsen, J; Berg, E; Bülow, J; Bisgaard, H.

I: Journal of Aerosol Medicine, Bind 12, Nr. 3, 1999, s. 187-196.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Harvard

Zak, M, Madsen, J, Berg, E, Bülow, J & Bisgaard, H 1999, 'A mathematical model of aerosol holding chambers', Journal of Aerosol Medicine, bind 12, nr. 3, s. 187-196.

APA

Zak, M., Madsen, J., Berg, E., Bülow, J., & Bisgaard, H. (1999). A mathematical model of aerosol holding chambers. Journal of Aerosol Medicine, 12(3), 187-196.

Vancouver

Zak M, Madsen J, Berg E, Bülow J, Bisgaard H. A mathematical model of aerosol holding chambers. Journal of Aerosol Medicine. 1999;12(3):187-196.

Author

Zak, M ; Madsen, J ; Berg, E ; Bülow, J ; Bisgaard, H. / A mathematical model of aerosol holding chambers. I: Journal of Aerosol Medicine. 1999 ; Bind 12, Nr. 3. s. 187-196.

Bibtex

@article{df7ffdb074c811dbbee902004c4f4f50,
title = "A mathematical model of aerosol holding chambers",
abstract = "A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during {"}breathing{"} was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London, Ontario, Canada), NebuChamber (Astra, S{\"o}dirt{\"a}lje, Sweden) and Nebuhaler (Astra) adapted for babies. The dose of fluticasone proportionate delivered by the Babyhaler (Glaxco Wellcome, Oxbridge, Middlesex, UK) was 80% of that predicted, probably because of incomplete priming of this spacer. Of the above-mentioned factors, initial loss of aerosol by impact on the chamber wall is most important for the efficiency of a spacer. With a VT of 195 mL, the AeroChamber and Babyhaler were emptied in two breaths, the NebuChamber in four breaths, and the Nebuhaler in six breaths. Insufficiencies of the expiratory valves were demonstrated by comparison of pressure flow curves during {"}inspiratory{"} flow with and without occluded expiratory openings. Insufficient inspiratory valves were demonstrated by comparison of {"}expiratory{"} pressure flow curves with and without occluded inspiratory openings. With children breathing through the spacers, mask pressure variations were generally on the same order as that seen with the mechanical respiratory, supporting the clinical relevance of the in vitro findings.",
keywords = "Aerosols, Anti-Inflammatory Agents, Budesonide, Equipment Design, Equipment Safety, Humans, Lung, Models, Theoretical, Nebulizers and Vaporizers, Pressure, Reproducibility of Results",
author = "M Zak and J Madsen and E Berg and J B{\"u}low and H Bisgaard",
year = "1999",
language = "English",
volume = "12",
pages = "187--196",
journal = "Journal of Aerosol Medicine and Pulmonary Drug Delivery",
issn = "1941-2711",
publisher = "Mary AnnLiebert, Inc. Publishers",
number = "3",

}

RIS

TY - JOUR

T1 - A mathematical model of aerosol holding chambers

AU - Zak, M

AU - Madsen, J

AU - Berg, E

AU - Bülow, J

AU - Bisgaard, H

PY - 1999

Y1 - 1999

N2 - A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London, Ontario, Canada), NebuChamber (Astra, Södirtälje, Sweden) and Nebuhaler (Astra) adapted for babies. The dose of fluticasone proportionate delivered by the Babyhaler (Glaxco Wellcome, Oxbridge, Middlesex, UK) was 80% of that predicted, probably because of incomplete priming of this spacer. Of the above-mentioned factors, initial loss of aerosol by impact on the chamber wall is most important for the efficiency of a spacer. With a VT of 195 mL, the AeroChamber and Babyhaler were emptied in two breaths, the NebuChamber in four breaths, and the Nebuhaler in six breaths. Insufficiencies of the expiratory valves were demonstrated by comparison of pressure flow curves during "inspiratory" flow with and without occluded expiratory openings. Insufficient inspiratory valves were demonstrated by comparison of "expiratory" pressure flow curves with and without occluded inspiratory openings. With children breathing through the spacers, mask pressure variations were generally on the same order as that seen with the mechanical respiratory, supporting the clinical relevance of the in vitro findings.

AB - A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London, Ontario, Canada), NebuChamber (Astra, Södirtälje, Sweden) and Nebuhaler (Astra) adapted for babies. The dose of fluticasone proportionate delivered by the Babyhaler (Glaxco Wellcome, Oxbridge, Middlesex, UK) was 80% of that predicted, probably because of incomplete priming of this spacer. Of the above-mentioned factors, initial loss of aerosol by impact on the chamber wall is most important for the efficiency of a spacer. With a VT of 195 mL, the AeroChamber and Babyhaler were emptied in two breaths, the NebuChamber in four breaths, and the Nebuhaler in six breaths. Insufficiencies of the expiratory valves were demonstrated by comparison of pressure flow curves during "inspiratory" flow with and without occluded expiratory openings. Insufficient inspiratory valves were demonstrated by comparison of "expiratory" pressure flow curves with and without occluded inspiratory openings. With children breathing through the spacers, mask pressure variations were generally on the same order as that seen with the mechanical respiratory, supporting the clinical relevance of the in vitro findings.

KW - Aerosols

KW - Anti-Inflammatory Agents

KW - Budesonide

KW - Equipment Design

KW - Equipment Safety

KW - Humans

KW - Lung

KW - Models, Theoretical

KW - Nebulizers and Vaporizers

KW - Pressure

KW - Reproducibility of Results

M3 - Journal article

C2 - 10623335

VL - 12

SP - 187

EP - 196

JO - Journal of Aerosol Medicine and Pulmonary Drug Delivery

JF - Journal of Aerosol Medicine and Pulmonary Drug Delivery

SN - 1941-2711

IS - 3

ER -

ID: 189336