The effect of posture on the regional deposition of an inhaled aerosol
The effect of posture on the regional deposition of an inhaled aerosol
Inhaled drugs continue to provide the foundation for treating airways disease in acute and chronic conditions, allowing the delivery of active agents directly to the site of the disease with minimal systemic absorption. The role of particle size and respiratory manoeuvre on deposition are appreciated but the impact that posture may have is not. Current understanding of respiratory physiology states changes in posture result in the ventilation gradients within the lung. This thinking is based on two-dimensional (2D) imaging which has the obvious limitation of projecting a three- dimensional (3D) structure in 2D. In recent years these restrictions have been overcome, particularly in the field of aerosol science, with the use of Single Photon Emission Computed Tomography (SPECT). This provides 3D information on the distribution of the isotopes and is aligned with the anatomical structures using Magnetic Resonance Imaging (MRI). From this background the hypothesis that the position in which an individual inhales an aerosol has an effect on its regional deposition within the lung was formulated. To test this, ten healthy subjects were recruited to a randomised, cross over, clinical trail. Each individual inhaled a nebulised suspension of human serum albumin (HSA) radiolabelled with ^^'^Tc on three separate occasions in three different positions (sitting, supine lying and right side lying). The aerosol was delivered in a controlled manner using a closed nebuliser circuit that regulated the subjects' respiratory pattern. The total and regional pulmonary deposition of the aerosol was assessed using planar 2D imaging and SPECT aligned with MRI. data sets demonstrated that posture had a significant effect on the regional deposition of an inhaled aerosol. The SPECT data set was analysed in terms of the central to peripheral distribution in a series of shells and in terms of the lung segments. The anatomical model highlighted uneven distribution of the aerosol within the lungs that changed dramatically with posture. This may have implications for the delivery of drugs to the lung.
University of Southampton
Quint, Matthew James
7371847e-31f7-444c-9440-4ec7e33b079a
2003
Quint, Matthew James
7371847e-31f7-444c-9440-4ec7e33b079a
Quint, Matthew James
(2003)
The effect of posture on the regional deposition of an inhaled aerosol.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Inhaled drugs continue to provide the foundation for treating airways disease in acute and chronic conditions, allowing the delivery of active agents directly to the site of the disease with minimal systemic absorption. The role of particle size and respiratory manoeuvre on deposition are appreciated but the impact that posture may have is not. Current understanding of respiratory physiology states changes in posture result in the ventilation gradients within the lung. This thinking is based on two-dimensional (2D) imaging which has the obvious limitation of projecting a three- dimensional (3D) structure in 2D. In recent years these restrictions have been overcome, particularly in the field of aerosol science, with the use of Single Photon Emission Computed Tomography (SPECT). This provides 3D information on the distribution of the isotopes and is aligned with the anatomical structures using Magnetic Resonance Imaging (MRI). From this background the hypothesis that the position in which an individual inhales an aerosol has an effect on its regional deposition within the lung was formulated. To test this, ten healthy subjects were recruited to a randomised, cross over, clinical trail. Each individual inhaled a nebulised suspension of human serum albumin (HSA) radiolabelled with ^^'^Tc on three separate occasions in three different positions (sitting, supine lying and right side lying). The aerosol was delivered in a controlled manner using a closed nebuliser circuit that regulated the subjects' respiratory pattern. The total and regional pulmonary deposition of the aerosol was assessed using planar 2D imaging and SPECT aligned with MRI. data sets demonstrated that posture had a significant effect on the regional deposition of an inhaled aerosol. The SPECT data set was analysed in terms of the central to peripheral distribution in a series of shells and in terms of the lung segments. The anatomical model highlighted uneven distribution of the aerosol within the lungs that changed dramatically with posture. This may have implications for the delivery of drugs to the lung.
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Published date: 2003
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Local EPrints ID: 465335
URI: http://eprints.soton.ac.uk/id/eprint/465335
PURE UUID: 681dd8e6-ab66-45dd-8ed4-e16abe91cb29
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Date deposited: 05 Jul 2022 00:38
Last modified: 16 Mar 2024 20:06
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Author:
Matthew James Quint
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