| Mode shift of an inhaled aerosol bolus is correlated with flow sequencing in the human lung. | |
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MedLine Citation:
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PMID: 11842063 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We studied the effects on aerosol bolus inhalations of small changes in convective inhomogeneity induced by posture change from upright to supine in nine normal subjects. Vital capacity single-breath nitrogen washout tests were used to determine ventilatory inhomogeneity change between postures. Relative to upright, supine phase III slope was increased 33 +/- 11% (mean +/- SE, P < 0.05) and phase IV height increased 25 +/- 11% (P < 0.05), consistent with an increase in convective inhomogeneity likely due to increases in flow sequencing. Subjects also performed 0.5-microm-particle bolus inhalations to penetration volumes (V(p)) between 150 and 1,200 ml during a standardized inhalation from residual volume to 1 liter above upright functional residual capacity. Mode shift (MS) in supine posture was more mouthward than upright at all V(p), changing by 11.6 ml at V(p) = 150 ml (P < 0.05) and 38.4 ml at V(p) = 1,200 ml (P < 0.05). MS and phase III slope changes correlated positively at deeper V(p). Deposition did not change at any V(p), suggesting that deposition did not cause the MS change. We propose that the MS change results from increased sequencing in supine vs. upright posture. |
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Authors:
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Christopher N Mills; Chantal Darquenne; G Kim Prisk |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 92 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2002 Mar |
Date Detail:
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Created Date: 2002-02-13 Completed Date: 2002-05-07 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States |
Other Details:
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Languages: eng Pagination: 1232-8 Citation Subset: IM; S |
Affiliation:
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Department of Medicine, University of California, San Diego, La Jolla, California 92093-0931, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Aerosols* Female Functional Residual Capacity Humans Inhalation / physiology* Lung / physiology* Male Middle Aged Posture / physiology* Pulmonary Ventilation / physiology* Reference Values Residual Volume Supine Position Vital Capacity |
| Chemical | |
Reg. No./Substance:
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0/Aerosols |
| Investigator | |
Investigator/Affiliation:
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G K Prisk / U CA San Diego, La Jolla; J B West / U CA San Diego, La Jolla |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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