| Liquid thickness vs. vertical pressure gradient in a model of the pleural space. | |
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MedLine Citation:
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PMID: 3597246 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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In recent studies using relatively noninvasive techniques, the vertical gradient in pleural liquid pressure was 0.2-0.5 cmH2O/cm ht, depending on body position, and pleural liquid pressure closely approximated lung recoil (J. Appl. Physiol. 59: 597-602, 1985). We built a model to discover why the vertical gradient in pleural pressure is less than hydrostatic (1 cmH2O/cm). A long rubber balloon of cylindrical shape was inflated in a plastic cylinder. The "pleural" space between the balloon and cylinder was filled with blue-dyed water. With the cylinder vertical, we measured pleural pressure by a transducer through side taps at 2-cm intervals up the cylinder. The pressure was measured with different amounts of water in the pleural space. With a clear separation between the balloon and the container, the vertical gradient in pleural liquid pressure was hydrostatic. As water was withdrawn from the pleural space, the balloon approached the wall of the container. Over an 8-cm-long midregion of the model where the balloon diameter matched the cylinder diameter, the vertical gradient was not hydrostatic and was virtually absent. In this region, the pleural liquid pressure was uniform and equal to the recoil of the balloon. In this section we could not see any pleural space. By scintillation imaging using 99mTc-diethylenetriamine pentaacetic acid in the water, we estimated the thickness of this flat "costal" pleural space to be approximately 20 microns. Radioactive tracer injected at the top of the pleural space appeared by 24 h at the bottom, which indicated a slow drainage of liquid by gravity.(ABSTRACT TRUNCATED AT 250 WORDS) |
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Authors:
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S J Lai-Fook; D C Price; N C Staub |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 62 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1987 Apr |
Date Detail:
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Created Date: 1987-07-24 Completed Date: 1987-07-24 Revised Date: 2007-11-14 |
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: 1747-54 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Body Fluids
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physiology* Catheters, Indwelling Manometry Models, Biological* Pleura / metabolism, physiology* Pressure |
| Grant Support | |
ID/Acronym/Agency:
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HL-1701/HL/NHLBI NIH HHS; HL-25816/HL/NHLBI NIH HHS; HL-36597/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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