| Effects of posture on flow-volume curve configuration in normal humans. | |
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MedLine Citation:
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PMID: 7174411 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Tien et al. (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 46: 565-570, 1979) found reproducible details in the configuration of averaged maximal expiratory flow-volume curves and suggested that these details may correspond to sudden relocations of airway choke points. The occurrence of choke points depends on factors affecting local airway pressure-diameter behavior. We postulated that changes in posture as they affect the distribution of lung recoil on airways might change the locations of choke points and thereby alter flow-volume configuration. Twenty normal adults performed five flow-volume curves in each of four postures (standing, supine, right, and left lateral recumbent). Volume was measured with a Krogh spirometer and airflow with a Fleisch No. 4 pneumotachometer. Curves were digitally filtered and plotted relative to upright total lung capacity. Five curves in each posture were averaged at increments of 0.1 l/s of flow and average volumes at given flows were compared using the Student's t test. Significant differences (P less than 0.01) in mean volumes at given flows occurred in all subjects from standing to supine and/or right to left lateral postures. Large changes in configuration were apparent in one of the two postural pairs in eight subjects. We conclude that changes in posture result in significant changes in flow-volume configuration in most normal adults. These findings are consistent with the wave-speed theory of flow limitation and suggest that small changes in local airway stresses can significantly alter the location and motion of airway choke points during forced expiration. |
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Authors:
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R Castile; J Mead; A Jackson; M E Wohl; D Stokes |
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: respiratory, environmental and exercise physiology Volume: 53 ISSN: 0161-7567 ISO Abbreviation: J Appl Physiol Publication Date: 1982 Nov |
Date Detail:
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Created Date: 1983-02-14 Completed Date: 1983-02-14 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 7801242 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 1175-83 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Airway Obstruction / physiopathology Female Forced Expiratory Flow Rates* Humans Lung Compliance Male Maximal Expiratory Flow-Volume Curves* Middle Aged Posture* Pulmonary Ventilation |
| Grant Support | |
ID/Acronym/Agency:
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HL-14580-06/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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