| Response of normal subjects to inspiratory resistive unloading. | |
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MedLine Citation:
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PMID: 2708236 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The purpose of this study was to examine the role of the normal inspiratory resistive load in the regulation of respiratory motor output in resting conscious humans. We used a recently described device (J. Appl. Physiol. 62: 2491-2499, 1987) to make mouth pressure during inspiration positive and proportional to inspiratory flow, thus causing inspiratory resistive unloading (IRUL); the magnitude of IRUL (delta R = -3.0 cmH2O.1(-1).s) was set so as to unload most (approximately 86% of the normal inspiratory resistance. Six conscious normal humans were studied. Driving pressure (DP) was calculated according to the method of Younes et al. (J. Appl. Physiol. 51: 963-1001, 1981), which provides the equivalent of occlusion pressure at functional residual capacity throughout the breath. IRUL resulted in small but significant changes in minute ventilation (0.6 1/min) and in end-tidal CO2 concentration (-0.11%) with no significant change in tidal volume or respiratory frequency. There was a significant shortening of the duration (neural inspiratory time) of the rising phase of the DP waveform and the shape of the rising phase became more convex to the time axis. There was no change in the average rate of rise of DP or in the duration or shape of the declining phase. We conclude that 1) the normal inspiratory resistance is an important determinant of the duration and shape of the rising phase of DP and 2) the neural responses elicited by the normal inspiratory resistance are similar to those observed with added inspiratory resistive loads. |
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Authors:
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C G Gallagher; R Sanii; M Younes |
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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, P.H.S. |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 66 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1989 Mar |
Date Detail:
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Created Date: 1989-06-02 Completed Date: 1989-06-02 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: 1113-9 Citation Subset: IM |
Affiliation:
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Department of Medicine, University of Manitoba, Winnipeg, Canada. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adult Humans Inhalation* Male Pressure Reference Values Respiration* Spirometry Time Factors Vital Capacity |
| Grant Support | |
ID/Acronym/Agency:
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HL-32030/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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