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Continuous blood densitometry - Fluid shifts after graded hemorrhage in animalsRapid fluid shifts in four pigs and two dogs subjected to graded hemorrhage are investigated. Arterial blood density (BD), mean arterial pressure (MAP), central venous pressure (CVP), arterial plasma density (PD), hematocrit (Hct) and erythrocyte density were measured. The apparatus and mechancial oscillator technique for measuring density are described. Fluid shifts between red blood cells and blood plasma and alterations in the whole-body-to-large vessel Hct, F(cell) are studied using two models. The bases of the model calculations are discussed. A decrease in MAP, CVP, and BP is detected at the beginning of hemorrhaging; continued bleeding results in further BD decrease correlating with volume displacement. The data reveal that at 15 ml/kg blood loss the mean PD and BD dropped by 0.99 + or - 0.15 and 2.42 + or 0.26 g/liter, respectively, and the Hct dropped by 2.40 + or 0.47 units. The data reveal that inward-shifted fluid has a higher density than normal ultrafiltrate and/or there is a rise in the F(cell) ratio. It is noted that rapid fluid replacement ranged from 5.8 + or - 0.8 to 10.6 + or - 2.0 percent of the initial plasma volume.
Document ID
Document Type
Reprint (Version printed in journal)
Hinghofer-Szalkay, H.
(NASA Ames Research Center Moffett Field, CA; Graz, Universitaet, Austria)
Date Acquired
August 12, 2013
Publication Date
January 1, 1986
Publication Information
Publication: American Journal of Physiology: Heart and Circulatory Physiology
Volume: 19
ISSN: 0363-6135
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits
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