NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Effects of regional hemoconcentration during LBNP on plasma volume determinationsBlood samples were obtained from forearm vein or artery with indwelling cannula (1) before, (2) during the last min, and (3) about 2 min after lower body negative pressure (LBNP) in 16 experiments to determine whether plasma volume (PV) estimates were affected by regional hemoconcentration in the lower body. Total hemoglobin (THb) was estimated with the CO method prior to LBNP. Hemoglobin (Hb) and hematocrit (Hct) values from (2) gave only a 3% (87 ml) loss in PV due to LBNP, assuming no change in THb. However, Hb and Hct values from (3) showed an 11% loss in PV (313 ml). This 72% underestimation of PV loss with (2) must have resulted from the sequestration of blood and subsequent hemoconcentration in the lower body during LBNP. The effects of LBNP on PV should be estimated 1-3 min after exposure, after mixing but before extravascular fluid returns to the circulation.
Document ID
19790063313
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Loeppky, J. A.
(Lovelace Foundation for Medical Education and Research Albuquerque, NM, United States)
Kobayashi, Y.
(Lovelace Foundation for Medical Education and Research Albuquerque, NM, United States)
Venters, M. D.
(Lovelace Foundation for Medical Education and Research Albuquerque, NM, United States)
Luft, U. C.
(Lovelace Foundation for Medical Education and Research Albuquerque, N. Mex., United States)
Date Acquired
August 9, 2013
Publication Date
August 1, 1979
Subject Category
Aerospace Medicine
Accession Number
79A47326
Funding Number(s)
CONTRACT_GRANT: NAS9-15483
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available