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Comparison of hemodynamic responses to lower body negative pressure and hemorrhage in baboons
Author(s) -
HinojosaLaborde Carmen,
Shade Robert,
Muniz Gary,
Bauer Cassondra,
Convertino Victor
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1206.2
Subject(s) - hypovolemia , hemodynamics , blood volume , blood pressure , medicine , central venous pressure , stroke volume , anesthesia , lower body , haemodynamic response , cardiology , heart rate
Lower body negative pressure (LBNP), an experimental model of hemorrhage (Hem), causes shifts in blood volume to the legs and elicits central hypovolemia. This study defined the levels of LBNP which equate to actual Hem. Male baboons (n=8) were sedated and instrumented for measurement of arterial pressure (AP), pulse pressure (PP), and central venous pressure (CVP). Stroke volume (SV) was calculated from the AP waveform. Blood was removed in four steps (7 min/step): 6.25%, 12.5%, 18.75%, and 25% of total blood volume. Shed blood was returned and the animals were allowed to recover. Four weeks after the Hem protocol, the same animals were subjected to four levels of LBNP which elicited equivalent changes in PP and/or CVP observed during Hem. Hemodynamic responses to Hem and matched LBNP levels are shown below (mean±SD).Hem (% blood vol) Delta CVP (mm Hg) Delta PP (mm Hg) Delta SV (% baseline) Matched LBNP (mm Hg)6.25 −2.4 ± 0.7 −3 ± 3 −6 ± 11 −22 ± 7 12.5 −3.6 ± 1.2 −10 ± 4 −26 ± 14 −40 ± 9 18.75 −4.1 ± 1.5 −16 ± 5 −41 ± 11 −53 ± 13 25 −4.7 ± 1.2 −20 ± 7 −51 ± 10 −72 ± 8These results indicate that stepwise Hem elicited hemodynamic changes which could be mimicked with distinct levels of LBNP. We conclude that LBNP levels can be used as surrogates for actual blood loss. This study supports the validity of LBNP as a human model of central hypovolemia associated with Hem. Funding Source: U.S. Army MRMC Combat Casualty Care Research Program.