Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage.
BACKGROUND
Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds.


METHODS
Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death.


RESULTS
After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively.


CONCLUSIONS
In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP.
Pestel
Gunther J
GJ
Department of Anesthesiology, Johannes Gutenberg-University, Mainz, Germany.
Fukui
Kimiko
K
Kimberger
Oliver
O
Hager
Helmut
H
Kurz
Andrea
A
Hiltebrand
Luzius B
LB
D000208:Acute Disease; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D003106:Colon / Q000098:blood supply / Q000378:metabolism; D004195:Disease Models, Animal; D006323:Heart Arrest / Q000378:metabolism / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology*; D006470:Hemorrhage / Q000378:metabolism / Q000503:physiopathology*; D020896:Hypovolemia / Q000378:metabolism / Q000503:physiopathology*; D007583:Jejunum / Q000098:blood supply / Q000378:metabolism; D017078:Laser-Doppler Flowmetry; D008099:Liver / Q000098:blood supply / Q000378:metabolism; D008833:Microcirculation / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*; D034421:Sus scrofa
D010100:Oxygen