Microvascular PO2 and blood velocity measurements in rat brain cortex during hemodilution with a plasma expander (Hespan) and a hemoglobin-based oxygen carrier (DCLHb).

Abstract

Hemodilution is widely used in various fields of clinical medicine such as vascular and cardiac surgery, orthopedics, etc. Replacing whole blood with a crystalloid fluid reduces blood viscosity, improves cerebral blood flow and enhances oxygen delivery to tissue, minimizing disturbances at the microcirculatory levell,2. Brain tissue possesses powerful regulatory mechanisms to maintain O2 delivery, and for the undamaged circulation an adequate oxygen supply can be sustained even during severe anemia3−5. Oxygen supply to tissue may be impeded at profound levels of hemodilution, because the compensatory hyperemic response may be exhausted at low levels of arterial oxygen capacity6. Few studies, however, have focused on the effect of anemia on oxygenation at the level of brain microvessels, where most of the oxygen exchange between blood and tissue takes place7−9.KeywordsOxygen TensionBlood VelocityExchange TransfusionPlasma ExpanderTissue Oxygen TensionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.