Vascular resistance and the efficacy of red cell substitutes in a rat hemorrhage model

Robert M. Winslow, Armando Gonzales, Maria L. Gonzales, Michael Magde, Michael McCarthy, Ronald J. Rohlfs, Kim D. Vandegriff
1998 Journal of applied physiology  
resistance and the efficacy of red cell substitutes in a rat hemorrhage model. J. Appl. Physiol. 85(3): 993-1003, 1998.-We have compared polyethylene glycol-modified bovine hemoglobin (PEG-Hb; high O 2 affinity, high viscosity, high oncotic pressure) and human hemoglobin cross-linked between the ␣-chains (␣␣-Hb; low O 2 affinity, low viscosity, low oncotic pressure) with a non-O 2 -carrying plasma expander (pentastarch, high viscosity and oncotic pressure) after a 50% (by volume) exchange
more » ... usion followed by a severe (60% of blood volume) hemorrhage. Mean arterial pressure and systemic vascular resistance rose significantly in the ␣␣-Hb but not in the PEG-Hb animals. Two-hour survival was greater in the PEG-Hb animals (93%) than in control (35%), pentastarch (8%), or ␣␣-Hb (6%) animals. In the PEG-Hb animals, there was no disturbance of acid-base balance, significantly less accumulation of lactic acid, and higher cardiac output than in the other groups. The data suggest that the rise in vascular resistance that follows ␣␣-Hb exchange transfusion offsets the additional O 2 transport provided by the cell-free hemoglobin. When resistance does not rise, as with PEG-Hb, even relatively small amounts of cell-free hemoglobin appear to be a very effective blood replacement.
doi:10.1152/jappl.1998.85.3.993 pmid:9729575 fatcat:gkv3qkjxuvhzvmiy37fe7qdm4u