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

Abstract

We have compared polyethylene glycol-modified bovine hemoglobin (PEG-Hb; high O2 affinity, high viscosity, high oncotic pressure) and human hemoglobin cross-linked between the alpha-chains (alpha alpha-Hb; low O2 affinity, low viscosity, low oncotic pressure) with a non-O2-carrying plasma expander (pentastarch, high viscosity and oncotic pressure) after a 50% (by volume) exchange transfusion followed by a severe (60% of blood volume) hemorrhage. Mean arterial pressure and systemic vascular resistance rose significantly in the alpha alpha-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 alpha alpha-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 alpha alpha-Hb exchange transfusion offsets the additional O2 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.

• Authors: R M Winslow, A Gonzales, M L Gonzales, M Magde, M McCarthy, R J Rohlfs, K D Vandegriff
• Journal: Journal of applied physiology (Bethesda, Md. : 1985) (J Appl Physiol (1985)) Vol. 85 Issue 3 Pg. 993-1003 (Sep 1998) ISSN: 8750-7587 [Print] United States
• PMID: 9729575 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Blood Substitutes
• Lactic Acid

Topics

• Animals
• Blood Pressure (drug effects, physiology)
• Blood Substitutes (therapeutic use)
• Blood Viscosity (drug effects, physiology)
• Blood Volume (drug effects, physiology)
• Exchange Transfusion, Whole Blood
• Heart Rate (physiology)
• Hemodynamics (drug effects, physiology)
• Hemorrhage (physiopathology, therapy)
• Lactic Acid (blood)
• Male
• Oxidation-Reduction
• Oxygen Consumption (drug effects)
• Rats
• Rats, Sprague-Dawley
• Stroke Volume (physiology)
• Vascular Resistance (drug effects, physiology)