Hemodynamic effects and oxygen transport properties of a new blood substitute in a model of massive blood replacement.
Recent concerns regarding the safety of the national blood supply have rekindled interest in the development of blood substitutes. Clinical studies have dampened the initial enthusiasm for fluorocarbon solutions as blood substitutes. The potential of hemoglobin solutions as blood substitutes has continued to stimulate investigations. However, the development of an ideal hemoglobin-derived blood substitute has eluded investigators for the past century. A persistent problem has been the inability to develop hemoglobin solutions that provide adequate oxygen and carbon dioxide exchange, while avoiding toxicity that precludes clinical safety and long-term survival. Traditionally, investigators have focused on human hemoglobin solutions. The use of outdated banked blood or pedigree human donor blood as a hemoglobin source poses continued disease transmission risks and a prohibitively limited supply. We evaluated the hemodynamic and gas transport effects of a new purified, polymerized bovine hemoglobin preparation. Bovine hemoglobin oxygen affinity is regulated by chloride ion. The concentration of chloride ions in human plasma results in excellent oxygen transport properties in a stroma-free environment. In addition, unlike human blood, bovine blood is a more disease-free hemoglobin source that is available in large supply. We exchange-transfused eight conscious sheep with this new polymerized bovine hemoglobin solution. All animals tolerated greater than or equal to 95% exchange transfusion to reach a final ovine hematocrit of 2.4 +/- 0.5% with stable hemodynamics and no clinical evidence of distress. The exchange transfusion with bovine hemoglobin polymer resulted in a final plasma hemoglobin concentration of 6.1 +/- 1.6 gm/dl, which supported oxygen consumption at baseline levels. All animals that were exchange transfused with this preparation survived long term with rapid resynthesis of ovine erythrocytes.
Vlahakes
G J
GJ
Department of Surgery, Massachusetts General Hospital, Boston 02114.
Lee
R
R
Jacobs
E E
EE
LaRaia
P J
PJ
Austen
W G
WG
D000818:Animals; D001802:Blood Substitutes; D001803:Blood Transfusion; D006439:Hemodynamics; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D012756:Sheep
D001802:Blood Substitutes; D010100:Oxygen