ABSTRACT

Immense scientific and commercial efforts continue toward the development of a safe and effective, synthetic, oxygen-carrying solution that could be used in place of blood or packed red blood cells (pRBCs). The term ‘‘blood substitute’’ is traditionally used to describe such solutions, but most solutions in development provide only two blood functions, oxygen delivery and volume expansion. Hemostasis, humoral and cellular immune defense, and drug and metabolic transport by protein binding are important functions of blood that are not imparted to currently developed blood substitutes. The term ‘‘RBC substitute’’ is more appropriate. However, because the plasma volume (PV) expansion of RBC substitutes is much greater than pRBCs and often greater than clinical colloids, we suggest that this new class of fluids may best be referred to as oxygen-carrying plasma expanders. Hemoglobin (Hb)-based oxygen carriers (HBOCs) will be the major focus of this review, because they have received greater research focus and commercialization, and are farther along in the regulatory process. However, a short discussion on perfluorocarbon solutions will also be presented.