Blood substitutes: oxygen-carrying acellular fluids.

Blood substitutes are acellular fluids that can transport and deliver oxygen to the tissues. The blood substitutes most likely to be available and effective for veterinary use are the hemoglobin-based oxygen carriers (HBOCs) containing modified human, mammalian, or recombinant hemoglobin. HBOCs can be stored at room temperature and do not require typing or crossmatching. Chemical modifications of hemoglobin affect its physiologic and pharmacologic properties and facilitate oxygen transport. Although many of the metabolic and toxicologic consequences of HBOC infusion are not fully understood, an approved product will likely be available in the near future.