Classifications of Blood Substitutes

There has been a global shortage of allogeneic human blood, and human blood transfusion has been associated with many side effects and complications. Thus, the pursuit for alternatives for human blood has continued over last 80 years. There are numerous products at various stages worldwide. For health care providers and scientific researchers to have a better understanding of blood substitutes, it is imperative that have a concise and practical classification system. This chapter described the different classifications of blood substitutes. Blood substitutes can be classified based on blood components into erythrocyte substitutes, leukocyte substitutes, platelet substitutes, and plasma substitutes. Erythrocyte substitutes can be classified as four major types: hemoglobin-based oxygen carriers, perfluorocarbon-based oxygen carriers, genetically engineered recombinant hemoglobins, and artificial or cultured erythrocytes. Erythrocyte substitutes can also be classified based on the source of hemoglobin, existence of cell membrane, and organic or inorganic oxygen carriers. Almost a century’s pursuit yielded only few products with limited clinical use in limited regions frustrated many but encouraged more. The accumulation of these efforts will eventually lead to a breakthrough which will have explosive growth in clinical applications.