[Artificial oxygen carriers. Alternatives to homologous blood transfusion?]

The expected explosion of costs in transfusion medicine due to the shortfall of healthy donors and the more frequent treatment of transfusion-associated complications (chronic hepatitis, cirrhosis, wound infection, tumor recurrence) increases the socio-economic importance of the development of safe and effective synthetic oxygen carriers as an alternative to the transfusion of homologous red blood cells. Currently two types of artificial oxygen carriers are experimentally and clinically investigated for their capacity to ensure adequate tissue oxygenation in the case of severe anemia. In addition to their oxygen transport capacity solutions based on free human or bovine hemoglobin provide vasoconstrictor properties. Their hyperoncotic properties make them particularly attractive for the treatment of severe hemorrhagic shock. Perfluorocarbon (PFC) emulsions allow an increase of the physically dissolved portion of arterial oxygen content. Due to their particulate nature (emulsion droplets) PFC may only be infused in low doses. Otherwise there is risk of overload and malfunction of phagocytic cells of the reticulo-endothelial system. In the case of an intraoperative blood-loss in preoperatively hemodiluted patients, bolus infusion of PFC represents an effective means to avoid immediate retransfusion of autologous blood and allows for further, extreme hemodilution without risking tissue hypoxia.