Transfusion and coagulation: an overview and recent advances in practice modalities. Part II: Pharmacologic adjuncts, cell salvage mechanisms, alternatives in blood donation.

ABSTRACT

Increasing public awareness of the risks associated with the transfusion of blood products has encouraged the development of alternatives to the use of homologous blood. Pharmacologic agents, cell salvage, and directed donations are three such mechanisms being utilized with greater frequency for blood and component therapy. At present, only three drugs are available for clinical use DDAVP, epsilon-aminocaproic acid, and tranexamic acid. Cell salvage is available in two system types. Salvage of whole blood in passive collection systems is simplest to use and returns more coagulation factors, but yields a larger volume with a lower hematocrit. Whole blood salvage with subsequent washing and resuspension in normal saline returns only red cells in saline with the majority of coagulation factors removed. The quality of red cells in each system remains relatively constant and the decision regarding which system to employ should be based on the nature of the surgical procedure and the anticipated blood loss. The development of directed donation programs, including autologous predonation and directed homologous donation, permits a reduction in the frequency and total number of units of homologous volunteer blood administered. Directed blood donation provides an additional source of donated blood, but is not demonstrably safer than the volunteer homologous pool, and in fact, may even be less safe. Given the increased complexity of maintaining a designated donor program, these issues of safety play an important role in the ability to maintain operation of large scale directed donation programs.