Safety of Salvaged Blood and Risk of Coagulopathy in Cardiac Surgery

Cardiac surgery patients are prone to anemia from several mechanisms: intraoperative blood loss, preexisting anemia, and hemodilution. Patients are very frequently transfused with allogeneic red blood cells (RBC), which in itself is associated with harm. The use of RBC salvage technology has been advocated to salvage blood lost in the operative field and to reduce the need of homologous blood transfusion. Direct cardiotomy suction from the surgical field and unprocessed blood retransfusion is a common practice during cardiopulmonary bypass, but which is associated with a powerful activation of the coagulation and inflammatory systems: thrombin generation, excessive fibrinolysis, and release of proinflammatory cytokines. Compared with direct cardiotomy suction, the use of RBC salvage technology is able to reduce the amount of microparticles and activated proteins of autologous blood before retransfusion. However, when compared with no retransfusion of blood from the operative field, processed blood also triggers coagulopathy and inflammation. Clinical studies are discordant regarding the benefit of RBC salvage use during and after cardiac operations. Meta-analysis suggests reduced need of homologous blood transfusion, but no effects on mortality and morbidity.