Cascade system activation by processing of autologous blood

Abstract Alternatives to allogeneic blood transfusion have been discussed for many years, and the reason for the recent increase in interest in this issue concerns the risks involved. Allogeneic blood transfusion may pose risks to certain patients groups with, for example, alloantibodies or rare blood subgroups. Other risks include transmission of infections. In the present article the use of autologous transfusion of blood salvaged intraoperatively and postoperatively, in orthopaedic and thoracic surgery, is discussed in the view of the different theories and experiences presented in this field. Effects on the coagulation cascade, the complement and cytokine systems, prostaglandins and leukotrienes are reviewed and discussed. Autologous transfusion is the most commonly used alternative to allogeneic blood transfusion used and it seems safe although the processing of shed blood influences the quality of the blood. Filtration of shed blood activates complement and leads to the release of cytokines. Washing and centrifugation of shed blood reduces the content of potentially toxic substances. Activated clotting factors, complement proteins and lymphokines, do not seem to pose any significant clinical problems if the transfusion volumes are kept within reasonable limits.