Optimizing transfusion practice

RANSFUSION therapy has undergone several changes over the years with supply challenges and the realization that blood transfusions are not innocuous.Blood conservation strategies have taken the forefront in research communities.Hematinic agents have been advocated as a means of increasing the hemoglobin concentration to counterbalance blood loss.Reducing preoperative exposure to anticoagulants has been debated to reduce the risk of perioperative bleeding.Alternatives to allogeneic blood such as autologous blood (i.e., preoperative autologous donation, acute normovolemic hemodilution, red cell salvage) have gained some acceptance in their role in reducing exposure to allogeneic blood.In addition to these strategies, the methods by which we assess the indication for transfusion have come into question.In the past, it was widely accepted that a decrease in hemoglobin concentration was associated with a decreased oxygen carrying capacity and that allogeneic transfusions increased tissue oxygenation.Now the benefit of transfusions has come into question, as efficacy has never been determined. 1,2eports that address transfusion therapy have tended to focus on the risks associated with transfusion, 3,4 and not the benefit of transfusion.Consequently, we have not defined the optimum circumstances for transfusion therapy.How do we best determine when a transfusion is indicated?We can attempt to provide evidence that impaired tissue oxygenation improves with a transfusion, but this has proven to be a difficult task.Ideally, the intracellular partial pressure of oxygen should be directly measured to determine tissue oxygenation, 5 but this cannot be done in clinical settings.In addition, there is significant interpatient variability in the critical point of oxygen delivery.Thus, the terminol-