Blood Transfusions

Abstract Anesthesiologists are major users of blood products due to the large number of transfusions that occur in the operating room and perioperative setting; thus it is important to be well versed in the practice of blood transfusion, including the indications, risks, and complications. Treatment of symptomatic anemia and bleeding frequently includes transfusion of packed red blood cells (PRBCs) in order to replace lost intravascular volume and maintain cardiac output, and to maintain hemoglobin levels adequate to preserve oxygen delivery to vital organs and other tissues. Transfusion of plasma containing blood products and platelets is performed in order to avoid or correct coagulopathies due to either qualitative or quantitative defects in coagulation enzymes or platelets. The risks and complications of blood transfusion include the possibility of transmission of blood-borne pathogens, immunologic reactions including hemolytic and febrile (non-hemolytic) transfusion reactions, pulmonary edema and respiratory failure due to either transfusion-related acute lung injury (TRALI) or transfusion-associated circulatory overload (TACO), and other derangements due to the transfusion of a large number of blood products such as hypothermia, hyperkalemia, citrate toxicity and acidosis. In the setting of massive hemorrhage or trauma, fixed ratios of blood products are typically administered as part of a “massive transfusion protocol” in order to reduce blood loss, decrease transfusion requirements, and improve mortality. In the absence of suitable donor blood product availability or patient consent to transfusion, several alternatives exist, including pre-deposit autologous blood donation (PABT), cell salvage, and acute normovolemic hemodilution (ANH).