[Blood Transfusion: a Guide to Clinical Decision Making]

Nowadays, management of hemotherapy is regulated in Germany by the transfusion act and several guidelines while the transfusing physician is responsible for correct implementation at the bedside. Indications for blood products have to be carefully adapted to the patient's current clinical situation and pre-existing diseases have to be considered as well. Today, for most perioperative elective surgeries, evidence-based transfusion thresholds for packed red blood cell concentrates (RBC) have been defined and should be considered. Platelet concentrates (PC) have to be transfused in bleeding patients with thrombocytopenia or -pathy. In addition, PC are indicated prophylactically in clinically stable, not bleeding patients with a platelet trough count of less than 10/nl. Therapeutic plasma or fresh frozen plasma (FFP) is indicated for balanced substitution of coagulation factors, coagulation inhibitors and fibrinolysis factors in massive transfusion settings, where dilution of coagulation factors takes place. Plasma exchange in adults with thrombotic-thrombocytopenic purpura (TTP) or adult hemolytic-uremic syndrome (HUS) also requires FFP. In addition, FFP might be indicated, if no coagulation factor concentrate is available (e.g. FV deficiency). Adverse transfusion reactions are rare nowadays; however, hemolytic and allergic reactions are not too uncommon. For severe hemolytic transfusion reactions, in almost all cases, wrong blood in tube (WBIT) at the diagnostic bedside blood withdrawal or a mix-up of blood components before transfusion is causative. Massive transfusion situations require a proactive management, which includes RBC, FFP and potentially also PC and coagulation factor concentrates. Prior to elective surgery, anemic patients should be diagnosed and treated for the cause of their anemia, if possible.