Transfusion of Packed Red Cells: Indications, Triggers and Adverse Events.

BACKGROUND: About four million units of packed red cells are transfused in Germany every year. The safety of blood transfusions is further improved by modern production methods and molecular diagnostic techniques.
METHODS: This review is based on selected publications,including the German guidelines and regulations and the German Transfusion Act.
RESULTS: Packed red blood cells are transfused to prevent tissue hypoxia. As the clinical manifestations of anemia are nonspecific, the indication for transfusion is based on surrogate parameters, such as the hemoglobin (Hb) concentration, in addition to clinical criteria. For patients with unimpaired cardiopulmonary and vascular function, transfusion is generally indicated at hemoglobin values of 6 g/dL (3.7 mmol/L) or less. Randomized controlled trials have shown that a restrictive transfusion strategy (trigger: Hb 7-8 g/dL) in certain patient groups is as effective as a more liberal strategy (trigger: Hb about 10 g/dL). The most frequent causes for transfusion errors are lack of informed consent, lack of identity checking and/or AB0 identity testing, and the drawing of blood samples in unlabelled tubes.
CONCLUSION: Overtransfusion, undertransfusion, as well as other transfusion errors can be markedly reduced by means of appropriate organizational measures and training.