[The practice guideline 'Blood transfusion' (third integral revision)].

The revised and expanded practice guideline 'Blood transfusion' describes the whole transfusion chain within the hospital for the first time. Despite compatibility tests before transfusion (determination of the ABO and Rhesus blood groups and detection of clinically relevant antibodies (C, c, D, E, e, Fy(a), Fy(b), Jk(a), Jk(b), M, S and s)), transfusion reactions can occur. So that a transfusion reaction can be recognised in time, the patient must be observed intensively for the first 5-10 minutes after the start of any new transfusion and the vital functions must be recorded. In patients with a Hb level of 4-6 mmol/l, the decision whether or not to transfuse should be made dependent on the patient's other characteristics. Thrombocyte transfusion is not indicated in case of thrombopenia due to increased breakdown or pooling. If leukaemia, tumour infiltration or drug toxicity is the underlying cause of thrombopenia, then a platelet count of 10 x 10(9)/l or 20 x 10(9)/l should be the transfusion trigger. Reduction of the number of blood transfusions can be achieved by the administration of epoetin in case of renal insufficiency: transfusion can thus be avoided in more than 70% of the patients concerned. Autotransfusion during surgery with severe blood loss also results in a reduction of the number of allogenic blood transfusions.