title: [Blood component therapy: differential indication for erythrocyte transfusion].
abstract: General principles for application of red blood cells depend on the amount of blood loss, on the oxygen-transport capacity, on the function of the transfused red cells and on the risks of blood transfusion. As a rule of thumb in acute blood loss red cells are wanted if the haemoglobin falls below 10 g/dl or the haematocrit below 30% and are urgently necessary if the haemoglobin falls below 8 g/dl and the haematocrit below 25%. In chronic normovolemic anaemia the indication for red cells is completely different. In the praeoperative state erythrocytes are given below 9 to 10 g/dl haemoglobin. Advantages and disadvantages of the different red cell preparations are discussed as follows: Whole blood is only indicated as fresh blood. Fresh blood stored not longer than 12 hours is only indicated in massive blood transfusion and in acute blood loss due to not yet cleared up haemorrhagic diatheses. A partial deplasmatized blood can be safely given instead of whle blood. Packed red cells not washed show a smaller volume risk and decrease the frequency of non-haemocytic transfusion reactons. The saline washed red cell concentrate does not reduce the frequency of alloimmunisation against tissue antigens, a decrease of the risk of hepatitis-B is questionable. The indication for washed red cells are to be found in febrile transfusion reactions due to leukocyte and platelet antibodies and in the transfusion preparation of dialysis patients. Leucocyte poor red cell concentrates can be prepared practically on by mechanically taking away the buffy coat. The frequency of alloimmunisation can be lowered down to 4% by this red cell preparation. The most expensive way of deep freezing red cells has its own indications. A decrease of hepatitis-B risk is present, hepatitis-B on the other hand cannot be safely avoided by using deeply frozen and thawed red cells.
mesh_terms: D000740:Anemia / Q000628:therapy*; D001692:Biological Transport; D001793:Blood Preservation; D001803:Blood Transfusion / Q000379:methods*; D004912:Erythrocytes; D005615:Freezing; D006474:Hemorrhagic Disorders / Q000628:therapy; D006509:Hepatitis B / Q000517:prevention & control; D006801:Humans; D010101:Oxygen Consumption; D006435:Renal Dialysis
vernacular_title: Blutbestandteile-Therapie: Differentialindikation zur Erthrozytengabe.