PREPARATION AND PRESERVATION OF RED-CELLS

Background: The production of blood components has undergone several c hanges during the last decades. Methods: Red blood cells will have sli ghtly different properties depending on the way of preparation: whethe r a hard or soft spin has been used, whether platelets and/or leukocyt es have been removed or not, and whether the red cells have been suspe nded in part of the original plasma or in an additive solution. Automa ted techniques are now often used for the separation of buffy coats, r ed cells and plasma. Recently, apheresis techniques have been applied for the preparation of red cells, mostly in combination with plasma or platelets. Continuous addition of the anticoagulant during collection reduces the delay between collection and separation, but the cost is higher and donor time longer. Results: Most of the methods for the pre paration and storage of red cells allow 35-42 days of storage with a m ean in vivo recovery of > 75%. However, the content of erythrocyte 2,3 -DPG is commonly lost within 1-2 weeks, caused by the accumulation of acid metabolites, but can be maintained longer with new systems of sto rage. Leukodepletion of red cells by filtration is used increasingly, but its importance in the majority of transfusions is still unclear. C onclusion: New options for the preparation and storage of red blood ce lls are available and undergo continuous evaluation.