Preparation and Storage of Red-cell Components
Red cells are transfused to treat clinically significant anemia or blood loss. They are produced by removing the majority of plasma from whole blood by centrifugation (Figure 2). Red cells produced from blood where the buffy coat has been removed to make platelets will contain slightly lower volume and hemoglobin content because of loss of some red cells into the buffy coat ( Table 3 ).
Production of platelet components from whole blood. WB = whole blood; LD = leukocyte depletion; PRP = platelet-rich plasma. (Figure 2 is a reproduced version.
Red-cell components are stored at 4 ± 2°C for a maximum of 35-49 days in additive solution or 28-35 days in plasma. The shelf life depends upon the combination of anticoagulant, storage medium, blood pack and whether any further processing steps are performed on the red-cell component (e.g. irradiation of the component).
For the vast majority of red-cell units processed, an additive solution containing adenine is added following separation to achieve a hematocrit of 50-70% and maintain red-cell quality during storage. The amount of residual plasma in a red-cell unit in additive solution is dependent on the hematocrit of the donor and how hard red cells have been centrifuged; it is between 5 and 30 mL. Red cells used for intrauterine transfusions and exchange or large-volume transfusion to neonates are normally stored or reconstituted in 100% plasma because of concerns over potential toxic effects of some of the constituents of additive solutions.
For patients with immunoglobulin A deficiency or severe allergic or anaphylactoid reactions to red cells, it may be necessary to remove > 90% of plasma by washing and re-suspending red cells in saline. Red cells from donors with rare phenotypes may be stored frozen for up to 30 years and are washed prior to transfusion to remove the cryoprotectant used to store them.
Transfusion Alter Transfusion Med. 2008;10(3):92-101. © 2008 Blackwell Publishing
This article is an advanced publication of a chapter to be published in the revised edition of the NATA textbook, Alternatives to Blood Transfusion in Transfusion Medicine, currently in preparation.
Cite this: Allogeneic Blood Components - Medscape - Sep 01, 2008.