Packed Red Blood Cells

In transfusion medicine, packed red blood cells (sometimes called stored packed red blood cells) are red blood cells (RBC, also called erythrocytes) that have been collected, processed, and stored in bags as blood product units available for blood transfusion purposes. The collection may be from a "whole blood" (WB) donation followed by component separation, or by RBC apheresis (sometimes called "double-red," due to the potential to donate two units' worth at once that way). The processing (often termed "manufacture," since the end result is deemed a biologic biopharmaceutical product) and the storage can occur at a collection center and/or a blood bank. RBCs are mixed with an anticoagulant and storage solution which provides nutrients and aims to preserve viability and functionality of the cells (limiting their so-called "storage lesion"), which are stored at refrigerated temperatures for up to 42 days (in the US), except for the rather unusual long-term storage in which case they can be frozen for up to 10 years. The cells are separated from the fluid portion of the blood after it is collected from a donor, or during the collection process in the case of apheresis. The product is then sometimes modified after collection to meet specific patient requirements.

The product is typically abbreviated RBC, pRBC, PRBC, and sometimes StRBC or even LRBC (the latter being to indicate those that have been leukoreduced, which is now true for the vast majority of RBC units). The name "Red Blood Cells" with initial capitals indicates a standardized blood product in the United States. Without capitalization, it is simply generic without specifying whether or not the cells comprise a blood product, patient blood, a etc. (with other generic terms for it being "erythrocyte" and "red cell").

RBCs are used to restore oxygen-carrying capacity to the blood of a patient that is suffering from an anemia due to trauma or other (perhaps chronic) medical problems, and are by far the most common blood component used in transfusion medicine. Historically they were transfused as part of whole blood, but in modern practice the RBCs and plasma components are transfused separately. The process of identifying a compatible blood product for transfusion is complicated, and giving incompatible RBCs to a patient can be fatal.