- Whole blood
Whole Blood is the term used in
transfusion medicinefor human bloodfrom a standard blood donation. The blood is typically combined with an anticoagulantduring the collection process, but is generally otherwise unprocessed. In the US, the capitalized "Whole Blood" means a specific standardized product for transfusion or further processing, where "whole blood" is any unmodified collected blood.
Historically, blood was transfused as Whole Blood without further processing. Most
blood banksnow split the Whole Blood into two or more components, typically red blood cellsand a plasma component such as Fresh Frozen Plasma. Plateletsfor transfusion can also be prepared from a unit of Whole Blood. Some blood banks have replaced this with platelets collected by Plateletpheresisbecause whole blood Platelets, sometimes called "random" platelets, must be pooled from multiple donors to get enough for a therapeutic dose.
The collected blood is generally separated into components by one of three methods. A centrifuge can be used in a "hard spin" which separates Whole Blood into plasma and red cells or for a "soft spin" which separates it into plasma, buffy coat (used to make platelets), and red blood cells. The third method is sedimentation: the Whole Blood simply sits overnight and the red cells and plasma are separated by gravity.
Whole Blood has similar risks to a transfusion of Red Blood Cells and must be
cross-matched to avoid hemolytic transfusion reactions. Most of the indications for use are identical to those for RBCs, and Whole Blood is not used because the extra plasma can contribute to transfusion associated circulatory overload (TACO), a potentially dangerous complication.
Whole Blood is sometimes "recreated" from stored red blood cells and
FFPfor neonatal transfusions. This is done to provide a final product with a very specific hematocrit (percentage of red cells) with type O red cells and type AB plasma to minimize the chance of complications.
Whole Blood is typically stored under the same conditions as Red Blood Cells and can be kept up to 35 days if handled properly.
If the blood will be used to make platelets, it is kept at room temperature until the process is complete. This must be done quickly to minimize the warm storage of RBCs in the unit.
* [http://www.fda.gov/cber/gdlns/crclr.pdf Circular of Information for Blood Products]
* Mark E. Brecher, MD, Chair and Editor. Technical Manual. 2005. 15th Edition. AABB, Bethesda, MD, United States.
Wikimedia Foundation. 2010.