is obtained by separating the liquid portion of blood from the cells. One unit of plasma is the plasma taken from a unit of whole blood. Plasma is frozen quickly after donation, usually within 8-24 hours of collection, to preserve the clotting factors. Frozen plasma can be stored up to one year, and thawed shortly before use. Frozen plasma contains all coagulation factors in close to normal concentrations.
Thawed plasma may be transfused up to 5 days after thawing and contains slightly decreased levels of Factor V (66+/-9%) and decreased Factor VIII levels (41+/-8%). Plasma is free of red blood cells, leukocytes and platelets, and in general must be ABO compatible with the recipient's red blood cells. Rh factor need not be considered. Since there are no viable leukocytes, plasma does not carry a risk of transmission of cytomegalovirus (CMV) or graft versus host disease (GVHD).