Plasma itself may be either stored or fresh frozen. Stored plasma until the early 1970s was the treatment of choice for blood volume depletion in burns and proved very useful as an initial temporary measure in hemorrhagic shock while whole blood was being typed and crossmatched. It was also useful in some cases of shock not due to hemorrhage. Stored plasma may be either from single donors, in which case it must be crossmatched before transfusion; or more commonly, from a pool of many donors. Pooled plasma dilutes any dangerous antibodies present in any one of the component plasma units, so that pooled plasma may be given without crossmatch. For many years it was thought that viral hepatitis in plasma would be inactivated after storage for 6 months at room temperature. For this reason, pooled stored plasma was widely used. In 1968 a study reported a 10% incidence of subclinical hepatitis even after storage for prescribed time periods. The National Research Council Committee On Plasma And Plasma Substitutes then recommended that 5% albumin solution be used instead of plasma whenever possible.

Fresh frozen plasma. Fresh frozen plasma is prepared from fresh whole blood within 6 hours after collection. Fresh frozen plasma used to be the treatment of choice for coagulation factor deficiencies such as factor VIII (hemophilia A), von Willebrand’s disease, or fibrinogen. Since large volumes were often required for hemophilia A, methods were devised to concentrate factor VIII. Concentrated factor VIII solutions and cryoprecipitate are both available commercially and have largely superseded the use of fresh frozen plasma in hemophilia A. All of these products, unfortunately, may transmit infection by viruses, including the hepatitis viruses and HIV-I. Heat treatment in conjunction with donor testing has nearly eliminated HIV-I infectivity of factor VIII concentrate and greatly reduced hepatitis B virus infections.