Cryoprecipitate

Cryoprecipitate is prepared in such a way that it contains significant levels of factor VIII and fibrinogen. It also contains von Willebrand factor and fibronectin. All other plasma proteins are present in only trace amounts in cryoprecipitate. The use of cryoprecipitate in the treatment of factor VIII deficiency or hemophilia A has been outlined by Brown and coworkers.^[142] Cryoprecipitate contains factor VIII:C (i.e., procoagulant activity), factor VIII:vWF (i.e., von Willebrand factor), fibrinogen, factor XIII, and fibronectin, which is a glycoprotein that may play a role in reticuloendothelial clearance of foreign particles and bacteria from the blood. Cryoprecipitate can also be used in the treatment of fibrinogen deficiencies and is preferable to commercially prepared fibrinogen preparations, which have a very high incidence of hepatitis, whereas the risk of hepatitis in cryoprecipitate is no greater than that from a single unit of blood.

Cryoprecipitate is frequently administered as ABO compatible; however, this probably is not very important, because the concentration of antibodies in cryoprecipitate is extremely low. Cryoprecipitate may contain RBC fragments, and cryoprecipitate prepared from Rh-positive individuals can possibly sensitize Rh-negative individuals to the Rh O antigen.

Cryoprecipitate should be administered through a filter and as rapidly as possible. The rate of administration should be at least 200 mL/hour, and infusion should be completed within 6 hours of thawing.

Commercial concentrates of factor VIII have been the standard therapy for hemophilia. Although heat inactivation of factor VIII concentrate reduces infectivity, such a risk is still present. Recombinant DNA techniques have been used to develop factor VIII, which is free of disease transmission.^[143] Mild cases of hemophilia may be treated without blood products by administration of DDAVP. Appropriate therapy is difficult to ascertain for patients who have inhibitors (i.e., alloantibodies) to factor VIII.

Fibrin glue is used occasionally by surgeons to create local hemostasis. It is prepared in a manner similar to that of cryoprecipitate. When FFP is thawed, the precipitate contains large amounts of fibrinogen. When centrifuged, about 4 mL of concentrated precipitate results. With added thrombin, it is applied locally, the efficacy of which is difficult to determine.