INTRODUCTION

Cryoprecipitate is a human blood component obtained from fresh frozen plasma (FFP) prepared from a unit of whole blood (WB). When FFP is thawed in the cold, a cryoprecipitate forms which is rich in fibrinogen, factor VIII, von Willebrand factor, factor XIII, and fibronectin.

COMPOSITION AND STORAGE

One unit of cryoprecipitate derived from a unit of whole blood contains a volume of 10-20 mL, 80-100 units of factor VIII which consists of both the procoagulant activity and the von Willebrand factor, 150-250 mg of fibrinogen, 50-100 units of factor XIII, and 50-60 mg of fibronectin. It can be stored at  -18° C for a maximum of one year. When ordered, cryoprecipitate is thawed in a 37° C waterbath and issued in individual bags or as a pooled product. Once thawed it must be kept at room temperature and has an expiration time of 6 hours for unpooled cryoprecipitate, and 4 hours for the pooled product.

THERAPEUTIC INDICATIONS

In the past, cryoprecipitate rich in factor VIII and von Willebrand factor, was considered the treatment of choice for factor VIII replacement in Hemophilia A and von Willebrand disease. The development of virally safe factor concentrates have supplanted the role of cryoprecipitate as the therapy of choice for treating these diseases. Currently, the primary indications for cryoprecipitate are for treating fibrinogen deficiency or dysfunction or as a source of fibrinogen for topical use (fibrin glue).

Fibrinogen Deficiency or Dysfunction: Cyroprecipitate is the product of choice for the management of bleeding patients with fibrinogen levels of <100 mg/dL or with a dysfibrogenemia. The recommended initial dose if 6-10 units. Each unit will raise the fibrinogen level by approximately 5-10 mg/dL in an average adult. The target hemostatic concentration of fibrinogen should be >100 mg/dL.

Fibrin Glue: Cryoprecipitate can be used as a source of fibrinogen to make fibrin glue. Fibrin glue can be used as a topical adhesive or hemostatic agent to decrease microvascular bleeding during surgical procedures. The use of topical fibrinogen or fibrin glue has been described in detail in the Transfusion Medicine Update, July 1992.

von Willebrand’s Disease: von Willebrand’s Disease is a congenital bleeding disorder consisting of heterogeneous deficiencies or abnormalities of the von Willebrand multimers. The therapy of choice in patients with mild or moderate von Willebrand’s disease, with the exception of type IIb, is desmopressin (DDAVP) 0.3m g/kg. DDAVP is a synthetic agent which causes the release of factor VIII and von Willebrand factor from endothelial stores. For severe von Willebrand’s disease the treatment of choice is a viral-inactivated factor VIII concentrate containing the high molecular weight von Willebrand multimers (Humate PÒ , Armour). The second line of therapy is cryoprecipitate in a recommended dose of 10-12 units as initial therapy. The dose should be repeated every 12 hours, as needed.

Hemophilia A: Hemophilia A is an X-linked inherited deficiency of the procoagulant activity portion of factor VIII. The first choice of treatment for mild (>5% level) Hemophilia A is DDAVP. For moderate (1-5% level) and severe (<1% level) Hemophilia the therapy of choice is factor VIII concentrates. These are considered safer than cryoprecipitate product because they undergo a viral inactivation treatment for transfusion transmitted viruses. When factor VIII concentrates are not available cryoprecipitate can be used. Each unit of cryoprecipitate contains at least 80 units of factor VIII.

Uremia: Uremic patients have multiple qualitative platelet abnormalities that can manifest as a prolonged bleeding time and bleeding diathesis. Hemodialysis is considered a first line treatment for this platelet defect, however, it is not always effective. If hemodialysis fails to reverse the defect or if this procedure cannot be performed, the treatment of choice is DDAVP. The effectiveness of the DDAVP is believed to be due to the release of endogenous large von Willebrand factor multimers into the circulation. However, its effectiveness is limited. Tachyphylaxis will usually occur after repeated infusions of DDAVP. For those patients who do not respond to DDAVP or who have a contraindication to the use of this agent, cryoprecipitate may be beneficial. Cryoprecipitate contains large von Willebrand multimers which presumably correct the bleeding diathesis. The cryoprecipitate is given as a dose of 10-12 units to be repeated every 12 hours, as needed.

COMPLICATIONS