Cryoprecipitate 101

Cryoprecipitate, or cryo for short, is a fresh frozen plasma (FFP)-derived concentrate including fibrinogen, factors VIII and XIII, von Willebrand factor, and fibronectin. Cryo contains only 40-50% of the coagulation factors found in a unit of plasma but is concentrated into a reduced 15-20 ml volume. Cryo is prepared from FFP as it is thawed slowly at 4° C. A precipitate forms at the bottom of the bag, which is then separated from the supernatant plasma. Cryo is stored frozen at at least 18° C and must be transfused within 6 hours of thawing or 4 hours of pooling. Each unit from a separate donor is suspended in 15 mL plasma prior to pooling.

Cryo is used most commonly for replacement of fibrinogen in patients that are bleeding or at increased risk of bleeding. Fibrinogen replacement may be indicated for hypofibrinogenemia (fibrinogen < 100 mg/dL) or dysfibrinogenemia. The target increase in fibrinogen level is 30-60 mg/dL in adults and 60-100 mg/dL in pediatric patients. Many institutions transfuse cryo prior to administration of factor VIIa concentrate to ensure adequate fibrinogen for clot formation given the cost and short half-life of factor VIIa of about 4 hours. Fibrinogen replacement can be monitored with a fibrinogen level assay and clinical response.

Cryo may be used to treat von Willebrand disease, Hemophilia A (factor VIII deficiency), or Factor XIII deficiency only when the appropriate plasma-derived or recombinant factor concentrates are unavailable and/or desmopressin (DDAVP) is ineffective or contraindicated. Cryo is sometimes useful if platelet dysfunction associated with renal failure does not respond to dialysis or DDAVP. Cryo also contains fibronectin; however there are no clear indications for fibronectin replacement.

Topical application of cryo in combination with thrombin as a “fibrin glue” has been used as a surgical hemostatic agent. This application is being discontinued due to the preferred commercially available virus-inactivated fibrin sealants with higher fibrinogen concentrations.

Historically, the dosing was a 10-unit pool for adults and 1-2 units/10kg for pediatric patients based on fibrinogen content. However, Blood Bank and Transfusion services should check with their blood supplier on actual fibrinogen content in individual and pre-pooled units as the fibrinogen content has likely increased (~325 mg) due to improved preparation. Therefore Blood Bank and Transfusion services can probably decrease the standard dose to 4-5 pooled units for adults and 1 unit/10 kg for kids.

A previous version of this post said that cryo is frozen at 1-6°C; this is incorrect. The correct temperature is 18°C, and has been corrected in the text. Thank you, astute readers, for correcting our errors! –Lablogatory editors

-Thomas S. Rogers, DO is a second-year resident at the University of Vermont Medical Center, a clinical instructor at the University of Vermont College of Medicine, and the assistant medical director of the Blood Bank and Transfusion Medicine service.