Cryoprecipitate

Cryoprecipitate, also called "Cryoprecipitated Antihaemophilic Factor", "Cryoprecipitated AHF", and "cryo" for short, is a frozen blood product prepared from plasma. To acquire cryoprecipitate, the fresh frozen plasma should be centrifuged and the precipitate should be collected.

It is often transfused as a four to six unit pool instead of as a single product. Many uses of the product have been replaced by factor concentrates, but it is still routinely stocked by many hospital blood banks.

Unlike fresh frozen plasma, compatibility testing is not strictly necessary, but cryo is given as ABO compatible when possible. (Compatibility is reversed for plasma products: O- type is the universal plasma recipient and AB+ type is the universal plasma donor.)

Composition

Each unit (around 10 to 15 mL) typically provides:^[1]

• Fibrinogen 150-250 mg with a half-life of 100-150 hours
• Factor VIII 80-150 U with a half-life of 12 hours
• von Willebrand factor 100-150 U with a half-life of 24 hours
• Factor XIII 50-75 U with a half-life of 150-300 hours.

Cryoprecipitate also contains fibronectin; however there are no clear indications for fibronectin replacement.

US standards require manufacturers to test at least four units each month, and the products must have an average of 150 mg or more of fibrinogen and 80 IU of factor VIII.^[2] Individual products may actually have less than these amounts as long as the average remains above these minimums. Typical values for a unit are substantially higher, and aside from infants it is rare to transfuse just one unit.

Indications

Indications for giving cryoprecipitate include:^[3]

• Haemophilia - Used for emergency back up when factor concentrates are not available.
• von Willebrand disease - Not currently recommended unless last reserve. ddAVP is first line, followed by factor concentrates.
• Hypofibrinogenaemia (low fibrinogen levels), as can occur with massive transfusions
• Afibrinogenemia
• Bleeding from excessive anticoagulation - Fresh frozen plasma contains most of the coagulation factors and is an alternative choice when anticoagulation has to be reversed quickly.
• Massive haemorrhage - RBCs and volume expanders are preferred therapies.
• Disseminated intravascular coagulation
• Uremic bleeding tendency

Adverse Effects

Adverse effects reported with the usage of cryoprecipitate include hemolytic transfusion reactions, febrile non-hemolytic reactions, allergic reactions (ranging from urticaria to anaphylaxis), septic reactions, transfusion related acute lung injury, circulatory overload, transfusion-associated graft-versus-host disease, and post-transfusion purpura. ^[4]

References