Cryoprecipitate is a specialized blood product used in transfusion medicine to manage severe or uncontrolled bleeding. It is a highly concentrated fraction of certain clotting proteins derived from plasma, not whole plasma itself. This product delivers high doses of necessary coagulation factors in a small volume, making it a powerful tool for rapidly stopping hemorrhage, often during major trauma or surgery.
The Essential Components
Cryoprecipitate is primarily a concentrated source of high-molecular-weight proteins that do not dissolve easily in cold plasma. The most concentrated component is Fibrinogen (Factor I), which is the foundational protein for a stable blood clot. A single unit is typically required to contain a minimum of 150 milligrams of Fibrinogen. Fibrinogen is converted into Fibrin by the enzyme Thrombin, forming the mesh-like structure that stabilizes a clot and seals the damaged blood vessel. Since cryoprecipitate is prepared in a small volume (usually 10 to 20 milliliters per unit), it provides a much more potent dose of Fibrinogen than an equivalent volume of Fresh Frozen Plasma (FFP).
Beyond Fibrinogen, the product also contains Factor XIII, which is crucial for cross-linking the Fibrin strands to create a durable, mechanically strong clot. It also includes Factor VIII, von Willebrand factor (vWF), and Fibronectin, a protein involved in cell adhesion and wound healing. Although it contains Factor VIII and vWF, commercial concentrates are typically preferred for treating Hemophilia A and von Willebrand disease, making Fibrinogen replacement the primary use of cryoprecipitate today.
Specific Conditions Requiring Treatment
The most frequent use of cryoprecipitate is to correct severe hypofibrinogenemia, a dangerously low level of Fibrinogen in the blood. When a patient is actively bleeding, the accepted target level for Fibrinogen replacement is above 1.5 grams per liter (150 mg/dL). In situations like major obstetric hemorrhage, a higher target of 2.0 g/L is often maintained due to the high risk of bleeding.
Cryoprecipitate is a standard component of Massive Transfusion Protocols (MTP), activated for patients experiencing life-threatening blood loss from trauma or major surgery. Rapid blood replacement in these scenarios dilutes the patient’s existing clotting factors, causing Fibrinogen to drop to critical levels first. Early administration of cryoprecipitate in an MTP is associated with improved survival by quickly restoring the ability to form a stable clot.
In cases of Disseminated Intravascular Coagulation (DIC), the clotting system is over-activated, and Fibrinogen is rapidly consumed, leading to severe bleeding. For a patient with DIC and active bleeding, cryoprecipitate is indicated when the Fibrinogen level falls below 1.0 g/L. The concentrated nature of the product minimizes the volume of fluid transfused, which is beneficial in critically ill patients sensitive to volume overload.
Cryoprecipitate may also be used to treat congenital deficiencies of Factor XIII or von Willebrand disease, particularly when purified, commercially available factor concentrates are not immediately accessible.
Preparation, Delivery, and Risks
The manufacturing process begins with Fresh Frozen Plasma (FFP), which is plasma separated from whole blood and frozen within hours of collection. The FFP is slowly thawed at a cold temperature, typically between 1 and 6 degrees Celsius. This controlled, cold-thawing process causes the high-molecular-weight proteins, including Fibrinogen, to precipitate out of the liquid plasma.
The resulting cold-insoluble material is separated by centrifugation, re-suspended in a small amount of the remaining plasma, and re-frozen for storage. Units are often pooled together, typically five to ten units, to create a single, clinically effective dose for an adult patient, as a single unit is insufficient to significantly raise a patient’s Fibrinogen level.
When needed, the product is thawed and administered intravenously through a standard blood administration set with a filter to catch any small aggregates. Due to the lack of a viral inactivation step, cryoprecipitate carries a theoretical risk of transmitting infections, though this risk is mitigated by rigorous screening and testing of blood donors.
Potential side effects for the recipient include allergic reactions, ranging from mild hives to severe anaphylaxis, and the possibility of fever. While the small volume reduces the risk compared to FFP, volume overload remains a possibility, and careful patient monitoring is necessary during and after transfusion.