Fibrinogen (RiaSTAP, Cryoprecipitate)

• Key Clotting Factor: Fibrinogen is substrate for fibrin clot formation; low levels impair hemostasis
• Common in Hemorrhage: Hypofibrinogenemia common in massive hemorrhage, trauma, obstetric hemorrhage, liver failure, DIC
• Target Levels: Typically target >150-200 mg/dL in active major bleeding; higher targets (>200-300 mg/dL) in obstetric hemorrhage or trauma-associated coagulopathy
• Two Main Products: Fibrinogen concentrate (RiaSTAP) offers rapid, predictable dosing without blood typing; cryoprecipitate more widely available but variable content and transfusion risks
• Massive Transfusion Protocols: Used as part of MTPs, often guided by labs (Clauss fibrinogen) or viscoelastic testing (TEG/ROTEM FIBTEM)
• Clinical Pearl: Fibrinogen is often the first coagulation factor to fall critically low in major trauma and OB hemorrhage, so early replacement can improve clot firmness

• Generic Name: Fibrinogen concentrate (human)
• Brand Names: RiaSTAP (fibrinogen concentrate), and cryoprecipitate (pooled plasma product)

Human plasma-derived fibrinogen replacement; hemostatic agent; coagulation factor concentrate

Mechanism of Action:

• Fibrinogen (factor I) is a soluble plasma glycoprotein synthesized in the liver and circulating in blood
• During hemostasis, thrombin cleaves fibrinogen into fibrin monomers, which polymerize and cross-link (via factor XIII) to form a stable fibrin clot
• Adequate fibrinogen levels are essential for clot strength and stability; low fibrinogen impairs clot formation and firmness
• Fibrinogen concentrate provides purified human fibrinogen; cryoprecipitate also provides von Willebrand factor, factor VIII, and factor XIII, which may be advantageous

Pharmacokinetics:

• Onset: Rapid increase in plasma fibrinogen levels within minutes to hours after IV administration
• Half-life: Approximately 3-4 days for fibrinogen; shorter in consumptive coagulopathy
• Dosing: Fibrinogen concentrate dosed in grams (typically 3-4 g for adults); cryoprecipitate dosed in units (typically 10 units for adults, each containing ~200-250 mg fibrinogen)

Available Forms:

• Fibrinogen concentrate (RiaSTAP): Lyophilized vials with standardized 1 g amounts, reconstituted with sterile water and given IV
• Cryoprecipitate: Frozen plasma product, each unit typically contains 200-250 mg fibrinogen, plus vWF, factor VIII, factor XIII; ABO-compatible transfusion preferred but not always required in emergency

Dosing for Hypofibrinogenemia and Bleeding (Adult):

Contraindications:

• Hypersensitivity to fibrinogen or human plasma products
• None absolute in life-threatening hemorrhage (benefits typically outweigh risks)

Major Precautions:

• Thrombosis risk: fibrinogen replacement may increase risk of VTE or arterial thrombosis, particularly in patients with underlying thrombotic tendencies
• Transmission of infectious agents: though rare with modern screening, any plasma-derived product carries theoretical risk
• Anaphylaxis or allergic reactions rare but possible

Common:

• Generally well-tolerated in acute bleeding settings
• Infusion-related reactions (fever, chills) more common with cryoprecipitate

Serious:

• Thrombotic events (VTE, MI, stroke) especially with overcorrection or underlying prothrombotic state
• Anaphylaxis or severe allergic reactions (rare)
• Transmission of infections (very rare with modern processing)

Laboratory Monitoring:

• Fibrinogen level (Clauss assay) before and after replacement
• Viscoelastic testing (TEG FIBTEM or ROTEM) for real-time assessment of clot firmness
• Coagulation panel (PT/INR, aPTT), hemoglobin, platelet count as part of massive transfusion monitoring

Clinical Monitoring:

• Cessation or control of bleeding
• Signs of thrombosis (chest pain, limb swelling, neurological changes)
• Transfusion reactions (fever, chills, hypotension)

• Trauma-associated coagulopathy: Major trauma with hypofibrinogenemia and active bleeding
• Massive hemorrhage: Any massive transfusion setting where fibrinogen levels fall below target
• Postpartum hemorrhage: Obstetric hemorrhage with hypofibrinogenemia (targets often higher, >200-300 mg/dL)
• Congenital fibrinogen deficiency: Afibrinogenemia or severe hypofibrinogenemia with bleeding or surgery
• DIC or liver failure with bleeding: Consumptive or synthetic hypofibrinogenemia with active hemorrhage

• 1. Lexicomp. (2024). Fibrinogen concentrate (human): Drug information. Wolters Kluwer.
• 2. Spahn, D. R., Bouillon, B., Cerny, V., et al. (2019). The European guideline on management of major bleeding and coagulopathy following trauma: Fifth edition. Critical Care, 23(1), 98. https://doi.org/10.1186/s13054-019-2347-3