From the Guidelines
The most critical ACT fibrinogen level for guiding treatment in patients with bleeding is a level of at least 1.5 g/L, as recommended by recent guidelines 1.
Importance of Fibrinogen Levels
Fibrinogen is a protein essential for blood clotting, and its levels are crucial in evaluating the risk of bleeding or thrombosis. The ACT fibrinogen level test measures the amount of functional fibrinogen in the blood using the activated clotting time (ACT) method. This test is useful for diagnosing bleeding disorders, monitoring disseminated intravascular coagulation (DIC), assessing liver function, and guiding treatment during major surgeries or trauma.
Clinical Significance of Low Fibrinogen Levels
Low fibrinogen levels may indicate conditions like liver disease, severe bleeding, or DIC, while elevated levels can suggest inflammation, infection, or pregnancy. Healthcare providers often order this test alongside other coagulation tests to get a comprehensive picture of a patient's clotting ability. The test requires a blood sample, and results are usually available within hours, making it valuable for time-sensitive clinical decisions regarding bleeding risk or clotting disorders.
Guideline Recommendations
Recent guidelines, such as the European guideline on management of major bleeding and coagulopathy following trauma: sixth edition 1, recommend treatment with fibrinogen concentrate or cryoprecipitate if major bleeding is accompanied by hypofibrinogenemia (viscoelastic signs of a functional fibrinogen deficit or a plasma Clauss fibrinogen level ≤ 1.5 g/L). An initial fibrinogen supplementation of 3–4 g is suggested, with repeat doses guided by viscoelastic testing and laboratory assessment of fibrinogen levels.
Key Points
- Fibrinogen levels are essential for evaluating bleeding risk and guiding treatment.
- A level of at least 1.5 g/L is recommended for guiding treatment in patients with bleeding.
- Fibrinogen concentrate or cryoprecipitate can be used to increase fibrinogen levels.
- Viscoelastic testing and laboratory assessment of fibrinogen levels can guide repeat doses of fibrinogen supplementation.
- Recent guidelines, such as the European guideline on management of major bleeding and coagulopathy following trauma: sixth edition 1, provide recommendations for fibrinogen supplementation in patients with bleeding.
From the Research
Fibrinogen Level and Its Disorders
- Fibrinogen is an abundant protein synthesized in the liver, present in human blood plasma at concentrations ranging from 1.5-4 g/L in healthy individuals 2.
- The normal concentration of fibrinogen in blood plasma is between 1.8 - 4.2 g/L 3.
- Decreased fibrinogen levels are observed in congenital afibrinogenemia, hypofibrinogenemia, dysfibrinogenemia, disseminated intravascular coagulation, fibrinolytic therapy, some more severe hepatic parenchymal disorders, and increased blood loss 3.
- Elevated fibrinogen levels occur in inflammatory diseases and neoplastic diseases, in pregnancy, and postoperative conditions 3.
Diagnosis of Fibrinogen Disorders
- The fibrinogen antigen assay is used to distinguish between qualitative and quantitative fibrinogen disorders 3.
- Functional fibrinogen measurement is also one of the basic coagulation screening tests 3.
- Laboratory testing for fibrinogen abnormalities includes routine coagulation testing and specialized laboratory investigations 4.
- The use of fibrinogen determination methods, such as the fibrinogen Clauss assay and prothrombin time (PT) derived fibrinogen assay, can help in the differential diagnosis of hypofibrinogenemia and dysfibrinogenemia 3.
Fibrinogen and Its Role in Coagulation
- Fibrinogen plays a fundamental role in coagulation through its support for platelet aggregation and its conversion to fibrin 5.
- Fibrin stabilizes clots and serves as a scaffold and immune effector before being broken down by the fibrinolytic system 5.
- Abnormalities in fibrin(ogen) and fibrinolysis result in a variety of disorders with hemorrhagic and thrombotic manifestations 5.