Fibrinogen

What it measures

Measures the functional level of fibrinogen, the protein converted to fibrin to form a clot. Used in bleeding, DIC, liver disease and massive transfusion.

Specimen and preparation

• Specimen: Citrated plasma (3.2% sodium citrate, 9:1)
• Tube: Light_blue top
• Preparation: Correct tube fill; test within 4 h.

Reference range

Reference ranges differ between laboratories, methods and populations. Always use the range printed on your own lab report.

Causes of high values

• Acute inflammation or infection (acute-phase reactant)
• Pregnancy and oral contraceptives
• Malignancy
• Smoking, cardiovascular disease

Causes of low values

• DIC
• Severe liver disease
• Massive hemorrhage with dilution
• Thrombolytic therapy
• Inherited afibrinogenemia or hypofibrinogenemia

Method

Clauss clotting method (high-concentration thrombin); antigen by immunoassay if dysfibrinogenemia suspected

Good to know

Below about 100 mg/dL (1.0 g/L) is critical in a bleeding patient; replace with cryoprecipitate or fibrinogen concentrate.

Related tests