Geisinger Medical Laboratories Test Catalog

FIBRINOGEN

• If the patient’s hematocrit (HCT) is >55%, the volume of anticoagulant in the tube must be adjusted. Contact a performing location for sodium citrate adjusted tubes or instruction for how to adjust the sodium citrate.
• When possible, use fresh venipuncture.
• Avoid prolong tourniquet time (< 1 minute) and hemolysis during collection as this will alter results.
• If indwelling catheter or butterfly collection device must be used, draw sample from a non-heparinized lumen or flush the line with 5 mL of saline and discard/use first 5-10 mL of blood for other purposes.
• Tubes should be >90% filled.
• Immediately mix gently after collection by inverting the tube end over end 5 to 6 times. Avoid vigorous mixing or additional inversion. Observe for the presence of clots or hemolysis and recollect if observed.

Note: Specimen suspected of thawing in transport, indicated by slant in aliquot or specimen in lid of tube, will have testing performed, and the comment “interpret results with caution as thawing suspected” added to results.

Hypofibrinogenemia, or low fibrinogen levels, may be congenital or acquired from bleeding, disseminated intravascular coagulopathy (DIC) or severe liver disease. Levels may be elevated in chronic inflammation, pregnancy, or early/moderate liver disease. Dysfibrinogenemia, or an abnormal fibrinogen protein, may result in bleeding or thrombosis. Dysfibrinogenemia may result in low levels using this methodology, therefore, if suspected recommend comparing results to a fibrinogen antigen level. In patients with dysfibrinogenemia the fibrinogen activity and fibrinogen antigen levels will be different.