Fibrinogen : 1000347

The aliquot must remain frozen. Freeze thaw cycle will adversely affect specimen integrity. CRITICAL FROZEN: Separate specimens must be submitted when multiple tests are ordered.

Test Code
FIBR or 1000347

Alias/See Also
Factor 1; Fibrinogen Activity

CPT Codes

Blue top tube, 3.2% sodium citrate.
• Obtain venous blood by clean venipuncture. Avoid slow-flowing draws and/or traumatic venipunctures as either of these may result in an activated or clotted specimen. Do not use needles smaller than 23 gauge. Do not leave the tourniquet on for an extended length of time before drawing the sample.
• A pilot tube (non-additive or light blue tube) before drawing coagulation specimens in light blue vacuum tubes is only necessary when using a butterfly blood collection set as this will cause reduced draw volume in the first tube. Discard the pilot tube.
• Fill light blue tubes as far as vacuum will allow and mix by gentle inversion. Exact ratio of nine parts blood to one part anticoagulant must be maintained. Inadequate filling of the sample tube will alter this ratio and may lead to inaccurate results. Patients who have hematocrit values above 55 percent should have the anticoagulant adjusted to maintain the 9:1 ratio. Use the following formula to determine the amount of anticoagulant to use: [(100 – Hct) / (595 – Hct) ]* total volume = amount of anticoagulant required.
• After collecting the blood, examine the tube to ensure that it is filled to within 90% of the fill line.
• Note: Specimens containing heparin should not be used for coagulation studies. If possible, stop heparin therapy before the draw to avoid contamination. Heparin interferes with most clotting assays. If heparinized line must be used to obtain the sample, flush line with 5mL saline and discard the first 5 mL of blood drawn into a syringe, or 6 “dead space” volumes of the line.

Transport Container
Blood collected in 3.2% sodium citrate (light blue top tube). Proper blood to anticoagulant ratio is required. The tubes must be at a 100 ± 10% fill volume to maintain the correct ratio. Centrifuge light blue-top tube at 1500 g for no less than 15 minutes or speed/time to consistently yield platelet-poor plasma (<10,000/µL). Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer, and place into a plastic transport tube (Min. 0.5 mL). Immediately freeze the aliquot and ship on dry ice.

Transport Temperature

Specimen Stability
After separation from cells: Ambient: 8 hours; Refrigerated: unacceptable; Frozen: 14 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Marked hemolysis; marked icterus; marked lipemia; received thawed; received refrigerated


Setup Schedule
Sunday - Saturday

Report Available
1 day

Reference Range
200-400 mg/dL

Clinical Significance
Quantitative determination of fibrinogen in plasma via clotting-based assay.

Fibrinogen is a plasma protein that is converted from a soluble protein to an insoluble polymer by the action of thrombin, resulting in the formation of a fibrin clot. Depressed levels of fibrinogen are observed in:

A. Acquired hypo- or afibrinogenemia. Acquired fibrinogen deficiency states occur especially as a result of intravascular proteolysis of fibrinogen by thrombin (disseminated intravascular coagulation, e.g., in obstetrics, after surgery), snake venoms or plasmin (primary hyperfibrinolysis after streptokinase, urokinase, or tPA therapy). Moderate hypofibrinogenemias may occur in cases of diminished production (in acute or chronic liver disease), loss into the intravascular space (e.g., in ascites or acute hemorrhage and burns) or increased degradation (in shock or carcinoma).

B. Congenital hypo- and afibrinogenemias. Temporarily elevated levels of fibrinogen are observed as a result of the behavior of fibrinogen as an acute phase protein:Transitory hyperfibrinogenemias may occur after operations, traumas, myocardial infarction, and infections. Persistent hyperfibrinogenemias may be seen in patients with neoplasias and chronic inflammatory disease.

Levels of fibrinogen increase slightly with age. Elevated fibrinogen levels are a risk factor for thrombosis.

Performing Laboratory
med fusion

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.