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Specimen Collection Manual and Test Catalog

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SOLUBLE FIBRIN MONOMERS

Geisinger Epic Procedure Code:  LAB3072    Geisinger Epic ID:  7159

SPECIMEN COLLECTION
Specimen type: 

Platelet-poor plasma


Preferred collection container: 
Alternate collection container: 
Other size blue-top (3.2% sodium citrate) tubes (e.g., 1.8 mL, 4.5 mL)
Specimen required: 

1 mL


Special notes: 

This test is offered at a limited number of performing laboratories and may only be collected and performed at testing sites (see below). 

  • 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 and recollect if observed.
  • Immediately transport at room temperature to Coagulation Laboratory after collection.


SPECIMEN PROCESSING
Processing instructions: 

Centrifuge within 60 minutes at designated speed and time to obtain platelet-poor plasma (<10,000/µL). Using a plastic pipette, carefully remove plasma from cells, avoiding platelet/buffy layer by leaving a thin layer of plasma on top the cells. Transfer centrifuged plasma into clearly labeled polypropylene tubes.


Transport temperature: 

Room temperature


Specimen stability: 

Room temperature: 2 hours


Rejection criteria: 

Clotted, hemolyzed, improperly filled tubes, improper anticoagulant ratio (HCT >55% and citrate not adjusted), refrigerated or frozen specimens, or stability exceeded.



TEST DETAILS
Reference interval: 

Negative


CPT code(s):  85366
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Methodology: 
Qualitative hemagglutination
Synonyms: 

Fibrin Monomer, Soluble Fibrin Monomers, SFM


Clinical significance: 

The assay can assist in diagnosing disseminated intravascular coagulation (DIC). Fibrin monomers are produced as soluble fibrinogen is transformed into insoluble fibrin clot. This intermediate product can form soluble complexes with fibrinogen or fibrinogen degradation products when thrombin levels are low (commonly observed in patients with DIC). These soluble complexes are then visualized using RBC agglutination. DIC is a clinical diagnosis, and no single test should be used to diagnose DIC. This assay should be correlated with other DIC tests (PT, APTT, D-Dimer, and platelet count). In neonates, interpret samples with caution, as the results are often positive, due to difficulty in sample collection.


Doctoral Director(s): 
Michelle Grant DO
Review Date:  03/04/2025

Performing Locations