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Specimen Collection Manual and Test Catalog

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D-DIMER

Geisinger Epic Procedure Code:  LAB2173    Geisinger Epic ID:  18327

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: 
  • 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 the first 10 mL of blood.
  • 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.


SPECIMEN PROCESSING
Processing instructions: 

For a single NaCit blue top tube collection create 1 aliquot NaCit and if additional plasma remains, create an additional aliquot NaCit. If multiple tubes are collected, then create 1 aliquot NaCit for each NaCIt blue top tube collected plus one additional aliquot NaCit. Aliquots should be 1.0-1.9 mL and all plasma-based coagulation tests must be moved to aliquot(s).


Transport temperature: 

Frozen on dry ice


Specimen stability: 

Room temperature (whole blood): 4 hours 
Room temperature (plasma off cells): 8 hours 
Frozen (plasma) -20°C: 2 weeks 
Frozen (plasma) -70°C: 6 months 


Rejection criteria: 

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

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.



TEST DETAILS
Reference interval: 

< 0.5 µg/mL FEU (fibrinogen equivalent units)

The cut-off value for exclusion of Deep Vein Thrombosis (DVT)/ Pulmonary Embolism (PE) is 0.5 µg/mL FEU. Results below this value are not suggestive of a PE or DVT in patients.


Additional information: 

Anticoagulation Impact on Coagulation Tests


CPT code(s):  85379
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.

Test includes: 

D-Dimer


Methodology: 
Immunoturbidity
Microlatex Agglutination
Synonyms: 

D-Dimer, DDI, DDIQ


Clinical significance: 

Increased levels of D-Dimer are often seen after blood clots (PE or DVT), trauma, surgery, malignancies, sepsis, COVID infection, pregnancy, or increased age.


Doctoral Director(s): 
Michelle Grant DO
Review Date:  08/11/2026

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