Specimen Collection Manual and Test Catalog
D-DIMER
Geisinger Epic Procedure Code: LAB2173 Geisinger Epic ID: 18327Platelet-poor plasma
1 mL
- 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.
Centrifuge 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. The centrifuged plasma should be aliquoted (1 mL per aliquot) into clearly labeled polypropylene tubes. Check the residual specimen for clot and if present discard sample and redraw specimen. If plasma is icteric, lipemic or hemolyzed a lab comment should be generated to notify staff. Freeze upright in non-thaw freezer.
Frozen on dry ice
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
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.
< 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.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.
D-Dimer
Microlatex Agglutination
D-Dimer, DDI, DDIQ
Increased levels of D-Dimer are often seen after blood clots (PE or DVT), trauma, surgery, malignancies, sepsis, COVID infection, pregnancy, or increased age.