D-Dimer, Quantitative

Collection Instructions:

Specimens must be filled to minimum fill indicator line on the tube. BD Vacutainer Plus Citrate Tube Draw Volume Guide

If collected utilizing a "butterfly" collection device (also known as a Safety-Lok Collection Set), an extra discard Blue Tube must be drawn first to remove air from the line. If this is not done, the Blue Top Tube will not be filled properly due to the vacuum in tube and a redraw will be required

Note:

Collection of blood for coagulation testing through intravenous lines that have been previously flushed with heparin should be avoided, if possible.

If the blood must be drawn through an indwelling catheter, possible heparin contamination and specimen dilution should be considered. To decrease chance of heparin contamination:

1. Flush the line with 5 mL of saline.
2. Then the 5 mL of blood or 6-times the line volume (dead space volume of the catheter) should be drawn into a discard tube before filling the Blue Top Tube for coagulation testing.

For samples collected from a normal saline lock (capped off venous port), twice the dead space volume of the catheter and extension set should be discarded.

Processing Instructions:

Whole blood samples must be centrifuged in a centrifuged that has been validated for platelet poor plasma (PLT < 10,000/uL).

Rejection Criteria:

Clotted samples

Improperly filled tubes (under or overfilled)

Wrong anticoagulant (3.8% sodium citrate is NOT acceptable)

Patients with hematocrit (HCT) >55% (red cell volume is >1/2 tube volume)

Hemolyzed samples

Stability time exceeded

Frozen whole blood samples