Specimen Requirements
Offsite Collection Instructions
The sample should be drawn 3 hours after injection of drug in order to compare to published peak levels. Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.
Rejection Criteria
Specimens will be rejected if not properly filled, clotted, grossly hemolyzed, contaminated with heparin, or received outside acceptable time limits.
Contraindication
Test is not indicated if the patient is receiving unfractionated heparin or other Anti-Xa drugs.
Container
Normal Volume
Full 2.7mL tube or 1mL plasma aliquot
Minimum Volume
Full 1.8mL tube or 1mL plasma aliquot