Activated Protein C Resistance

Message
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Refer to Coagulation Collection Procedures for directions.


Test Code
117762


Alias/See Also
APCR


CPT Codes
85307

Preferred Specimen
Plasma, FROZEN


Minimum Volume
1 mL


Instructions
Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.(1) Evacuated collection tubes must be filled to completion to ensure a proper blood-to- anticoagulant ratio.(2,3) The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples unless the sample is collected using a winged (butterfly) collection system. With a winged blood collection set a discard tube should be drawn first to account for the dead space of the tubing and prevent under-filling of the evacutated tube.(4,5) When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternative anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. Print and use the Specimen Collection Bulletin as a tube-filling guide.


Transport Container
Blue-top (sodium citrate) tube


Transport Temperature
FREEZE


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis; clotted specimens; specimens that have thawed in transit; tubes <90% full; improperly labeled specimen; specimen collected in tube other than 3.2% citrate.


Methodology
This assay measures the effect of adding aPC on the activated partial thromboplastin time (aPTT) of the patient sample.[8,9] An aPTT is performed twice, once with and again without added aPC. The ratio of the two clotting times is reported. The patient sa

Setup Schedule
Daily 1st and 3rd shift




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.