Test Details
Methodology
Chromogenic
Result Turnaround Time
2 - 3 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Monitor prophylactic fondaparinux levels in patient plasma6
Limitations
Severe hemolysis, bilirubinemia, and lipemia may interfere with this assay. Improper sample preparation or handling may affect assay results or sample stability, especially after freezing. Release of platelet factor 4 resulting from inadequate removal of platelets or platelet activation of the sample may reduce the measured heparin concentration. A therapeutic range has not been established.
Footnotes
Specimen Requirements
Specimen
Plasma, frozen
Volume
1 mL
Container
Blue-top (sodium citrate) tubes
Collection Instructions
Citrated plasma samples should be collected by double centrifugation. 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, except when using a winged blood collection device (ie, "butterfly"), in which case a discard tube should be used.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 alternate 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. Centrifuge and carefully remove the plasma using a plastic transfer pipette, being careful not to disturb the cells. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.
Storage Instructions
Freeze. Stable refrigerated for four hours.
Causes for Rejection
Hemolysis; clotted specimen; specimen contaminated with heparin (ie, drawn with blood gases)
LOINC® Map
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
500465 | Anti-Xa-Fondaparinux | 500466 | Anti-Xa-Fondaparinux | mg/L | 74217-1 | |
Order Code | 500465 | |||||
Order Code Name | Anti-Xa-Fondaparinux | |||||
Order Loinc | ||||||
Result Code | 500466 | |||||
Result Code Name | Anti-Xa-Fondaparinux | |||||
UofM | mg/L | |||||
Result LOINC | 74217-1 |