Laboratory Medicine
Test Directory / Anti-Xa assay (Unfractionated Heparin (UFH), Fragmin/Dalteparin, Enoxaparin/Clexane, Innohep/Tinzaparin, Rivaroxaban, Apixaban or Orgaran/Danaparoid)
Anti-Xa assay (Unfractionated Heparin (UFH), Fragmin/Dalteparin, Enoxaparin/Clexane, Innohep/Tinzaparin, Rivaroxaban, Apixaban or Orgaran/Danaparoid)
Citrated Plasma
| Test | Anti-Xa assay (Unfractionated Heparin (UFH), Fragmin/Dalteparin, Enoxaparin/Clexane, Innohep/Tinzaparin, Rivaroxaban, Apixaban or Orgaran/Danaparoid) |
|---|---|
| Common Abbreviations | |
| Profile | Coagulation Screen added on the same sample |
| Clinical Indication | APTT ratio (APR) are no longer in use to monitor UFH, and anti-Xa must be requested. Low molecular weight heparin (LMWH) and Rivaroxaban/Apixaban (DOAC) therapy is usually not monitored. LMWH measuring may be required when the patient is pregnant, obese, very young, elderly and those who have kidney disease or dysfunction. DOAC monitoring may be required if overdosed, compliance or prior surgery. Contact Consultant Haematologist for further advice. |
| Specimen Type | Blood |
| Sample Type | Citrated Plasma |
| Minimum Volume | 1 x 3mL (adult) 1 x 1mL (paed) (citrated plasma must be filled to bottle line) |
| Special Precautions | Must state the type of anticoagulant on form and time sample taken post dose Fondaparinux and Edoxaban levels are sent to Sheffield |
| Stability | 4 hours |
| Turnaround Time | 1 hours (urgent) 4 hours (routine) |
| Laboratory | York Hospital for all anti-Xa tests Scarborough for LMWH and UFH anti-Xa |
| Reference Interval | See manufacturer's guidance for reference range |
| Limitations | Haemolysis, gross lipaemia, high haematocrit may interfere with measurement. Over or under filled samples cannot be used due to ratio between blood and citrate |
| Additional Information |
