Department of Haematology
- Manipulation of the prothrombin time (PT) to International Normalised ratio (INR) provides a standardised measure of anticoagulant therapy with Vitamin K antagonists, but is not valid for patients receiving other anticoagulants, screening for coagulation defects, or as a marker for the severity of liver dysfunction. If the request does not fulfill these criteria, the INR will not be performed.
- Samples that are under filled, overfilled or haemolysed give erroneous results and therefore will not be tested.
- Test performed at CGH and GRH
- GHNHSFT Warfarin Loading Guidelines
- GHNHSFT Guidelines for the Management of Oral Anticoagulants During Invasive Procedures
- BCSH Guidelines on Oral Anticoagulation
2ml, 3ml or 3.5ml Trisodium Citrate sample
- Urgent, clinical emergency: 30 minutes
- Other urgent sample: 60 minutes
- Routine: 2 hours
For therapeutic ranges, please see BCSH Guidelines.
GP telephone ranges:
INRs of <1.5 or >5.0