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Laboratory Medicine

Test Directory / International Normalised Ratio (INR)

International Normalised Ratio (INR)

Citrated Plasma

TestInternational Normalised Ratio (INR)
Common AbbreviationsINR
Clinical IndicationCalculation derived from the Prothrombin Time (PT/MNPT^ISI). Used to monitor Warfain.
Specimen TypeBlood
Sample TypeCitrated Plasma
Minimum Volume1 x 3mL (adult) 1 x 1mL (paed) (citrated plasma must be filled to bottle line)
Special PrecautionsOnly use for Warfarin monitoring.
Stability24 hrs at room temp
Turnaround Time1 hour (urgent) 4 hours (routine)
LaboratoryYork & Scarborough Hospital
Reference IntervalN/A
LimitationsHaemolysis, 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
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