Prothrombin Time (PT) International Normalise Ratio (INR)

CG0110

Synonym(s):
Specimen Container
3.2% Sodium Citrate Tube
Specimen Requirement
Citrated Whole Blood
Adult: 2 mL
Paediatric and Neonate: 1 ml

- Gently invert the tubes several times to prevent clotting. Clotted specimen is not suitable for testing.

- To collect blood to the designate marking. Over or under filling will compromise the test results.

- When using a winged blood collection set for venipuncture and a coagulation tube is the first tube drawn, draw a discard tube first.

- When obtaining specimens from indwelling lines that may contain heparin, the line should be flushed with 5mL of saline; and the first 5mL of blood or 6-times the line volume (dead space volume of the catheter) be drawn off and discarded before the coagulation tube is filled.

- For those samples collected from a normal saline lock (capped off venous port) twice the dead space volume of the catheter and extension set should be discarded.
Specimen Storage/Transport Send to laboratory as soon as possible after blood collection. Do not send in ice.
Orderable as Urgent? Yes
Turn Around Time
Stat: 1 hr
Routine: 2 - 3 hrs
Reference Value(s)
Age GroupGenderReference Intervals (secs)
0 mins - 2 daysboth14.4 - 16.4
3 days - 30 daysboth13.5 - 16.4
31 days - 11 monthboth11.5 - 15.3
1 years - 5 yearsboth12.1 - 14.5
6 years - 10 yearsboth11.7 - 15.1
11 years - 16 yearsboth12.7 - 16.1
17 years and aboveboth11.6 - 14.2
 
Recommended INR range for oral anticoagulation (warfarin): 2.0 - 3.5
Testing Laboratory Location KKH
Laboratory Haematology
Contact Number 6394 1373
Day and Time Performed
Daily, 24 hrs
Orderable on CPOE? Yes
Downtime Form

63170-Form-1080 Haematology Laboratory Downtime Form

Change History Notes

  • 12 Sep 2024 04:30 PM

    ​Updated Specimen Container.

  • 06 Feb 2023 12:00 AM

    ​​​Updated Specimen Storage / Transport, Downtime Form.

  • 21 Oct 2022 12:00 AM

    ​Updated Specimen Requirement, Specimen Storage / Transport.

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Last Updated - 05 Apr 2025