Activated Partial Thromboplastin Time & Prothrombin Time (APTT & PT)

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)	Prothrombin Time (PT) Activated Partial Thromboplastin Time (APTT) 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.
07 Feb 2023 12:00 AM

Updated Specimen Storage / Transport, Downtime Form.
21 Oct 2022 12:00 AM

Updated Specimen Requirement, Specimen Storage / Transport.

Last Updated - 05 Apr 2025