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Laboratory Medicine

Test Directory / Activated Partial Thromboplastin Time

Activated Partial Thromboplastin Time

Citrated Plasma

TestActivated Partial Thromboplastin Time
Common AbbreviationsAPTT
ProfileCoagulation Screen ( if required during authorisation: Actin FS APTT / APTT Mixing studies to exclude coagulation inhibitor presence)
Clinical IndicationScreening test for secondary haemostasis. Abnormal results may suggest factor deficiency
Specimen TypeBlood
Sample TypeCitrated Plasma
Minimum Volume1 x 3 mL (adult) 1 x 1 mL (paed) (citrated plasma must be filled to bottle line)
Special PrecautionsMust state if patient is on anticoagulants (DOAC, Warfarin, Heparin); known coagulation disorders; clinical symptoms (bleeding, bruising).
Stability4-6 hours
Turnaround Time1 hour (urgent) 4 hours (routine)
LaboratoryYork & Scarborough Hospital
Reference IntervalReference range printed on final report.
LimitationsHaemolysis, gross lipaemia, high haematocrit may interfere with measurement. Over or under filled samples cannot be used due to ratio between blood and citrate
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