PTD - 8

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Test Directory -  APTT (Activated Partial Thromboplastin Time)

Synonyms

APT, APTR, Heparin screen, Hep

Clinical Indications

.Activated Partial Thromboplastin Time (APTT) ordered as part of coagulation screen for an investigation of a possible bleeding disorder or thrombotic episode; to monitor unfractionated (standard) heparin anticoagulant therapy. Monitor haemostatic integrity.

Part of Profile

Coagulation screen

Request Form 

Combined Pathology Blood form (Yellow/Black or Blue for GP's)

Availability

On Request

Specific Criteria

  DO NOT use heparinised syringes / lines for collecting coagulation screens. Patient should be bled with minimal stasis, and samples received in lab within 2 hours of collection.

Turnaround Time

2 hours

Specimen

 Citrated whole blood

Volume

 3ml

Container

  1 x Blue capped vacutainer tubes

Collection

  Samples must be received by lab within 2 hours of collection.

Lab. Handling

 

Causes for Rejection

Inadequately labelled, unlabelled, haemolysed, under-filled, clotted  or lipaemic samples.

Limitations

  Activated sample, sample haemolysis or lipaemia..

Reference Range

  Unheparanised APTT ratio =  0.8 - 1.2
Heparin therapeutic APTT ratio = 1.5 2.5

Interpretation

See test reports

Version 1.0 / January 2013