Activated Partial Thromboplastin Time
Clinical Background:
This is the time it takes anticoagulated plasma to clot after being exposed to phospholipids, activators and calcium. It is used as part of the clotting screen and is sensitive to deficiencies in F...
This is the time it takes anticoagulated plasma to clot after being exposed to phospholipids, activators and calcium. It is used as part of the clotting screen and is sensitive to deficiencies in Factors XII, XI, IX, VII, X, V, II and Fibrinogen, in addition it may also detect deficiencies in the contact factors (High Molecular Weight Kininogen and Pre-Kallikrein). The test is also sensitive to Heparin (both Unfractionated and Low Molecular Weight) and the Lupus Anticoagulant. APTT can be increased by a number of the Direct Oral Anticoagulants which are being used more widely
Test Details
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Discipline:
Haemostasis
Haemostasis
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Specimen Container Adult:
Light blue - sodium citrate
Light blue - sodium citrate
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Specimen Container Paediatric:
Light blue - sodium citrate
Light blue - sodium citrate
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Minimum Volume Adult:
2.7mL
2.7mL
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Minimum Volume Paediatric:
1.3mL
1.3mL
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Special Requirement:
Tube must be correctly filled to line, to ensure correct ratio of blood to anticoagulant, ensure adequate mixing.
Tube must be correctly filled to line, to ensure correct ratio of blood to anticoagulant, ensure adequate mixing.
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Sample Stability:
8 hrs
8 hrs
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Transport Requirements:
Samples should be transported to lab without delay
Samples should be transported to lab without delay
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Freq Analysis:
Continuous
Continuous
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Add On Test:
All urgent add ons via telephone on 0191 28 24718, and must be confirmed via email to the appropriate email address
tnu-tr.bloodsciencesadditions@nhs.net (internal)
Read MoreAll urgent add ons via telephone on 0191 28 24718, and must be confirmed via email to the appropriate email address
tnu-tr.bloodsciencesadditions@nhs.net (internal)
tnu-tr.bloodsciencesadditions@nhs.net (external)
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Quality Assurance:
UK NEQAS Blood Coagulation
UK NEQAS Blood Coagulation
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Reference Ranges:
APTT 25 - 37 seconds
Note: For Haemostatic tests, paediatric reference ranges may be different to adult ranges. Please see
https://www.newcastlelaboratories.com/lab_service/core-247/
for details....
Read MoreAPTT 25 - 37 seconds
Note: For Haemostatic tests, paediatric reference ranges may be different to adult ranges. Please see
https://www.newcastlelaboratories.com/lab_service/core-247/
for details.
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Factors Affecting Result:
Heparin will prolong the APTT
Heparin will prolong the APTT
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Other Info:
As part of a coagulation screen.
As part of a coagulation screen.
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Routine Contact Name:
Peter Strong
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Routine Telephone:
0191 282 0332
0191 282 0332
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Routine Email:
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Specialist Test:
No
No
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Specialist Contact Name:
Haematology/Haemostasis Health care Scientist
Haematology/Haemostasis Health care Scientist
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Specialist Telephone:
0191 213 9758
0191 213 9758