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:
tnu-tr.bloodsciencesadditions@nhs.net (external)
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:
RVI or Freeman Section Leaders
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Routine Telephone:
RVI: 0191 2820332, Freeman: 0191 2231195
RVI: 0191 2820332, Freeman: 0191 2231195
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Specialist Test:
No
No
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Specialist Contact Name:
Haematology and Haemostasis Healthcare Scientist
Haematology and Haemostasis Healthcare Scientist
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Specialist Telephone:
0191 2139758
0191 2139758
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Specialist Email:
alison.brown93@nhs.net
alison.brown93@nhs.net