Activated Partial Thromboplastin Time/ Heparin

Pathology category

Haematology

Code

APTT/HEP

Referral code

Request form

Test information

Must be analysed within 4 hours of collection

Guidelines

Pre-analytical

Lipaemic, jaundiced or haemolysed plasma may cause problems with testingSample transport should be at 4-25C and reach the laboratory ASAPPlease note: the samples must arrive the same day as collection otherwise they will be rejected by the laboratory

Reference range

Time is reagent dependent.Normal ratio = 0.8-1.2

Tube type

Tube type info

2.7ml blue top citrate1.8ml Paediatric citrate

Special requirements

Minimum volume

1 tube minimum 90% full – this is essential to ensure correct ratio of anti-coagulant to blood

Assay frequency

Routine

TAT Inpatient (urgent)

1 hour

TAT Inpatient

4 hours

TAT GP/Outpatient

4 hours

Referral lab

local