Skip to main content

Please note that this is a beta version of our website. Should you encounter any bugs, glitches, lack of functionality or other problems on the website, please let us know immediately so we can rectify these accordingly. Your help in this regard is greatly appreciated! You can email us.

Login to North West London Pathology – consumables service

If you need a new account or you have a query about your order, please telephone the pathology call centre on 0203 313 5353.

If you have forgotten your password you can reset this yourself. Please click here if you have forgotten your password.

Results Line and Enquiries

0203 313 5353

Activated partial thromboplastin time ratio (APTTR)

Category Haematology
Test background

The APTTR is derived from the activated partial thromboplastin time (APTT) of the patient and the midpoint of the APTT reference range. The APTTR is used to monitor unfractionated heparin therapy and is only reported under those circumstances.

Clinicial Indications

Monitoring of unfractionated heparin dosage.

Reference range

Therapeutic range dependent on clinical requirement for anticoagulation.

Sample & container required 4.5 mL sodium citrate (pale blue top) adults1.8 mL sodium citrate (pale blue top) paediatrics
Turnaround time 4 hours
Notes

Special handling: avoid prolonged stasis during venepuncture. Sample must be received by lab within 4 hours of collection. Please note: samples will be rejected if underfilled or overfilled.