Thrombin time

Keywords: Thrombin, TT

Specimen:

4.5 mL blood added to 0.5mL citrate.

Method:

Thrombin added to platelet-poor plasma at 37°C; the clotting time is recorded.

Reference Interval:

Varies with laboratory and method. Guide: typically 14-16 seconds.

Application:

Investigation of possible acquired or inherited disorders of haemostasis.

Occasionally indicated in the investigation of unexplained thrombosis.

Interpretation:

Prolonged in afibrinogenaemia, hypofibrinogenaemia, dysfibrinogenaemia. Prolonged by heparin (corrects with protamine and reptilase), FDP / D Dimer, paraproteins (partial correction with protamine).

Reference:

Bain et al. Dacie and Lewis Practical Haematology. 11th Ed. 2012.