Thrombin Clotting Time

883

1 mL platelet-poor plasma collected in 3.2% sodium citrate (light blue-top) tube

0.5 mL

Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial (s). Freeze immediately and transport on dry ice.

Frozen

Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days

Hemolysis

Set up: Mon-Sat; Report available: Next day

Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: no effect; Heparin (UFH or LMWH): prolonged; Dabigatran or Argatroban (Thrombin Inhibitors): prolonged; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect.

13-19 seconds

This test, also known as thrombin time, is useful for evaluating the presence of heparin and other direct thrombin inhibitor anticoagulants in specimens with prolonged coagulation studies. It is also used to aid in the diagnosis of congenital and acquired disorders of fibrinogen.

Anticoagulant interference: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Vitamin K antagonists (eg. warfarin): no effect; Heparin (UFH or LMWH): prolonged; Dabigatran or Argatroban (Direct Thrombin Inhibitors): prolonged; Rivaroxaban, Apixaban, Edoxaban (Factor Xa Inhibitors): no effect.