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Test Code LAB324 Thrombin Time

Important Note

Blue tubes that are not filled to the required line will not be processed, due to result integrity being affected.  

Useful For

  • Assessing fibrin formation
  • Increased thrombin time may indicate an abnormality of fibrinogen such as:
    •  dysfibrinogenaemia
    • severe hypofibrinogenemia
    • congenital afibrinogenemia
    • acquired hypofibrinogenemia (DIC, fibrinolysis, liver diseases)
  • Increased thrombin time can also be seen in the presence of antithrombins:
    • Therapeutic: heparin, hirudin, argatroban, etc.
    • Abnormal: FDP, appearing during myelomas, etc.

Methodology

Clot Detection

Performing Laboratory

Bozeman Health Laboratory Services

Specimen Requirements

Specimen Type: Whole blood
Container/Tube: Blue top (3.2% sodium citrate)

Specimen Volume: Full tube

Collection Instructions: Click here to link to a You Tube video tutorial

1. Immediately after draw, invert tubes several times to mix blood with additive.

2. Send specimen in original tube.

3. If there is a delay in transport of >4 hours, specimen must be double-centrifuged to prepare a platelet-free plasma specimen as follows:

a. Immediately centrifuge at 3,200 rpm for 15 minutes.

b. Carefully remove plasma from cells avoiding platelet/buffy coat, and transfer plasma into a plastic tube.

c. Centrifuge plastic tube at 3,200 rpm for 15 minutes.

d. Carefully remove top portion of plasma and transfer plasma into a plastic tube leaving approximately 250 mcL in bottom to discard.

e. Double-centrifuged plasma should be aliquoted (0.5 mL-1 mL each) into clearly labeled plastic tubes. (Glass vial is not acceptable.)

Note: Number of tests ordered will determine number of aliquots needed, generally 1 aliquot per test.

f. Specimens should be frozen at <-40° C, if possible, and sent together in same container with at least 5 lbs of dry ice. Specimens must arrive in a frozen state.

Additional Information: Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

Specimen Transport Temperature

Ambient (whole blood) <4 hours/Frozen (plasma) >4 hours

Specimen Stability

Specmen Type Temperature Time
Whole Blood (unspun) Ambient 4 hours
Plasma Na Citrate Ambient 8 hours
  Frozen 14 days
Plasma Na Citrate (on Heparin Therapy) Ambient 2 hours

Reference Values

15.0-18.0 seconds

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

85670