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Test Code Billings Clinic: 2005 Thrombin Time (TT), Plasma

Important Note

For specimens being sent from reference clients outside of Billings:

This test will be forwarded to Mayo Medical Laboratories for testing due to specimen stability constraints.  Please order Billings Clinic Test Code 9568 (Mayo Test Code TT).

Performing Laboratory

Billings Clinic Laboratory: Coagulation

Useful For

  • The main utility of the thrombin time test is to detect or exclude the presence of heparin or heparin-like anticoagulants (which act by enhancing antithrombin's inhibition of thrombin and other procoagulant enzymes) when used in conjunction with the reptilase time (RT) in evaluating unexplained prolonged clotting times.
  • Identifying the cause of a prolonged prothrombin time, activated partial thromboplastin time, or dilute Russell's viper venom time when used in conjunction with the RT and fibrinogen assay

Methodology

Optical

Specimen Requirements

Specimen Collection and Handling:

  • Draw blood in a light blue-top (3.2% sodium citrate) tube.
  • Immediately after draw, gently invert tube(s) at least 6 times to mix well.
  • Spin down, remove plasma, spin plasma again, and place 1 mL of citrate platelet-poor plasma in plastic vial immediately after specimen collection.
  • Double-centrifuged specimens are critical for accurate results as platelet contamination may cause spurious results.

 

Specimen Transport:

  • Send specimen ambient.
  • DO NOT refrigerate or freeze.
  • Samples must be tested within 4 hours of draw

Storage/Stability

Specimen Type Temperature Time
Plasma Ambient 4 hours

Reject Due To

  • Frozen specimens
  • Refrigerated specimens
  • Clotted samples
  • Specimens > 4 hours old
  • Incorrect collection tube
  • Incorrect fill volume (too full or not enough)

Reference Values

Results are included with patient’s report.

Day(s) Test Set Up

Daily

Test Classification and CPT Coding

85670 - Thrombin Time, plasma

LOINC Code Information

Reporting Name LOINC Code
Thrombin Time 3243-3