Lab Test

Argatroban (Dilute Thrombin TIme)

Test Codes

EPIC: LAB6884

Department

Coagulation

Instructions

Specimens with hematocrit values greater than 55% must have anticoagulant adjusted. Specimens must be recollected using a specified whole blood to sodium citrate ratio. Contact the performing Laboratory for specific instructions.

Specimen Collection Criteria

Collect: One Light Blue-top 3.2% Sodium Citrate tube.

TUBE MUST BE FULL.

Physician Office/Draw Specimen Preparation

For optimal results, maintain whole blood specimen at room temperature (20-26°C or 68-78.8°F) prior to transport. Transport whole blood to the Laboratory within 4 hours of collection. If transport within 4 hours is not possible, the following procedure must be followed for accurate results:

  1. Centrifuge the capped tube at 1500 x g for 15 minutes.
  2. Transfer plasma with a plastic pipette into a plastic polypropylene centrifuge tube, cap and centrifuge an additional 15 minutes at 1500 x g to obtain platelet poor plasma (PPP) which has a platelet count less than 10 bil/L. Plasma with a platelet count of less than 10 bil/L is critical for accurate results.
  3. Immediately remove only the top two-thirds of the PPP and transfer it into a plastic tube.
  4. Freeze (-20°C/-4°F or below) the PPP immediately.
  5. Transport frozen on DRY ICE. Specimen must remain frozen during transport.   

Preparation for Courier Transport

Transport: Whole blood at room temperature (20-25°C or 68-77°F), or plasma obtained through the process listed above, frozen (-20°C/-4°F or below).

Rejection Criteria

  • Glass tubes and 3.8% Sodium Citrate tubes.
  • Specimens that are clotted or grossly hemolyzed.
  • Inappropriate specimen volume.
  • Thawed or partially thawed specimens.

In-Lab Processing

Whole blood specimens must be processed as follows upon receipt in the Laboratory:

  1. Centrifuge the capped tube at 1500 x g for 15 minutes.
  2. Transfer plasma with a plastic pipette into a plastic polypropylene centrifuge tube, cap and centrifuge an additional 15 minutes at 1500 x g to obtain platelet poor plasma (PPP) which has a platelet count less than 10 bil/L. Plasma with a platelet count of less than 10 bil/L is critical for accurate results.
  3. Immediately remove only the top two-thirds of the PPP and transfer it into a plastic tube.
  4. Test specimen immediately. If testing is not possible upon receipt, freeze the PPP.

Storage

Specimen Stability for Testing:

Whole Blood
Room Temperature (20-26°C or 68-78.8°F): 4 hours
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Plasma Aliquot
Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Frozen (-20°C/-4°F or below): 30 days

Laboratory

Royal Oak Coagulation Laboratory

Performed

Monday – Friday, 7:00 am – 3:30 pm.
Results available within 24 hours. 

Reference Range

Therapeutic Range: 0.6-1.8 mcg/mL.

Test Methodology

Clotting Assay (IL-ACL TOP).

Interpretation

The dilute thrombin time should not be affected by warfarin or lupus anticoagulant.

Clinical Utility

The dilute thrombin time is a clotting test that can be used for quantitative measurement of argatroban in plasma. Argatroban is typically monitored using the aPTT. However, in some cases, a patient's baseline aPTT may be abnormal due to lupus anticoagulant or other coagulapathies, making monitoring of argatroban difficult. In these cases, argatroban levels can provide a more accurate assessment of drug levels.

CPT Codes

80299

Contacts

Last Updated

3/29/2023

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