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HelpTest Code TT Thrombin Time
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
Patient Preparation
No special patient preparation required
Special Collection Instructions
Properly filled 9:1 ratio (blood to anticoagulant)
Collection Method
Venous Draw; properly filled 9:1 ratio (blood to anticoagulant)
Minimum Volume
0.5 ml of plasma from a properly filled 1.8 mL or 2.7 mL NaCitrate (light blue) tube
Container
Light Blue Sodium Citrate
Preferred Specimen
2.7mL Lt. Blue (3.2% NaCitrate)
Acceptable Specimens
1.8 mL Lt. Blue (3.2% NaCitrate) tube
Reference or Target Ranges
15.8 - 24.9 seconds
Reportable Units
seconds
Critical Value
Not defined for this assay
Reasons for Rejection
| Hemolysis Threshold | Mild ok; gross reject |
| Icterus Threshold | Mild ok; gross reject |
| Lipemia Threshold | Mild ok; gross reject |
| Interfering Subtances/Other | Short draws, over draws, clotted, improperly labeled, samples > 4 hours from collection |
Specimen Stability
| Ambient | Plasma – 4 hours |
| Refrigerated (4°C to 8°C) | N/A |
| Frozen(-70°C to -20°C) | 2 weeks@ -20°C; 1 year @ -70°C |
Performance Information
| Days and Time Performed | 24/7 |
| Expected Turn Around Time | Stat:1 hour on arrival to lab Routine:4 hours on arrival to lab |
| Stat Availability | Yes |
| Performing Bench | Coagulation |
| Methodology/Method Description | Werfen ACL TOPS - Photo-optical clot-detection system |
CPT Codes
85670