Dilute Thrombin Time Panel
Test Mnemonic
DTT
CPT Codes
- 85730 - QTY (1)
- 85670 - QTY (1)
Includes
- Dilute Thrombin Time
- APTT Screen
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Plasma | Sodium citrate (Lt. Blue) | Centrifuge, aliquot and freeze ASAP. | Collection tube must be filled to total fill volume. Inadequately filled tubes will be rejected. Non-testing sites: Centrifuge sample, aliquot plasma into a separate tube and label with Epic Beaker labels. Specimens should be frozen (-20C or colder). |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| N/A | Collection tube must be filled to total fill volume. Inadequately filled tubes will be rejected. |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 4 Hours |
| Frozen | 14 days at -20 C; 6 months at -70 C |
| Refrigerated | Unacceptable |
Days Performed
Sun - Sat
Turnaround Time
6 hours
Methodology
| Name | Description |
|---|---|
| Clotting Assay |
Reference Range
| APTT Screen | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Days | 1 Days | Normal | 28.2-47.4 | sec | 1 Months | 3 Months | Normal | 21.7-43.5 | sec | 2 Days | 5 Days | Normal | 22.9-52.0 | sec | 6 Days | 30 Days | Normal | 23.1-48.0 | sec | 4 Months | 11 Months | Normal | 25.3-37.3 | sec | 1 Years | 5 Years | Normal | 21.3-31.6 | sec | 6 Years | 10 Years | Normal | 23.1-31.6 | sec | 11 Years | 16 Years | Normal | 23.1-32.5 | sec | 17 Years | 99 Years | Normal | 24.0-35.1 | sec |
| Dilute Thrombin Time | |||||
| Sex | Age From | Age To | Type | Range | Range Unit |
| 1 Years | 999 Years | Normal | <18.6 | sec |
Clinical Info
The DTT is used for measuring and monitoring direct thrombin inhibitors (DTI). The expected therapeutic range for the appropriate DTI (dabigatran, bivalirudin and argatroban) will be provided based on the medication selected when placing the order. DTT is not affected by optical interferences (hemolysis, icteria, lipemia), high or low fibrinogen, coumadin, enoxaparin or direct Xa inhibitors (e.g., apixaban, rivaroxaban). However, unfractionated heparin is known to interfere with the DTT assay.