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HelpTest Code PTT Activated Partial Thromboplastin Time (APTT), LAB325
Performing Laboratory
St. Luke's Hospital Cedar Rapids
Specimen Requirements
Container/Tube:
Required: Full blue-top (sodium citrate) 1.8 mL tube
Hemolyzed or short draw specimen is not acceptable.
Specimen Volume: 0.5 mL sodium citrate plasma
Uncentrifuged Specimens: Remain at room temperature and spun within 6-8 hours of collection.
Centrifuged Specimens: Stored refrigerated or room temperature and tested within 8-12 hours. If testing is not completed within 12 hours, plasma should be removed from the cells and frozen at -20° C for up to 3 months.
NOTE: Patients with a hematocrit of >55% must be recollected using an altered amount of sodium citrate.
Reference Values
|
|
PTT (seconds) |
||
|
Age |
Low |
High |
Critical |
|
0-15 day |
28.8 | 47.8 |
≥62.0 |
|
≥16 days |
21.0 | 37.0 |
≥62.0 |
Day(s) Test Set Up
Monday through Sunday
Useful For
The activated partial thromboplastin time test is sensitive to all coagulation factors except factors VII and XIII, it is an effective screening test for the entire intrinsic coagulation system.
Methodology
Clot Based Assay
Test Classification and CPT Coding
85730
Report Available
STAT within 1 hour upon receipt
Routine within 2 hours upon receipt