Home
HelpTest Code PTT Activated Partial Thromboplastin Time (APTT)
Additional Codes
|
Test ID |
| PTT |
|
EPIC Test ID |
| LAB325 |
Performing Laboratory
St. Luke's Hospital Cedar Rapids
Specimen Requirements
Container/Tube:
Preferred: 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
Stability: Centrifuged specimens at 2-4°C or at 18-24°C must be tested within 4 hours of specimen collection.
Collection Instructions: Centrifuge immediately after draw. Forward promptly. If there is a delay in transport of >4 hours or if mailing time exceeds 4 hours, spin down, remove plasma from cells and freeze immediately in plastic vial. Send specimen frozen. Specimen stability is ≤2 weeks when frozen at -20° C.
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 |
|
0-1 day |
32.9 |
52.5 |
≥78.0 |
|
2-5 days |
26.5 | 57.7 |
≥78.0 |
|
6-29 days |
27.0 | 53.3 |
≥78.0 |
|
1-3 months |
25.4 | 48.3 |
≥68.0 |
|
4-11 months |
29.6 | 41.4 |
≥68.0 |
|
1 – 5 years |
24.9 | 35.0 |
≥58.0 |
|
6 – 10 years |
27.0 | 35.0 |
≥58.0 |
|
11 – 16 years |
27.0 | 36.0 |
≥58.0 |
|
>17 year |
28.0 | 39.0 |
≥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, so 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