All tests · Coagulation Studies
Coagulation Studies
Normal range 25–35 seconds. Specimen: Plasma (sodium citrate).
Also known as: PTT, partial thromboplastin time.
| Specimen | Plasma (sodium citrate) |
|---|---|
| Conventional range | 25–35 seconds |
| SI range | 25–35 seconds |
| Conversion factor | ×1 (conventional → SI) |
| Critical value | > 70 seconds (bleeding risk) |
| Panel | Coagulation Studies |
Convert any Activated Partial Thromboplastin Time (aPTT) result between units on the unit converter.
The standard teaching reference range for Activated Partial Thromboplastin Time (aPTT) is 25–35 seconds. This value is measured in plasma (sodium citrate).
A commonly taught critical (panic) value is > 70 seconds (bleeding risk). Critical results are reported to the provider immediately under your facility's policy.
Source: Adult reference values compiled from Pagana & Pagana, Mosby's Diagnostic and Laboratory Test Reference, and Fischbach & Dunning, A Manual of Laboratory and Diagnostic Tests. Reference ranges vary by laboratory, method, age, sex, and population — always use the range printed on the actual result.
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