🩸 Coagulation Test Interpretation
UseLocalise a coagulation abnormality to the intrinsic, extrinsic or common pathway and separate deficiency from…
SourceStandard interpretation of PT/aPTT and the mixing study
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
Methodology · worked example, guidelines & full notes
Isolated PT rise: VII deficiency, early warfarin/vitamin K deficiency, liver disease.
When to use
Localise a coagulation abnormality to the intrinsic, extrinsic or common pathway and separate deficiency from inhibitor.
How it works
PT = extrinsic/common; aPTT = intrinsic/common. Mixing study: corrects = deficiency, does not correct = inhibitor.
Key points
- Isolated PT rise: VII deficiency, early warfarin/vitamin K deficiency, liver disease.
- Isolated aPTT rise: haemophilia, vWD, heparin, lupus anticoagulant.
- DIC: low fibrinogen, high D-dimer, low platelets, prolonged PT/aPTT.
- Normal PT/aPTT with bleeding: consider platelet/vessel disorder, XIII deficiency, mild vWD.
References
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| View | Mixing study |
|---|
→InterpretationMixing study (1:1 normal plasma)
- Corrects：Suggests a factor deficiency (corrected by normal plasma)
- Does not correct：Suggests an inhibitor (lupus anticoagulant, factor inhibitor)
| View | PT/aPTT combinations |
|---|
→InterpretationPT/aPTT combinations
- PT ↑ aPTT normal：Extrinsic: factor VII deficiency, early vitamin K deficiency/warfarin, liver disease
- aPTT ↑ PT normal：Intrinsic: VIII/IX/XI (haemophilia), vWD, heparin, lupus anticoagulant
- PT ↑ aPTT ↑：Common pathway: late vitamin K deficiency, DIC, liver disease, severe fibrinogen ↓
Verification & sources · governance
FAQ
Frequently asked questions
- What are the limits and cautions when using Coagulation Test Interpretation?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- Does Coagulation Test Interpretation upload patient data? Where is it calculated?
- Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
- How is Coagulation Test Interpretation calculated in practice? Can you show a worked example?
- Inputs: View Mixing study → Result: Interpretation Mixing study (1:1 normal plasma)（Corrects: Suggests a factor deficiency (corrected by normal plasma), Does not correct: Suggests an inhibitor (lupus anticoagulant, factor inhibitor)） Inputs: View PT/aPTT combinations → Result: Interpretation PT/aPTT combinations（PT ↑ aPTT normal: Extrinsic: factor VII deficiency, early vitamin K deficiency/warfarin, liver disease, aPTT ↑ PT normal: Intrinsic: VIII/IX/XI (haemophilia), vWD, heparin, lupus anticoagulant, PT ↑ aPTT ↑: Common pathway: late vitamin K deficiency, DIC, liver disease, severe fibrinogen ↓）