🌡️ SIRS Criteria Calculator
Check the SIRS criteria for systemic inflammatory response (≥ 2 of 4).
Clinical takeaway
Non-specific — many non-infectious causes.
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When to use
Screen for systemic inflammation; with infection, prompt sepsis evaluation.
How it works
1 point each: temp > 38 or < 36°C; HR > 90; RR > 20 or PaCO₂ < 32; WBC > 12 or < 4 ×10⁹/L or > 10% bands. ≥ 2 = SIRS.
Key points
- Non-specific — many non-infectious causes.
- Sepsis-3 favours qSOFA/SOFA for risk stratification.
- Still used for screening alongside clinical judgement.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.
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.
| Temperature > 38°C or < 36°C | No |
|---|---|
| Heart rate > 90/min | No |
| RR > 20/min or PaCO₂ < 32 mmHg | No |
| WBC > 12 or < 4 ×10⁹/L or > 10% bands | No |
→SIRS criteria0/4
- Interpretation：< 2 criteria.
| Temperature > 38°C or < 36°C | Yes |
|---|---|
| Heart rate > 90/min | Yes |
| RR > 20/min or PaCO₂ < 32 mmHg | Yes |
| WBC > 12 or < 4 ×10⁹/L or > 10% bands | Yes |
→SIRS criteria4/4
- Interpretation：≥ 2 criteria met = SIRS. With suspected infection, evaluate for sepsis.
Frequently asked questions
- What is SIRS Criteria Calculator?
- Check the SIRS criteria for systemic inflammatory response (≥ 2 of 4).
- How is SIRS Criteria Calculator calculated? What is the core formula?
- 1 point each: temp > 38 or < 36°C; HR > 90; RR > 20 or PaCO₂ < 32; WBC > 12 or < 4 ×10⁹/L or > 10% bands. ≥ 2 = SIRS.
- When is SIRS Criteria Calculator used?
- Screen for systemic inflammation; with infection, prompt sepsis evaluation.
- What are the key clinical points for SIRS Criteria Calculator?
- Non-specific — many non-infectious causes. Sepsis-3 favours qSOFA/SOFA for risk stratification. Still used for screening alongside clinical judgement.
- What are the limits and cautions when using SIRS Criteria Calculator?
- 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.
- How is SIRS Criteria Calculator calculated in practice? Can you show a worked example?
- Inputs: Temperature > 38°C or < 36°C No, Heart rate > 90/min No, RR > 20/min or PaCO₂ < 32 mmHg No, WBC > 12 or < 4 ×10⁹/L or > 10% bands No → Result: SIRS criteria 0 /4（Interpretation: < 2 criteria.） Inputs: Temperature > 38°C or < 36°C Yes, Heart rate > 90/min Yes, RR > 20/min or PaCO₂ < 32 mmHg Yes, WBC > 12 or < 4 ×10⁹/L or > 10% bands Yes → Result: SIRS criteria 4 /4（Interpretation: ≥ 2 criteria met = SIRS. With suspected infection, evaluate for sepsis.）