SIRS Criteria Calculator
Screen for Systemic Inflammatory Response Syndrome using temperature, HR, RR, and WBC criteria.
Understanding this tool
Why nurses use it
SIRS criteria (temperature, heart rate, respiratory rate, WBC) historically framed systemic inflammation and sepsis recognition. Many sepsis pathways still reference SIRS alongside clinical assessment.
When to use it
Use within sepsis screening context — ≥2 criteria suggest SIRS but do not diagnose sepsis without infection and clinical judgment.
Calculate
How to use this calculator
- Tick abnormal parameters from latest observations and labs.
- Count criteria met.
- Follow sepsis pathway if clinically suspected infection.
How the calculation works
SIRS is met when ≥2 of: temp <36 or >38°C, HR >90, RR >20 or PaCO₂ <32, WBC abnormal. Non-specific — interpret with source of infection.
Formula used by this tool — verify units before applying at the bedside.
Worked example
Limitations & clinical notes
- SIRS is non-specific and has been superseded by sepsis definitions in many pathways.
- Always follow local sepsis screening (NEWS2/MEWS).
References
Key sources: Surviving Sepsis Campaign 2026.
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Disclaimer: This calculator is for educational and bedside double-check purposes only. It does not replace institutional protocols, prescriber orders, pharmacist verification, or clinical judgment. Always follow your local policies — especially for high-risk medications, infusions, pediatrics, and critical care. If the patient is acutely unwell, escalate immediately rather than relying on any calculator output.