SIRS Criteria and Sepsis Definition
Identifies systemic inflammatory response syndrome (SIRS) and sepsis. Two or more SIRS criteria with suspected infection = sepsis (Sepsis-2 definition).
Score interpretation
Fewer than 2 of the 4 SIRS criteria.
→ If infection is suspected, still assess for organ dysfunction (NEWS2, lactate, SOFA) — Sepsis-3 does not require SIRS.
SIRS without a suspected infection source; consider non-infective causes (pancreatitis, trauma, burns).
→ Look for the cause and reassess for infection.
2 or more SIRS criteria with suspected or confirmed infection. Sepsis-3 (Singer 2016) now defines sepsis as infection with organ dysfunction (acute SOFA rise of 2 or more).
→ Sepsis pathway: cultures, lactate, prompt antibiotics, fluids; assess organ dysfunction and septic shock.
Interpretation bands for the SIRS / Sepsis. Apply clinical judgement and local guidance.
References
Related
Curated clinical cross-links plus same-class fallbacks.
- Dapsone · Anti-inflammatory / Antimicrobial
- Doxycycline (Systemic — Ocular Rosacea / Blepharitis) · Tetracycline Antibiotic — Anti-inflammatory (Ocular Rosacea / MGD)
- Lidocaine (IV Infusion — Opioid-Sparing Analgesia) · Local Anaesthetic (IV Systemic — Opioid-Sparing / Anti-inflammatory)
- Methylprednisolone (Surgical — Anti-Inflammatory) · Corticosteroid (Systemic — IV)
- Dexamethasone (ICU / ARDS) · Systemic Corticosteroid
- Acitretin · Systemic retinoid (Vitamin A derivative)
Featured in these MRCEM clinical pathways
The SIRS / Sepsis is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.
MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.