Adult Sepsis Primer

Definitions — Levy CCM 2003 / SSC 2026

SIRS: ≥ 2 of 4 criteria: Temp >38°C or <36°C; HR >90; RR >20 or PaCO₂ <32; WBC >12k, <4k, or >10% bands
Sepsis: SIRS + suspected or confirmed infection. SSC 2026: "Sepsis is a clinical diagnosis and should not be ruled in or ruled out using a single biomarker or diagnostic test."
Severe Sepsis: Sepsis + ≥1 organ dysfunction (per Levy 2003 criteria)
Septic Shock: Sepsis + persistent hypotension requiring vasopressors to maintain MAP ≥ 65 mmHg despite adequate fluid resuscitation; OR lactate > 4.0 mmol/L

SSC 2026: qSOFA is not recommended as a standalone screening tool. Use NEWS, NEWS2, MEWS, or SIRS for screening acutely ill patients. SIRS-based definitions remain standard for SSC bundles and this tool.

Step 1 — SIRS Criteria

Temperature > 38°C (100.4°F) OR < 36°C (96.8°F)

Core temperature; rectal, bladder, or esophageal preferred

Heart rate > 90 bpm

Respiratory rate > 20 breaths/min OR PaCO₂ < 32 mmHg

WBC > 12,000/µL OR < 4,000/µL OR > 10% band forms

SIRS CRITERIA MET

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Step 2 — Organ Dysfunction Assessment (Severe Sepsis)

Cardiovascular: SBP < 90 or MAP < 65 mmHg

Or SBP drop >40 mmHg from baseline

Pulmonary: PaO₂/FiO₂ < 300 OR new need for mechanical ventilation

Renal: Creatinine > 2.0 mg/dL or urine output < 0.5 mL/kg/hr × 2h

Hepatic: Bilirubin > 2 mg/dL or INR > 1.5 (not on anticoagulation)

Hematologic: Platelets < 100,000/µL

Neurologic: Altered mental status (new confusion, GCS change)

Metabolic: Lactate > 2 mmol/L

Dysfunctional organs: 0

Step 3 — Septic Shock Assessment

Persistent MAP (mmHg) after fluid resuscitation

Lactate (mmol/L)

Patient age (years) — for MAP target

SSC 2026 Fluid: Balanced crystalloids preferred over 0.9% saline (except TBI → use NS). At least 30 mL/kg in first 3 hrs. For BMI >30 use adjusted/ideal body weight. Recommend against starches and gelatin.

Evidence Base

Surviving Sepsis Campaign 2026 International Guidelines for Management of Sepsis and Septic Shock. Crit Care Med 2026. 129 statements, 46 new. Primary guideline for this tool.
Levy MM, et al. 2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference. Crit Care Med 2003. PMID 12682500
Evans L, et al. Surviving Sepsis Campaign 2021 guidelines. Crit Care Med 2021. PMID 34605781
Rhodes A, et al. Surviving Sepsis Campaign 2016 guidelines. Crit Care Med 2017. PMID 28005360
Singer M, et al. The Third International Consensus Definitions for Sepsis (Sepsis-3). JAMA 2016. PMID 26903338

YBEMUS · Guy Youngblood, MD, FACEP, FAAEM
CCEMRP · BCM/CHRISTUS Children's PEM Fellowship
For educational use. Not a substitute for clinical judgment.

🧫 Adult Sepsis Primer