Sepsis Diagnosis and Criteria

Introduction to Sepsis Diagnosis

• The Surviving Sepsis Campaign guidelines recommend that sepsis diagnosis requires documented or suspected infection plus any combination of general variables, inflammatory markers, hemodynamic changes, organ dysfunction indicators, or tissue perfusion abnormalities 1, 2
• Sepsis can be diagnosed based on documented or suspected infection plus any combination of general variables, inflammatory markers, hemodynamic changes, organ dysfunction indicators, or tissue perfusion abnormalities 1, 2

General Variables for Sepsis Diagnosis

• Fever (>38.3°C) or hypothermia (<36°C) is a general variable used in sepsis diagnosis, as recommended by the Surviving Sepsis Campaign guidelines 2
• Tachycardia (>90/min) is a general variable used in sepsis diagnosis, according to the Surviving Sepsis Campaign guidelines 1
• Tachypnea is a general variable used in sepsis diagnosis, as recommended by the Surviving Sepsis Campaign guidelines 3
• Significant edema or positive fluid balance is a general variable used in sepsis diagnosis, according to the Surviving Sepsis Campaign guidelines 3
• Hyperglycemia without diabetes is a general variable used in sepsis diagnosis, as recommended by the Surviving Sepsis Campaign guidelines 3

Inflammatory Variables for Sepsis Diagnosis

• Leukocytosis, leukopenia, or bandemia is an inflammatory variable used in sepsis diagnosis, according to the Surviving Sepsis Campaign guidelines 3
• Elevated C-reactive protein or procalcitonin is an inflammatory variable used in sepsis diagnosis, as recommended by the Surviving Sepsis Campaign guidelines 3

Hemodynamic Variables for Sepsis Diagnosis

• Arterial hypotension (SBP <90 mmHg, MAP <70 mmHg) is a hemodynamic variable used in sepsis diagnosis, according to the Surviving Sepsis Campaign guidelines 3

Organ Dysfunction Variables for Sepsis Diagnosis

• Hypoxemia, oliguria, acute kidney injury is an organ dysfunction variable used in sepsis diagnosis, as recommended by the Surviving Sepsis Campaign guidelines 3
• Coagulation abnormalities, ileus is an organ dysfunction variable used in sepsis diagnosis, according to the Surviving Sepsis Campaign guidelines 3
• Thrombocytopenia, hyperbilirubinemia is an organ dysfunction variable used in sepsis diagnosis, as recommended by the Surviving Sepsis Campaign guidelines 3

Tissue Perfusion Variables for Sepsis Diagnosis

• Hyperlactatemia (>1 mmol/L) is a tissue perfusion variable used in sepsis diagnosis, according to the Surviving Sepsis Campaign guidelines 3
• Decreased capillary refill or mottling is a tissue perfusion variable used in sepsis diagnosis, as recommended by the Surviving Sepsis Campaign guidelines 3

Pediatric Populations and Sepsis Diagnosis

• In pediatric populations, altered mental status is listed as one of the required indicators of altered organ function, along with hypoxemia, increased lactate, or bounding pulses, according to the Surviving Sepsis Campaign guidelines 1, 3, 4

Practical Application of Sepsis Diagnosis

• The Surviving Sepsis Campaign guidelines recommend systematically assessing all categories of sepsis criteria when evaluating a patient with suspected infection, rather than focusing on any single finding 5, 6
• A patient with pneumonia presenting with fever, tachycardia, tachypnea, and hypoxemia meets sepsis criteria without any alteration in mental status, according to the Surviving Sepsis Campaign guidelines 1

Diagnostic Criteria for Sepsis and Septic Shock (Cited Evidence)

SOFA Score Components 7

• Respiratory dysfunction – A PaO₂/FiO₂ ratio below the normal range (e.g., < 400 mmHg) contributes 1 point, with progressively lower ratios (down to < 100 mmHg with mechanical ventilation) adding up to 4 points.
• Coagulation dysfunction – Platelet counts decreasing from mild thrombocytopenia (≈150 × 10⁹/L) to severe thrombocytopenia (≈20 × 10⁹/L) are scored 1–4 points respectively.
• Hepatic dysfunction – Serum bilirubin rising from mildly elevated levels (≈1–2 mg/dL) to markedly high levels (> 12 mg/dL) yields 1–4 points.
• Cardiovascular dysfunction – Mean arterial pressure (MAP) falling below normal (≈70 mmHg) scores 1 point; the need for high‑dose vasopressors scores 4 points.
• Neurologic dysfunction – Glasgow Coma Scale scores from 13–14 (1 point) to < 6 (4 points) reflect increasing severity.
• Renal dysfunction – Serum creatinine rising from modest elevation (≈1.2–1.9 mg/dL) to severe elevation (> 5 mg/dL) or oliguria (< 200 mL/day) scores 1–4 points.

These component thresholds are derived from the World Journal of Emergency Surgery (2017).

Alternative Diagnostic Variables (Surviving Sepsis Campaign) 8

These variables are recommended by the Surviving Sepsis Campaign as outlined in Critical Care Medicine (2013).

Pediatric Sepsis Diagnostic Considerations 8

• In children, sepsis is identified by the presence of infection plus temperature dysregulation (fever or hypothermia), tachycardia, and at least one sign of organ dysfunction such as altered mental status, hypoxemia, elevated lactate, or bounding peripheral pulses.

Guideline source: Critical Care Medicine (2013) as referenced by the Surviving Sepsis Campaign.

Practical Algorithmic Application 8

• After confirming suspected or documented infection, clinicians should apply the alternative variable set (above) when full SOFA scoring is impractical; the presence of any combination of these variables supports a sepsis diagnosis.

If a patient meets the sepsis definition, clinicians must then assess for septic shock by confirming persistent hypotension requiring vasopressors to maintain MAP ≥ 65 mmHg *and* lactate elevation (> 2 mmol/L) despite adequate fluid resuscitation.

These steps are endorsed by the Surviving Sepsis Campaign (Critical Care Medicine, 2013).