What are the diagnostic criteria and management approach for sepsis in adults?

Sepsis Diagnostic Criteria

Sepsis is diagnosed when a patient has documented or suspected infection plus life-threatening organ dysfunction, operationalized as an increase in Sequential Organ Failure Assessment (SOFA) score of ≥2 points, which corresponds to an in-hospital mortality >10%. 1

Core Diagnostic Framework

Primary Definition (Sepsis-3)

• Sepsis requires two components: documented or suspected infection PLUS organ dysfunction (≥2 point increase in SOFA score) 1
• The term "severe sepsis" is redundant and should not be used 1
• Sepsis represents a dysregulated host response to infection causing life-threatening organ dysfunction 1

Quick Bedside Screening (qSOFA)

For rapid identification in emergency departments, general wards, or out-of-hospital settings, use the qSOFA score (≥2 of the following indicates higher risk): 1

• Respiratory rate ≥22/min
• Altered mental status
• Systolic blood pressure ≤100 mmHg

A qSOFA score ≥2 predicts higher mortality and need for intensive care, allowing earlier intervention. 2

Comprehensive Diagnostic Variables

The Surviving Sepsis Campaign provides a broader framework when evaluating suspected infection—assess ALL of the following categories systematically: 3

General Variables

• Fever (>38.3°C) or hypothermia (<36°C) 3
• Tachycardia (>90/min) 3
• Tachypnea 3
• Significant edema or positive fluid balance 3
• Hyperglycemia without diabetes 3

Inflammatory Markers

• Leukocytosis, leukopenia, or bandemia 3
• Elevated C-reactive protein or procalcitonin 3

Hemodynamic Variables

• Arterial hypotension (SBP <90 mmHg, MAP <70 mmHg) 3

Organ Dysfunction Indicators

• Hypoxemia, oliguria, acute kidney injury 3
• Coagulation abnormalities, ileus 3
• Thrombocytopenia, hyperbilirubinemia 3

Tissue Perfusion Abnormalities

• Hyperlactatemia (>1 mmol/L) 3
• Decreased capillary refill or mottling 3

Septic Shock Criteria

Septic shock is defined as sepsis with persistent hypotension despite adequate fluid resuscitation (requiring vasopressors to maintain MAP ≥65 mmHg) PLUS serum lactate >2 mmol/L in the absence of hypovolemia—this combination carries >40% hospital mortality. 1, 4

Specific hemodynamic criteria: 4

• Systolic BP <90 mmHg, MAP <65 mmHg, or SBP decrease >40 mmHg
• Vasopressor requirement to maintain MAP ≥65 mmHg
• Elevated lactate >2 mmol/L

Clinical Application Pearls

Important Nuances

• A patient with pneumonia presenting with fever, tachycardia, tachypnea, and hypoxemia meets sepsis criteria without altered mental status. 3 This emphasizes that no single finding is required—assess all categories systematically.
• Altered mental status is particularly important in pediatric populations as a required indicator of altered organ function 3
• Systemic symptoms (altered mental status, dyspnea, gastrointestinal symptoms, muscle weakness) strongly predict severe sepsis and should be considered warning signs 5

Common Pitfalls to Avoid

• Do not rely on SIRS criteria alone—they have inadequate specificity and sensitivity 1
• Do not use biomarkers (procalcitonin, CRP, lactate) in isolation to exclude sepsis 6
• Do not wait for all criteria to be met before initiating treatment—sepsis should be considered in any patient with infection and abnormal vital signs, evidence of systemic inflammation, or end-organ dysfunction 6
• The traditional hypotension threshold of SBP <90 mmHg may delay recognition; qSOFA uses ≤100 mmHg for earlier identification 2

Immediate Actions Upon Diagnosis

• Measure lactate immediately and remeasure within 2-4 hours if elevated 4
• Obtain at least two sets of blood cultures before antimicrobials 4
• Initiate broad-spectrum IV antimicrobials within 1 hour of recognition 4
• Administer at least 30 mL/kg IV crystalloid bolus within first 3 hours for sepsis-induced hypoperfusion 4