What are the criteria for sepsis (Systemic Inflammatory Response Syndrome)?

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Last updated: May 29, 2025View editorial policy

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From the Guidelines

Sepsis criteria are defined as suspected or documented infection plus an acute increase in the Sequential Organ Failure Assessment (SOFA) score by 2 or more points, with the quick SOFA (qSOFA) criteria used for rapid bedside screening, including respiratory rate ≥22 breaths/minute, altered mental status, and systolic blood pressure ≤100 mmHg. The definition of sepsis has evolved over time, with the current Sepsis-3 criteria emphasizing the importance of organ dysfunction caused by a dysregulated host response to infection 1. The qSOFA criteria provide a simple and effective way to screen adult patients with suspected infection, with patients having at least two of the three clinical abnormalities being at risk of poor outcomes typical of sepsis 1. Septic shock is identified when sepsis is accompanied by persistent hypotension requiring vasopressors to maintain mean arterial pressure ≥65 mmHg and serum lactate >2 mmol/L despite adequate fluid resuscitation 1.

The Sepsis-3 criteria have been widely adopted and are considered the current standard for defining sepsis, with earlier criteria such as Systemic Inflammatory Response Syndrome (SIRS) parameters being less specific 1. The use of qSOFA criteria has been shown to be effective in identifying patients at risk of sepsis, particularly in low-resource settings where access to laboratory tests and other diagnostic tools may be limited 1.

Key points to consider when evaluating sepsis criteria include:

  • The presence of suspected or documented infection
  • The acute increase in SOFA score by 2 or more points
  • The use of qSOFA criteria for rapid bedside screening, including respiratory rate, altered mental status, and systolic blood pressure
  • The identification of septic shock when sepsis is accompanied by persistent hypotension requiring vasopressors and serum lactate >2 mmol/L despite adequate fluid resuscitation.

Overall, the prompt identification of sepsis using these criteria is crucial, as early intervention with antibiotics, fluid resuscitation, and source control can significantly improve survival rates in sepsis 1.

From the Research

Sepsis Criteria

The criteria for sepsis involve a life-threatening organ dysfunction caused by a dysregulated host response to infection 2. This can be identified using various scoring systems, such as the Sequential Organ Failure Assessment (SOFA) score and the Quick SOFA (qSOFA) score 3, 2.

Key Diagnostic Features

Some key diagnostic features of sepsis include:

  • Organ dysfunction as a key diagnostic feature 3
  • Measurement of serum lactate 2
  • Respiratory, gastrointestinal, genitourinary, and skin and soft tissue infections as common sources of sepsis 2
  • Pneumonia as the most common cause of sepsis 2

Scoring Systems

Scoring systems used to identify sepsis include:

  • Sequential Organ Failure Assessment (SOFA) score 3, 2
  • Quick SOFA (qSOFA) score 3, 2
  • These scoring systems help in the early diagnosis of sepsis and septic shock 3, 2

Diagnostic Markers

Diagnostic markers for sepsis include:

  • Clinical parameters such as fever, tachycardia, and hypotension 4
  • Laboratory parameters such as lactate levels and procalcitonin 2
  • Microbiological parameters such as blood, urine, and sputum cultures 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Sepsis: Diagnosis and Management.

American family physician, 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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