What is better to use than Systemic Inflammatory Response Syndrome (SIRS)?

From the Guidelines

The Sequential Organ Failure Assessment (SOFA) score or quick SOFA (qSOFA) are better to use than Systemic Inflammatory Response Syndrome (SIRS) criteria for identifying patients with suspected infection who are at risk for poor outcomes.

Key Points

• SOFA evaluates multiple organ systems (respiratory, cardiovascular, hepatic, coagulation, renal, and neurological) with specific measurements for each, providing a more comprehensive assessment of illness severity 1.
• The qSOFA is a simplified bedside tool requiring only three clinical criteria: altered mental status, systolic blood pressure ≤100 mmHg, and respiratory rate ≥22 breaths/minute.
• Two or more positive qSOFA criteria should prompt clinicians to consider sepsis, investigate for organ dysfunction, intensify monitoring, and initiate or escalate appropriate therapy.
• These tools are superior to SIRS because they better predict mortality and ICU admission in patients with suspected infection, as SIRS criteria (temperature, heart rate, respiratory rate, and white blood cell count) have been found to be overly sensitive but not specific enough, often identifying patients with non-infectious conditions and missing cases of serious infection, leading to both overtreatment and undertreatment 1.

Supporting Evidence

• A study published in Intensive Care Medicine in 2001 discussed the controversies surrounding the definition of sepsis and the importance of considering noninfective causes of SIRS, such as tissue injury, surgery/trauma, and pancreatitis 1.
• Another study published in Critical Care in 2023 compared clinical outcomes between aggressive and non-aggressive intravenous hydration for acute pancreatitis, highlighting the importance of using tools like SOFA to assess illness severity and predict outcomes 1.

Clinical Implications

• Clinicians should use SOFA or qSOFA to identify patients with suspected infection who are at risk for poor outcomes, rather than relying solely on SIRS criteria.
• This approach can help reduce overtreatment and undertreatment, and improve patient outcomes by prompting earlier intervention and more targeted therapy.

From the Research

Alternatives to Systemic Inflammatory Response Syndrome (SIRS)

• The Sequential Organ Failure Assessment (SOFA) score has been shown to have greater prognostic accuracy for in-hospital mortality than SIRS criteria in several studies 2, 3, 4.
• The quick SOFA (qSOFA) score has also been found to be a better predictor of mortality than SIRS criteria in some studies 5, 4.
• A study found that SOFA score had greater discriminatory capacity for in-hospital mortality than qSOFA and SIRS criteria 2.
• Another study found that qSOFA had greater accuracy than SIRS for predicting mortality and ICU-free days in patients with suspected infection outside the ICU 5.
• A comparison of SOFA, qSOFA, and SIRS scores found that SOFA and qSOFA were superior prognostication tools compared to SIRS to predict sepsis mortality, with SOFA being better than qSOFA 3.

Comparison of Scoring Systems

• A study compared the efficacies of qSOFA, SOFA, and SIRS scores to predict sepsis mortality and found that SOFA yielded the best result with an area under the curve (AUC) of 0.868 3.
• Another study found that the area under the receiver operating curve for qSOFA ≥2 and SOFA were comparable and significant, whereas SIRS ≥2 was not statistically significant 4.
• A study found that the AUROC of in-hospital mortality of patients with an increase in SOFA, qSOFA, and SIRS criteria of 2 or more points was 0.96,0.95, and 0.95, respectively 6.

Clinical Implications

• The use of SOFA and qSOFA scores may be preferred over SIRS criteria for predicting mortality in patients with sepsis 2, 5, 3, 4.
• Clinicians should consider using SOFA and qSOFA scores in conjunction with other clinical assessments to predict mortality and guide treatment decisions 2, 3.