What is used for measuring Sepsis (Systemic Inflammatory Response Syndrome)?

From the Guidelines

Sepsis is most accurately measured using the Sequential Organ Failure Assessment (SOFA) score, which evaluates six organ systems, and the quick SOFA (qSOFA) score for rapid bedside assessment, as recommended by the most recent guidelines 1. The SOFA score assesses the degree of organ dysfunction in six systems: respiratory, cardiovascular, hepatic, coagulation, renal, and neurological, with a score of ≥2 indicating organ dysfunction 1. For rapid assessment, the qSOFA score looks at three criteria: altered mental status, respiratory rate ≥22 breaths/minute, and systolic blood pressure ≤100 mmHg, with the presence of two or more of these criteria indicating poor outcomes 1. Key laboratory markers used to diagnose and monitor sepsis include:

• Lactate levels (>2 mmol/L indicates tissue hypoperfusion)
• Procalcitonin (elevated in bacterial infections)
• C-reactive protein (CRP)
• Complete blood count showing leukocytosis or leukopenia Blood cultures are essential to identify the causative pathogen, and the Systemic Inflammatory Response Syndrome (SIRS) criteria can also be used, although they are less specific 1. These measurements help clinicians diagnose sepsis early, assess its severity, and monitor response to treatment, which is crucial as sepsis is a life-threatening condition requiring immediate intervention, as emphasized in the most recent guidelines 1.

From the Research

Measures for Sepsis

The following are measures used for predicting the prognosis of septic patients:

• Sequential Organ Failure Assessment (SOFA) score 2, 3, 4, 5
• Quick SOFA (qSOFA) score 2, 4, 6, 5
• Logistic Organ Dysfunction System (LODS) score 2
• Adult Sepsis Event's eSOFA organ dysfunction criteria 4
• Plasma lactate concentration 6

Comparison of Measures

Studies have compared the predictive ability of these measures:

• SOFA score and qSOFA score: SOFA score has higher accuracy than qSOFA score, but qSOFA is simpler to use 2, 5
• qSOFA score and LODS score: LODS score has higher accuracy than qSOFA score 2
• eSOFA and SOFA score: eSOFA identifies a smaller, more severely ill sepsis cohort compared with the SOFA score, but with good overlap and similar clinical characteristics 4
• Combining qSOFA with plasma lactate concentration: comparable to the standard SOFA score in predicting mortality 6

Predictive Ability

The predictive ability of these measures has been evaluated using area under the receiver operating characteristic (AUROC) curve:

• SOFA score: AUROC ranges from 0.75 to 0.84 3, 5
• qSOFA score: AUROC ranges from 0.55 to 0.68 2, 6
• LODS score: AUROC of 0.67 2
• eSOFA: AUROC of 0.774 4
• Simple SOFA score: AUROC ranges from 0.78 to 0.82 5