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

From the Guidelines

Sepsis should be diagnosed through a combination of clinical assessment, laboratory tests, and imaging studies, with the primary criteria including suspected or confirmed infection along with signs of organ dysfunction, as defined by the Sequential Organ Failure Assessment (SOFA) score or the quick SOFA (qSOFA) criteria, as recommended by the most recent guidelines 1. The diagnosis of sepsis is a critical process that requires prompt identification and treatment to prevent morbidity, mortality, and poor quality of life.

Key Diagnostic Criteria

• Suspected or confirmed infection
• Signs of organ dysfunction, as defined by the SOFA score or qSOFA criteria
• At least two of the following qSOFA criteria: respiratory rate ≥22 breaths/minute, altered mental status, or systolic blood pressure ≤100 mmHg

Laboratory Tests and Imaging Studies

• Complete blood count
• Comprehensive metabolic panel
• Lactate levels (>2 mmol/L suggests tissue hypoperfusion)
• Blood cultures (ideally before antibiotic administration)
• Other relevant cultures based on suspected infection sites
• Procalcitonin and C-reactive protein may provide additional information but aren't definitive alone
• Imaging studies should be directed at identifying the infection source

Treatment

• Prompt initiation of treatment is crucial, including broad-spectrum antibiotics within one hour
• Fluid resuscitation with 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L
• Vasopressors if fluids don't restore adequate blood pressure The Sepsis-3 definitions suggest that patients with at least two of the three clinical variables may be prone to poor outcome typical of sepsis: low blood pressure (systolic blood pressure ≤ 100 mmHg), high respiratory rate (≥ 22 breaths per minute), or altered mentation (Glasgow coma scale < 15) 1.

Importance of Early Diagnosis

Early diagnosis is critical because sepsis represents a dysregulated host response to infection that can rapidly progress to multi-organ failure and death, with mortality increasing significantly for each hour treatment is delayed 1. Some concerns about the new definition of sepsis have been reported, but the use of qSOFA score as a warning for patients with suspected infection who are likely to have poor outcome is recommended 1. The use of a feasible, low-cost method of rapidly identifying patients requiring critical care is crucial, especially in low-resource settings 1. In summary, the diagnosis of sepsis requires a combination of clinical assessment, laboratory tests, and imaging studies, with prompt initiation of treatment being crucial to prevent morbidity, mortality, and poor quality of life, as recommended by the most recent guidelines 1.

From the Research

Diagnosis of Sepsis

• The diagnosis of sepsis is challenging and requires a combination of clinical evaluation, laboratory tests, and imaging studies 2, 3, 4.
• Vital signs, such as blood pressure, respiratory rate, body temperature, and heart rate, are important in the early diagnosis and severity of sepsis 5.
• The Sequential Organ Failure Assessment (SOFA) score is a useful tool for early diagnosis and assessment of sepsis 5, 6, 4.
• Laboratory tests, such as complete blood count (CBC), serum lactate, and procalcitonin, can aid in the diagnosis and management of sepsis 2, 4.
• Imaging studies, such as chest X-rays and CT scans, may be indicated to identify the source of infection 4.

Clinical Evaluation

• Patients with sepsis may present with subtle symptoms, particularly older patients and those who are immunocompromised 4.
• The clinical manifestation of sepsis can include fever, hypotension, tachycardia, and tachypnea 3, 4.
• A thorough physical examination and medical history are essential in the diagnosis of sepsis 3.

Biomarkers and Scoring Systems

• The SOFA score is a widely used scoring system to assess organ dysfunction in sepsis 5, 6, 4.
• Serum lactate and procalcitonin are useful biomarkers in the diagnosis and management of sepsis 4.
• The complete blood count (CBC) can provide valuable information on the patient's health status and guide clinicians in the early identification of patients at high risk of developing sepsis 2.