What are the diagnostic criteria for sepsis?
Sep 16, 2025
Source: Cainiu Health
Dr. Liu Feng
Introduction
Clear evidence of an infection source is present, such as a positive culture for pathogens like bacteria or fungi, or clinical manifestations of infectious diseases such as pneumonia or urinary tract infection. Infection serves as the foundation for sepsis. Signs of systemic inflammatory response are also present, including body temperature above 38.3°C or below 36°C, heart rate exceeding 90 beats per minute, and respiratory rate exceeding 20 breaths per minute.
Sepsis diagnosis requires a comprehensive assessment of infection manifestations and the body's response. It is generally determined by identifying the infection source, presence of systemic inflammatory response, organ dysfunction, hemodynamic abnormalities, and elevated biomarkers. The specific analysis is as follows:
1. Identify the infection source: Clear evidence of infection must be present, such as positive culture results for pathogens like bacteria or fungi, or clinical signs of infectious diseases such as pneumonia or urinary tract infection. Infection serves as the foundation for sepsis development.
2. Presence of systemic inflammatory response: Signs of inflammation including body temperature above 38.3°C or below 36°C, heart rate exceeding 90 beats per minute, or respiratory rate over 20 breaths per minute indicate excessive immune system activation.
3. Organ dysfunction: At least one indicator of organ impairment must be present, such as altered mental status, reduced urine output, decreased blood oxygen saturation, or abnormal coagulation function, indicating that the infection has disrupted normal organ function.
4. Hemodynamic monitoring abnormalities: Low blood pressure, with systolic pressure below 90 mmHg, or the need for vasopressor agents to maintain blood pressure, suggests circulatory system dysfunction due to infection.
5. Elevated biomarkers: Increased blood levels of inflammatory biomarkers such as procalcitonin and C-reactive protein can help assess the severity of infection and intensity of the inflammatory response.
Diagnosis of sepsis should be made by qualified physicians based on a comprehensive evaluation of all these criteria; it should not rely solely on a single finding. When symptoms suggestive of infection—such as high fever or confusion—occur, immediate medical evaluation is essential. Early treatment focusing on controlling the infection and correcting organ dysfunction is critical to prevent disease progression and serious complications.
