Sepsis is a life‑threatening condition in which an infection triggers a dysregulated systemic response that leads to organ dysfunction. It represents the body’s failure to control the local effects of a pathogen, causing widespread inflammation and tissue damage.
Explanation
Historically sepsis was defined as systemic inflammatory response syndrome (SIRS) in the presence of suspected or documented infection, but contemporary definitions emphasize organ dysfunction resulting from an abnormal host response. Microorganisms or their toxins stimulate immune cells to release cytokines and other mediators, leading to vasodilation, increased vascular permeability and coagulopathy. These changes impair tissue perfusion and can rapidly progress to septic shock, characterized by persistent hypotension requiring vasopressor support. Common sources of sepsis include pneumonia, urinary tract infections, intra‑abdominal infections and skin or soft‑tissue infections. Early clinical features may include fever or hypothermia, rapid heart rate, rapid breathing, confusion and decreased urine output; laboratory findings often show elevated lactate levels and abnormal white blood cell counts. Prompt recognition and management are critical: early broad‑spectrum antibiotics, aggressive fluid resuscitation and source control improve outcomes. Sepsis disproportionately affects the elderly, neonates and immunocompromised patients and remains a major cause of mortality worldwide.
Clinical Notes and Management
- Diagnostic criteria: suspicion of infection plus evidence of organ dysfunction such as hypotension, altered mental status or elevated serum lactate.
- Pathophysiology: host immune response becomes dysregulated, causing endothelial injury, coagulation activation and impaired oxygen delivery.
- Management bundle: rapid administration of antibiotics, intravenous fluids, blood cultures before antibiotics and identification of the infection source for control.
- Prognosis: early recognition improves survival; delayed treatment can lead to septic shock, multi‑organ failure and death.
Sepsis highlights the fine balance between host defence and pathology; understanding its pathogenesis and implementing early intervention are key to reducing morbidity and mortality.
Related Terms: Septicemia, Septic Shock, Systemic Inflammatory Response Syndrome, Bacteremia, Infection