Sepsis.

Sepsis is defined as a dysregulated host response to infection that leads to life-threatening organ dysfunction. The infectious insult triggers a dysregulated immune response that variably activates and suppresses multiple body system functions. Susceptibility to either developing or succumbing to sepsis is influenced by pathogen load and virulence; site of infection; host factors, including genetics, biological variability, comorbidities, immunosuppression, and extremes of age; and a wide range of external influences, such as social deprivation and local environment. Increasing appreciation of the underlying pathobiology has identified differing biological signatures with variable temporal evolution. This variability highlights the requirement to individualise treatment with targeted interventions guided by rapidly accessible biomarkers. Although improved outcomes have been obtained with better prevention, early recognition, and treatment, sepsis is a major cause of global mortality and morbidity. All populations having the benefits currently enjoyed by a privileged few is imperative. This Seminar aims to unravel the complexity of the condition, describing epidemiology and pathophysiology, evolving fundamental shifts, patient management, current challenges, and future developments.