Sepsis and Severe Infections: Pathophysiology, Biomarker Discovery, and Advances in Critical Care Management

Sepsis — a life-threatening organ dysfunction arising from a dysregulated host response to infection — remains a leading cause of mortality in hospitalised patients worldwide, despite decades of intensive research. This chapter reviews current understanding of sepsis pathophysiology, encompassing coagulation dysregulation, endothelial dysfunction, mitochondrial failure, and immunological paralysis, alongside the evolving Sepsis-3 diagnostic framework. It evaluates the utility of established and emerging biomarkers — including procalcitonin, lactate, presepsin, and novel proteomic and transcriptomic signatures — and critically appraises recent advances in resuscitation strategies, source control, antibiotic stewardship, adjunctive therapies, and personalised approaches to sepsis management in the intensive care unit.