INTRODUCTION
Sepsis is a clinical syndrome that has physiologic, biologic, and biochemical abnormalities caused by a dysregulated host response to infection. Sepsis and the inflammatory response that ensues can lead to multiple organ dysfunction syndrome and death.The epidemiology, definitions, risk factors, clinical presentation, diagnosis, and outcomes of sepsis are reviewed here. The pathophysiology and treatment of sepsis are discussed separately. (See "Pathophysiology of sepsis" and "Evaluation and management of suspected sepsis and septic shock in adults".)
EPIDEMIOLOGY
Incidence — In the late 1970s, it was estimated that 164,000 cases of sepsis occurred in the United States (US) each year [1]. Since then, rates of sepsis in the US and elsewhere have on balance increased although many of these are derived from academic institutions or on claims-based analyses [2-9]:
●One national database analysis of discharge records from hospitals in the US estimated an annual rate of more than 1,665,000 cases of sepsis between 1979 and 2000 [2].
●Another retrospective population-based analysis reported increased rates of sepsis and septic shock from 13 to 78 cases per 100,000 between 1998 and 2009 [3].