Pathophysiology of the Sepsis Syndromes

Abstract

Sepsis results when invasion of the body by microorganisms (including bacteria, fungi, viruses, and parasites) causes alterations in the normal homeostatic balance maintained by the human host in health. Patients with sepsis or septic shock may present with a constellation of variable symptoms and signs including fever or low body temperature, tachypnea, tachycardia, low blood pressure, low urine output, mental status changes, and multiple laboratory abnormalities such as high white blood cell counts, hyperglycemia, and hypoxemia. The number and severity of these clinical manifestations represent a spectrum of clinical conditions, which may progress along a disease continuum from sepsis to more severe sepsis and septic shock. The frequency of these clinical conditions is rising as a result of changing population risk factors, and the mortality rate for severe sepsis and septic shock has remained high, ranging between 40% and 60%.