The Role of the Endothelium in Systemic Inflammatory Response Syndrome and Sepsis

The terms systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, septic shock and multiorgan failure (MOF) are currently used to characterize the progressive stages of a very complex and therapeutically challenging disorder of the immune and inflammatory systems. Although SIRS is a result of a systemic activation of the innate immune system regardless of cause, sepsis, severe sepsis, and septic shock are accompanied by proven or suspected infection with or without impaired organ function. Despite tremendous research efforts for over 20 years, sepsis remains the leading cause of death in intensive care units (ICUs). SIRS and sepsis occur in approximately 750,000 patients per year in the United States, with a rising incidence of approximately 1.5% per year (1). With a mortality rate of currently 30% to 70%, sepsis and related disorders represent a major burden to the U.S. health care system, with costs estimated to be approximately $16.7 billion per year (2).