Gram-Negative Sepsis (1)Historicallv. sepsis has often been defined as the presence of pathogenic microorganisms or their toxins in the bloodstream, and the term has been used more or less interchangeably with bacteremia. More recently, we have developed the term sepsis syndrome, which we define as the systemic response to infection—expressed as tachycardia, fever or hypothermia, tachypnea, and evidence of inadequate organ perfusion or organ dysfunction. When sepsis syndrome is accompanied by hypotension, it is referred to as septic shock. If the hypotension does not respond to fluid therapy, it is referred to as refractory septic shock. Our intent in developing the description of sepsis syndrome was to focus on the clinical manifestations of sepsis and to deemphasize the importance of such parameters as blood culture findings, which are not immediately available. Our hope in so doing was to foster detection and treatment of the systemic response to sepsis prior to documentation of bacteremia or septic shock and, thereby, to improve outcome.
Incidence and Epidemiology
The true incidence of sepsis is difficult to determine precisely because it is not a reportable disease and is often omitted as a cause of death in patients with severe underlying disease. However, it has been estimated that between 100,000 and 300,000 cases of sepsis occur each year in the United States with an associated mortality of 20 to 50 percent. As a result, septicemia is the 13th leading cause of death in the United States.