The burden of sepsis on health care is significant. Worldwide, 13 million people become septic each year and 4 million die. In the United States alone, this accounts for approximately 750 000 cases per year, 215 000 resultant deaths, and annual costs of 16.7 billion dollars.
Not only is the incidence of severe sepsis higher than that of the major cancers (Figure 1.1) but it has also estimated that in the United Kingdom just under 37 000 deaths are caused annually by the condition – a figure higher than that for lung cancer, or for breast and bowel cancer combined (Figure 1.2). Mortality rates for severe sepsis are 30 to 50%; for septic shock, even higher than 50%.
Furthermore, the incidence of sepsis is increasing and will continue to do so as the population ages.
Clinicians are challenged to manage this disease in an aging population with multiple co-morbidities, relative immunosuppression and a changing pattern of causative microorganisms.
The primary change introduced was a more comprehensive list of signs and symptoms that may accompany the disease.
This list is described in Chapter 2. In addition, a staging system was proposed for the purpose of incorporating both host factors and response to a particular infectious insult.
This concept, termed PIRO (Predisposition, Infection, Response, Organ dysfunction) addresses the need to define, diagnose and treat patients with sepsis more precisely, as a variety of evidence-based interventions now exist to improve outcomes in severe sepsis and septic shock.
The PIRO model remains hypothetical and is currently being evaluated in several studies.
