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The definition of sepsis is two or more systemic inflammatory response criteria plus a known or suspected infection.
Severe sepsis is sepsis with acute organ dysfunction. Acute organ dysfunction can manifest in any organ, and frequently manifests clinically as shock, respiratory failure, acute kidney injury, hematologic or metabolic disturbances, or neurologic decline. Septic shock is a form of severe sepsis where the organ dysfunction involves the cardiovascular system.
Sepsis results in a complex set of interactions between the inciting microbes and the host immune response, which triggers the inflammatory cascade and coagulation pathway.
Management of sepsis patients involves early infection recognition, source control, fluid therapy, antibiotics, and hemodynamic supportive care. Early goal-directed therapy is the term for current early fluid resuscitation strategies that target central venous or mixed venous oxygen saturation.
The most common parameters used in monitoring septic patients are pulse oximetry, arterial blood pressure, central venous pressure, central venous or mixed venous oxygen saturation, and blood lactate. Other parameters that may guide therapy include cardiac output, systemic vascular resistance, and extravascular lung water. Each of these parameters is complementary and may assist in both the early and late management of sepsis, organ dysfunction, and shock.
Sepsis care bundles have become an integral part of the “Surviving Sepsis Campaign,” which aimed to improve survival from severe sepsis. These multifaceted interventions facilitate compliance with evidence-based guideline recommendations by creating two “bundles” that are sequentially completed at 6 and 24 hours.
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DEFINITIONS AND EPIDEMIOLOGY
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Sepsis has been a life-threatening medical condition since the first steps in evolution. Antimalarial compounds were prescribed for fever in China as early as 2735 bc and Hippocrates recognized the anti-infective properties of wine and vinegar around 400 bc. The basic premise of infection and immune response were recognized from the time that Marcus Terentius Varro in 100 bc noted that “small creatures invisible to the eye, fill the atmosphere, and breathed through the nose cause dangerous diseases.” These early concepts carried through the Black Death plague of the middle ages and Janssen’s invention of the microscope, to Louis Pasteur’s germ therapy, and on to Ignaz Semmelweis and Joseph Lister’s antisepsis practices. At the turn of the last century, William Osler recognized that “the patient appears to die from the body’s response to infection rather than from it.”
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Despite clear advances in understanding infection and the immune response, sepsis was not recognized as a specific medical entity deserving of recognition and focused study until the 1970s. In order to facilitate the study of sepsis, in 1992 the American College of Chest Physicians (ACCP) and the Society of Critical Care Medicine (SCCM) jointly developed a set of consensus definitions for sepsis and related disorders (Table 64-1).1 In so doing, the ACCP/SCCM consensus definitions immediately created a clinically applicable definition that may be used at the bedside and can be used equally to identify ...