Sepsis is a continuum of physiologic stages characterized by infection, systemic inflammation, and hypoperfusion leading to tissue injury and organ failure (see Table 26-1 for definitions to utilize for sepsis syndromes). Risk factors for sepsis include extremes of age, cancer, immunodeficiency, chronic organ failure, genetic factors (male and non-white ethnic origin in North America), bacteremia, and genetic polymorphisms associated with immune regulation. Pulmonary, gastrointestinal, genitourinary, and bloodstream infections account for the majority of cases.
TABLE 26-1Definitions Related to Sepsis |Favorite Table|Download (.pdf) TABLE 26-1Definitions Related to Sepsis
|Condition ||Definition |
|Bacteremia (fungemia) ||Presence of viable bacteria (fungi) within the bloodstream |
|Infection ||Inflammatory response to invasion of normally sterile host tissue by the microorganisms |
|Systemic inflammatory response syndrome (SIRS) ||Systemic inflammatory response to a variety of clinical insults that can be either infectious or noninfectious |
|Sepsis ||SIRS secondary to an infection |
|Severe sepsis ||Sepsis associated with organ dysfunction, hypoperfusion, or hypotension |
|Septic shock ||Sepsis with persistent hypotension despite fluid resuscitation |
|Multiple-organ dysfunction syndrome (MODS) ||Presence of altered organ function requiring intervention to maintain homeostasis |
The development of sepsis is complex and multifactorial. The key factor in the development of sepsis is inflammation. Infection or injury is controlled through pro- and anti-inflammatory mediators. Systemic responses ensue when there is an overwhelming pro-inflammatory response.
The clinical presentation of sepsis varies and the development of clinical manifestations may differ from patient to patient (see Tables 26-1 and 26-2). The cumulative burden of sepsis complications is the leading factor in mortality. The most common complications are disseminated intravascular coagulation (DIC), acute respiratory distress syndrome (ARDS), acute kidney injury (AKI), and hemodynamic compromise.
TABLE 26-2Systemic Inflammatory Response Criteria |Favorite Table|Download (.pdf) TABLE 26-2Systemic Inflammatory Response Criteria
|Temperature ||>38°C (100.4°F) or <36°C (96.8°F) |
|Heart rate ||>90 beats/min |
|Respiratory rate ||>20 breaths/min or PaCO2< 32 mm Hg |
|White blood cells ||>12,000 cells/mm3 or <4000 cells/mm3 or >10% bands |
Gram-positive and gram-negative bacteria are major causes of sepsis, but fungal species and viruses can also cause sepsis. Microbiologic cultures should be obtained before anti-infective therapy is initiated; however, antibiotic therapy should not be delayed until the return of gram stain or culture data. Cultures take 6 to 48 hours for results to be returned and often reveal no growth of bacterial organisms but negative cultures do not rule out infection. Rapid identification of bacteria or fungi from blood cultures can be performed on positive blood cultures with results available within 2 hours of initial growth.
The goal of sepsis treatment is to decrease morbidity and mortality. Treatment is aimed at early goal-directed resuscitation; reduction or elimination of organ failure; treatment and elimination of the source of infection; avoidance of adverse reactions; and provision of cost-effective therapy. The speed and appropriateness of ...