Septic shock is a serious medical condition causing such effects as multiple organ failure and death in response to infection and sepsis. Its most common victims are children and the elderly, as their immune systems cannot cope with the infection as well as those of full-grown adults, as well as immunocompromised individuals. Septic shock kills about 50% of its victims.

Types

A subclass of distributive shock , shock refers specifically to decreased tissue perfusion resulting in end-organ dysfunction. Cytokines TNFα, IL-1β, IL-6 released in a large scale inflammatory response results in massive vasodilation, increased capillary permeability, decreased systemic vascular resistance, and hypotension. The decreased intravascular volume (plasma volume) results in the above tissue hypoxia. Finally, in an attempt to offset decreased blood pressure, ventricular dilatation and myocardial dysfunction will occur.

The various shock conditions include: septic shock, systemic inflammatory response syndrome, toxic shock syndrome, adrenal insufficiency, and anaphylaxis.

Causes

The process of infection by bacteria or fungi can result in systemic signs and symptoms that are variously described. In rough order of serverity, these are bacteremia or fungemia ; septicemia; systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis or sepsis syndrome; septic shock; refractory septic shock; multiple-organ dysfunction syndrome, and death.

The condition develops as a response to certain microbial molecules which trigger the production and release of cellular mediators, such as tumor necrosis factor (TNF); these act to stimulate immune response. Besides TNFα, other cytokines involved in the development of septic shock include interleukin-1β, and interferon γ.

Treatment primarily consists of antimicrobial chemotherapy, removal of the source of infection, and hemodynamic, respiratory, and metabolic support. Antimediator agents may be of some limited use in certain clinical situations.

See also

• anaphylactic shock
• neurogenic shock
• cardiogenic shock