Sepsis is defined by life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock is a subset of sepsis marked by profound circulatory, cellular, and metabolic abnormalities and associated with a greater risk of mortality than with sepsis alone. Sepsis can occur as a result of bacterial, fungal, viral, or parasitic infections. This condition is life-threatening, and early recognition and management with fluid resuscitation, appropriate antibiotic therapy, and source control is imperative for the best outcome. Patients at the extremes of age or who are immunocompromised are most at risk.

From a microbiologic standpoint, infections due to bacteria (possibly that the patient is already colonized with) are common causes of septic shock. But many other organisms including fungi, parasites, and higher-order bacteria can also cause septic shock. Signs and symptoms may be specific to the etiology (pneumonia, intra-abdominal sources, urinary sources, etc). Generally, patients may present with fever or hypothermia, tachycardia, tachypnea, and leukocytosis. Delirium and oliguria may be seen. Laboratory evaluation commonly reveals signs of organ hypoperfusion including elevated lactate, elevated creatinine, and abnormal liver function tests.

Rapid administration of appropriate anti-microbial therapy is the most important factor for patient survival. Supportive therapy with fluid resuscitation and pressor support is necessary. Elimination of a local site of infection (by draining an abscess or removing an infected intravenous catheter) is also frequently required for patient recovery.