Septic shock

Definition

Septic shock is a serious condition that occurs when an overwhelming infection leads to life-threatening low blood pressure.

See also:

• Acute respiratory distress syndrome
• Disseminated intravascular coagulation
• Meningococcemia
• Waterhouse-Friderichsen syndrome

Alternative Names

Bacteremic shock; Endotoxic shock; Septicemic shock; Warm shock

Causes, incidence, and risk factors

Septic shock occurs most often in the very old and the very young. It also occurs in people who have other illnesses.

Any type of bacteria can cause septic shock. Fungi and (rarely) viruses may also cause the condition. Toxins released by the bacteria or fungi may cause tissue damage, and may lead to low blood pressure and poor organ function. Some researchers think that blood clots in small arteries cause the lack of blood flow and poor organ function.

The body also produces a strong inflammatory response to the toxins. This inflammation may contribute to organ damage.

Risk factors for septic shock include:

• Diabetes
• Diseases of the genitourinary system, biliary system, or intestinal system
• Diseases that weaken the immune system such as AIDS
• Indwelling catheters (those that remain in place for extended periods, especially intravenous lines and urinary catheters)
• Leukemia
• Long-term use of antibiotics
• Lymphoma
• Recent infection
• Recent surgery or medical procedure
• Recent use of steroid medicines

Symptoms

Septic shock can affect any part of the body, including the heart, brain, kidneys, liver, and intestines. Symptoms may include:

• Cool, pale extremities
• High or very low temperature, chills
• Lightheadedness
• Low blood pressure, especially when standing
• Low urine output
• Palpitations
• Rapid heart rate
• Restlessness, agitation, lethargy, or confusion
• Shortness of breath

Signs and tests

Blood tests may be done to check for infection, low blood oxygen level, disturbances in the body's acid-base balance, or poor organ function or organ failure.

A chest x-ray may show pneumonia or pulmonary edema.

Treatment

Septic shock is a medical emergency. Patients are usually admitted to the intensive care unit of the hospital.

Treatment may include:

• Breathing machine (mechanical ventilation)
• Drugs to treat low blood pressure, infection, or blood clotting
• Fluids given directly into a vein (intravenously)
• Oxygen
• Surgery

There are new drugs that act against the extreme inflammatory response seen in septic shock. These may help limit organ damage.

Hemodynamic monitoring -- the evaluation of the pressures in the heart and lungs -- may be required. This can only be done with special equipment and intensive care nursing.

Expectations (prognosis)

Septic shock has a high death rate. The death rate depends on the cause of the infection, how many organs have failed, and how quickly and aggressively medical therapy is started.

Complications

Respiratory failure, cardiac failure, or any other organ failure can occur.

Calling your health care provider

Go directly to an emergency department if you develop symptoms of septic shock.

Prevention

Prompt treatment of bacterial infections is helpful. However, many cases of septic shock cannot be prevented.

References

Vincent J, Septic Shock. In: Fink MP, Abraham E, Vincent J, Kochanek PM, eds. Textbook of Critical Care. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2005: chap 147.

Jones AE, Kline JA. Shock. In: Marx, JA, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 6th ed. Philadelphia, Pa: Mosby Elsevier; 2006: chap 4.