Overview

Sepsis is a potentially life-threatening condition caused by the body's response to an infection. The body normally releases chemicals into the bloodstream to fight an infection. Sepsis occurs when the body's response to these chemicals is out of balance, triggering changes that can damage multiple organ systems.

If sepsis progresses to septic shock, blood pressure drops dramatically. This may lead to death.

Sepsis is caused by infection and can happen to anyone. Sepsis is most common and most dangerous in:

  • Older adults
  • Pregnant women
  • Children younger than 1
  • People who have chronic conditions, such as diabetes, kidney or lung disease, or cancer
  • People who have weakened immune systems

Early treatment of sepsis, usually with antibiotics and large amounts of intravenous fluids, improves chances for survival.

Symptoms

Signs and symptoms of sepsis

To be diagnosed with sepsis, you must have a probable or confirmed infection and all of the following signs:

  • Change in mental status
  • A first (upper) number in a blood pressure reading — also called the systolic pressure — that's less than or equal to 100 millimeters of mercury (mm Hg)
  • Respiratory rate higher than or equal to 22 breaths a minute

Signs and symptoms of septic shock

Sepsis can progress to septic shock when certain changes in the circulatory system, the body's cells and how the body uses energy become more abnormal. Septic shock is more likely to cause death than sepsis is. To be diagnosed with septic shock, you must have a probable or confirmed infection and both of the following:

  • The need for medication to maintain blood pressure greater than or equal to 65 millimeters of mercury (mm Hg).
  • High levels of lactic acid in your blood (serum lactate) after you have received adequate fluid replacement. Having too much lactic acid in your blood means that your cells aren't using oxygen properly.

When to see a doctor

Most often, sepsis occurs in people who are hospitalized or who have recently been hospitalized. People in the intensive care unit are especially vulnerable to developing infections, which can then lead to sepsis. If you develop signs and symptoms of sepsis after surgery or after being hospitalized, seek medical care immediately.

Causes

While any type of infection — bacterial, viral or fungal — can lead to sepsis, the most likely varieties include:

  • Pneumonia
  • Infection of the digestive system (which includes organs such as the stomach and colon)
  • Infection of the kidney, bladder and other parts of the urinary system
  • Bloodstream infection (bacteremia)

Risk factors

Sepsis and septic shock are more common if you:

  • Are very young or very old
  • Have a compromised immune system
  • Have diabetes or cirrhosis
  • Are already very sick, often in a hospital intensive care unit
  • Have wounds or injuries, such as burns
  • Have invasive devices, such as intravenous catheters or breathing tubes
  • Have previously received antibiotics or corticosteroids

Complications

Sepsis ranges from less to more severe. As sepsis worsens, blood flow to vital organs, such as your brain, heart and kidneys, becomes impaired. Sepsis can also cause blood clots to form in your organs and in your arms, legs, fingers and toes — leading to varying degrees of organ failure and tissue death (gangrene).

Most people recover from mild sepsis, but the average mortality rate for septic shock is about 40 percent. Also, an episode of severe sepsis may place you at higher risk of future infections.

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References
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