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.
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.
While any type of infection — bacterial, viral or fungal — can lead to sepsis, the most likely varieties include:
- 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)
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
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.
Doctors often order several tests to try to pinpoint underlying infection.
A blood sample drawn from two distinct sites is tested for:
- Evidence of infection
- Clotting problems
- Abnormal liver or kidney function
- Impaired oxygen availability
- Electrolyte imbalances
Other laboratory tests
Depending on your symptoms, your doctor may also want to run tests on one or more of the following bodily fluids:
- Urine. If your doctor suspects that you have a urinary tract infection, he or she may want to check your urine for signs of bacteria.
- Wound secretions. If you have a wound that appears infected, testing a sample of the wound's secretions can help show what type of antibiotic might work best.
- Respiratory secretions. If you are coughing up mucus (sputum), it may be tested to determine what type of germ is causing the infection.
If the site of infection is not obvious, your doctor may order one or more of the following imaging tests:
- X-ray. X-rays are good for visualizing problems in your lungs.
- Computerized tomography (CT). Infections in your appendix or pancreas are easier to see on CT scans. This technology takes X-rays from a variety of angles and combines them to depict cross-sectional slices of your body's internal structures.
- Ultrasound. This technology uses sound waves to produce real-time images on a video monitor. Ultrasound may be particularly useful to check for infections in your gallbladder or ovaries.
- Magnetic resonance imaging (MRI). MRIs may be helpful in identifying soft tissue infections. This technology uses radio waves and a strong magnet to produce cross-sectional images of the internal structures of your body.
Early, aggressive treatment boosts your chances of surviving sepsis. People who have sepsis require close monitoring and treatment in a hospital intensive care unit. If you have sepsis or septic shock, lifesaving measures may be needed to stabilize breathing and heart function.
A number of medications are used in treating sepsis and septic shock. They include:
Antibiotics. Treatment with antibiotics should begin immediately. Initially you'll receive broad-spectrum antibiotics, which are effective against a variety of bacteria. The antibiotics are administered intravenously (IV).
After learning the results of blood tests, your doctor may switch to a different antibiotic that's targeted to fight the particular bacteria causing the infection.
- Intravenous fluids. People who have sepsis often receive intravenous fluids right away, usually within three hours.
- Vasopressors. If your blood pressure remains too low even after receiving intravenous fluids, you may be given a vasopressor medication, which constricts blood vessels and helps to increase blood pressure.
Other medications you may receive include low doses of corticosteroids, insulin to help maintain stable blood sugar levels, drugs that modify the immune system responses, and painkillers or sedatives.
People who have sepsis often receive supportive care that includes oxygen. Depending on your condition, you may need to have a machine help you breathe. If your kidneys have been affected, you may need to have dialysis.
Surgery may be needed to remove sources of infection, such as collections of pus (abscesses), infected tissues or gangrene.