Sepsis is a potentially life-threatening complication of an infection. Sepsis occurs when chemicals released into the bloodstream to fight the infection trigger inflammatory responses throughout the body. This inflammation can trigger a cascade of changes that can damage multiple organ systems, causing them to fail.
If sepsis progresses to septic shock, blood pressure drops dramatically, which may lead to death.
Anyone can develop sepsis, but it's most common and most dangerous in older adults or those with weakened immune systems. Early treatment of sepsis, usually with antibiotics and large amounts of intravenous fluids, improves chances for survival.
Symptoms & causes
Many doctors view sepsis as a three-stage syndrome, starting with sepsis and progressing through severe sepsis to septic shock. The goal is to treat sepsis during its early stage, before it becomes more dangerous.
To be diagnosed with sepsis, you must exhibit at least two of the following symptoms, plus a probable or confirmed infection:
Body temperature above 101 F (38.3 C) or below 96.8 F (36 C)
Heart rate higher than 90 beats a minute
Respiratory rate higher than 20 breaths a minute
Your diagnosis will be upgraded to severe sepsis if you also exhibit at least one of the following signs and symptoms, which indicate an organ may be failing:
Significantly decreased urine output
Abrupt change in mental status
Decrease in platelet count
Abnormal heart pumping function
To be diagnosed with septic shock, you must have the signs and symptoms of severe sepsis — plus extremely low blood pressure that doesn't adequately respond to simple fluid replacement.
When to see a doctor
Most often sepsis occurs in people who are hospitalized. People in the intensive care unit are especially vulnerable to developing infections, which can then lead to sepsis. If you get an infection or if you develop signs and symptoms of sepsis after surgery, hospitalization or an infection, seek medical care immediately.
While any type of infection — bacterial, viral or fungal — can lead to sepsis, the most likely varieties include:
Bloodstream infection (bacteremia)
The incidence of sepsis appears to be increasing in the United States. The causes of this increase may include:
Aging population. Americans are living longer, which is swelling the ranks of the highest risk age group — people older than 65.
Drug-resistant bacteria. Many types of bacteria can resist the effects of antibiotics that once killed them. These antibiotic-resistant bacteria are often the root cause of the infections that trigger sepsis.
Weakened immune systems. More Americans are living with weakened immune systems, caused by HIV, cancer treatments or transplant drugs.
Sepsis is more common and more dangerous if you:
Are very young or very old
Have a compromised immune system
Are already very sick, often in a hospital's intensive care unit
Have wounds or injuries, such as burns
Have invasive devices, such as intravenous catheters or breathing tubes
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 mortality rate for septic shock is nearly 50 percent. Also, an episode of severe sepsis may place you at higher risk of future infections.