Sepsis

Sepsis Definition Sepsis is the body's response to infection — an inflammatory process marked by an elevated heart rate, rapid breathing and abnormal temperature. Even a minor infection, such as strep throat or influenza, can trigger sepsis. It's usually not life-threatening. But complications of sepsis can cause serious illness and death. Severe sepsis occurs when your natural immune response to an infection goes into overdrive, triggering widespread inflammation and blood clotting in tiny vessels throughout your body. One or more organs may stop working properly or fail. Sepsis can lead to a dangerous drop in blood pressure (septic shock). About 750,000 people in the United States get severe sepsis each year, and more than 200,000 people die of it. Those at increased risk include older adults, hospital and surgery patients, and people with impaired immune systems. Neonatal sepsis affects a small percentage of newborns, particularly low-birth-weight and premature infants. Most commonly, bacterial infections lead to sepsis, but it may result from any type of infection — bacterial, viral, parasitic or fungal. Although sepsis often can't be prevented, getting prompt medical care for infections can reduce your risk.

Symptoms Sepsis develops in response to an infection somewhere in your body. Common infection sites include the lungs (pneumonia), kidneys, skin, abdomen, bowel and pelvis. If you're in the hospital or have had surgery, bacteria may enter your body through openings for tubes used to drain or give fluids (catheters and intravenous lines), surgical wounds or bedsores. Sometimes the source of the infection is unknown. Sepsis can develop quickly. Signs and symptoms include:   

Fever or low body temperature (hypothermia) Fast heart rate Rapid breathing

Signs and symptoms indicating that sepsis has progressed to severe sepsis or septic shock include:     

Change in mental status, such as confusion or decreased alertness Diarrhea Low blood pressure — dizziness when you stand up Warm, flushed skin or skin rash or bleeding Decreased urine output

Newborns who have difficulty breathing, are unusually sleepy, eat poorly, or have persistently high or low temperatures may have sepsis.

Causes When bacteria or other germs (infectious organisms) invade your body, your immune system mounts a defense that serves to control the infection and keep it from spreading. Inflammation in the affected area is one part of this defense. Inflammation helps the body repair and heal damaged tissues. Normally, a delicate balance of chemical signals called immune mediators or regulators start — and then stop — the inflammatory process. In sepsis, however, the process becomes exaggerated. Inflammation extends beyond the infection site and affects the whole body. Severe sepsis involves a complex cascade of events. The infectious agent and its toxic products provoke the release of too many immune regulators. This triggers widespread inflammation and prompts the formation of microscopic clots in blood vessels throughout the body. At the same time, the overactive inflammatory response interferes with the body's natural ability to break down blood clots. As a result, even as the heart works harder to pump blood, the clots prevent enough oxygen from reaching body organs and tissues. The out-of-control immune system chemicals may also damage body tissues. In neonatal sepsis, the newborn may be exposed to bacteria or a virus in the birth canal because of pregnancy complications, such as premature rupture of membranes (water breaking). An infection or bleeding in the mother can also lead to neonatal sepsis. Newborns who require an IV tube or another catheter may develop an infection in the hospital.

Risk factors Sepsis can occur in anyone with an infection, but you're more likely to develop the condition if you:   

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Are over age 65 Have a bacterial infection in your blood (bacteremia) Have a poorly functioning or weakened immune system because of cancer or cancer treatment, diabetes or another chronic disease, or an immunesuppressing disease such as AIDS Are taking immune-suppressing drugs Have pneumonia Are in the hospital Have severe injuries, such as bullet wounds or large burns Had medical treatment with an invasive device Have a genetic tendency for sepsis

Black people are more likely than are white people to get sepsis, and black men face the highest risk.

When to seek medical advice Most often sepsis occurs in people who are hospitalized. People in the intensive care unit (ICU) 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 following surgery, hospitalization or an infection, seek medical care promptly.

Tests and diagnosis Diagnosing sepsis can be difficult because signs and symptoms, such as fever, rapid heartbeat and rapid breathing, can be caused by other disorders. To make the diagnosis, your doctor will ask about your symptoms and medical history and will perform a physical exam. You'll have blood tests to check your complete blood count and to test your blood for bacteria or other infectious agents. In addition, your doctor may test your urine, saliva, stool or other secretions for bacteria. If you have sepsis, test results may show:      

High or low white blood cell count, sometimes with immature white blood cells Low platelet count or blood clotting abnormalities Blood culture that's positive for bacteria Acidosis — too much acid in the blood Abnormal (depressed) kidney or liver function Chest X-rays or blood tests showing impaired oxygen availability in blood or tissue

If you have no obvious infection, your doctor may order imaging tests such as X-ray, CT, ultrasound or magnetic resonance imaging (MRI) to try to find a source of infection.

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). Complications of sepsis include: 

Severe sepsis. One or more of your organs malfunction or fail.

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Septic shock. Your cardiovascular system begins to fail, and your blood pressure remains low even after you're given what seem to be adequate intravenous fluids. Multiple organ failure. Several organs begin to fail.

Most people recover from sepsis, but about 15 percent of those who get it die. The death rate is higher for severe sepsis (20 percent) and higher still for septic shock (45 percent to 60 percent). People who are older, have underlying health problems or get an infection in the hospital face a higher risk of dying of sepsis than do others who get it. Premature infants are more likely to die of neonatal sepsis than are full-term infants.

Treatments and drugs Early, aggressive treatment boosts your chances of surviving sepsis. People with severe sepsis require close monitoring and treatment in a hospital intensive care unit. If you have severe sepsis or septic shock, lifesaving measures may be needed to stabilize breathing and heart function. A priority in treating sepsis is to identify the source and type of the infection and treat it. Your medical team will test blood, urine, sputum or other body fluids to identify the infectious agent — most often, bacterial. Surgery to remove sources of infection, such as medical devices, intravenous lines and surgical drainage tubes, may be needed. Doctors will also drain any collections of pus (abscesses). A number of different types of medications are used in treating sepsis. They include: 

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Antibiotics. Treatment with antibiotics begins immediately — even before the infectious agent is identified. 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 more appropriate against the particular bacteria causing the infection. 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. Activated protein C. People with severe sepsis whose organs are failing or who are at high risk of dying may receive a newer drug called activated protein C (Xigris). This drug interferes with some of the body's responses to severe infection, helping to curb the overactive inflammatory reaction, but it can cause serious bleeding. Others. Other medications you may receive include low doses of corticosteroids, insulin to help maintain stable blood sugar levels, and painkillers or sedatives.

People with severe sepsis usually receive supportive care including intravenous fluids and oxygen. Depending on your condition, you may need mechanical ventilation (respirator) in case of breathing problems or dialysis for kidney failure.

Prevention Many cases of sepsis aren't preventable. But you can take steps to avoid infections and to protect yourself from illnesses that weaken your immune system.    

Wash your hands thoroughly after preparing or eating food, coughing or sneezing, and using the toilet. Get recommended pneumonia and flu shots. Seek prompt medical care for any serious infection. If you're hospitalized because of illness or for surgery, wash your hands after handling any soiled material. Alert the medical staff if catheters, drainage tubes or bandages become loose or if you see redness, swelling or pus on these sites. Tell the staff if wounds become wet or exposed to outside debris.