Sepsis does not discriminate. It can affect anyone, of any race, of any age, at any time. However, certain factors can put one at higher risk than others. Sepsis occurs when a local infection spreads to other parts of the body including vital organ systems. Therefore, any infection puts patients at risk of developing sepsis. The most common infections that lead to sepsis are: pneumonia, abdominal infections, kidney and urinary tract infections, certain viruses (i.e. influenza) and parasites (i.e. malaria). Certain additional factors that predispose patients to develop sepsis include:
Sepsis can be caused by a previous or underlying medical condition but always starts with an infection. Most common are infections in the lungs (e.g. pneumonia), urinary tract, skin (e.g. cellulitis), abdomen (e.g. appendicitis), or gallbladder. Any infection that could potentially spread throughout the body or is not treated in a timely manner poses a risk of causing sepsis or septic shock. Other causes of infection can stem from invasive procedures such as open surgeries, insertion of catheters and/or procedures where bacteria could be introduced directly into the bloodstream. Sepsis can be caused by a variety of microbes, such as fungi or viruses (influenza) but the most frequent microbes are bacteria. The introduction of vaccines, such as the polio and flu vaccines, has dramatically reduced the number of viruses and bacterial infections that used to cause sepsis.
The symptoms of sepsis are highly variable and all depend on the initial infection - where it is located, what organism is causing the infection, and what new organs the infection can reach. In most cases, septic patients experience:
- Fever or chills
- Fast heart rate
- Increased breathing rate
- Altered mental status/confusion
- High blood sugar levels (hyperglycemia)
Many other symptoms may be present, depending on the infection. If the infection has moved to the lungs, a septic patient may experience difficulty breathing. Infection in the heart often leads to low blood pressure (hypotension) because the heart cannot pump blood as efficiently. When the infection is in the brain, patients often experience confusion and are less aware of their surroundings. If the infection occurs in the kidney(s), patients will often urinate less often because the infection stops the kidneys from functioning properly and producing enough urine. These same symptoms are present when people develop sepsis sometimes making it difficult for doctors to determine if this is just an infection or has progressed to sepsis.