Infections are caused by germs: viruses, bacteria and fungus. The most common infections that require either coming into the hospital in the first place, or that occur as a complication of being in the hospital, are caused by bacteria.
Sepsis - is the response of the body against a germ, and can occur from an infection in any part of the body. Weakness and ache are common symptoms of sepsis. Fever, a fast heart-beat and fast breathing are common signs of sepsis. The body's immune system tries to fight the infection, but with some infections, antibiotics are needed to help the body defend itself. If the infection gets worse it can involve the kidneys, brain, lungs and other organs of the body (see section on Multiple Organ Failure). And at its worst, some infections can affect the heart and blood vessels of the body, causing the blood pressure to fall. This is called septic shock and is very serious; it is one of the most common causes of death of patients who come into ICUs.
Ventilator-associated pneumonia - is a complication of being on a breathing machine (see Information Sheet on Mechanical Ventilators). Since being on a breathing machine often means having a tube in the lungs, germs from outside the body can move down through the tube into the lungs causing an infection called pneumonia. Since the germs are coming from the hospital, this can be very serious because the germs present in the hospital are often more difficult to treat than germs you catch at home. As a general rule, the longer a patient is on a breathing machine, the longer there is a risk of getting a ventilator-associated pneumonia.
Catheter-related infections - happen when germs from outside the body enter through a thin hollow tube, called a catheter, that is put into the body. The germs can enter a catheter that is in a blood vessel of the body used to give fluids and medicines or to measure pressure. Or the germs can enter a catheter that is in the bladder opening to drain urine, which can lead to an infection of the bladder or kidneys.
Multiple-drug-resistant infections - are infections with germs that are not killed by the normal antibiotics. These germs can come from inside or outside the hospital, causing lung, catheter and other infections. These germs have been mentioned a lot recently in the news because they are an increasing reason for serious complications, especially for patients who are in an ICU.