What is Nosocomial Pneumonia?

Nosocomial pneumonia, or hospital-acquired pneumonia, is a lung infection which arises during a person's stay in the hospital. After infections of the urinary tract, pneumonia is the second most frequent type of nosocomial infection. Most cases are caused by bacteria, and the disease can occur toward the beginning or the end of a person's hospital stay, with an early-onset pneumonia having a better outlook. Nosocomial pneumonia can be serious because patients who are ill in the hospital often have less resistance to disease, and there may be dangerous disease-causing microorganisms, or germs, present. Patients who are on ventilators are more at risk of developing the illness.

Causes of nosocomial pneumonia include bacteria, viruses and, in rare cases, fungi. When pneumonia occurs early during a patient's stay, the outlook is often better. This is because late-onset pneumonia is more likely to be associated with microorganisms which are resistant to drugs. While patients on ventilators have an increased risk of acquiring pneumonia, the risk is also increased for older patients, those who have had long-term lung disease or chest surgery, and alcoholics.

Symptoms of nosocomial pneumonia may include a high temperature, a rapid breathing rate, difficulty breathing and a cough which produces colored phlegm. It is important to distinguish nosocomial pneumonia from other diseases which can sometimes appear similar, such as congestive heart failure, where the failing heart causes fluid to build up in the lungs. Investigations which may be carried out include blood tests, X-rays, and taking samples of cells and secretions from the airways.

Methods of treating nosocomial pneumonia will vary depending on the cause — most often this will be bacteria — and an appropriate course of antibiotics will be required. It is not usually possible to delay treatment long enough to identify the specific type of bacteria, so a choice of antibiotics is made based on the most likely causes. Different types of bacteria are typically involved in causing early and late onset nosocomial pneumonia, so considering when the disease started helps doctors decide which drugs to use.

Generally, treatment for nosocomial pneumonia is continued for around two weeks. Most patients will improve within this time, although some individuals may require slightly shorter or longer treatment periods, depending on how the infection responds to drugs. The outlook, or prognosis, will depend on the cause, and on the person's own state of health. For older or weaker patients, the disease could be more severe and, for those types of pneumonia caused by microorganisms resistant to drugs, the prognosis is likely to be less favorable.