Many bacteria, viruses, and even fungi can cause pneumonia in people who are hospitalized.
The most common symptom is a cough that produces sputum, but chest pain, chills, fever, and shortness of breath are also common.
Diagnosis is based on a person’s symptoms and the results of x-rays or a computed tomography (CT) scan of the chest.
Antibiotics, antiviral drugs, or antifungal drugs are used, depending on which organism has most likely caused the pneumonia.
Pneumonia acquired in the hospital is usually more severe than pneumonia acquired in the community because the infecting organisms tend to be more aggressive. They are also less likely to respond to antibiotics (called resistance) and are, therefore, harder to treat. Additionally, people in hospitals tend to be sicker even without pneumonia than those living in the community and therefore are not as able to fight the infection.
(See also Overview of Pneumonia.)
People who are hospitalized and seriously ill, especially if they have another illness that requires treatment with a breathing machine (mechanical ventilator), are at greatest risk of acquiring pneumonia. Other risk factors include
Previous antibiotic treatment
Coexisting illness such as heart, lung, liver, or kidney dysfunction
Age older than 70
Recent abdominal or chest surgery
Possibly the use of proton pump inhibitors (omeprazole, esomeprazole, lansoprazole, or pantoprazole) for treatment of gastroesophageal reflux disease
Organisms that do not normally cause pneumonia in healthy people can cause pneumonia in people who are hospitalized or debilitated because many of these people have an immune system that is less able to resist infection. The most likely organisms depend on what organisms are prevalent in the hospital and sometimes depend on what other illnesses the person has.
Hospital-acquired pneumonia is most commonly caused by the following bacteria:
MRSA, P. aeruginosa, and other gram-negative intestinal bacteria often are resistant to certain antibiotics.
Viruses and fungi are increasingly being recognized as causes of hospital-acquired pneumonia.
Symptoms are generally the same as those for community-acquired pneumonia:
Pneumonia acquired in the hospital may be more difficult for doctors to recognize than pneumonia acquired in the community. For example, many hospitalized people who develop pneumonia, such as older people, those with breathing tubes who are receiving mechanical ventilation, those with dementia, and those who are critically ill, may be unable to describe symptoms such as chest pain, shortness of breath, and weakness. In those cases, pneumonia is often suspected on the basis of fever and an increase in the respiratory rate and the heart rate.
Older people who have pneumonia may also have confusion, loss of appetite, restlessness and agitation, falling, and incontinence (an involuntary loss of urine).
The diagnosis of hospital-acquired pneumonia is based on a person’s symptoms and the results of a chest x-ray or a chest CT scan. Doctors usually take a sample of blood so they can try to grow (culture) the bacteria in the laboratory and identify it.
People who have hospital-acquired pneumonia may be very sick, so doctors may need to identify the organism that is causing pneumonia to determine the best treatment. For these reasons, sometimes doctors do bronchoscopy to obtain specimens from within the lung itself to try to identify the organism. During bronchoscopy, a flexible viewing tube is inserted into the trachea and lungs. Samples of pus, secretions, or even lung tissue can be collected for examination. If no secretions are visible, an area of the lung can be washed with fluid, which can then be retrieved for analysis (a procedure called bronchoalveolar lavage). If fluid has collected in the lining of the lung (called a pleural effusion), doctors may place a needle into the chest to collect this fluid for culture (a procedure called thoracentesis).
Treatment of hospital-acquired pneumonia is with antibiotics that are chosen based on which organisms are most likely to be the cause and the specific risk factors the person has. People who are seriously ill may be placed in an intensive care unit and sometimes put on a ventilator. Treatments include intravenous antibiotics, oxygen, and intravenous fluids.
These drugs are given alone or are combined.
Some people with hospital-acquired pneumonia are very ill. Pneumonia is often treated with strong antibiotics and, if needed, a mechanical ventilator. People who are expected to die soon may not wish to receive such aggressive treatment. People with severe or terminal disorders should discuss with their doctors and family members their wishes for treatment of pneumonia or other serious complications when they enter the hospital.