Hospital-acquired pneumonia is lung infection that develops in people who have been hospitalized, typically after about 2 days or more of hospitalization.
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.
Antibiotic, antiviral, or antifungal medications 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. The infecting organisms are also less likely to respond to antibiotics (called antibiotic 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.
In the United States, hospital-acquired pneumonia is the most common infection associated with medical care. In Europe, approximately 500,000 cases of hospital-acquired pneumonia occur each year.
Risk Factors for Hospital-Acquired Pneumonia
People who are hospitalized and seriously ill, especially if they are on a breathing machine (mechanical ventilator), are at greatest risk of acquiring pneumonia while in the hospital.
Other risk factors include:
Previous antibiotic treatment
Coexisting illness such as heart, lung, liver, or kidney dysfunction
Age older than 70 years
Recent abdominal or chest surgery
Poor oral hygiene
Debilitation
Depressed consciousness
Inhalation of tiny particles from the mouth into the airways (aspiration)
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.
Ventilator-associated pneumonia is a subset of hospital-acquired pneumonia that develops at least 48 hours after the person has been placed on a breathing machine (ventilator) or within 48 hours of being taken off the breathing machine. Ventilator-associated pneumonia often involves organisms that are more resistant to antibiotics and leads to poorer outcomes than other forms of hospital-acquired pneumonia.
Causes of Hospital-Acquired Pneumonia
Hospital-acquired pneumonia is most commonly caused by the following bacteria:
Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus [MRSA])
Gram-negative bacteria, such as Pseudomonas aeruginosa and Haemophilus influenzae
MRSA, P. aeruginosa, and other gram-negative intestinal bacteria often are resistant to certain antibiotics.
Viruses and fungi are also causes of hospital-acquired pneumonia, especially in people whose immune system is weakened.
Symptoms of Hospital-Acquired Pneumonia
The symptoms of hospital-acquired pneumonia are generally the same as those for community-acquired pneumonia:
A general feeling of weakness (malaise)
Cough that produces sputum (thick or discolored mucus)
Shortness of breath
Fever
Chills
Chest pain
Pneumonia acquired in the hospital may be more difficult for doctors to recognize than pneumonia acquired in the community. For example, many people who are in the hospital and develop pneumonia, such as older adults, 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 adults who have pneumonia may also have confusion, loss of appetite, restlessness and agitation, falling, and incontinence (an involuntary loss of urine).
Did You Know...
|
Diagnosis of Hospital-Acquired Pneumonia
A chest x-ray or chest computed tomography (CT) scan
Sometimes blood cultures
Sometimes bronchoscopy or thoracentesis
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 may 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
Antibiotics
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.
People may be treated with 2 or more antibiotics at the same time.
End-of-life issues in serious pneumonia
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 their wishes for treatment with their doctors and family members if pneumonia or other serious complications develop during a period of hospitalization.
Prognosis for Hospital-Acquired Pneumonia
Despite receiving excellent treatment, a high percentage of people who develop hospital-acquired pneumonia die. However, death is often related to the underlying health problems that allowed the pneumonia to develop (for example, widespread cancer).
Prevention of Hospital-Acquired Pneumonia
In people who are hospitalized after surgery, breathing exercises (using a handheld device called an incentive spirometer) that help to encourage deep breaths may be used to help prevent pneumonia (see also Chest Physical Therapy).
Elevating the head of the bed, focusing on oral hygiene, and encouraging people who can to breathe deeply and walk around may reduce the risk of hospital-acquired pneumonia.
Doctors may also try to reduce the use of medications that cause drowsiness and evaluate the person for swallowing difficulties (to reduce the risk of aspiration).
