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 Community-Acquired Pneumonia Community-acquired pneumonia is lung infection that develops in people outside a hospital. Many bacteria, viruses, and fungi can cause pneumonia. The most common symptom of pneumonia is a cough... read more 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 Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more 
.)
Risk Factors of Hospital-Acquired Pneumonia
People who are hospitalized and seriously ill, especially if they have another illness that requires treatment with a breathing machine Mechanical Ventilation Mechanical ventilation is use of a machine to aid the movement of air into and out of the lungs. Some people with respiratory failure need a mechanical ventilator (a machine that helps air get... read more (mechanical ventilator), are at greatest risk of acquiring pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more . 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 Gastroesophageal Reflux Disease (GERD) In gastroesophageal reflux disease, stomach contents, including acid and bile, flow backward from the stomach into the esophagus, causing inflammation in the esophagus and pain in the bottom... read more
Debilitation
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.
Causes of Hospital-Acquired Pneumonia
Hospital-acquired pneumonia is most commonly caused by the following bacteria:
Staphylococcus aureus Staphylococcus aureus Infections Staphylococcus aureus is the most dangerous of all of the many common staphylococcal bacteria. These gram-positive, sphere-shaped (coccal) bacteria (see figure How Bacteria Shape Up)... read more
(including methicillin-resistant Staphylococcus aureus [MRSA Methicillin-resistant Staphylococcus aureus (MRSA) Staphylococcus aureus is the most dangerous of all of the many common staphylococcal bacteria. These gram-positive, sphere-shaped (coccal) bacteria (see figure How Bacteria Shape Up)... read more ])Gram-negative bacteria Overview of Gram-Negative Bacteria Bacteria are classified by how they appear under the microscope and by other features. Gram-negative bacteria are classified by the color they turn after a chemical process called Gram staining... read more such as Pseudomonas aeruginosa Pseudomonas Infections Any of several types of the gram-negative bacteria Pseudomonas, especially Pseudomonas aeruginosa, can infect different parts of the body, particularly in people who have serious... read more and Haemophilus influenzae Haemophilus influenzae Infections Haemophilus influenzae are gram-negative bacteria that can cause infection in the respiratory tract, which can spread to other organs. Infection is spread through sneezing, coughing,... read more
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 of Hospital-Acquired Pneumonia
Symptoms are generally the same as those for community-acquired pneumonia Symptoms Community-acquired pneumonia is lung infection that develops in people outside a hospital. Many bacteria, viruses, and fungi can cause pneumonia. The most common symptom of pneumonia is a cough... read more :
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 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).
Diagnosis of Hospital-Acquired Pneumonia
A doctor's evaluation of symptoms
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 Bronchoscopy Bronchoscopy is a direct visual examination of the voice box (larynx) and airways through a viewing tube (a bronchoscope). A bronchoscope has a camera at the end that allows a doctor to look... read more 
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 Procedures Done With Bronchoscopy Bronchoscopy is a direct visual examination of the voice box (larynx) and airways through a viewing tube (a bronchoscope). A bronchoscope has a camera at the end that allows a doctor to look... read more ). If fluid has collected in the lining of the lung (called a pleural effusion Pleural Effusion Pleural effusion is the abnormal accumulation of fluid in the pleural space (the area between the two layers of the thin membrane that covers the lungs). Fluid can accumulate in the pleural... read more 
), doctors may place a needle into the chest to collect this fluid for culture (a procedure called thoracentesis Thoracentesis Thoracentesis is the placement of a needle through the skin into the chest cavity to withdraw a sample of fluid. In thoracentesis, fluid that has collected abnormally in the pleural space (termed... read more ).
Prognosis of 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).
Spotlight on Aging: Pneumonia
Pneumonia occurs more commonly in older than in younger people, and it also tends to be more serious. In many older people, the infection spreads beyond the lungs. Older people have weakened defenses against infection. The mechanisms that clear microorganisms from the airways are not as effective in older people as they are in younger people. Weakness may make coughing less vigorous. Aging also weakens the immune system. Older people at greater risk of developing pneumonia include those
Infection with some of the microorganisms that cause pneumonia can be prevented with vaccinations Vaccines to prevent pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more Most older people who get pneumonia are treated in the hospital with intravenous antibiotics. Pneumonia can cause older people to get very sick very quickly, and older people tend to respond less well to oral antibiotics. |
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 Mechanical Ventilation Mechanical ventilation is use of a machine to aid the movement of air into and out of the lungs. Some people with respiratory failure need a mechanical ventilator (a machine that helps air get... read more . Treatments include intravenous antibiotics, oxygen, and intravenous fluids.
These drugs are given alone or are combined.
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 with their doctors and family members their wishes for treatment Advance Directives Health care advance directives are legal documents that communicate a person’s wishes about health care decisions in the event the person becomes incapable of making health care decisions. There... read more of pneumonia or other serious complications when they enter the hospital.
