About Pneumonia

Pneumonia is an infection of the lungs that has the potential to be life-threatening. Together, pneumonia and the flu are the seventh most common cause of death in the United States and cause thousands of hospital stays each year. In 2002, 64,954 people died of pneumonia. (National Center for Health Statistics, 2005.)

Read on for more information, or click on a topic in the list:

What is pneumonia?
What are the symptoms?
What are the causes?
How is it diagnosed?
How is it treated?

Pneumonia is an illness in which the alveoli become inflamed and flooded with fluid. Pneumonia can result from a variety of causes, including infection with bacteria, viruses, fungi, or parasites. Pneumonia may also result from chemical or physical irritation of the lungs. The disease can range from mild to life-threatening.

Symptoms of pneumonia include:

• Cough that produces greenish or yellow sputum or blood
• High fever that may be accompanied by shaking chills
• Shortness of breath
• Pleuritic chest pain, either felt or worsened during deep breaths or coughs
• Headaches
• Sweaty or clammy skin
• Loss of appetite
• Fatigue or weakness
• Blueness of the skin
• Nausea
• Vomiting
• Joint pains or muscle aches
• Mental confusion

Over 100 microorganisms can cause pneumonia. The most common are viruses and bacteria that enter the body through the mouth or nose, or through infections already in the bloodstream. Pneumonia can also develop after a cold, flu, or other illness through an infection that is already in the bloodstream.

Viral pneumonia is commonly caused by viruses such as influenza virus, respiratory syncytial virus (RSV), adenovirus, and metapneumovirus. Although viral pneumonia is usually less severe than bacterial pneumonia, it can damage the lungs and may allow bacteria to cause a more serious infection.

Streptococcus pneumoniae is the most common bacterial cause of pneumonia in all age groups except newborn infants. This is a Gram-positive bacteria which often lives in the throats of people who do not have pneumonia. Gram-negative bacteria cause pneumonia less frequently. These bacteria often live in the stomach or intestines and may enter the lungs if vomit is inhaled. Less common causes of pneumonia include atypical bacteria, fungi, and inhaled irritants.

Patients with the following risk factors are more likely to get pneumonia:

• Age 65 years and older
• Heart problems
• Cancer treatments, such as chemotherapy
• Medication that weakens the immune system
• Smoking
• Alcohol abuse

A combination of medical history, physical exam, and various test should be used to diagnose pneumonia.

• Medical history. The doctor should ask questions about other medical problems, use of medications, smoking habits, and whether the patient has had a vaccination for flu or pneumonia.

• Physical examination. This may reveal fever or sometimes low body temperature, an increased respiratory rate, low blood pressure, a fast heart rate, or a low amount of oxygen in the blood, as indicated by pulse oxymetry or blood gas analysis. Patients who are struggling to breathe, confused, or who have blue-tinged skin require immediate attention.
  
  Listening to the lungs with a stethoscope can reveal several things. A lack of normal breath sounds, the presence of rales, or whispered pectoriloquy can identify areas of the lung that are stiff and full of fluid consolidation. The doctor may also use palpation and percussion on the chest wall to further localize consolidation, and palpate for increased vibration of the chest while the patient is speaking.
• Chest x-ray. An important test for detecting pneumonia or its complications is a chest x-ray. Chest x-rays can show areas of opacity that represent consolidation. Although a normal chest x-ray indicates pneumonia is less likely, pneumonia is sometimes not seen on x-rays because the disease is either in its initial stages or because it involves a part of the lung not easily seen by x-ray. In such cases, chest CT can reveal pneumonia not seen on the x-ray. (Other problems, like lung scarring and congestive heart failure, can mimic pneumonia on x-ray.)
  
• Sputum cultures. If a patient is not getting better with antibiotics, or if the practitioner has concerns about the diagnosis, a culture of the patient’s sputum may be requested. Sputum cultures generally take at least two to three days, so they are used mainly to confirm that the infection is sensitive to an antibiotic that has already been started.
  
• Other tests. A complete blood count may show a high white blood cell count, indicating the presence of an infection or inflammation. (In some patients with immune system problems, the white blood cell count may appear deceptively normal.)
  
  A blood culture may also be used to look for infection in the blood. Any bacteria identified are then tested to see which antibiotics will be most effective. Blood tests may be used to evaluate kidney function (important when prescribing certain antibiotics) or to look for low blood sodium, a sign of extra anti-diuretic hormones produced when the lungs are diseased.
  
  Specific blood serology tests for other bacteria (Mycoplasma, Legionella and Chlamydophila) and a urine test for Legionella antigen are available.
  
  Respiratory secretions can also be tested for the presence of viruses such as influenza, respiratory syncytial virus, and adenovirus.

Early diagnosis and treatment provide the best chance for a full recovery. For young, otherwise healthy patients, oral antibiotics, rest, fluids, and home care are sufficient for complete resolution. Treatment at a hospital may be required for patients who have severe difficulty breathing, other lung problems, or signs of complications.

The Centers for Medicare & Medicaid Services and the Joint Commission for the Accreditation of Healthcare Organizations have determined that the following treatments are indicators of quality care for pneumonia:

• Blood culture taken prior to antibiotic
• Antibiotic within eight hours
• Oxygenation assessment within 24 hours
• Advice for smokers on how to stop smoking

More Information

Doctors can find more information about treating pneumonia in Best Practices for Pneumonia.

Information in this document is compiled from Wikipedia.com, 2005.