Pneumonia - Diagnosis

Bronchoalveolar lavage (BAL) may be done at the same time as bronchoscopy. This involves injecting high amounts of saline through the bronchoscope into the lung and then immediately sucking the fluid out. The fluid is then analyzed in the laboratory. Studies find BAL to be an effective method for detecting specific infection-causing organisms.

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The procedure is usually very safe, but complications can occur. They include allergic reactions to the sedatives or anesthetics, asthma attacks in susceptible patients, and bleeding. Fever may follow the procedure.

Lung Biopsy. In very severe cases of pneumonia or when the diagnosis is unclear, particularly in patients with damaged immune systems, a lung biopsy may be required. A lung biopsy involves taking some tissue from the lungs and examining it under a microscope.

A Lung Tap. This procedure typically uses a needle inserted between the ribs to draw fluid out of the lung for analysis. It is known by a number of names including lung aspiration, lung puncture, thoracic puncture, transthoracic needle aspiration, percutaneous needle aspiration, and needle aspiration. It is a very old procedure that is not done often any more, particularly in children, since it is invasive and poses a slight risk for collapsed lung. Some experts argue, however, that a lung tap is more accurate than other methods for identifying bacteria and the risk it poses is slight. Given the increase in resistant bacteria, they believe its use should be reconsidered in young people.

Ruling Out Other Disorders that Cause Coughing or Affect the Lung

Common Causes of Persistent Coughing. Over 30 million people seek medical help each year for persistent coughing, which is nearly always temporary and harmless when other symptoms, such as fever, are not present. The four most common causes of persistent coughing are asthma, postnasal drip, gastroesophageal reflux disease (GERD), and chronic bronchitis. Other obvious common causes of chronic cough include heavy smoking or the use of heart drugs known as ACE inhibitors.

Acute Bronchitis. Acute bronchitis is an infection in the passages that carry air from the throat to the lung. The infection causes a cough that produces phlegm. Acute bronchitis is almost always caused by a virus and usually clears up on its own within a few days; in some cases, acute bronchitis caused by a cold can last for several weeks.

Chronic Bronchitis. Chronic bronchitis causes shortness of breath and is often accompanied by infection, mucus production, and coughing, but it is a long-term and irreversible condition. The same microbes that cause pneumonia can cause chronic bronchitis, and symptoms of the two disorders are often similar. They include fatigue, coughing, fever, and production of sputum. There are significant differences between chronic bronchitis and pneumonia:

Patients with bronchitis are less likely to have wheezing, shortness of breath, chills, very high fevers, and other signs of severe illness.
Those with pneumonia usually cough up heavy sputum, which is also more likely to contain blood.
X-rays of patients with bronchitis are unlikely to show fluid or consolidation in the lung.