Aspiration pneumonia

Definition

Aspiration pneumonia is an inflammation of the lungs and bronchial tubes caused by inhaling foreign material (usually food, drink, vomit, or secretions from the mouth) into the lungs. This may progress to form a collection of pus in the lungs (lung abscess).

Causes, incidence, and risk factors

Aspiration of foreign material (often the stomach contents) into the lung can be a result of disorders that affect normal swallowing, disorders of the esophagus (esophageal stricture, gastroesophageal reflux), or decreased or absent gag reflex in unconscious or semi-conscious individuals. Old age, dental problems, use of sedative drugs, anesthesia, coma, and excessive alcohol consumption are also causal or contributing factors. The response of the lungs depends upon the characteristics and amount of the aspirated substance. The more acidic the material, the greater the degree of lung injury, although this may not necessarily lead to pneumonia.

The injured lungs may become infected with multiple species of anaerobic bacteria or aerobic bacteria. A collection of pus may form in the lung. A protective membrane may form around the abscess.

Symptoms

• Fever
• Fatigue
• Cough:
  • With foul-smelling sputum
  • With sputum containing pus or blood
  • With greenish sputum
• Chest pain
• Shortness of breath
• Bluish discoloration of the skin caused by lack of oxygen
• Rapid pulse (heart rate)
• Wheezing

• Sweating, excessive
• Swallowing difficulty
• Breath odor

Signs and tests

Physical examination may reveal crackling sounds in the lungs.

These tests also help diagnose this condition:

• Chest x-ray
• Sputum culture
• CBC
• Blood culture
• Bronchoscopy
• Swallowing studies

Treatment

Hospitalization may be required for management of the illness. Treatment measures vary depending on the severity of the pneumonia. Antibiotics, which treat the organisms in the environment, may be given. Patients may receive special antibiotics to treat organisms that may live in the mouth.

The types of organisms present depend on the health of the patient and where they live (private residence, chronic nursing facility, for instance).

Patients may need to have their swallowing function assessed. If there is difficulty with proper swallowing, other methods of feeding the patient may be necessary.

Expectations (prognosis)

The outcome depends on the severity of the pneumonia, the type of organism, the extent of lung involvement. If acute respiratory failure develops, the patient may have a prolonged illness or die.

Complications

• Spread of infection to the blood stream (bacteremia)
• Spread of infection to other areas of the body
• Low blood pressure
• Shock
• Acute respiratory distress syndrome
• Pneumonia with lung abscess

Calling your health care provider

Call your health care provider, go to the emergency room, or call the local emergency number (such as 911) if shortness of breath, wheezing, chills, fever, or chest pain occur.

Prevention

• Awareness of the risk of aspiration
• Avoid behaviors which may lead to aspiration

Illustrations

Pneumococci organism

Bronchoscopy

Lungs

Respiratory system

Page Content:

Anaerobic pneumonia; Aspiration of vomitus; Necrotizing pneumonia ; necrotizing pneumonia