Aspiration pneumonia

Definition

Aspiration pneumonia is inflammation of the lungs and airways to the lungs (bronchial tubes) from breathing in foreign material.

Alternative Names

Anaerobic pneumonia; Aspiration of vomitus; Necrotizing pneumonia; Aspiration pneumonitis; Chemical pneumonitis

Causes, incidence, and risk factors

Aspiration pneumonia is caused by breathing foreign materials (usually food, liquids, vomit, or fluids from the mouth) into the lungs. This may lead to:

• A collection of pus in the lungs (lung abscess)
• An inflammatory reaction
• A lung infection (pneumonia)

Aspiration of foreign material into the lungs can be caused by:

• Anesthesia
• Coma
• Decreased or absent gag reflex in people who are not alert (unconscious or semi-conscious)
• Dental problems
• Disorders that affect normal swallowing
• Disorders of the esophagus (esophageal stricture, gastroesophageal reflux)
• Excessive alcohol use
• Medications that affect alertness
• Old age
• Sedatives

Acidic material that is breathed into the lungs can cause severe lung injury. However, it may not necessarily lead to pneumonia.

Symptoms

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

Other symptoms that can occur with this disease:

• Breath odor
• Excessive sweating
• Swallowing difficulty

Signs and tests

A physical examination may reveal crackling sounds in the lungs and a rapid pulse (heart rate).

The following tests may also help diagnose this condition:

• Arterial blood gas
• Blood culture
• Bronchoscopy
• Chest x-ray
• Complete blood count (CBC)
• CT scan of the chest
• Sputum culture
• Swallowing studies

Treatment

Some people may need to be hospitalized. Treatment depends on the severity of the pneumonia. You may receive antibiotics, which treat bacteria. Some people may get special antibiotics to treat bacteria that live in the mouth.

The type of bacteria that caused the pneumonia depends on:

• Your health
• Where you live (at home or in a long-term nursing facility, for example)
• Whether you've recently been hospitalized
• Recent antibiotic use

You may need to have your swallowing function tested. Patients who have trouble swallowing may need to use other feeding methods to reduce the risk of aspiration.

Expectations (prognosis)

The outcome depends on:

• The severity of the pneumonia
• The type of bacteria causing the pneumonia
• How much of the lungs are involved

If acute respiratory failure develops, the patient may have a long-term illness or die.

Many people who have aspiration pneumonia have other serious health problems, which may affect the outlook for recovery.

Complications

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

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 you have:

• Chest pain
• Chills
• Fever
• Shortness of breath
• Wheezing

Prevention

• Avoid behaviors that may lead to aspiration, such as excessive alcohol use
• Become aware of the risk of aspiration

References

Limper AH. Overview of pneumonia. In: Goldman L, Ausiello D. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 97.