Aspiration pneumonia is a lung infection that occurs when a person unintentionally inhales material from the nose, throat, or stomach.
What is going on in the body?
In a person with aspiration pneumonia, substances from the stomach, throat, or nose enter the airway and lungs. Often, a chemical burn of the lungs, accompanied by inflammation, occurs within a few hours. This is known as "aspiration pneumonitis". In addition, the aspirated material is contaminated with bacteria that naturally inhabit the digestive tract. Pneumonia, which is a lung infection, may then develop in one or both lungs. The infection most commonly occurs in the lower part of the lungs.
What are the causes and risks of the infection?
Aspiration pneumonia is more likely in a person who is:
debilitated, or very weak
intoxicated by alcohol
unconscious from a medical condition
being fed by a stomach tube, either a nasogastric tube or a tube placed into the stomach surgically
- on a ventilator, or artificial breathing machine
What can be done to prevent the infection?
Diligent care by healthcare professionals is critical in helping to prevent aspiration pneumonia. The airway must always be open and stable in people with altered mental status or abnormal swallowing. Feeding and breathing tubes should be checked for proper positioning and functioning. Avoiding alcohol intoxication will help to prevent aspiration pneumonia.
How is the infection diagnosed?
Tests used to diagnose aspiration pneumonia include:
- chest x-ray
- arterial blood gases, which measure oxygen and carbon dioxide levels in the blood
- complete blood count, or CBC, which counts red and white blood cells
- blood culture, which checks for bacteria present in the blood
- sputum culture, which checks for bacteria in material from the lungs
The results of these tests help the healthcare provider select the best treatment.
Long Term Effects
What are the long-term effects of the infection?
Life-threatening illness may result from aspiration pneumonia, including:
- atelectasis, which is a collapsed or poorly inflated lung
- a lung abscess, or pus-filled cavity
- respiratory failure
- sepsis or blood infection
- pleuritis, or an infection in the membranes surrounding the lungs
What are the risks to others?
Aspiration pneumonia is not a direct risk to family members or other caregivers. However, the person may develop a more serious infection if the condition is not effectively treated. This more serious infection may be highly contagious.
What are the treatments for the infection?
Oxygen therapy and antibiotic medications are the standard treatments. Antibiotics are given through a vein. A ventilator, or artificial breathing machine, may be needed to keep an open airway and provide oxygen. The trachea may need suctioning to clear secretions and aspirated particles out of the airway. Medications given by aerosol to help open the airways can also be helpful.
What are the side effects of the treatments?
Antibiotics may cause stomach upset, diarrhea, and in some cases, an allergic reaction. Occasionally, the antibiotic may not cure the lung infection. Sometimes a ventilator actually increases a person's risk for aspiration pneumonia.
What happens after treatment for the infection?
Antibiotic treatment will be given for several weeks. Special breathing treatments may be continued after discharge from the hospital.
How is the infection monitored?
A chest x-ray is the best way to tell whether the aspiration pneumonia is clearing and responding to medication. A sputum culture and blood tests may be repeated during a checkup. Any new or recurring symptoms should be reported to the healthcare professional.
Harrison's Principles of Internal Medicine, 12th Edition, by (1991)
The Right Test: A Physicians' Guide to Laboratory Medicine, 2nd Edition, by Speicher (1993)
Fundamentals of Diagnostic Radiology, by Brant (1994)