by Horn D
(Nosocomial Pneumonia)


Pneumonia is an infection of the lungs. It is deep in the small airways and air sacs of the lungs. These air sacs swell and fill with fluid or pus.

Hospital-acquired pneumonia (HAP) is one that develops:

  • More than 48 hours after being in a hospital
  • Was not there when someone entered the hospital


HAP is caused by:

  • Bacteria (most common) including MRSA
  • Fungus—more common in those with a weak immune system

Risk Factors

HAP is more common in older adults. Other things that raise the risk of HAP are:

  • Prior hospital stay
  • Use of a tube in the throat
  • Recent heart or lung surgery
  • Health issues, such as:
  • Kidney disease
  • Lung disease, or
  • A problem with central nervous system
  • Poor nutrition or problems getting nutrition
  • Acid controlling medicine


Symptoms may include:

  • New fever
  • Increased coughed up fluid
  • New or increased cough
  • Problems breathing
  • Changes in thinking or behavior—more common in people over 70 years of age


The doctor will ask about symptoms and past health. They may also ask about any recent medical care. An exam will be done. HAP will be suspected based on symptoms. Tests can confirm the diagnosis. Tests may include:

Images of the lungs, such as:

Fluids will be tested to find out which germ is causing the problem. This can be done with:

  • Blood tests
  • Test of coughed up fluid


Medicine to fight the infection may include:

  • Antibiotics—for HAP caused by bacteria
  • Antifungal medicine—for HAP caused by a fungus

Over-the-counter medicine may also be needed. It can help to ease fever and pain.

Fluid in the lungs may block the flow of oxygen into the blood. Oxygen therapy may be needed. It will increase the level of oxygen in the blood.


Things that help reduce the risk of HAP include:


American Lung Association 

Centers for Disease Control and Prevention 


Health Canada 

Lung Association 


Hospital-acquired pneumonia. EBSCO DynaMed website. Available at: Accessed April 28, 2022.

Hospital-acquired pneumonia. Merck Manual Professional Version website. Available at: Accessed April 28, 2022.

Hospital-acquired pneumonia (HAP) prevention. Craig Hospital website. Available at: Accessed April 28, 2022.

Lanks CW, Musani AI, et al. Community-acquired pneumonia and hospital-acquired pneumonia. Med Clin North Am. 2019;103(3):487-501.

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