# Pneumonia
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**Pneumonia** is an inflammation of the [[lungs|lung]] tissue, typically due to an [[infection]]. It can be bacterial, viral, fungal or even due to an aspiration of secretions or other material (in which case it is called "chemical pneumonia"). Pneumonia causes difficulty in [[pulmonary ventilation]] because it effectively blocks [[alveolar gas exchange]] and thus oxygenation. It's one of the leading causes of death by infectious disease.
There are four types of pneumonia classifications, but a lot are overlaps.
- **Community Acquired Pneumonia** or **CAP** is when pneumonia is acquired just out and about in the real world. For some reason it's typically associated with Gram positive bacteria.
- **Health Care Associated Pneumonia** or **HCAP** is pneumonia that happens to someone who is not hospitalized but does have frequent contact with healthcare.
- It it typically due to aspiration, and typically to immunocompromised patients.
- **Hospital Acquired Pneumonia** or **HAP** is when pneumonia happens to someone currently hospitalized.
- It is the second most common [[healthcare associated infection|HAI]] (second only to UTIs)
- HAPs increase length of stay on average 4-9 days and have a 13-55% mortality.
- **Ventilator Associated Pneumonia** or **VAP** is pneumonia acquired by someone who is on a [[ventilator]]
## Risk Factors
- being [[mechanical ventilation|ventilator]] dependent
- this increases the chances of acquiring pneumonia by 20 times
- underlying conditions such as [[COPD]], [[heart failure]], [[cystic fibrosis]], or [[cancer]]
- anything that makes you immunocompromised
- age
- older adults have many normal age-related changes that increase the chances of pneumonia, such as:
- decreased amount of cilia which clear things from the respiratory tract
- decreased elasticity in the alveoli, as well as thickened alveolar walls
- weakened immune systems
- weakened muscles used to clear the lungs
- [[smoking]]
- recent [[surgery]]
- especially due to the effects of [[general anesthesia]], such as loss of the gag reflex, sleepy cilia, altered level of consciousness.
## Signs & Symptoms
The signs and symptoms of pneumonia are all pretty much what you expect, coughing, shortness of breath, etc. These may not be clear in older adults though, and [[altered mental status]] might be the first sign for this population.
## Diagnostic Tests
Pneumonia can be diagnosed with an X-ray, cultures, a CBC or even a bronchoscopy. Pneumonia on an X-ray looks like a cloudy area, where typically it's mostly black.
![[pneumonia.png]]
>[!abstract]- Healthy lungs for reference
![[lung x-ray.png]]
## Prevention
Preventing pneumonia is the most the is best done through the pneumonia [[vaccine]]. It is recommended for people age 65+ and for people with chronic illnesses.
There are two similar but different pneumonia vaccines
- **PCV13** protects against 13 different causative organisms
- **PCV23** protects against 23 different causative organisms
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