Pneumonia Overview and Symptoms

Study Notes

Pneumonia is an inflammation of the air sacs (alveoli) in the lungs.
Often caused by bacteria, viruses, or fungi.
Fluid or pus can fill the air sacs, making breathing difficult.
Affects all ages, but more serious in older adults, infants, and those with weakened immune systems.

Symptoms range from mild to life-threatening.
Common symptoms include cough (with or without phlegm), fever, shortness of breath, and chills.
Additional symptoms: sharp chest pain, headache, excessive sweating, loss of appetite and energy, confusion (especially in older adults), fast breathing, vomiting, difficulty drinking or eating (in infants and children).
Body temperature might be lower than normal in adults.

Caused by microbes like bacteria, viruses, fungi, and mycoplasma.
Acquired through infected ventilators, or inhalation of bacteria in food, drink, or saliva.
Certain infectious environments (hospitals, communities) can increase risk.
Inhalation of chemicals and environmental agents can also cause pneumonia.

Bacterial Pneumonia: Most common, caused by Streptococcus pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila. High fever, sweating, bluish lips/nails, confusion can occur.
Viral Pneumonia: Often less severe, affects young children/elderly. Starts with flu-like symptoms, wheezing, high fever.
Mycoplasma Pneumonia: Not a virus or bacteria, but shares traits with both. Causes mild pneumonia, commonly in older children/young adults.
Fungal Pneumonia: Fungi from soil or bird droppings; can cause pneumonia in those with weakened immune systems or those inhaling large amounts of the organisms. Examples include Pneumocystis jirovecii pneumonia (PCP), Cryptococcus, Histoplasma, and Coccidioides.
Hospital-Acquired Pneumonia (HAP): Acquired during a hospital stay, potentially harder to treat due to antibiotic-resistant bacteria.
Community-Acquired Pneumonia (CAP): Acquired outside of a hospital setting.
Aspiration Pneumonia: Acquired by inhaling bacteria from food, drink, or saliva (risk if swallowing problems, sedation).
Ventilator-Associated Pneumonia (VAP): Acquiring pneumonia while on a ventilator.

Infants (birth to 2 years), individuals aged 65 years or older.
People with chronic medical conditions (e.g., asthma, cystic fibrosis, diabetes).
Smokers, heavy drinkers, drug users, weakened immune systems.

Chest X-ray and physical exam (listening to lungs with a stethoscope).
Blood tests, sputum tests, pulse oximetry, urine tests, CT scans, fluid samples (from the lungs).
Bronchoscopy (camera into airways) might be needed.

Initial treatment (empiric) focused on likely organisms; later treatment (individualized) based on specific organisms and severity.
Antibiotics, antifungals, antivirals.
Intravenous antibiotics (if severe).
Drugs like levofloxacin, Cefuroxime, Cefpodoxime, cefprozil, oseltamivir, zanamivir, rimantadine, amantadine, ganciclovir (viral infections), azithromycin, clarithromycin (mycoplasma).
Over-the-counter pain relievers (e.g., acetaminophen).
Rest is essential for managing symptoms.

Bacteremia (bacteria spreads to bloodstream): can lead to organ failure or septic shock.
Lung abscesses (cavities in the lungs).
Impaired breathing (acute respiratory distress syndrome), pleural effusion (fluid around lungs), and death, can occur.
Complications are common in people with underlying diseases or compromised immune systems.

Vaccination (PPSV23 and PCV13) against pneumococcal bacteria.
Vaccination is recommended for high-risk groups (e.g., elderly, children, people with certain health conditions).
Maintenance of healthy habits to boost immune system (e.g. healthy lifestyle, regular exercise).
Avoiding contact with those infected.
Avoidance of areas with high concentrations of fungal pathogens.