Learning objectives

• Signs and symptoms of pneumonia
• Management of pneumonia

Definition and mechanisms

• Pneumonia is an infection that inflames the alveoli in one or both lungs
• The alveoli may fill with fluid or pus causing cough with phlegm or pus, fever, and difficulty breathing
• Caused by bacteria (Streptococcus pneumoniae), bacteria-like organisms (Mycoplasma pneumoniae), viruses, or fungi
• Can also be caused by aspiration of food, fluids, vomit, or saliva
• Can be mild to life-threatening
• The disease may be classified by where it was acquired, such as community- or hospital-acquired or healthcare-associated pneumonia

Signs and symptoms

Classification

• Pneumonia is most commonly classified by where or how it was acquired: 
  • Community-acquired pneumonia
  • Aspiration pneumonia
  • Healthcare-associated pneumonia
  • Hospital-acquired pneumonia
  • Ventilator-associated pneumonia
• It may also be classified by the area of the lung affected: 
  • Lobar pneumonia 
  • Bronchial pneumonia 
  • Acute interstitial pneumonia

Risk factors

• Children < 2 years of age
• Adults > 65 years of age
• Hospitalization – ICU – long-term care facility
• Chronic disease: asthma, COPD, or heart disease
• Smoking
• Pregnancy
• Weakened or suppressed immune system: HIV/AIDS
• Neurological conditions making swallowing difficult: dementia, Parkinson’s disease, or stroke

Complications

• Bacteremia or sepsis
• Difficulty breathing, requiring a ventilator
• Pleural effusion
• Lung abscess

Prevention

• Vaccination: pneumococcal vaccine, flu, COVID-19
• Practice good hygiene
• Do not smoke

Diagnosis

• Medical history
• Physical exam
• Blood tests
• Chest X-ray
• Pulse oximetry
• Sputum test
• CT scan
• Arterial blood gas test
• Pleural fluid culture
• Bronchoscopy

Management

Be aware that:

• Anesthesia can contribute to postoperative pneumonia by causing gastric contents like stomach acid to enter the lungs, resulting in pulmonary complications and increased risk of infection
• Pulmonary infections and pneumonia are the most common cause of pulmonary ARDS

Suggested reading

• Morgan, A., Glossop, A., 2016. Severe community-acquired pneumonia. BJA Education 16, 167–172.
• Sadashivaiah, JB., Carr, B., 2009. Severe community-acquired pneumonia. Continuing Eduction in Anaesthesia Critical Care & Pain. 9;3:87-91.