Pathophysiology of Pneumonia


  • Inflammatory response
    • Attraction of neutrophils
    • Release of inflammatory mediators
    • Accumulation of fibrinous exudates, red blood cells, and bacteria
  • As a result, the inflammatory process attracts more neutrophils, edema of the airways occurs, and fluid leaks from the capillaries and tissues into alveoli
    • Alveoli fill with fluid and debris (consolidation)
    • Increased production of mucus (airway obstruction)
  • Normal O2 transport is affected, leading to clinical manifestations of hypoxia (e.g., tachypnea, dyspnea, tachycardia)
  • Resolution of infection
    • Macrophages in alveoli ingest and remove debris
    • Normal lung tissue restored
    • Gas exchange returns to normal