Clinical meaning
Pneumonia is an infection of the lung parenchyma causing inflammation and consolidation (filling of alveoli with fluid, white blood cells, and debris). Bacteria, viruses, or fungi enter the lungs through inhalation or aspiration, overwhelming local defense mechanisms. The inflammatory response causes alveolar edema, impaired gas exchange, and the characteristic productive cough with purulent sputum. Community-acquired pneumonia (CAP) is the most common type.
Exam relevance
Risk factors: - Age > 65 years - Chronic lung disease (COPD, asthma) - Smoking - Impaired immune system - Dysphagia or risk for aspiration - Recent hospitalization - Poor oral hygiene - Immobility
Diagnostics: - Monitor temperature (fever is common but may be absent in elderly) - Monitor respiratory rate, effort, and oxygen saturation - Auscultate breath sounds (listen for crackles over affected area) - Monitor sputum characteristics (color, amount, odor) - Report changes in mental status (may be first sign in elderly)