Pneumonia is an acute infection of the lung parenchyma causing alveolar inflammation, exudate formation, and impaired gas exchange. Community-acquired pneumonia (CAP) accounts for >1.5 million Canadian hospitalizations annually; healthcare-associated pneumonia (HCAP), hospital-acquired (HAP), and ventilator-associated pneumonia (VAP) carry higher mortality (15–50%) due to drug-resistant organisms. Hypoxemic respiratory failure develops when alveolar flooding creates intrapulmonary shunting — blood perfuses unventilated alveoli, bypassing gas exchange. Untreated or undertreated pneumonia rapidly progresses to sepsis, ARDS, and respiratory failure requiring mechanical ventilation. Top 3 oxygenation and monitoring priorities: (1) Continuous SpO₂ monitoring — target ≥94% (≥88–92% in COPD); (2) Assess work of breathing and access-to-oxygen escalation pathway; (3) Early recognition of sepsis (qSOFA ≥2) and rapid antibiotic administration within 1 hour. Common NCLEX trap: Students choose oxygen titration as the first intervention for a dyspneic pneumonia patient — WRONG if SpO₂ is already ≥94%. The priority is positioning (high Fowler's 90°) first to reduce work of breathing, then oxygen per titrated target. For COPD patients, target SpO₂ 88–92% — over-oxygenation eliminates hypoxic drive. On the exam, writers often pair stable-sounding options with unstable data—notice...