Diagnose It Answer — April 18, 2026

72-year-old male presents with a 4-day history of worsening dyspnea and increased sputum production. Today his breathing has become severe at rest. He is using pursed-lip breathing and is leaning forward with hands on his knees. He describes his cough as 'thick and green' — much worse than his usual morning cough. He denies chest pain or rigors.

50 pack-year smoking history, quit 5 years ago. Diagnosed with severe COPD (GOLD Stage III) — FEV1/FVC 0.58, FEV1 42% predicted on last PFTs. Uses tiotropium inhaler daily, fluticasone/salmeterol combination, and albuterol PRN (states he has been using his rescue inhaler 'constantly' for the past two days without relief). Had a similar exacerbation requiring hospitalization last winter.

BP 138/84 mmHg, HR 102 bpm, RR 30 breaths/min (labored), Temp 37.8°C, SpO2 84% on room air — cautiously titrated to 88–92% on 2L nasal cannula (avoiding hyperoxia). Patient is barrel-chested, visibly air-hungry, and using sternocleidomastoid and intercostal muscles with each breath.

Diffuse expiratory wheezing bilaterally with markedly prolonged expiration. Decreased air entry at both bases. No crackles. Percussion: bilateral hyperresonance consistent with air trapping. Accessory muscle use persists despite nebulized albuterol/ipratropium given back-to-back x3. IV methylprednisolone 125mg given. Azithromycin 500mg PO started empirically for presumed bacterial trigger. Pursed-lip breathing coaching provided. Pulse oximetry target 88–92% — rationale explained to patient and nurse.

ABG on 2L NC: pH 7.34, PaCO2 58 mmHg (hypercapnia — chronic compensated; baseline CO2 likely 48–50), PaO2 54 mmHg, HCO3 31 mEq/L (elevated — chronic metabolic compensation). Sputum: purulent, Gram stain pending. WBC 11,800/µL with mild left shift. CRP 48 mg/L. Procalcitonin 0.8 ng/mL (modest elevation). Chest X-ray: bilateral hyperinflation, flattened diaphragms, increased AP diameter, increased lung markings — no consolidation, no pneumothorax.