Chronic Obstructive Pulmonary Disease

Definition and epidemiology (Lancet 2017;389:1931)

  • Progressive airflow limitation caused by airway and parenchymal inflammation
Emphysema vs. Chronic Bronchitis
Emphysema Chronic Bronchitis
Definition Dilation/destruction of parenchyma (path definition) Productive cough >3 mo/y × ≥2 y (clinical definition)
Pathophysiology Tissue destruction
V/Q: ↑ dead space fraction → hypercarbia, but only mild hypoxemia
Small airways affected V/Q: ↑ shunt fraction → severe hypoxemia, hypercapnia PHT, cor pulmonale
Clinical manifestations Severe, constant dyspnea
Mild cough
Intermittent dyspnea
Copious sputum production
Physical exam “Pink puffer”
Tachypneic, noncyanotic, thin
Diminished breath sounds
“Blue bloater”
Cyanotic, obese,