The Common Vein

• Clinical Definition: Productive cough for at least 3 months in each of 2 consecutive years (where other causes of cough are excluded)
• One of the two main phenotypes of Chronic Obstructive Pulmonary Disease (COPD), often coexisting with emphysema

• Tobacco Smoke: Cigarette smoking is the primary cause (>90% of cases)
• Environmental: Long-term exposure to air pollution, industrial dusts, and chemical fumes
• Genetic: Alpha-1 Antitrypsin Deficiency (less common driver for pure bronchitis, more for emphysema)
• Infections: Recurrent pediatric respiratory infections may predispose to adult disease

• Chronic airflow obstruction (not fully reversible)
• Mucus hypersecretion and plugging
• V/Q mismatch (low V/Q areas) leading to hypoxemia and hypercapnia
• Increased pulmonary vascular resistance (hypoxic vasoconstriction)

• Mucous Gland Hypertrophy: Enlargement of submucosal glands (increased Reid Index >0.4)
• Goblet Cell Hyperplasia: Increased number of mucus-secreting cells in small airways
• Squamous Metaplasia: Loss of ciliated epithelium impairing clearance
• Fibrosis: Bronchiolar wall thickening and peribronchial fibrosis

• Chronic inhalation of irritants triggers sustained inflammation (neutrophils, macrophages, CD8+ lymphocytes)
• Oxidative stress promotes tissue damage and inflammation
• Protease-antiprotease imbalance
• Overproduction of mucus + impaired ciliary function = mucus retention
• Chronic hypoxemia leads to pulmonary hypertension and Cor Pulmonale (Right Heart Failure)

• Clinical: Based primarily on the history of productive cough (3 months/2 years)
• Spirometry (PFTs): Required for COPD diagnosis. Shows obstructive pattern (FEV₁/FVC < 0.70) that is not fully reversible
• Labs: CBC (polycythemia from chronic hypoxia), ABG (hypoxemia, hypercapnia)

• “Blue Bloater” (Classic Phenotype): Cyanosis (hypoxemia) and fluid retention (edema)
• Productive cough (sputum often typically white/mucoid, becoming purulent during exacerbations)
• Dyspnea on exertion (typically less severe than in “pure” emphysema)
• Signs of Right Heart Failure: Peripheral edema, elevated JVP
• Rhonchi and wheezing on auscultation

• “Dirty Lungs”: Prominent bronchovascular markings (irregular, coarse)
• Tram-tracking: Parallel linear densities representing thickened bronchial walls
• Cardiomegaly: Enlarged heart outline if Cor Pulmonale is present

CT Chest

• Bronchial Wall Thickening: Diffuse and circumferential
• No Emphysema: Absence of significant parenchymal destruction (in pure chronic bronchitis)
• Air Trapping: Mosaic attenuation on expiratory scans

• Smoking Cessation: The single most important intervention to slow progression
• Bronchodilators: LAMA (Long-acting muscarinic antagonists) and LABA (Long-acting beta-agonists)
• Inhaled Corticosteroids: For patients with frequent exacerbations or asthma overlap
• Phosphodiesterase-4 Inhibitors: Roflumilast (for severe cases)
• Oxygen Therapy: If resting SaO2 ≤ 88% (to improve survival)
• Pulmonary Rehabilitation: To improve exercise tolerance
• Antibiotics/Steroids: During acute exacerbations