Clinical meaning
Chronic Obstructive Pulmonary Disease encompasses chronic bronchitis (excessive mucus production with productive cough for ≥ 3 months in 2 consecutive years) and emphysema (destruction of alveolar walls leading to air trapping). Chronic inflammation driven primarily by cigarette smoke causes goblet cell hyperplasia, smooth muscle hypertrophy, and loss of elastic recoil. Over time, patients develop a hypoxic drive where low oxygen (rather than high CO2) triggers breathing.
Exam relevance
Risk factors: - Cigarette smoking (primary cause, > 80% of cases) - Secondhand smoke exposure - Occupational dust and chemical exposure - Indoor air pollution (biomass fuels) - Alpha-1 antitrypsin deficiency - History of frequent respiratory infections - Age > 40 years
Diagnostics: - Monitor respiratory rate, depth, and pattern - Monitor oxygen saturation (target 88-92% for known CO2 retainers) - Observe for accessory muscle use, pursed-lip breathing, barrel chest - Auscultate breath sounds and report diminished sounds or wheezing - Monitor sputum color, amount, and consistency - Assess for peripheral edema (sign of right heart failure)