Chronic obstructive pulmonary disease (COPD) is a preventable and treatable condition defined by persistent, usually progressive airflow limitation that is not fully reversible. It is a leading cause of death in the United States and worldwide, and it is a high-frequency NCLEX-RN topic because so much of its management depends on safe nursing judgment, particularly around oxygen delivery. COPD encompasses two clinical phenotypes that frequently overlap in the same person: - Emphysema: destruction of alveolar walls leads to loss of elastic recoil, air trapping, and hyperinflation. The classic picture is a thin, barrel-chested person who uses pursed-lip breathing and has minimal cough — sometimes described as a 'pink puffer.' - Chronic bronchitis: chronic airway inflammation and mucus hypersecretion produce a productive cough on most days for at least three months per year over two or more consecutive years. The classic picture is a person who is overweight with a chronic productive cough and cyanosis — sometimes described as a 'blue bloater.' The single most important modifiable risk factor is cigarette smoking, which accounts for roughly 85 percent of cases. Other...