COPD phenotypes: Blue Bloaters vs. Pink Puffers The two most stereotypical forms of COPD are pink puffers and blue bloaters, as shown above (4). These patients have different physiology and clinical presentation: - Pink Puffers: These patients have classic “dry emphysema,” with destruction of the alveoli causing ineffective CO2 clearance and airway obstruction. Patients are trying to maintain a near-normal PaCO2, causing chronic dyspnea (eventually leading to weight loss from persistently increased work of breathing). Overall this physiological derangement is similar to asthma as discussed above. The primary life-threat is increased work of breathing leading to diaphragmatic exhaustion. These patients present with respiratory distress and tachypnea. - Blue Bloaters: These patients have an overlap syndrome of COPD plus obesity-hypoventilation syndrome. The combination of obesity plus airflow obstruction causes a dramatic increase in the work of breathing, which is the dominant physiologic problem. To adapt, patients develop substantial chronic hypercarbia. When these patients decompensate, they manifest with severe hypercapnia, hypoventilation, and obtundation. #Diagnosis #COPD #PinkPuffers #BlueBloaters #Comparison #Phenotypes