Clinical phenotypes in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous disease, that is defined by the degree of obstruction rendered by the forced expiratory volume in the first second (FEV1). This is a good parameter to define the severity of the disease but does not account for its heterogeneity and does not provide a good comprehension of its different clinical behaviors and responses to treatment. Therefore, the classification of these patients in different clinical phenotypes has been attempted, trying to search for common clinical behaviors and responses to treatment. These phenoptypes must be validated in longitudinal studies. Some of the phenotypes detected are COPD with chronic respiratory failure and responsive to home oxygen therapy, COPD with upper lobe emphysema and responsive to volume reduction surgery, COPD with frequent exacerbation behavior, COPD resembling bronchitis and responsive to Roflumilast and possibly, COPD with systemic involvement. Historically, the phenotypes pink puffer, blue bloater, chronic bronchitis were defined. In the next years, we will know if the definitions of these phenotypes will aid in the management of patients with COPD. (Rev Med Chile 2012; 140: 926-933).