TY - CHAP M1 - Book, Section TI - Chronic Obstructive Pulmonary Disease: Epidemiology, Pathophysiology, Pathogenesis, and α1-Antitrypsin Deficiency A1 - Senior, Robert M. A1 - Pierce, Richard A. A1 - Atkinson, Jeffrey J. A2 - Grippi, Michael A. A2 - Elias, Jack A. A2 - Fishman, Jay A. A2 - Kotloff, Robert M. A2 - Pack, Allan I. A2 - Senior, Robert M. A2 - Siegel, Mark D. PY - 2015 T2 - Fishman's Pulmonary Diseases and Disorders, 5e AB - Chronic obstructive pulmonary disease (COPD) is defined as a disease state characterized by airflow obstruction that is not fully reversible and for which there is no other explanation for the obstruction. The obstruction is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles and gas. Unlike earlier definitions, this definition does not mention emphysema or chronic bronchitis. According to criteria set by the Global Initiative for Obstructive Lung Disease,1 airflow obstruction is present when there is a reduction of the postbronchodilator FEV1/FVC ratio below 0.7 and its severity is graded by the percentage of the postbronchodilator FEV1 of the predicted normal FEV1 (Table 40-1). However, 0.7 as the cutoff value for the FEV1/FVC ratio has been controversial as it may be too high for all age groups and lead to misdiagnosis of COPD in healthy middle-aged and older individuals.2 Alternatively, use of the lower limit of normal (LLN) for the FEV1/FVC ratio has been recommended,3 but it is uncertain whether this criterion improves the detection of clinically significant COPD or prognosis in elderly individuals.4,5 Classification of COPD by GOLD has undergone further refinement recently with addition of self-reported severity of dyspnea and history of COPD exacerbations.1Chapter 42 comments further about risk stratification.6 SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1122358782 ER -