Severity staging of chronic obstructive pulmonary disease: differences in pre- and post-bronchodilator spirometry

• Published in: Yonsei medical journal 2009, 50(5), , pp.672-676
• Main Authors: Lin, Sheng-Hsiang, Kuo, Ping-Hung, Kuo, Sow-Hsong, Yang, Pan-Chyr
• Format: Article
• Language: English
• Subjects: Bronchodilator Agents; Fenoterol; Forced Expiratory Volume - drug effects; Humans; Original; Practice Guidelines as Topic; Prognosis; Pulmonary Disease, Chronic Obstructive - diagnosis; Spirometry - methods; 의학일반
• ISSN: 0513-5796; 1976-2437
• DOI: 10.3349/ymj.2009.50.5.672

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines for chronic obstructive pulmonary disease (COPD) uses the post-bronchodilator spirometry for diagnosis and severity staging. We evaluated differences in the severity classification of COPD, based on pre- and post-bronchodilator spirometry. From 2000 to 2004, 207 COPD patients who underwent spirometry before and after inhalation of 400 microg of fenoterol were analyzed. A responder to the bronchodilator test (BDT) was defined by the American Thoracic Society (ATS) as an increase in forced expiratory volume in one second (FEV(1)) or forced vital capacity > or = 12% and > or = 200 mL, and by the European Respiratory Society (ERS) as an increase in FEV(1) > or = 10% of the predicted value. COPD severity was classified according to the 2008 GOLD guidelines. For the entire study population, the FEV(1) increased by 11.8 +/- 12.5% of baseline after BDT and 41.1% and 27.1% of subjects were classified as responders using the ATS and ERS criteria, respectively. Based on pre-BDT spirometry, 55, 85, 58, and 9 patients were classified as Stage I-IV COPD, respectively. Sixty-seven (32.4%) patients changed severity staging after BDT, including 20.0%, 28.2%, 44.8%, and 66.7% of pre-BDT patients Stages I through IV, respectively. More ATS or ERS BDT-responders had a change in severity staging than non-responders (52.9% vs. 18.9% and 62.5% vs. 21.2%, both p < 0.001). Our data suggest that the severity staging of COPD using pre-BDT spirometry might lead to significant differences as compared to staging, based on post-BDT spirometry, as recommended by the current GOLD guidelines.