Spirometry in chronic obstructive lung disease (COPD).

Introduction T common criterion recommended for diagnosis of chronic obstructive lung disease (COPD) is demonstration of “progressive irreversible airway obstruction” on spirometry. The Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) has recommended spirometry as the gold standard for diagnosis of COPD. However, spirometry is not widely available and spirometric test results are not always optimally recorded or interpreted except when performed by experienced personnel. Experts have differed on spirometric criteria for diagnosis of COPD. GOLD1 now recommends that post bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio of <0.70 must be used for diagnosing COPD. Demonstration of “irreversible airway obstruction” i.e. absence of bronchodilator reversibility is no more required for diagnosis of COPD. Although there is now a consensus; spirometric criteria continue to have limitations. The simplification of spirometry criteria by GOLD experts is perhaps to encourage spirometry for diagnosis of COPD in primary-care settings worldwide.2 However; widespread spirometric testing has resulted in a large number of individuals without respiratory symptoms, labeled as COPD.3 On the other hand physicians continue to diagnose COPD based solely on symptoms. Individuals with symptoms but normal spirometry were earlier included as “at risk” for COPD. The revised GOLD guidelines do not include this group as there is incomplete evidence that these cases always progress to COPD. The United States Preventive Services Task Force, an independent panel of experts in primary care and prevention that systematically reviews the evidence of effectiveness and develops recommendations for clinical preventive services suggest spirometry evaluation in a person presenting with shortness of breath, chronic cough, increased sputum production, wheezing, and/or a family history of alpha1-antitrypsin deficiency.4 A combination of symptoms and spirometry may therefore be a more relevant way of diagnosing COPD in individuals exposed to the causative factor. Role of spirometry in COPD requires basic understanding of spirometry, its importance in the management of COPD with knowledge of how to perform spirometry correctly and its interpretation (Chart). American Thoracic Society and European Spirometry in Chronic Obstructive Lung Disease (COPD)