Physiological and radiological characterisation of patients diagnosed withchronic obstructive pulmonary disease in primary care

Background-Chronic obstructive pulmonary disease (COPD) is common although often poorly characterised, particularly in primary care. However, applicat ion of guidelines to the management of such patients needs a clear understa nding of the phenotype. In particular, the British guidelines for the manag ement of COPD recommend that the diagnosis is based on appropriate symptoms and evidence of airflow obstruction as determined by a forced expiratory v olume in one second (FEV1) of <80% of the predicted value and an FEV1/VC ra tio of <70%. Methods-A study was undertaken of 110 patients aged 40-80 years who had pre sented to their general practitioner with an acute exacerbation of COPD. Th e episode was treated at home and, when patients had recovered to the stabl e state (two months later), they were characterised by full lung function t ests and a high resolution computed tomographic (HRCT) scan of the chest. Results-There was a wide range of impairment of FEV1 which was in the norma l range (greater than or equal to 80%) in 30%, mildly impaired (60-79%) in 18%, moderately impaired (40-59%) in 33%, and severely impaired (<40%) in 1 9% of patients. A reduced FEV1/VC ratio was present in all patients with an FEV1 of <80% predicted but also in 41% of those with an FEV1 of greater th an or equal to 80% predicted. Only 5% of patients had a substantial broncho dilator response suggesting a diagnosis of asthma. Emphysema was present in 51% of patients and confined to the upper lobes in most (73% of these pati ents). HRCT evidence of bronchiectasis was noted in 29% of patients and was predominantly tubular; most (81%) were current or ex-smokers. A solitary p ulmonary nodule was seen on 9% of scans and unsuspected lung malignancy was diagnosed in two patients. Conclusions-This study confirms that COPD in primary care is a heterogeneou s condition. Some patients do not fulfil the proposed diagnostic criteria w ith FEV1 of greater than or equal to 80% predicted but they may nevertheles s have airflow obstruction. Bronchiectasis is common in this group of patie nts, as is unsuspected malignancy. These findings should be considered when developing recommendations for the investigation and management of COPD in the community.