Exacerbations of COPD Diagnosed in Primary Care: Changes in Spirometry and Relationship to Symptoms

Abstract

The study objective was to assess spirometric changes during resolution of acute exacerbations of COPD diagnosed and treated in primary care and their relationship to clinical features. Spirometry was carried out on 101 patients with AECOPD presenting to a primary care physician on the day of presentation, days 5, 10–14, 28, and 56 after presentation and traces were analyzed including quality and reproducibility. Eighty-three patients produced at least one technically acceptable spirometer trace at presentation and 60 patients produced acceptable traces at all time points. The increase in FEV1 and VC occurred during the first 5 days after presentation, with a median increase in postbronchodilator FEV1 of 55 ml (IQR, −63 to 128, p = 0.003) and VC of 90 ml (IQR −78 to 308 ml, p < 0.001). The improvement in prebronchodilator values related to the bronchodilator reversibility at presentation and was strongest for VC (by day 28: r = 0.522, p < 0.001). Patients presenting with purulent sputum demonstrated improvements in FEV1 and VC but this was limited to FEV1 in those with mucoid sputum. The initial dyspnoea score related to the changes in spirometry. It is possible to obtain clinically useful spirometric traces in most patients presenting with an acute exacerbation in primary care. Some patients present with changes in sputum characteristics and cough without increased breathlessness. However, exacerbations characterized by increased breathlessness are associated with increases in airflow obstruction that may be influenced by sputum characteristics and/or changes in airway reactivity.