A pilot study to monitor changes in spirometry and lung volume, following an exacerbation of Chronic Obstructive Pulmonary Disease (COPD), as part of a supported discharge program.

ABSTRACT

BACKGROUND: One-third of patients with an exacerbation of Chronic Obstructive Pulmonary Disease(COPD) are re-hospitalised at 90 days. Exacerbation recovery is associated with reductions in lung hyperinflation and improvements in symptoms and physical activity. We assessed the feasibility of monitoring these clinical parameters in the home. We hypothesised that the degree of change in spirometry and lung volumes differs between those who had an uneventful recovery and those who experienced a further exacerbation. METHODS: Hospitalised patients with an acute exacerbation of COPD referred for a supported discharge program participated in the study. Spirometry and Inspiratory Vital Capacity(IVC) were measured in the home at Days 1, 14 and 42 post-discharge. Patients also completed Medical Research Council(MRC), Borg and COPD Assessment Test(CAT) scores and were provided with a tri-axial accelerometer. Any new exacerbation events were recorded. RESULTS: Sixty-five patients with 72 exacerbation episodes were recruited. Fifty percent experienced a second exacerbation. Adequate IVC measurements were achieved by 90%, while only 70% completed spirometry. Uneventful recovery was accompanied by significant improvements in physiological measurements at day14, improved symptom scores and step count, p < 0.05. Failure of MRC to improve was predictive of re-exacerbation(Area Under Receiver Operating Curve(AUROC) 0.6713) with improvements in FEV1≥100 ml(AUROC 0.6613) and mean daily step count ≥396 steps(AUROC 0.6381) predictive of recovery. CONCLUSION: Monitoring the pattern of improvement in spirometry, lung volumes, symptoms and step count following a COPD exacerbation may help to identify patients at risk of re-exacerbation. It is feasible to carry out these assessments in the home as part of a supported discharge programme.