Clinical and Exacerbation Characteristics May Predict Treatment Response in Acute Exacerbations of COPD

COPD exacerbations are associated with high treatment failure. We examined clinical and exacerbation characteristics based on patients’ physiological response to treatment. Patients with an acute exacerbation of COPD (AECOPD) were recruited within 72 hours of hospitalisation (n=129). Exacerbation treatment was according to best practice. Bedside spirometry and COPD assessment test (CAT) were performed at recruitment and at discharge. Baseline demographic and medical data was collected. Mortality and hospital presentation for AECOPD within 90 days of discharge were recorded. Patients were categorised based on observed change in FVC; Group 1: ≥200ml (n=61); Group 2: 100-200ml (n=16); Group 3: ≤100ml (n=52). Clinical characteristics and outcomes were compared using multinomial logistic regression. Age, baseline lung function, exacerbation severity, comorbidity score, previous exacerbation rate and sex distribution were comparable across groups. At recruitment Group 3 had higher CAT score compared to Group 1, RR 1.06, p=0.024. However they had a smaller drop in FVC from baseline (5% vs 22.6%), RR 0.95, p=0.00 and were less hyperinflated (inspiratory capacity 1.77L vs 1.52L, RR 2.44, p=0.018). Ten percent of Group 3 patients died vs 3% (Group 1) and 0% (Group 2). More than 50% represented to hospital (Group 1:31%; Group 2:31%), RR 2.58 compared to Group 1, p=0.02. There were no significant clinical or exacerbation differences between Groups 2 and 1. COPD exacerbations are heterogeneous. Those with greater physiological impairment at onset have a greater treatment response and improved outcomes.