OBJECTIVES: Exacerbations of chronic obstructive pulmonary disease (COPD) are common in emergency departments (ED). Guidelines recommend administration of inhaled bronchodilators, systemic corticosteroids and antibiotics along with non-invasive ventilation (NIV) for patients with respiratory acidosis. We aimed to determine compliance with guideline recommendations for patients with treated for COPD in ED in Europe (EUR) and South East Asia/Australasia (SEA) and to compare management and outcomes. METHODS: In each region, an observational prospective cohort study was performed that included patients presenting to EDs with the main complaint of dyspnoea during three 72-hour periods. This planned sub-study included those with an ED primary discharge diagnosis of COPD. Data were collected on demographics, clinical features, treatment, disposition and in-hospital mortality. We determined overall compliance with guideline recommendations and compared treatments and outcome between regions. RESULTS: 801 patients were included from 122 EDs (66 EUR and 46 SEA). Inhaled bronchodilators were administered to 80.3% of patients, systemic corticosteroids to 59.5%, antibiotics to 44% and 60.6% of patients with pH <7.3 received NIV. The proportion administered systemic corticosteroids was higher in SEA (EUR vs. SEA for all comparisons; 52% vs. 66%, p<0.001) as was administration of antibiotics (40% vs. 49%, p=0.02). Rates of NIV and mechanical ventilation were similar. Overall in-hospital mortality was 4.2% (SEA 3.9% vs. EUR 4.5%, p=0.77). CONCLUSION: Compliance with guideline recommended treatments, in particular administration of corticosteroids and NIV, was sub-optimal in both regions. Improved compliance has the potential to improve patient outcome. This article is protected by copyright. All rights reserved.