The clinical journey of patients with a severe exacerbation of Chronic Obstructive Pulmonary Disease (COPD): from the ambulance to the emergency department to the hospital ward

Abstract

Introduction:Chronic obstructive pulmonary disease (COPD) is a common respiratory condition that causes significant morbidity and mortality in Australia and worldwide. Exacerbations of COPD are acute complications of this chronic lung condition that often require emergency management by ambulance, emergency department (ED) and hospital services. Given the high morbidity and mortality experienced by patients with COPD, better understanding of the epidemiology of these patients presenting for emergency healthcare is required, as well as identification of predictive factors for adverse outcomes from exacerbations of COPD. Methods:This Master of Philosophy project involved a retrospective observational study of patients who presented to an ED in the state of Queensland and received either an ED or hospital diagnosis of COPD in 2015 and 2016. Administrative data from the ambulance, ED, hospital and death registry databases were linked to provide a comprehensive picture of the emergency pathway for patients experiencing an exacerbation of COPD. The linked data were then analysed for epidemiological trends and multivariate logistic regression analyses were completed to identify predictive factors for adverse health outcomes for these patients.Results:16,166 patients (49% female and 51% male) had 29,332 presentations to an ED in Queensland and received either an ED or hospital principal diagnosis of COPD during 2015 and 2016. These patients had a significant comorbidity burden with 54% having two or more comorbidities and 27% having ten or more. Greater than ten comorbidities was associated with increased odds of having more than one admission (OR 4.3, 95%CI 3.1-5.8), longer than average length of stays (OR 22.1, 95%CI 18.1-27.2) and all-cause mortality (OR 5.3, 95%CI 4.2-6.8). Furthermore, these patients had high rates of current and prior smoking, with smoking associated with increased odds of more than one admission (OR 2.3, 95%CI 1.9-2.7). Of the ED presentations, 69% involved ambulance transport, much higher than the national all cause presentation rate of 25%, and most of these (74%) involved administration of oxygen and/or other medications by paramedics. Pre-hospital oxygen administration was associated with having greater than one admission (OR 1.3, 95%CI 1.1-1.5), greater than average lengths of stay (OR 1.5, 95%CI 1.3-1.6) and mortality (OR 1.6, 95%CI 1.5-1.8). These patients had significant rates of admission with 86% receiving ongoing care including hospital, short stay or observation ward admission or inter-hospital transfer. Of the ambulance presentations, 90% were admitted or received ongoing care compared with 75% of patients who self-presented (OR 31.9, 95% CI 29.8-34.1). Finally, once discharged, these patients had high rates of re-presentation within 48 hours or 30 days, with patients discharged from the ED having higher re-presentation rates than patients discharged from an admission, short stay or observation unit. Conclusions:COPD places considerable burden on the emergency healthcare pathway including ambulances and EDs in Queensland. Patients with COPD most commonly present to the ED by ambulance and receive extensive pre-hospital management. These patients have significant comorbidities and experience high rates of admission and mortality. More research is required to investigate the emergency pathway and enhance healthcare practice and policy for COPD management.