EDITORIAL
INT J TUBERC LUNG DIS 18(12):1387 Q 2014 The Union http://dx.doi.org/10.5588/ijtld.14.0762
COPD exacerbations: reducing the burden by predicting the future? THE GLOBAL human and economic costs of chronic obstructive pulmonary disease (COPD) are enormous. In the United States, COPD is responsible for more than 130 000 deaths and 715 000 hospitalizations each year, at an economic cost of US$50 billion/year; US$30 billion of these costs are direct health care expenditures related largely to the management of ‘acute lung attacks’, more commonly known as exacerbations.1 Although most exacerbations are minor and can be treated at home with increased use of bronchodilators or institution of antibiotics and/or systemic corticosteroids, some episodes are fraught with severe breathlessness and malaise, leading to urgent emergency visits, hospitalizations and even death. There are interventions that can reduce the risk of exacerbations and death; however, their maximal benifits occur when they are implemented at the earliest point of an exacerbation. Unfortunately, identifying severe exacerbations before the onset of severe symptoms is no easy feat. At present, few tools exist for clinicians to predict imminent exacerbations, with only a prior history of exacerbation demonstrating any clinically useful value for future risk.2 We fare no better at diagnosing exacerbations. Unlike myocardial infarctions or congestive heart failure, in which simple blood-based tests can provide accurate diagnostic information, we lack a similar test for COPD exacerbations. At best, we are left with clinical judgment to surmise the most likely cause for symptoms as non-specific as cough and dyspnea. In this issue, two studies add to our current body of knowledge on COPD exacerbations. The first, by Oh et al.,3 addresses our present deficiencies in identifying frequent exacerbators. In a cohort of 380 COPD patients, emphysema severity as visualized on computed tomographic (CT) imaging was found to be strongly predictive of developing frequent exacerbations. The second study, by Quintana et al.,4 evaluates easily obtained clinical characteristics associated with poor clinical outcomes during COPD exacerbations. A greater risk of death was found with increased age, use of chronic oxygen therapy or non-invasive mechanical ventilation, use of accessory muscles on presentation, and altered neurologic status. The authors propose that together these characteristics could form a simple clinical tool to identify severe COPD exacerbations that require urgent and maximal medical intervention.
Both studies aid in our ability to identify those COPD patients at greatest risk for the worst clinical outcomes. Nonetheless, the work is far from complete. Not only should we identify the frequent exacerbators, but early recognition of an impending COPD exacerbation should be the next steps from the work of Oh et al. and Quintana et al. Can we learn to predict imminent COPD exacerbations, to avoid ever reaching the stage where we triage by respiratory failure and neurologic compromise (by then possibly far too late to meaningfully alter outcomes)? Is there an equivalent troponin or a B-type natriuretic peptide for COPD exacerbations that can help us intervene before it’s too late? Such a tool, implemented far before the onset of severe symptoms, would surely save lives and reduce the permanent morbidities that are the consequences of severe lung attacks. JANICE M. LEUNG, MD* DON D. SIN, MD MPH*† *Centre for Heart Lung Innovation, St. Paul’s Hospital †Division of Respiratory Medicine University of British Columbia and St. Paul’s Hospital Vancouver, BC Canada e-mail: [email protected] Acknowledgements DDS is a Canada Research Chair in COPD and JML is a fellow with the Michael Smith Foundation for Health Research. Conflict of interest: DDS has served on the advisory board of Almirall and has received research funding from AstraZeneca over the past 36 months.
References 1 American Lung Association. Chronic obstructive pulmonary disease (COPD) fact sheet. Chicago, IL, USA: ALA, 2014. http:// www.lung.org/lung-disease/copd/resources/facts-figures/COPDFact-Sheet.html Accessed October 2014 2 Hurst J R, Vestbo J, Anzueto A, et al. Susceptibility to exacerbation in chronic obstructive pulmonary disease. N England J Med 2010; 363: 1128–1138. 3 Oh Y M, Sheen S S, Park J H, et al. Emphysematous phenotype is an independent predictor for frequent exacerbation of COPD. Int J Tuberc Lung Dis 2014; 18: 1407–1414. 4 Quintana J, Esteban C, Unzurrunzaga A, et al. Prognostic severity scores for patients with COPD exacerbations attending emergency departments: a prospective study. Int J Tuberc Lung Dis 2014; 18: 1415–1420.
INT J TUBERC LUNG DIS 18(12):1387 Q 2014 The Union http://dx.doi.org/10.5588/ijtld.14.0762
COPD exacerbations: reducing the burden by predicting the future? THE GLOBAL human and economic costs of chronic obstructive pulmonary disease (COPD) are enormous. In the United States, COPD is responsible for more than 130 000 deaths and 715 000 hospitalizations each year, at an economic cost of US$50 billion/year; US$30 billion of these costs are direct health care expenditures related largely to the management of ‘acute lung attacks’, more commonly known as exacerbations.1 Although most exacerbations are minor and can be treated at home with increased use of bronchodilators or institution of antibiotics and/or systemic corticosteroids, some episodes are fraught with severe breathlessness and malaise, leading to urgent emergency visits, hospitalizations and even death. There are interventions that can reduce the risk of exacerbations and death; however, their maximal benifits occur when they are implemented at the earliest point of an exacerbation. Unfortunately, identifying severe exacerbations before the onset of severe symptoms is no easy feat. At present, few tools exist for clinicians to predict imminent exacerbations, with only a prior history of exacerbation demonstrating any clinically useful value for future risk.2 We fare no better at diagnosing exacerbations. Unlike myocardial infarctions or congestive heart failure, in which simple blood-based tests can provide accurate diagnostic information, we lack a similar test for COPD exacerbations. At best, we are left with clinical judgment to surmise the most likely cause for symptoms as non-specific as cough and dyspnea. In this issue, two studies add to our current body of knowledge on COPD exacerbations. The first, by Oh et al.,3 addresses our present deficiencies in identifying frequent exacerbators. In a cohort of 380 COPD patients, emphysema severity as visualized on computed tomographic (CT) imaging was found to be strongly predictive of developing frequent exacerbations. The second study, by Quintana et al.,4 evaluates easily obtained clinical characteristics associated with poor clinical outcomes during COPD exacerbations. A greater risk of death was found with increased age, use of chronic oxygen therapy or non-invasive mechanical ventilation, use of accessory muscles on presentation, and altered neurologic status. The authors propose that together these characteristics could form a simple clinical tool to identify severe COPD exacerbations that require urgent and maximal medical intervention.
Both studies aid in our ability to identify those COPD patients at greatest risk for the worst clinical outcomes. Nonetheless, the work is far from complete. Not only should we identify the frequent exacerbators, but early recognition of an impending COPD exacerbation should be the next steps from the work of Oh et al. and Quintana et al. Can we learn to predict imminent COPD exacerbations, to avoid ever reaching the stage where we triage by respiratory failure and neurologic compromise (by then possibly far too late to meaningfully alter outcomes)? Is there an equivalent troponin or a B-type natriuretic peptide for COPD exacerbations that can help us intervene before it’s too late? Such a tool, implemented far before the onset of severe symptoms, would surely save lives and reduce the permanent morbidities that are the consequences of severe lung attacks. JANICE M. LEUNG, MD* DON D. SIN, MD MPH*† *Centre for Heart Lung Innovation, St. Paul’s Hospital †Division of Respiratory Medicine University of British Columbia and St. Paul’s Hospital Vancouver, BC Canada e-mail: [email protected] Acknowledgements DDS is a Canada Research Chair in COPD and JML is a fellow with the Michael Smith Foundation for Health Research. Conflict of interest: DDS has served on the advisory board of Almirall and has received research funding from AstraZeneca over the past 36 months.
References 1 American Lung Association. Chronic obstructive pulmonary disease (COPD) fact sheet. Chicago, IL, USA: ALA, 2014. http:// www.lung.org/lung-disease/copd/resources/facts-figures/COPDFact-Sheet.html Accessed October 2014 2 Hurst J R, Vestbo J, Anzueto A, et al. Susceptibility to exacerbation in chronic obstructive pulmonary disease. N England J Med 2010; 363: 1128–1138. 3 Oh Y M, Sheen S S, Park J H, et al. Emphysematous phenotype is an independent predictor for frequent exacerbation of COPD. Int J Tuberc Lung Dis 2014; 18: 1407–1414. 4 Quintana J, Esteban C, Unzurrunzaga A, et al. Prognostic severity scores for patients with COPD exacerbations attending emergency departments: a prospective study. Int J Tuberc Lung Dis 2014; 18: 1415–1420.
