Chronic obstructive pulmonary disease (COPD) is characterized by persistent and progressive airflow limitation caused by an inflammatory response in the airways and the lungs to noxious particles or gases.As COPD progresses, patients may experience episodes of acute worsening of respiratory symptoms,which can result in hospital admission. Exacerbations of COPD impose a major burden on healthcare systems worldwide and account for more than 50% of the total cost of COPD. In a 2006 UK report,respiratory diseaseswere the most common cause of hospital admissions and COPD accounted for 2.6% of all emergency hospital admissions.1This issue is also topical in the US since the announcement in October 2015 that Medicare reimbursement will be reduced for acute care hospitals whose rates for COPD readmission exceed a predetermined threshold.
Exacerbations of COPD have a number of clinical implications. Many patients take more than a month to recover and some never return to their original level of symptoms.2Certain patients are particularly prone to exacerbations; these have been termed ‘frequent exacerbators’, have a decreased quality of life, faster disease progression and an increased mortality risk.3
In order to reduce hospital admissions in COPD, we need a clearer understanding of the factors that cause them. It has been estimated that 70–80% of COPD exacerbations are triggered by viral or bacterial respiratory infections.4 Risk factors include current smoking, older age at diagnosis, more severe COPD, low body mass index, increasing deprivation, previous COPD admissions and interventions, comorbidities, home oxygen use, a lung infection within the previous year, other chronic respiratory disease and a lack of routine physical exercise.5.6In addition, there is highrisk of recurrent exacerbations in the 8-week period after the initial exacerbation.2
At present, strategies aimed at preventing exacerbations are the best option for reducing hospital admissions; recommended strategies are discussed below and in the Global Initiative for ChronicObstructive Lung Disease (GOLD) guidelines.7In order to reduce hospitalisations and improve outcomes, early detection and interventionis critical.
Unfortunately, many patients with COPD do not report their exacerbations to their healthcare providers. There is a need to educate patients about the signs and symptoms of exacerbations and encourage them to seek advice at an early stage.
The most cost-effective nonpharmacological strategy to reduce hospital admissions is smoking cessation.8 Other strategies known to reduce hospitalisation include influenza and pneumococcal vaccination.2A recent systematic review and meta-analysis analysed studies of pulmonary rehabilitation. Results from randomised controlled trials suggested that pulmonary rehabilitation strategies reducehospital admissions in COPD admissions, but results from cohort studies did not.9This probably reflects the varying standard of pulmonary rehabilitation programmes, which should include exercise training, education, and behaviour change. Self-management strategies have hadmixed results: some studies showing a decrease in hospitalisation in people who learnt to self-manage,10 other suggesting that these strategies are potentially harmful.11 More studies are needed to optimise these approaches.
In terms of pharmacological interventions, long acting bronchodilators have been shown to reduce the incidence of exacerbations. These include the long-acting muscarinic antagonist (LAMA) tiotropium12 and the long-acting inhaled β2 agonist (LABAs)salmeterol, formoterol and indacaterol.13Inhaled corticosteroids (ICS) are also beneficial in CODP but their use is only recommended in combination with LABAs.7 Several combinations of LABAs, LAMAs and ICS have also been investigated.2 The phosphodiesterase 4 inhibitorroflumilast may also be used to reduce exacerbationsin patients with chronic bronchitis, severe airflow limitation, and frequent exacerbations that are not adequately controlled by long-acting bronchodilators.7 However, despite the routine use of this therapeutic intervention, the frequency of hospitalisations remains problematic.
Although not yet recommended for use, many other strategies are currently being explored to reduce exacerbations of COPD. These include the use of prophylactic antibiotics and the use of cardiovascular drugs such as statins and beta-blockers, but these strategies need further investigation.2
In conclusion, more studies are needed to clarify the role of self-management and pulmonary rehabilitation on reduction in exacerbations. However, some common themes have emerged. In particular, patient education regarding inhaler techniques and nutrition should begin in the hospital and requires prompt follow-up (ideally within 2 weeks of discharge).14Many pharmacological and nonpharmacological strategies are available to prevent exacerbations, but the degree of reduction of exacerbation frequency by such interventions is limited. There is a need for the development and validation of novel interventions.
Strategies to prevent exacerbations in COPD
Adapted from the GOLD guidelines7
Low Risk: ≤ 1 per year and no hospitalization for exacerbation: patient group A or B
High Risk: ≥ 2 per year or ≥ 1 with hospitalization: patient group C or D
1. British Thoracic Society, The Burden of Lung Disease. //www.brit-thoracic.org.uk/document-library/delivery-of-respiratory-care/burden-of-lung-disease/burden-of-lung-disease-2006 Accessed 24 August 2016, 2006;.
2. Qureshi H, Sharafkhaneh A, Hanania NA, Chronic obstructive pulmonary disease exacerbations: latest evidence and clinical implications, Ther Adv Chronic Dis, 2014;5:212-27.
3. Soler-Cataluna JJ, Martinez-Garcia MA, Roman Sanchez P, et al., Severe acute exacerbations and mortality in patients with chronic obstructive pulmonary disease, Thorax, 2005;60:925-31.
4. Sethi S, Murphy TF, Infection in the pathogenesis and course of chronic obstructive pulmonary disease, N Engl J Med, 2008;359:2355-65.
5. Hunter LC, Lee RJ, Butcher I, et al., Patient characteristics associated with risk of first hospital admission and readmission for acute exacerbation of chronic obstructive pulmonary disease (COPD) following primary care COPD diagnosis: a cohort study using linked electronic patient records, BMJ Open, 2016;6:e009121.
6. Bahadori K, FitzGerald JM, Levy RD, et al., Risk factors and outcomes associated with chronic obstructive pulmonary disease exacerbations requiring hospitalization, Can Respir J, 2009;16:e43-9.
7. Global Initiative for Chronic Obstructive Lung Disease, Pocket Guide to COPD Diagnosis, Management and Prevention, Updated 2015. //www.goldcopd.it/materiale/2015/GOLD_Pocket_2015.pdf Accessed 24 August 2016, .
8. Christenhusz LC, Prenger R, Pieterse ME, et al., Cost-effectiveness of an intensive smoking cessation intervention for COPD outpatients, Nicotine Tob Res, 2012;14:657-63.
9. Moore E, Palmer T, Newson DR, et al., Pulmonary rehabilitation as a mechanism to reduce hospitalizations for acute exacerbations of chronic obstructive pulmonary disease: A systematic review and meta-analysis, Chest, 2016;.
10. Bucknall CE, Miller G, Lloyd SM, et al., Glasgow supported self-management trial (GSuST) for patients with moderate to severe COPD: randomised controlled trial, BMJ, 2012;344:e1060.
11. Fan VS, Gaziano JM, Lew R, et al., A comprehensive care management program to prevent chronic obstructive pulmonary disease hospitalizations: a randomized, controlled trial, Ann Intern Med, 2012;156:673-83.
12. Vogelmeier C, Hederer B, Glaab T, et al., Tiotropium versus salmeterol for the prevention of exacerbations of COPD, N Engl J Med, 2011;364:1093-103.
13. Wang J, Nie B, Xiong W, et al., Effect of long-acting beta-agonists on the frequency of COPD exacerbations: a meta-analysis, J Clin Pharm Ther, 2012;37:204-11.
14. Postma D, Anzueto A, Calverley P, et al., A new perspective on optimal care for patients with COPD, Prim Care Respir J, 2011;20:205-9.