New GOLD standard in COPD guidelines

In late 2016, the Global Initiative for Chronic Obstructive Lung Disease guidelines were updated.¹ This article addresses the changes in these guidelines and the implication for clinical practice. 

Definition of COPD

The definition of COPD has been revised to recognise the importance of precipitating factors. ‘COPD is a common, preventable and treatable disease that is characterised by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles or gases. The chronic airflow limitation that is characteristic of COPD is caused by a mixture of small airways disease (eg. obstructive bronchiolitis) and parenchymal destruction (emphysema), the relative contributions of which vary from person to person”.^1,2

The risk of developing COPD is related to tobacco smoke, indoor air pollution, occupational exposures, outdoor air pollution, genetic factors, age and gender, lung growth and development, socioeconomic status, asthma and airway hyper-reactivity, chronic bronchitis and infections. 

ABCD assessment tool

The assessment of COPD has been refined to include assessment of symptoms and risk of future exacerbations. With the original assessment tool, it was sometimes difficult to classify patients as some patients fell into more than one group. The spirometric assessment has been removed from the assessment tool which has simplified the classification. However, spirometry is still required for confirmation of diagnosis and to assess severity of airflow limitation (Figure 1). Spirometric assessment is based on post-bronchodilator FEV1/FVC ratio less than 70%.

To assess symptoms, two assessment tools are used – the Medical Research Council Scale and the COPD Assessment Test. Exacerbation history is based on the number of exacerbations in the previous 12 months. Figure 2 illustrates the revised ABCD classification. The revised tool provides a more individualised approach to patient assessment and management.

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Pharmacological treatment 

Bronchodilator therapy remains the mainstay in the management of stable COPD. Pharmacological therapies are used to reduce symptoms, reduce the severity and frequency of exacerbations, and to improve exercise tolerance and health status. The main groups of medications include:

• Beta-agonists – these relax smooth muscle by stimulating the beta-2 adrenergic receptors. Beta-agonists can be classified into short-acting (SABA) and long-acting (LABA), eg. salbutamol (SABA), salmeterol (LABA), indacaterol (LABA), vilanterol (LABA), formoterol (LABA), olodaterol (LABA)•
• Antimuscarinic drugs block the bronchoconstrictor effects of acetylcholine on M3 muscarinic receptors. These can also be classified into short-acting (SAMA) and long-acting (LAMA), eg. ipratropium (SAMA), tiotropium (LAMA), umeclidinium (LAMA), aclidinium bromide (LAMA), glycopyrronium (LAMA)
• Combining bronchodilators may increase the degree of bronchodilation while lowering the risk of side effects compared to increasing the dose of a single bronchodilator agent
• Methylxanthines – this group of drugs remain controversial as to their mechanism of action. There is evidence of bronchodilation in stable COPD. Theophylline is the most commonly used. However, there are significant drug interactions with its use and clearance of the drug declines with age
• Inhaled corticosteroids (ICS) should not be used as a single agent in the management of COPD. In patients with moderate to severe COPD, the use of ICS combined with a LABA is more effective than using either agent alone in improving lung function, health status and reducing exacerbations.¹

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To date, there is no conclusive clinical trial evidence that any existing medications for COPD modify the long-term decline in lung function.¹

Pharmacological algorithms are given for the initiation, escalation or de-escalation of treatment according to the individual assessment of symptoms and exacerbation risk. In previous publications of GOLD reports, recommendations were only given for treatment initiation. Table 1 illustrates the pharmacological treatment options according to the patient’s COPD classification. 

Inhaler technique

The use of multiple devices, lack of education on technique and older age may lead to poor inhaler technique. Assessment and regular review of inhaler technique has been added to the guidelines in an attempt to improve therapeutic outcomes. To improve technique, it is recommended that patients are educated and trained with the appropriate devices. The choice of device should be tailored to the individual depending on the patient’s ability to use it and taking their preference into account. 

Nonpharmacologic therapies 

There is increased evidence for pulmonary rehabilitation, self-management, integrated care and palliative care. Pulmonary rehabilitation has been shown to be the most effective intervention to improve dyspnoea, exercise tolerance and health status.³

Management of co-morbidities

Many patients with COPD have a co-existing illness such as diabetes, cardiovascular disease, osteoporosis or depression, to mention but a few. In general, the presence of co-morbidities should not affect COPD treatment and co-morbidities should be treated according to standards and guidelines. Lung cancer is common in patients with COPD. Gastro-oesophageal reflux is common and is associated with an increased risk of exacerbations and therefore should be managed optimally. 

Osteoporosis is common due to recurrent use of oral steroids, lack of weight bearing exercise and being over or underweight. GOLD recommends that treatments for co-morbidities should kept as simple as possible to avoid polypharmacy.¹

Conclusion

This article has focused on the GOLD (2017) guidelines for the diagnosis, management and prevention of COPD. The definition, classification, pharmacological, non-pharmacological, the importance of inhaler technique and co-morbidities have been addressed. 

There have been significant changes to the assessment tool which has simplified the classification of COPD which will enable practitioners to individualise the patient’s management and treatment and ultimately improve patient outcomes and quality of life.

References

1. Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017. Available from: http://www.goldcopd.org
2. Vogelmeier CF, Criner GJ, Martinez FJ et al. (2017) Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary. European Respiratory Journal.
3. McCarthy B, Casey D, Devane D et al. (2015) Pulmonary rehabilitation for chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews (2)