Management of COPD

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in the UK and worldwide. It is estimated to cost the NHS over £800 million annually, with nearly 24,000 attributable deaths in 2010,¹ making it the fourth biggest cause of years of life lost in the UK.²

Despite the burden of COPD, many patients remain undiagnosed and suffer significant disability without having adequate treatment. It is estimated that 4.7% of patients in a general practice will have clinically significant COPD,³ but this is just the tip of the iceberg that underestimates the prevalence of the disease in the community.

COPD is a preventable and treatable disease with multisystem effects. The pulmonary component is characterised by airflow limitation that is not fully reversible and is usually progressive over time.⁴ The major cause is smoking,⁵ but occupational and environmental factors are well recognised.^6,7

The aim of management is to identify patients early in the course of disease, when risk factors can be controlled and potential disability prevented. Once diagnosed, the aim is to relieve symptoms, improve exercise capacity and functional ability and, to prevent and treat complications.

Further reading: The rise of COPD in elderly women

Diagnosing COPD

History

Many patients with COPD have symptoms long before they are diagnosed. Cough and breathlessness are the predominant symptoms that tend to gradually worsen over time as lung function declines. Cough may be productive of sputum that is usually low volume. Typically there is a steady decline in symptoms and function, punctuated by exacerbations. These are characterised by an increase in breathlessness and a change in the volume and/or colour of sputum, and may be diagnosed as chest infections or winter bronchitis prior to the diagnosis of COPD.⁴

Weight loss and anorexia are common in advanced disease, but patients are also at an increased risk of malignancy, and symptoms suggestive of malignancy should be investigated further. Cardiovascular disease and depression are common comorbidities in patients with COPD and evidence of these should be sought in the history.

Examination findings

Physical examination findings in COPD are variable and rarely diagnostic.⁴ A prolonged expiratory phase is common and bilateral polyphonic wheeze may be heard. In advanced disease, signs of hyperinflation such as “barrel chest” (increased antero-posterior diameter), hyper-resonant percussion note and reduced breath sounds may be observed. Patients may use accessory muscles and pursed lip breathing to help relieve breathlessness. The presence of peripheral oedema may indicate cor pulmonale.⁸

Differential diagnosis

The diagnosis of COPD is usually straightforward from the history and spirometry. However it may be difficult to separate patients with chronic asthma from COPD, and indeed sometimes they co-exist. Asthma typically presents from a younger age. Symptoms in COPD tend to be progressive whereas asthma symptoms vary from day to day and have a more marked diurnal variation. This reflects reversible airflow obstruction in asthma in contrast to the relatively fixed airflow obstruction seen in COPD. A caveat to this is seen in longstanding, poorly controlled asthma where little or no reversibility may be seen.⁹ A significant smoking history is usually present in COPD and is variably present in asthma. A history of allergy, rhinitis, eczema or a family history of asthma is more common in asthmatic patients.

Investigations

Post-bronchodilator spirometry should be performed in all patients in whom there is a suspicion of COPD. The Forced Expiratory Volume in 1 second (FEV1) and Forced Vital Capacity (FVC) are measured and a predicted value based on age and height is calculated. Airflow obstruction is present when the ratio of absolute FEV1/FVC is less than 0.7. However, in elderly patients a ratio of <0.7 may be normal and hence COPD may be overdiagnosed in these patients.¹⁰ The severity of airflow obstruction is given by the percentage predicted of FEV1 (Box 1). Formal reversibility testing is not required unless there is a suspicion of asthma. A chest radiograph is not diagnostic in COPD but may show evidence of hyperinflation. It is useful to rule out other co-existing chest pathologies.

Functional assessments of dyspnoea using the modified Medical Research Council grading and exercise tolerance using a six-minute walk test are helpful. Combined with body mass index (BMI) and percent predicted FEV1, they contribute to the BODE index, which enables an estimation of survival (BMI, Degree of Obstruction, Dyspnoea, Exercise tolerance).¹¹ Additional investigations and their indications are considered in Box 2.

COPD: red flags

Patients with COPD have a multisystem disease and exposure to cigarette smoke, which is a strong risk factor for many other diseases. Haemoptysis may occur during exacerbations, but can also be an indicator of lung cancer. Patients should be urgently assessed and evaluated with a chest radiograph, and considered for computerised tomography (CT) of the chest and bronchoscopy.¹² A history of copious sputum and recurrent infections raises the possibility of bronchiectasis and should be evaluated by high-resolution CT. Where there is clinical evidence of cor pulmonale (raised jugular venous pressure, peripheral oedema) an echocardiogram of the heart should be performed to assess for pulmonary hypertension. Cardiovascular disease accounts for a considerable number of deaths in patients with COPD,¹³ and attention to modifying risk factors and secondary prevention is important.

Management of COPD

Only a handful of treatments in COPD alter the course of the disease and improve survival. The majority of treatments focus on symptom palliation and prevention of exacerbations. Management requires a multidisciplinary approach with support and education for the patient.

Smoking cessation

The first goal of treatment should be to stop smoking. This is the single most effective and cost-effective treatment for COPD.⁴ Stopping smoking has been shown to slow the rate of decline in lung function in patients with COPD,¹⁴ and reduce mortality.¹⁵

Smoking cessation can increase the quit rate by up to 70%,¹⁶ and is most effective when counselling is combined with pharmacotherapy. Pharmacotherapy options include nicotine replacement, bupropion or varenicline, and the choice should take into account patient preference, previous quit attempts and presence of comorbidities including cardiovascular disease and depression.¹⁷

Inhaled therapy

Current recommendations from NICE,¹⁷ European Respiratory Society and American Thoracic Society,⁴ recommend a stepwise approach to pharmacological treatment taking into account the severity and clinical status of the patient.

For patients who are breathless or have exercise limitation, a short acting beta-agonist (SABA, eg. salbutamol) or a short acting anti-muscarinic agent (SAMA, eg. ipratropium) should be prescribed in the first instance. These agents improve breathlessness, exercise capacity and deliver small improvements in lung function.¹⁸ For persistently breathless patients, the addition of either a long acting anti-muscarinic (LAMA, eg. tiotropium) or a long acting beta-agonist (LABA, eg. formoterol, salmeterol, indacaterol) improves lung function, quality of life and reduces rates of exacerbations.^19.20 SAMAs should be stopped when LAMAs are prescribed.

Inhaled corticosteroids (ICS) improve symptoms and reduce disease exacerbations,²¹ but they may lead to an increased risk of pneumonia and oral candidiasis. Combination therapy of ICS with LABA may lead to improvements in quality of life and lung function.^22,23 NICE currently recommends that combination ICS/LABA therapy is offered to patients with severe disease or in those patients who have persistent breathlessness or exacerbations despite receiving a long acting bronchodilator.

Oral treatments

Long-term treatment with oral corticosteroids (OCS) is not recommended in COPD patients. High doses of OCS (>30mg/day) may improve lung function over a short time-period, but do not deliver meaningful improvements in symptoms. Lower doses (<15mg/day) do not appear to be effective.²⁴ OCS lead to an increased risk of diabetes, osteoporosis, muscle weakness and adrenal suppression. Some patients are unable to wean off a maintenance dose and in these patients, bone mineral density must be monitored and they should be offered prophylaxis against insufficiency fractures.

Oral theophyllines have a bronchodilator effect, primarily mediated through phosphodiesterase inhibition. However, side effects, notably nausea, may limit the tolerability for patients. Theophyllines have notable drug interactions and monitoring of drug levels are also required.

Phosphodiesterase 4 inhibitors such as roflumilast improve lung function and reduce exacerbations,²⁵ but are not currently recommended for general use in NICE guidance.

Mucolytics reduce sputum viscosity, making expectoration easier. In patients with chronic productive cough, they reduce the rate of exacerbations and number of days of disability.²⁶ Mucloytics should be continued if the patient notices a benefit, but otherwise discontinued after a trial.

Low-dose azithromycin may be considered in COPD patients with recurrent disease exacerbations despite adequate inhaled therapy, as it has been shown to reduce the rate of exacerbation,²⁷ where it is thought to have immunomodulatory effect rather than direct bacterial inhibition. Caution is needed in patients with a long QT interval and there is a risk of hearing loss.

Pulmonary rehabilitation

Pulmonary rehabilitation combines a tailored, multidisciplinary programme of exercise with education and patient support. It may be delivered at home, or more usually, in a group setting supervised by physiotherapists and aims to restore the patient to the best possible physical and social functioning. A typical programme includes muscle strength and endurance training, respiratory muscle training, disease education and, self-management. It produces significant benefits in respiratory symptoms, exercise capacity and enhances the patient’s sense of control over their condition.²⁸ All patients who feel disabled by COPD should be assessed for pulmonary rehabilitation.

Vaccinations

Pneumococcal and annual influenza vaccinations are recommended in patients with COPD. Influenza A vaccination reduces the rates of exacerbations and improves mortality.^29,30 A meta-analysis of pneumococcal vaccination in COPD showed a reduction in exacerbations, but no change in rates of pneumonia or mortality.³¹

Oxygen

Oxygen is primarily used as a treatment for hypoxaemia rather than breathlessness. Patients with very severe COPD, evidence of cor pulmonale, or resting oxygen saturations ‰¤92% on air should be assessed in a specialist centre for long-term oxygen therapy (LTOT). LTOT is indicated where the PaO2 is ‰¤7.3kPa on air, or where the PaO2 is ‰¤8kPa with evidence of pulmonary hypertension, peripheral oedema or significant nocturnal oxygen desaturation. LTOT improves survival and quality of life in COPD,³² and is usually delivered by a concentrator for a minimum of 15 hours per day.

Ambulatory oxygen may be delivered by cylinders or portable concentrators. Patients with evidence of exercise-related oxygen desaturation below 90% and who have improvements in symptoms or exercise capacity with oxygen therapy, should be considered for ambulatory oxygen. Short burst oxygen may be used in a palliative setting for severe breathlessness not relieved by other treatments.¹⁷

Surgical treatment of COPD

Lung transplantation is an option for patients with end stage disease who have not responded to maximal medical therapy. Careful assessment of potential patients is vital to ensure that this scarce resource is allocated to those patients in whom the benefits most outweigh the risks. Older patients have a poorer survival following transplant and therefore an age >65 years is considered a relative contra-indication to transplant.³³

Lung volume reduction surgery is an option for patients with significant breathlessness, despite optimal medical therapy, and evidence of lung hyperinflation. In a select group of patients, symptoms, exercise capacity and survival are improved.³⁴ Bronchoscopic techniques including endobronchial valves are currently being investigated as a safer, less invasive alternative.³⁵

Conclusion

Patients with undiagnosed COPD may present to their GP or hospital specialist with acute respiratory symptoms on a background of chronic respiratory symptoms. Recognition of at-risk patients and referral for initial investigations is important to help prevent further decline and manage symptoms. Where complications arise, or there is evidence of uncontrolled symptoms, recurrent exacerbations or severe disease, referral to a specialist service
is advised.

Conflict of interest: none declared 

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William McNulty, Omar Sharif Usmani

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References