Chronic obstructive pulmonary disease - Clinical review

Diagnosing and managing COPD in primary care. By consultant chest physician Dr Nicholas Hopkinson

All patients with COPD should undergo a spirometry  test
All patients with COPD should undergo a spirometry test

Section 1: Epidemiology and aetiology

COPD is an umbrella term incorporating chronic bronchitis and emphysema.

The condition is the UK's fifth biggest killer, claiming about 30,000 lives each year.1

In England alone, an estimated 3m people have COPD, of whom more than 2m are undiagnosed.1

COPD is a slowly progressive condition and its symptoms are often dismissed by patients, who may regard them as a normal feature of ageing, or as a 'smoker's cough'.

The symptoms of COPD include breathlessness (especially evident on exertion), a persistent cough lasting longer than three weeks, excessive sputum production and wheezing.

The risk of developing chest infections also increases, particularly during the winter months. Regular diagnoses of winter bronchitis should be considered an indicator of possible COPD.

Aetiology and prevalence
The single largest cause of COPD is smoking, which is responsible for more than 80% of cases.2

Among continuous smokers, the risk of developing COPD is at least 25%.3 A relatively small number of cases are caused by an inherited deficiency in the production of alpha-1 antitrypsin (A1AT), which dramatically increases susceptibility to the effects of smoke.

Prevalence increases with age and rates of COPD are higher in more deprived communities.4 The link to social class is partly explained by smoking rates, partly by occupations associated with exposure to dust fumes and chemicals5 (factory work and cleaning), and partly by adverse early life conditions that affect lung development.

Heart disease, diabetes, hypertension, osteoporosis and psychological disorders are commonly reported comorbidities.6

Section 2: Making the diagnosis

The effects of COPD are progressive and largely irreversible,so early diagnosis is crucial. It should be considered in people aged over 35 years who have risk factors and symptoms suggestive of the condition.

Physical inactivity is apparent even in patients with early COPD7 and breathlessness is often overlooked. Patients scoring two or more out of five on the MRC dyspnoea scale should be considered for further investigation, because an intervention is likely to be required, even if the final diagnosis is not COPD.

Additional signs of COPD include a hyperinflated chest, pursed lip breathing, cyanosis and peripheral oedema (particularly around the ankles). Younger patients and non-smokers presenting with these signs and symptoms should be considered for A1AT testing.

Spirometry
All patients with symptoms should undergo a quality-assured spirometry test to establish the presence of airflow obstruction. Airflow obstruction can be diagnosed if the ratio of the patient's FEV1 to forced vital capacity (FVC) is less than the predicted value for someone of their age, height and sex.

A fixed ratio of 0.7 has been used, but this may overestimate COPD prevalence in older and underestimate it in younger patients.

The severity of airflow obstruction in COPD is based on the percentage of the predicted FEV1: 100-80% would indicate mild COPD, 80-50%, moderate, 50-30%, severe, and <30% very severe. These are also referred to as stages I to IV of the disease, respectively.2

FBC to identify anaemia or a raised red cell count should be conducted as routine. A chest X-ray can help to identify abnormalities that require referral for a CT scan. Patients whose symptoms seem disproportionately severe for their spirometry results should be referred.

The presence of coexisting cardiac risk factors and disease should also be considered.

Asthma and COPD
Misdiagnosis of COPD as asthma (and vice versa) is common in patients presenting for the first time.

Waking at night with breathlessness or wheezing, and 20% or greater diurnal or day-to-day variability in peak flow is common in asthma but uncommon in COPD.

Chronic productive cough is uncommon in asthma but common in COPD. Breathlessness tends to be persistent and progressive in COPD, but variable in asthma.

If in doubt, consider response to drug therapy - a large (400ml) response to either bronchodilators or 30mg oral prednisolone daily for a fortnight suggests asthma.

If any doubt remains, the patient should be referred for imaging or measurement of the transfer factor for carbon monoxide. A history of atopy suggests asthma, but chronic asthma may develop into fixed airflow obstruction in later life.

Section 3: Managing the condition

Management depends on the stage and severity of the patient's COPD. This is defined according to the degree of airflow obstruction, symptoms (assessed using a validated patient-reported outcome measure such as the simple, self-completed COPD assessment test score)8 and exacerbation frequency.

The British Lung Foundation (BLF) COPD patient pathway is a useful resource that healthcare professionals and patients can use to identify best practice treatment at every stage of the disease, as are the NICE guidelines and the outcomes strategy for COPD (see section 6).

Smoking cessation
Management should focus on high-value interventions. Smoking cessation is the most important treatment for patients with COPD.

Many patients quit spontaneously, but all should be offered help to quit at every opportunity. This should include behavioural support and pharmacotherapy, such as NRT (or varenicline if that is ineffective).

The National Centre for Smoking Cessation and Training provides short online training modules in smoking cessation support, which can be taken by any healthcare professional.

IT-literate patients can also find support themselves, using the NHS Smokefree website (www.nhs.uk/smokefree).

Pulmonary rehabilitation
Pulmonary rehabilitation programmes, which provide supervised exercise and education for patients with COPD, have been shown to reduce hospital admissions, exacerbations and home visits.9,10

Pulmonary rehabilitation has a much greater impact on symptoms than pharmacotherapy, at a much lower cost. It is important for health professionals to understand what is involved, because a clear explanation improves the chances that patients will participate.

Involving local peer support groups, such as the BLF Breathe Easy network, can also improve uptake and compliance. Overall, there is an urgent need to improve commissioning of pulmonary rehabilitation.

Pharmacotherapy
Annual flu vaccination and one pneumococcal vaccination are recommended for COPD patients.

Most patients take inhaled medication. Attention to inhaler technique is vital and use of spacers with metered dose inhalers (MDI) should be encouraged. Dry powder devices have a much lower carbon footprint and are in some cases significantly cheaper than MDI equivalents.

In milder disease, short-acting bronchodilators have a role. For patients with persistent breathlessness, a long-acting beta-2 agonist and/or a long-acting antimuscarinic can be added; these also tend to reduce exacerbation frequency.

In patients with repeated exacerbations and an FEV1 below 50%, inhaled corticosteroids are indicated. Newer bronchodilators offer no particular benefits over existing therapies in the same class.

Regular antibiotics may help some patients with recurrent exacerbations, but should generally be initiated after secondary care review.

Lung volume reduction surgery improves survival in selected patients. Patients with reduced oxygen saturations at rest or who desaturate on exercise should have an assessment for oxygen therapy.

Section 4: Prognosis

COPD is a long-term, progressive illness. Providing consistent support to encourage self-management, medicines adherence (with appropriate technique), and compliance with smoking cessation and pulmonary rehabilitation can slow progression and improve quality of life.

The BODE index (calculated using BMI, airflow obstruction, dyspnoea and exercise levels) can be used to track improvements in prognosis.11 In patients with more advanced disease, secondary care referral may be made for consideration of lung volume reduction interventions. Sleep-disordered breathing may influence outcomes.

Section 5: Case study

A 62-year-old smoker visits her GP because of a chest infection. She has had chest infections for several years in the winter and mentions that even on a good day, she cannot get around as well as she used to.

Her spirometry shows an FEV1 of 58% predicted, with an FEV1/FVC ratio of 52%. She has a few crackles at the left lung base.

The patient receives a short course of antibiotics and steroids, and is started on a salbutamol MDI.

She has tried to quit smoking before, but failed. Her GP offers her a referral for smoking cessation support and now she has learnt that her lungs are damaged, she has an additional incentive and quits.

At review a few weeks later, she feels much better. Her GP advises her to keep active to maintain her fitness and she has flu and pneumococcal vaccination.

Ten years later, she has become more breathless and has two exacerbations a year. She can only walk about 100m before she has to stop. Her FEV1 is now 36% predicted.

The patient is on triple inhaled therapy and has completed pulmonary rehabilitation. She is referred to a COPD clinic, where a CT scan reveals upper lobe predominant emphysema.

Detailed lung function shows marked hyperinflation and a gas transfer of 30% predicted. She goes on to gain significant benefit from lung volume reduction surgery.

Section 6: Evidence base

Clinical trials

  • Lokke A, Lange P, Scharling H et al. Developing COPD: a 25 year follow up study of the general population. Thorax 2006; 61: 935-9.

This large, 25-year study showed the absolute risk of COPD among smokers to be even greater than estimated.

  • Puhan MA, Gimeno-Santos E, Scharplatz M et al. Pulmonary rehabilitation following exacerbations of chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2011; 10.

This study confirms the efficacy of pulmonary rehabilitation in reducing hospital admissions and mortality, and improving quality of life.

Guidelines

  • NICE. Chronic obstructive pulmonary disease (update): full guideline. CG101. London, NICE, October 2010.

Online

Guidance for patients and clinicians on care that should be offered at every stage. Includes NICE quality standards and best practice examples.

Patient information, professional and patient self-management packs, and links to a patient helpline and local support groups.

This collaboration between the British Thoracic Society and the Primary Care Respiratory Society includes guides to commissioning, providing and integrating care, and offers examples of good practice.

Their 2012 Guide to the relative value of COPD interventions is also available to download.

  • Contributed by Dr Nicholas Hopkinson, consultant chest physician and clinical lead for COPD at the Royal Brompton Hospital, London, clinical senior lecturer at Imperial College London, medical adviser for the British Lung Foundation and chairman of the British Thoracic Society specialist advisory group on COPD
CPD IMPACT: EARN MORE CREDITS

These further action points may allow you to earn more credits by increasing the time spent and the impact achieved.

  • Review patients who are smokers over the age of 40; calculate their MRC dyspnoea score and consider spirometry.
  • Arrange a teaching session with the local respiratory nurse to look at spirometry interpretation.
  • Write a protocol for referral to the pulmonary rehabilitation service after discussion with colleagues.

Click here to take a test on this article and claim a certificate on MIMS Learning

References

1. DH. An Outcomes Strategy for Chronic Obstructive Pulmonary Disease (COPD) and Asthma in England. 2011.

2. NICE. Chronic obstructive pulmonary disease (update): full guideline. CG101. London, NICE, October 2010.

3. Lokke A, Lange P, Scharling H et al. Thorax 2006; 61: 935-9.

4. Young RP, Hopkins R, Black PN et al. Thorax 2006; 61(5): 394-9.

5. Health and Safety Executive. COPD.

6. Chatila WM, Thomashow BM, Minai OA et al. Amer Thorac Soc 2008; 5(4); 549-55.

7. Shrikrishna D, Patel M, Tanner RJ et al. Eur Respir J 2012; 40(5): 1115-22.

8. Impress Guide to Pulmonary Rehabilitation. 2011.

9. Puhan MA, Gimeno-Santos E, Scharplatz M et al. Cochrane Database Syst Rev 2011; 10.

10. Griffiths TL, Phillips C, Davies S et al. Thorax 2001; 56: 779-84.

11. Powrie DJ. Thorax 2004; 59: 427.

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