COPD

Definition/diagnostic criteria Chronic obstructive pulmonary disease (COPD) refers to a group of diseases that cause airflow obstruction and respiratory symptoms. It includes emphysema and chronic bronchitis. The airflow obstruction is fixed (non-reversible), distinguishing it from asthma. The diagnosis is suspected on the basis of symptoms and signs and is supported by spirometry.

Epidemiology In the UK there are 1.3 million people with a diagnosis of COPD. Each year, around 30,000 people die in the UK from COPD. Although there are 115,000 new diagnoses per year, most people with COPD are not diagnosed until they are in their 50s or older and many more people may remain undiagnosed. The UK has the 12th highest recorded rate of deaths from COPD in the world.

Diagnosis

Clinical Features COPD should be suspected in anyone over the age of 35 with appropriate risk factors who present with symptoms including exertional breathlessness, chronic cough, regular sputum production, frequent winter ‘bronchitis’ or wheeze. Risk factors for developing COPD include causes of chronic irritation to the airways. The most common risk factor is a history of smoking tobacco but smoking of illicit drugs, poorly controlled asthma, indoor and outdoor pollution should be considered.

Other conditions can present with similar symptoms to COPD so clinicians should assess for other causes of these symptoms including lung cancer, asthma and cardiac causes.

Investigations Spirometry must be quality assured and only be performed and interpreted by healthcare professionals with appropriate training and accreditation. Post-bronchodilator spirometry will show an obstructive pattern with an FEV1/FVC (or VC if that is greater) below the lower limit of normal (LLN), ie, Z-score < – 1.645.

The severity of obstruction is then based on the FEV1/FVC Z-score (see Table).

Table. Spirometry interpretation – Z-score thresholds for severity classification

Consider tests to look at differential diagnoses and common co-morbidities. All new COPD diagnoses should have a CXR and FBC. A BMI is also recommended.

Evidence of COPD on CXR or CT scan should lead to an assessment of risk factors and symptoms. Spirometry should be performed to confirm evidence of airflow obstruction.

Treatment  At diagnosis, and at subsequent appointments, patients should be supported to understand their condition and understand the steps that they can take to stay well. Patient information and self-management plans are available from Asthma and Lung UK.

Smoking cessation Non-pharmacological management of COPD should be the bedrock of any treatment plan. Stopping smoking is the single most important treatment for COPD. You should offer to keep patients up to date with key vaccinations including influenza, pneumococcal and Covid-19 vaccines.

Physical activity It is also crucial to get patients more active – deconditioning creates a worsening cycle of breathlessness and disability. Pulmonary rehabilitation is an important treatment for COPD as it provides exercise classes designed for people with long-term lung conditions as well as information about looking after your body and lungs, advice on managing your lung condition and techniques to manage breathlessness. Despite its strong evidence base we need to do much more to encourage patients to attend and realise the benefits of pulmonary rehabilitation.

Medications Pharmacological therapy for COPD is used to reduce symptoms, reduce the frequency and severity of exacerbations, and improve exercise tolerance and health status.

• LABAs and LAMAs both improve lung function, breathlessness, health status and exacerbation rates. In combination they improve FEV1, symptoms and exacerbations more than monotherapy.
• A number of studies have shown that blood eosinophil counts predict the magnitude of the effect of ICS (added on top of regular maintenance bronchodilator treatment) in preventing future exacerbations. ICS containing regimens have little or no effect at a blood eosinophil count <100 cells/µL. The threshold of a blood eosinophil count ≥300 cells/µL identifies the top of the continuous relationship between eosinophils and ICS, and can be used to identify patients with the greatest likelihood of treatment benefit with ICS.
• The treatment effect of ICS containing regimens is higher in patients with high exacerbation risk (two or more exacerbations or one hospitalisation in the previous year). Thus, the use of blood eosinophil counts to predict ICS effects should always be combined with clinical assessment of exacerbation risk (as indicated by the previous history of exacerbations).
• Inhaler technique should be checked regularly. This can include the sharing of the relevant Asthma and Lung UK inhaler video.
• Mucolytics can be useful for people with stable COPD who have a regular productive cough. They work by making the sputum less viscous and therefore easier to clear.
• Oxygen is an important treatment for patients whose saturations are 92% or less breathing air or if there are signs of Cor Pulmonale (raised JVP, peripheral oedema), cyanosis or polycythaemia. Do not start oxygen without specialist assessment.

Management of comorbidities Multimorbidity is common in COPD patients and should be actively checked for. These include cardiovascular disease, metabolic syndrome, osteoporosis, depression, anxiety, and lung cancer. These comorbidities affect health status, hospitalisations and mortality independently of the severity of airflow obstruction due to COPD.

Prevention and management of exacerbations Patients should be given information about their condition and effective self-management. This should include how to recognise an exacerbation and when to seek help.

Features of an acute exacerbation include an increase in breathlessness, new or worsening cough and wheeze. This can usually be managed with an increase in short-acting bronchodilators.

These symptoms are non-specific so, if symptoms are not improving, a detailed assessment is crucial to establish the cause of the symptoms and the severity of any exacerbation. For patients with a significant increase in breathlessness interfering with daily activities then 30mg prednisolone for 5 days should be considered. Where there are sputum colour changes and increase in volume or thickness suggesting possible bacterial infection then an antibiotic may be required.

Patients with regular flare-ups should have a review of the cause of their symptoms and underlying diagnosis and co-morbidities. Be aware of short- and long-term effects of oral corticosteroids including adrenal suppression and osteoporosis. Consider osteoporosis prophylaxis in patients receiving three or more courses of prednisolone per year.

Although guidelines suggest considering a rescue pack of antibiotics and steroids for patients to use in an exacerbation, it is crucial to ensure that appropriate patients have adequate instructions for use, and monitoring. Incomplete governance around rescue packs could lead to patients using antibiotics and/or steroids at the wrong time, in the wrong way or for the wrong condition, leading to inappropriate use and putting them at risk of harm.

Prognosis COPD is a chronic progressive condition with gradual decline in lung function and increasing symptoms over time. There is a significant relationship between lower (FEV1) and risk of exacerbation and death. Smoking cessation can reduce the rate of decline in lung function and exacerbations in COPD in addition to decreasing mortality from smoking-related conditions such as lung cancer and CVD. Increased symptoms, chronic hypoxia and cor pulmonale are all linked to increased mortality. Low body mass index is often due to muscle wasting and cachexia and is linked to increased morbidity and mortality.

Exacerbations accelerate the rate of decline in lung function, reduce quality of life and increase risk of mortality. Exacerbations requiring hospital treatment are associated with poorer prognosis and increased risk of death. The reported 5-year mortality rate following a hospitalisation due to COPD exacerbation is around 50%.

Written by Dr Andrew Whittamore, who is a GPwSI in Respiratory medicine based in Hampshire