Challenges in COPD
Respiratory medicine consultant Dr Mike Morgan on six common COPD dilemmas in primary care
Respiratory medicine consultant Dr Mike Morgan on six common COPD dilemmas in primary care
The clinical management of COPD is more complicated than many realise. It includes making a clear diagnosis, providing self-management information, having a plan for chronic stable disease and another for unscheduled care. It is also necessary to be able to identify when patients need hospital care or when end-of life discussions are appropriate. Many cases also go unrecognised. The British Lung Foundation (BLF) has recently highlighted this discrepancy in the report Invisible lives – finding the missing millions with COPD. This article will look at six common dilemmas in primary care and provide guidance on each.
1. Deciding when to start inhaled steroids
COPD results from airway inflammation leading to permanent damage of the lung. In many cases, the damage has already been done by the time symptoms become obvious, so the rationale for using corticosteroids to slow down or reverse inflammation is not entirely obvious.
But – assuming that neutrophilic airway inflammation continues – then adding in inhaled steroids is logical, to slow down the rate of decline of lung function.
Inhaled steroids have been shown to reduce the frequency of exacerbations and are therefore recommended for patients with frequent exacerbations when the FEV1 is less than 50% predicted.
Patients at this stage are usually already taking a long-acting bronchodilator so the logical step is to deliver the inhaled steroid in a combination inhaler – fluticasone/salmeterol or budesonide/formoterol.
Note that much of the evidence for this comes from clinical trials where patients with any bronchodilator reversibility have been excluded. In real life, this may only be a small proportion of your COPD patients, who may have more reactive airways and a better response to inhaled steroids.
Consequently, the updated NICE guidance recommends inhaled steroids either:
• in combination with a long-acting
ß-agonist (LABA) in patients with an FEV1 <50% who suffer exacerbations or persistent breathlessness on a short-acting ß-agonist (SABA) or short-acting muscarinic antagonist (SAMA) alone, or
• in combination with a LABA in patients with an FEV1 ?50% who suffer persistent exacerbations or breathlessness on a SABA or SAMA and a LABA.
NICE. Management of chronic obstructive pulmonary disease in adults in primary and secondary care (partial update). CG101 June 2010
O'Reilly J, Jones MM, Parnham J, Lovibond K et al. Management of stable chronic obstructive pulmonary disease in primary and secondary care: summary of updated NICE guidance. BMJ 2010;340:c3134.
2. Knowing when to refer for oxygen therapy
There is still a lot of confusion surrounding oxygen therapy and the supportive evidence underpinning oxygen advice is inadequate. But as a general rule, oxygen therapy should only be provided where hypoxaemia can be demonstrated.
People with COPD may eventually develop chronic respiratory failure – defined as PaO2 less than 7.3kPa at sea level. Once this has occurred, treatment with long-term oxygen therapy for more than 15 hours a day is likely to prolong survival. There is no benefit giving oxygen to people who don't reach this threshold.
At a practice level, oximetry screening is recommended in patients at risk – with an FEV1 less than 50% predicted – who should be referred to the local oxygen assessment service if SpO2 is less 92%.
The patients will then have a confirmatory arterial blood gas and be recommended an oxygen flow rate – usually delivered by oxygen concentrator. Additional ambulatory or portable oxygen is provided to enable patients to leave the house. The most popular form of oxygen prescription used to be short-burst oxygen therapy for occasional use, but there's no evidence to support its use in the absence of demonstrable hypoxaemia.
Other ways of dealing with episodic breathless are likely to be more effective – such as rehabilitation, fans and medication.
In future, the prescription of the occasional cylinder outside a palliative care setting is likely to be discouraged.
3. Assessing fitness to fly
Air travel poses risks to us all – venous thromboembolism, for example – but those with COPD are also vulnerable to rapid changes in cabin pressure and an oxygen level equivalent to breathing 15.1% oxygen.
Aircraft cabins are pressurised to a pressure equivalent to an altitude of 8,000ft and consequently the lung is subject to decompression on ascent, making pneumothoraces theoretically more likely in patients with emphysema, but this is not proven.
The bigger risk to patients with COPD is the exposure to hypoxia and possible respiratory failure, which can be predicted and corrected with supplemental in-flight oxygen. The British Thoracic Society produces guidelines on fitness to fly assessment, though these are currently being updated.
Most airlines are willing to supply additional oxygen to travellers if it is booked in advance. Airlines vary in their charging policies, however, so it is very important for the traveller to clarify the cost or availability at the outset. The BLF (www.lunguk.org) has been calling for a change in legislation so that no passenger who needs supplementary oxygen should have to pay extra when travelling on planes.
Simple oxygen saturation measurements may be used to screen patients:
• Those with a resting SpO2 at 95% or above will not need oxygen.
• Those with severe COPD and SpO2 92-95% will require arterial blood gases and a hypoxic challenge with 15.1% oxygen to ascertain the need for oxygen.
• Those who are already using oxygen at sea level or have SpO2 less than 92% will definitely need in-flight oxygen.
It is important to remember that patients may also need to arrange oxygen in the airport and at their destination.
Coker RK, Partridge MR. What happens to patients with respiratory disease when they fly? Thorax 2004;59:919-20
4. Differentiating COPD from asthma
It is not always easy to distinguish asthma from COPD, especially in older patients, but may be helpful to do so. The clinical pointers towards asthma include:
• early age of onset
• family history
• lack of smoking
• variable nature of symptoms.
Asthma may also present later in life, in smokers who have had a significant occupational exposure or received ß-blockers or NSAIDs.
Distinguishing asthma from COPD is therefore largely based on a good clinical history, backed up by the demonstration of variable airflow obstruction and, if necessary, some specialist tests of airway inflammation – induced sputum differential, nitric oxide – or bronchial challenge testing.
If significant airway obstruction reverses to normal following a bronchodilator, then asthma is likely. It is also likely if the FEV1 response to a bronchodilator is greater than 400ml. But some patients with smoking damage may also have asthma, so reversibility to normal is not always possible.
Specialist help may be required at this point if a clear definition is required.
5. Deciding who will benefit from pulmonary rehabilitation
COPD patients who maintain higher levels of physical activity are likely to live longer and are less likely to be admitted. Pulmonary rehabilitation includes physical exercise training and supported self-management education. The benefits of rehabilitation include improvements in exercise performance, quality of life and reduction in healthcare use.
Rehabilitation is very popular with patients and one of the most effective treatments available for COPD and other chronic respiratory diseases. People with all grades of disability will benefit from rehabilitation, but in recent years most services have been limited by capacity, so in practice only those with more significant exercise limitation – scoring 3 to 5 on the MRC Dyspnoea Scale – have been referred for formal rehabilitation, usually in an outpatient setting.
Anyone who is still disabled despite being on optimum medication should be referred to a formal rehabilitation programme. But emphasise to those in earlier stages of the disease they should maintain their physical activity, either independently or through community exercise programmes.
A important recent discovery has been that immediate post-exacerbation rehabilitation can greatly reduce the risk of hospital re-admission.
Seymour JM, Moore L, Jolley CJ et al. Outpatient pulmonary rehabilitation following acute exacerbations of COPD. Thorax 2010;65:423-8
6. Recognising advanced COPD
The course of COPD is not as predictable as some malignant diseases, so it may be difficult to raise end-of-life issues with patients.
This is made even more difficult by the unpredictable nature of exacerbations resulting in hospital admissions where the risk of death has been as high as 15%, although the introduction of acute non-invasive ventilation for respiratory failure has improved the outlook.
Many people with COPD will eventually die from the condition and it is reasonable, as the disease progresses, to discuss end-of-life care with patients. This would include preferred choices with regard to hospital admission, non-invasive ventilation, palliative care referral and symptom management.
There is no clear threshold definition of advanced disease where discussion of end-of-life issues should be raised, but there are a number of pointers to poor prognosis including:
• very severe airflow obstruction – an FEV1 less than 30% predicted
• poor nutritional status – BMI less than 19
• respiratory failure
• repeated hospital admissions.
People admitted to hospital with respiratory failure have only a 50% chance of surviving two years.
Dr Mike Morgan is consultant physician in respiratory medicine at University Hospital of Leicester
It is estimated that although around 3.7 million people have COPD in the UK, only 900,000 of them have been diagnosed. As part of the annual World COPD Day on 17 November the British Lung Foundation will be appealing to the missing millions of people who are at the beginning of the patient journey, and are experiencing symptoms such as persistent cough and breathlessness, to visit their GP for spirometry. Alternatively, people can go to the BLF website to take the online breath test at www.lunguk.org/breathtestOxygen therapy should only be provided for demonstrable hypoxaemia Oxygen concentrator therapy