Chronic obstructive pulmonary disease (COPD) is characterised by airflow obstruction. This is usually progressive, not fully reversible and does not change markedly over several months.
Kay Holt, MA, MSc, Dip Respiratory Medicine, BSc (Hons), RGN.
Nurse Practitioner, Cleveleys Group Practice, Wyre Primary Care Trust, Lancashire.
The disease is predominantly caused by smoking (NICE, 2004), which is the most important risk factor (Siafakas et al, 1995). About 15-20% of smokers develop COPD.There are other risk factors, such as a family history and airway hyper-responsiveness, but it is not clearly predictable which smokers will develop the disease. Smoking cessation is the only effective intervention to slow the accelerated decline in lung function.Spirometry by a trained health professional gives an indication of lung health by measuring airway obstruction. As a screening tool in smokers it has the potential to detect early changes before any significant symptoms are evident.
Terms used in respiratory disease
The public may be more familiar with the terms ‘chronic bronchitis’ or ‘emphysema’ to describe COPD. Many patients prefer to say they have ‘chronic asthma’ as they feel there is less blame attached to a condition that children can experience.- Chronic bronchitis is diagnosed entirely on the patient’s history and the production of sputum on most days for at least three months in at least two consecutive years- Emphysema is defined in structural and pathological terms, describing the destructive process that goes on in the lungs, usually as a result of smoking- Chronic asthma is characterised by variable airway obstruction that is reversible spontaneously or with treatment.
COPD can incorporate features of any of the above but is an objective diagnosis based on spirometric assessment.Spirometry measures airflow and lung volumes, and with the correct equipment and training COPD diagnosis can be undertaken competently in primary care.
In 1999 spirometry was available in about 60% of general practices (Rudolf et al, 1999). This number is steadily rising as a result of drivers such as guidance from the National Institute for Clinical Excellence, and the new GP contract. Severity of COPD is based on the patient’s forced expiratory volume in one second (FEV1), which is the volume of air that can be exhaled in the first second of a forced expiratory manoeuvre.Unfortunately, patients typically present when much lung volume is already lost, blaming their increasing respiratory symptoms on their age and smoking. It is not unusual for a patient to be first diagnosed with an FEV1 of less than 50% of predicted value for age, height and gender.About one in five smokers suffers from a persistent smoker’s cough, yet most do not realise it could be the early warning signs of a devastating lung disease.Other symptoms of COPD include breathlessness on mild exertion, persistent sputum production and frequent winter colds.
A MORI survey of 866 members of the public, undertaken for the British Thoracic Society COPD Consortium in 2001, highlighted the low level of public awareness of the condition. Only 3% of the public knew that persistent production of phlegm could be a warning sign. Six in 10 smokers have experienced one or more possible early COPD symptoms, yet less than half (47%) have seen their GP about them.
Two-thirds of people in the survey had never heard of COPD, even though it kills more than 30,000 people a year in the UK. There are an estimated 600,000 diagnosed cases of COPD in the UK but this could be the tip of the iceberg owing to the lack of awareness of symptoms among the general population.Health professionals play a vital role in improving the diagnosis and early detection of COPD and raising awareness of the condition among their patients. If a health professional is asked to imagine a typical COPD patient, most would think of an elderly man; however, current evidence suggests that women are even more susceptible to the deleterious effect of tobacco smoke than men (Gold et al, 1996; Xu et al, 1994; Leynaert et al, 1997; Prescott et al, 1997; Langhammer et al, 2000; Vollmer et al, 2000). COPD is on the increase - especially in women, with more and more young females taking up smoking.Spirometry can detect very early or mild COPD and can even detect those patients with subtle changes in their airways who are at risk of COPD if they continue smoking.
Several treatments are available to help with the symptoms of COPD but smoking cessation is the only intervention that has a significant impact on the rate of decline of FEV1. This measure gives a very good indication of an individual’s ‘lung health’ in the same way as cholesterol and blood pressure may help predict cardiac health, yet spirometry is not commonly used as a screening tool.
Spirometry, in conjunction with smoking cessation initiatives, has the potential to impact significantly on public health.The Global Initiative for Chronic Obstructive Lung Disease guidelines (GOLD, 2004) state that patients who have chronic cough and sputum production with a history of exposure to risk factors should be tested for airway obstruction even if they do not have dyspnoea.
Cough and airflow obstruction are manifestations of different pathological processes:- Cough arises from mucosal inflammation and secretions- Airflow obstruction arises from emphysematous changes. Although the processes frequently co-exist in the lungs of smokers, cough and sputum are not necessarily associated with airflow obstruction. When deciding which smokers to screen for COPD, however, the evidence suggests that smokers with chronic cough will be more likely to demonstrate airflow obstruction.Van Schayck et al (2002) found 18% of smokers screened had an FEV1 <80% predicted and that when smokers were pre-selected on the basis of chronic cough, the proportion with an FEV1 <80% predicted increased to 27%. Freeman et al (2002) found that only 12% of smokers or ex-smokers with no previous respiratory history had COPD, and suggested it may be more worthwhile screening symptomatic patients who smoke.
One aim of early detection of COPD in smokers is to encourage them to stop. One systematic review (Badgett and Tanaka, 1997) concludes that there is no evidence that spirometry, as an isolated intervention, aids smoking cessation. But even so, there is now a place for spirometry, combined with education and smoking-cessation advice, as a valuable tool in the early detection of COPD and individualising future smoking risk.
Spirometry screening assessment
At Cleveleys Group Practice in Lancashire, symptomatic smokers or ex-smokers are offered a spirometry screening assessment. This involves a 15-minute appointment with a nurse practitioner and includes:- A respiratory history- Spirometry using a desktop spirometer- Advice about the results and referral for further assessment, for example, reversibility testing and chest X-ray, where appropriate- Advice on stopping smoking and contact details for the local smoking-cessation service.
GPs or other health professionals encourage patients to make appointments for this assessment, and the service is advertised on a poster in the waiting room. Several hundred patients have attended spirometry screening assessments over the past five years, leading to improved diagnosis of COPD and other respiratory conditions. The practice COPD register has now more than 200 patients, with 94 diagnosed with mild COPD (FEV1 >50% predicted).A small 12-month retrospective study was carried out to evaluate the impact of the intervention on smokers. Inclusion criteria were:- Current smoker- Smoked for more than 20 pack years- Spirometry never performed in past- Asthma or COPD never previously diagnosed.Results of the study Fifty-six smokers screened between September 2002 and September 2003 met the inclusion criteria:- Thirty-seven (66%) demonstrated airway obstruction (FEV1 <80% predicted and FEV1/FVC <70%)- Seven others had potential airway obstruction with a normal FEV1 but FEV1/FVC <70%- Twelve (21%) had normal spirometry.
All patients were offered smoking-cessation advice and referral to the local smoking-cessation support service.Those with airway obstruction were counselled on their declining lung health using the Fletcher Peto Graph (Fletcher and Peto, 1977) as a tool to individualise the future risk of continued smoking. Patients with potential airway obstruction were advised on their risk of developing COPD, while those with normal lung function were informed that their lung health was good and the benefits of stopping smoking were stressed.
In January 2004 these 56 patients were followed up to ask how many had stopped smoking and still did not smoke. The results were:- Thirteen (35%) of those with airway obstruction had quit- Four (57%) of those patients with potential airway obstruction had quit- Four (33%) of those with normal lung function had quit.Smoking cessation improves respiratory symptoms and prevents accelerated decline in lung function in all smokers with or without COPD (Willemse et al, 2004). It is encouraging that, in this small practice-based study, smokers screened and found to have normal lung function were as successful at quitting smoking as those with airway obstruction.
Author’s contact details
Kay Holt, Nurse Practitioner, Cleveleys Group Practice, Cleveleys Health Centre, Cleveleys FY5 3LF. Email: email@example.com
Key priorities for implementation from the NICE COPD guidelines- A diagnosis of COPD should be considered in patients over the age of 35 who have a risk factor (generally smoking)- The presence of airflow obstruction should be confirmed by performing spirometry- Patients with COPD should be encouraged to stop smoking- Long-acting inhaler bronchodilators (beta2-agonists or anticholinergics) should be used to control symptoms and improve exercise capacity in patients who continue to experience problems despite the use of short-acting drugs- Inhaled corticosteroids should be added to long-acting bronchodilators to reduce exacerbation frequency in patients with an FEV1 less than or equal to 50% predicted- Pulmonary rehabilitation should be made available to all appropriate patients with COPD- COPD care should be delivered by a multidisciplinary team.Source: NICE, 2004
SPIROMETRY AND COPD
WHAT IS SPIROMETRY?- Spirometry is a simple test to measure the amount of air a person can breathe out, and the amount of time taken to do so- A spirometer is a device used to measure how effectively and how quickly the lungs can be emptied- A spirogram is a volume-time curve.SPIROMETRY MEASUREMENTS USED FOR DIAGNOSIS OF COPD INCLUDE:- FVC (forced vital capacity): maximum volume of air that can be exhaled during a forced manoeuvre- FEV1 (forced expired volume in one second): volume expired in the first second of maximal expiration after a maximal inspiration. This is a measure of how quickly the lungs can be emptied- FEV1/FVC: FEV1, expressed as a percentage of the FVC, gives a clinically useful index of airflow limitation.The ratio FEV1/FVC is between 70% and 80% in normal adults; a value less than 70% indicates airflow limitation and the possibility of COPD. FEV1 is influenced by age, sex, height and ethnicity. It is best considered as a percentage of the normal predicted value.Source: GOLD, 2004
‘Margaret Jones’, a 56 year-old civil servant, attended her GP last November with a severe cold that had ‘gone on her chest’. This seemed to have been happening more often in recent years. She expected her GP to prescribe her antibiotics and advise her to stop smoking again. The GP did prescribe her usual antibiotics but this time he inquired more about her everyday symptoms and she revealed symptoms of cough and sputum most mornings now. He suggested that she see the nurse practitioner for a ‘lung check’ once this chest infection had cleared up.The infection cleared up with the antibiotics and Margaret soon got back to normal. She forgot about the GP’s suggestion. A few months later a colleague at work was diagnosed with lung cancer and Margaret began to worry about her own risks. She was becoming more breathless on walking from her car to work and climbing steps. She made an appointment for a lung health check with the nurse at the practice.At her appointment, Margaret discussed her symptoms and past history with the nurse and took a spirometry test. This revealed that there was airway obstruction and that her FEV1 was 53% of predicted. The results were carefully explained to Margaret but they came as a shock.Her uncle had been diagnosed with emphysema many years before and had been desperately breathless for years before he died. After further tests the nurse explained to Margaret that she had chronic obstructive pulmonary disease and she was given information to read. Margaret began to realise the implications of continuing to smoke and decided to try to stop with the support of the local smoking-cessation services. A chest X-ray and blood test were arranged. Margaret was relieved that these were normal as she had feared she had lung cancer.Six months later Margaret has now managed to quit smoking and her morning cough is improved. She is still short of breath on exertion but has some inhalers that help. She understands her lungs will never improve but that stopping smoking has slowed down their decline. She has been advised to have annual flu and pneumonia vaccines and to seek medical help at the first signs of a chest infection.Margaret is coming to terms with living with a chronic lung condition and knows she will not be as active as she had hoped in her planned retirement. She worries about travelling abroad and is considering joining the local pulmonary rehabilitation group to help her cope with her breathlessness and remain active. She is now trying to persuade her 30-year-old son to stop smoking to prevent him suffering as she is.
WORLD COPD DAY - NOVEMBER 17 2004
Various initiatives around the world will encourage public awareness and health professional recognition of COPD. In the UK, the British Lung Foundation is joining forces with Superdrug to offer a free spirometry test at selected stores. Spirometry is available in many primary care settings and, with more publicity about COPD, perhaps patients will request this procedure in the way they ask for blood pressure and cholesterol checks.More details from GOLD, www.goldcopd.org and British Lung Foundation, www.lunguk.org
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