This article was first published in PrimaryCare Today on November 2011
Chronic Obstructive Pulmonary Disease (COPD) disease is the 5th biggest killer in the UK, causing more deaths than cancer of the bowel, breast or prostate. An estimated 3 million people in the UK have COPD, although only an estimated 1.5% of the population have been correctly diagnosed. Worldwide, COPD is the third leading cause of death and kills on average one person every 10 seconds.
Despite these challenging statistics relatively few people have heard of COPD. It is against this background that, in July 2011, the European Respiratory Society (ERS), American Thoracic Society (ATS), American College of Chest Physicians (ACCP) and the American and College of Physicians (ACP) updated the 2007 ACP clinical practice guideline on the diagnosis and management of stable COPD.
The new guidelines address pharmacologic management, pulmonary rehabilitation and oxygen therapy; they do not cover smoking cessation, surgical/implantation options, palliative care, end-of-life care, depression or nocturnal ventilation.
The guidelines include a set of recommendations, classified as either strong or weak recommendations. Strong recommendations offer benefits that clearly outweigh the risks and the burden. Where benefits are finely balanced with the risks and the burden the recommendation is classified as weak.
- Spirometry should be obtained to diagnose airflow obstruction in patients with respiratory symptoms. It should not be used to screen for airflow obstruction in individuals without respiratory symptoms. (Moderate quality evidence).
- For stable COPD patients with respiratory symptoms and FEV1 <60% predicted, treatment with inhaled bronchodilators is recommended (Moderate quality evidence).
- Clinicians should prescribe continuous oxygen therapy in patients with COPD who have severe resting hypoxemia i.e.PaO2 <55 mm Hg or SpO2 <88%. (Moderate quality evidence).
- Clinicians should prescribe mono-therapy using either long-acting inhaled anticholinergics or long-acting inhaled beta-agonists for symptomatic patients with COPD and FEV1 <60% predicted. Clinicians should base the choice of specific monotherapy on patient preference, cost and adverse effect profile. (Moderate quality evidence).
- Clinicians should prescribe pulmonary rehabilitation (see also below) for symptomatic patients with an FEV1 <50% predicted. (Moderate quality evidence).
- For stable COPD patients with respiratory symptoms and FEV1 between 60% and 80% predicted, treatment with inhaled bronchodilators may be used. (Low quality evidence).
- Clinicians may administer combination inhaled therapies (long-acting inhaled anticholinergics, long-acting inhaled beta-agonists, or inhaled corticosteroids) for symptomatic patients with stable COPD and FEV1 <60% predicted (Moderate quality evidence).
- Clinicians may consider pulmonary rehabilitation for exercise-limited patients with an FEV1 <50% predicted. (Moderate quality evidence).
The new COPD Guidelines state that "the use of routine spirometry for patients without respiratory symptoms could lead to unnecessary testing, increased costs, unnecessary disease labelling, and the harms of long-term treatment with no known preventive effect on avoiding future symptoms". It is certainly true that in these challenging economic times unnecessary spirometry testing and long-term treatment exact a heavy toll on global healthcare systems and patients alike. Equally, there is a heavy price to be paid in failing to detect COPD at an early stage where medical intervention may produce better clinical outcomes.
The need to confirm diagnosis of COPD at an early stage is increasingly appreciated by primary care physicians. Spirometry will support or exclude a diagnosis of COPD in patients complaining of significant symptoms such as exertional breathlessness, chronic cough, regular sputum production and frequent winter 'bronchitis'. Whilst spirometry testing cannot be done routinely on everyone who may have COPD it is now possible to identify those at risk of COPD through fast, simple and cost effective case selection using the latest COPD screeners.
COPD screeners are not peak flow meters. Peak flow is not the best means of measuring airways obstruction and FEV1 alone cannot make a good assessment of obstruction or differentiate restrictive lung disorders. To make a good assessment the combination of FEV1, FEV6 (as an acceptable surrogate for FVC) the FEV1 ratio and FEV1 as a percent of predicted is required. All this might sound complicated, but low cost COPD screeners can do all this automatically in a simple two-minute test of respiratory function. Using FEV6 instead of FVC makes it much simpler to get a repeatable reading and for screening purposes is perfectly adequate to determine the presence and severity of airways obstruction. Unlike diagnostic spirometers these simple screeners can be used by staff with very little training to identify those people who definitely do not have COPD. False negatives for COPD are rare, since it is very hard to produce a result which is better than the subject’s best.
Case selection using COPD screeners allows medical professionals to conserve their overstretched spirometry resources and focus on those who need diagnostic spirometry and disease management to protect their quality of life.
|I: Mild COPD||
FEV1/FVC < 0.7
FEV1 80% predicted
|At this stage, the patient may not be aware that their lung function is abnormal.|
|II: Moderate COPD||
EV1/FVC < 0.7
50% FEV1 < 80% predicted
|Symptoms usually progress at this stage, with shortness of breath typically developing on exertion.|
|III: Severe COPD||
FEV1/FVC < 0.7
30% FEV1 < 50% predicted
|Shortness of breath typically worsens at this stage and often limits patients' daily activities. Exacerbations are especially seen beginning at this stage.|
|IV: Very Severe COPD||
FEV1/FVC < 0.7
FEV1 < 30% predicted or
FEV1 < 50% predicted plus chronic respiratory failure
|At this stage, quality of life is very appreciably impaired and exacerbations may be life-threatening.|