Approximately 900,000 people in England and Wales have been diagnosed with Chronic Obstructive Pulmonary Disease (COPD).
COPD is the term used to describe chronic bronchitis and emphysema (NICE, 2004).
Chronic bronchitis and emphysema are both diseases of the lung characterised by:
“chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible” (WHO, 2008, p. 1).
COPD is a long-term, progressive disease of the lungs that causes:
shortness of breath
loss of appetite and weight
The symptoms are mild initially, but get worse as the disease progresses.
Despite the large number of people diagnosed with the condition, research suggests that COPD is actually under-diagnosed and there may be as many as 3.4-3.8 million cases in England (Shahab et al., 2006).
It is the fifth most common cause of death in the UK, resulting in over 30,000 deaths per annum (National Statistics, 2006).
It is estimated that by 2020, it will be the third most common cause of death worldwide (Lopez et al., 2006).
When a person inhales:
air travels to their lungs via two airways called bronchi. Inside the lungs, the bronchi subdivide into smaller airways known as bronchioles, which eventually subdivide into tiny air sacs called alveoli. Capillaries (tiny blood vessels) within the walls of the air sacs enable oxygen to be added to blood and carbon dioxide to be removed; this can take place within about 0.4 seconds as the blood passes through the interface.
In someone with emphysema:
the walls of these air sacs are destroyed by lung inflammation. This results in the bronchioles collapsing and air becoming trapped in the air sacs. The air sacs become overstretched, thus interfering with the persons’ ability to exhale. Over time, these air sacs are likely to break and be replaced by one large air space. These larger sacs are less elastic and thus are unable to force air completely out of the lungs when exhaling. This is when the person will have to breathe harder in order to inhale enough oxygen and to exhale carbon dioxide.
A diagnosis of emphysema is made on clinical grounds and is confirmed by characteristic readings from spirometer investigations. It should be considered in any patient who presents with a combination of cough, sputum production, or dyspnoea, or with a history of exposure to risk factors for the disease.
A number of large cohort studies have shown risk factors to include:
living or working in polluted environments
Smoking is the largest risk factor for COPD, and 20% of long-term smokers will eventually develop clinically significant levels of COPD and 80% will develop lesser degrees of lung damage (Garcia-Aymerich et al., 2003).
Garcia-Aymerich J P, Farrero E F, Felez M A, Izquierdo J P, Marrades R M, Anto J M. (2003) Risk factors of readmission to hospital for a COPD exacerbation: a prospective study. Thorax 2003; 58: 100 – 5.
Lopez, A D, et al, (2006) Chronic obstructive pulmonary disease: current burden and future projections. Eur Respir J; 2006: 27 (2), 188-207.
National Institute of Clinical Excellence (NICE, 2004). Chronic obstructive pulmonary disease. NICE clinical guidelines on management of chronic obstructive pulmonary disease in adults in primary and secondary care. Clinical Guideline 12 (February 2004); Developed by the National Collaborating Centre for Chronic Conditions, London.
National Statistics (2006) Health Statistics Quarterly 30 http://www.statistics.gov.uk/downloads/theme_health/HSQ30.pdf [Last accessed 29/082010].
Shahab L, Jarvis M, Britton J, West R (2006) Prevalence, diagnosis and relation to tobacco dependence of chronic obstructive pulmonary disease in a nationally representative population sample. Thorax 2006; 61:1043-1047.
WHO (2008) World Health Organisation: Definition of COPD. WHO: Geneva 2008