About COPD

What is COPD?

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable pulmonary disease, characterised by chronic airflow obstruction resulting in increasing breathlessness and exercise limitation [1]. The airflow limitation is usually progressive and not fully reversible and is associated with an abnormal inflammatory response of the lung to noxious particles or gases [1].

COPD Information

Pathophysiology of COPD

The pathological changes characteristic of COPD include chronic inflammation with an increase in the number of inflammatory cells, neutrophils, macrophages and lymphocytes in small and large airways [2] and structural changes due to repeated injury and repair [1]. These inflammatory and structural changes, found within the proximal airways, peripheral airways, lung parenchyma and pulmonary vasculature, increase with disease severity and persist on smoking cessation [1,3].

As a result of the inflammation and narrowing of the peripheral airways, the forced expiratory volume in 1 second (FEV1) declines [1]. This reduction in FEV1 and FEV1/ forced vital capacity (FVC) ratio and also possibly the accelerated decline in FEV1 that is characteristic of COPD, correlate with the extent of inflammation, fibrosis and luminal exudates in the small airways [1].

Stages of COPD

The four stages of COPD are [1]:

• Stage I: Mild COPD: Airway limitation is mild (FEV1/FVC < 0.70; FEV1 ≥ 80% predicted normal) and the patient may be unaware that their airflow in the lungs is reduced and that he/she has abnormal lung function. Symptoms may include chronic cough and sputum production but these are not always present.
• Stage II: Moderate COPD: This stage is characterised by worsening airflow limitation (FEV1/FVC < 0.70; 50% ≤ FEV1 < 80% predicted normal). On exertion, shortness of breath usually develops and cough and sputum production may also be present. The patient usually seeks medical attention at this stage.
• Stage III: Severe COPD: Airflow limitation worsens (FEV1/FVC < 0.70; 30% ≤ FEV1 < 50% predicted normal) and the patient presents with greater shortness of breath, reduced exercise capacity, fatigue and repeated exacerbations that impact on his/her quality of life.
• Stage IV: Very severe COPD: At this stage, airflow limitation is severe (FEV1/FVC < 0.70; FEV1 < 30% predicted normal or FEV1 < 50% predicted normal plus the presence of chronic respiratory failure). Exacerbations may be life threatening and quality of life is significantly impaired.

Causes of COPD

Worldwide, cigarette smoking is the leading cause of COPD [1]. Long-term exposure to other lung irritants, such as air pollution, dust or chemical fumes may also contribute to the disease.

COPD symptoms

COPD symptoms include progressive breathlessness (dyspnoea), wheezing, chronic cough (‘smokers cough’), excessive sputum production and decreased exercise tolerance [1,2], all of which impact considerably on the patient’s daily activities and quality of life [1,4,5]. Episodes of acute worsening of these symptoms often occur (a COPD exacerbation) and may require medical intervention. Treatment for COPD can include oral steroids, antibiotics and/or hospitalisation.

Morning burden

In between exacerbations, evidence suggests that symptom severity may be variable throughout the day with typical COPD symptoms, in particular breathlessness, as well as patients’ ability to perform activities such as getting washed and dressed, being particularly problematic in the morning [7].

Goals of COPD treatment and management

The goals of COPD treatment and management [1] are to:

• relieve COPD symptoms
• prevent disease progression
• improve health status
• improve exercise tolerance
• prevent and treat complications
• prevent and treat COPD exacerbations
• reduce mortality
• prevent or minimise side effects from treatment.

Cessation of cigarette smoking should also be included as a goal throughout the management programme.

COPD treatment options

There is no cure for COPD, but pharmacological treatment can control and prevent COPD symptoms, reduce the frequency and severity of exacerbations, improve health status and improve exercise tolerance [1].

Inhaled bronchodilators are central to the symptomatic management of COPD. The two principal classes of long-acting bronchodilators are long-acting β2-agonists (LABAs) such as formoterol, and long-acting muscarinic antagonists (LAMAs) such as tiotropium [1].

For patients with more severe COPD and a history of exacerbations, guidelines recommend the addition of an inhaled corticosteroid (ICS) to a long-acting bronchodilator [1]. Go to the About Symbicort® (COPD) page to read about one such combination therapy. In addition, vaccines, antibiotics and a variety of non-medicinal COPD treatments such as pulmonary rehabilitation, exercise, oxygen therapy and surgery are also used [1].

References

1. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. Updated 2009. Available at: http://www.goldcopd.com. Last accessed 11 December 2009.  
2. Babusyte A, Stravinskaite K, Jeroch J, et al. Patterns of airway inflammation and MMP-12 expression in smokers and ex-smokers with COPD. Respir Res. 2007;14;8:81.
3. Hogg JC. Pathophysiology of airflow limitation in chronic obstructive pulmonary disease. Lancet 2004;364:709-21.
4. Miravitlles M, Anzueto A, Legnani D, et al. Patient's perception of exacerbations of COPD - the PERCEIVE study. Respir Med 2007;101:453-460.
5. Haughney J, Partridge MR, Vogelmeier C, et al Exacerbations of COPD: quantifying the patient's perspective using discrete choice modelling. Eur Respir J 2005;26:623-629.
6. Carrasco-Garrido P, de Miguel Diez J, Rejas-Gutierrez J, et al. Negative impact of chronic obstructive pulmonary disease on the health-related quality of life of patients. Results of the EPIDEPOC study. Health Qual Life Outcomes 2006;4:31.
7. Partridge MR, Karlsson N, Small IR. Patient insight into the impact of chronic obstructive pulmonary disease in the morning: an internet survey. Curr Med Res Opin 2009;25:2043-2048.