Written by epgonline.org - Last updated 29 May 2018
Chronic obstructive pulmonary disease, or COPD, is a collective term for the conditions previously described separately as emphysema and chronic bronchitis. At the Ciba Guest Symposium in 1959 a combined definition for what was initially termed ‘chronic obstructive airway disease’ was proposed. Emphysema refers to the loss of normal lung parenchyma, where alveolar walls become destroyed and bullae form, with an associated loss of surface area for gaseous exchange. Bronchitic changes refer to chronic narrowing and inflammation of the airways. Most people diagnosed with COPD will have changes from both pathological processes.
COPD is largely secondary to smoking tobacco, although other factors such as exposure to pollution or a genetic predisposition also contribute to the burden of disease. Particularly in the developing world, poorly ventilated smoke from heating and cooking fires is a leading cause of pollution that can directly lead to COPD.
Clinically, COPD is characterised by airway obstruction that is unchanging over the course of several months, and spirometry can give a very clear identification in this case. Local guidance is variable, although a generally accepted definition of airflow obstruction is: forced vital capacity and forced expired volume in one second (FEV1) as less than 70% of expected, or less than 80% of expected in the presence of pulmonary symptoms. It is generally progressive, and patients are susceptible to both infective and non-infective exacerbations.
Lifestyle interventions are the largest modifying factor; smoking cessation and increased exercise (as tolerated) will slow disease progression. Core components of medical treatment are bronchodilators, steroids and oxygen.
Bronchiectasis is the other condition included within this section. Airways become widened leading to inefficient mucus clearance. Excessive sputum, recurrent infection and breathlessness are common symptoms, while the classic examination finding is expiratory rhonchi. Bronchiectasis is a frequent consequence of cystic fibrosis, while the major acquired causes include tuberculosis, pneumonia, inhaled foreign bodies, allergic bronchopulmonary aspergillosis and bronchial tumours.
Treatment revolves around controlling infections and bronchial secretions, although there does seem to be a role for surgery – removing obstructions that would cause disease progression. Inhaled steroids also may improve disease progression and symptoms.
Eschenbacher WL. Defining airflow obstruction. Chronic Obstr Pulm Dis 2016;3:515–518.