chronic obstructive pulmonary disease
Written by Wong Sze Yuin
Last Reviewed: April 2019
Review Due: April 2020
‘a chronic, obstructive disease of the airways characterized by progressive airflow limitation that interferes with normal breathing and is not fully reversible’
'chronic bronchitis is defined clinically as production of sputum on most days for at least three consecutive months in at least two years'
'emphysema is defined histologically as abnormal, permanent enlargement of air spaces distal to the terminal bronchiole with alveolar wall destruction'
Occupational exposure to dust, fumes and chemicals
Alpha-1 antitrypsin deficiency
SIGNS AND SYMPTOMS
Consider COPD in patients over 35 presenting with these characteristic symptoms:
Regular sputum production (white or clear)
Frequent winter ‘bronchitis’
In patient's with mild COPD, there may be few or little signs on examination. More signs, including some of those below, may be present in severe disease.
Use of accessory muscles
Coarse flapping tremor/asterixis
Reduced chest expansion
Reduced air entry
The hallmark of COPD is chronic inflammation that affects central and peripheral airways, lung parenchyma and alveoli, and pulmonary vasculature. Changes are progressive and usually irreversible.
There is narrowing and remodelling of airways, increased number of goblet cells, enlargement of mucus-secreting glands of the central airways and subsequent vascular bed changes leading to pulmonary hypertension.
Host response to inhaled stimuli generates the inflammatory reaction responsible for the changes in the airways, alveoli, and pulmonary blood vessels. Activated macrophages, neutrophils, and leukocytes are the core cells in this process.
In emphysema, the final outcome of the inflammatory responses is elastin breakdown and subsequent loss of alveolar integrity.
In chronic bronchitis, these inflammatory changes lead to ciliary dysfunction and increased goblet cell size and number, causing excessive mucus secretion.
FEV1:FVC <0.7 (Obstructive)
No/little reversibility with bronchodilator
Raised Haematocrit (Secondary Polycythaemia)
May show hyperinflation, flattened diaphragm, large central pulmonary arteries, bullae and decreased peripheral vascular markings
Alpha 1 Antitrypsin Level
If suspicion of deficiency, for example in those with a positive family history, non-smokers or young patients
Smoking cessation advice
One-off pneumococcal vaccination
Annual influenza vaccination
SABA: Short Acting Beta2 Agonists (e.g. Salbutamol)
LABA: Long Acting Beta2 Agonists (e.g. Salmeterol)
LAMA: Long Acting Muscarinic Antagonists (e.g. Tiotropium)
LCCI: LABA + Inhaled Corticosteroid
An estimated 1.2 million people are affected by COPD in the UK. There are 115,000 new diagnoses a year.
Kumar and Clark’s Clinical Medicine ninth edition
Oxford Handbook of Clinical Medicine ninth edition