Frontal Chest X-Ray of a patient with a history of Chronic Obstructive Pulmonary Disease (COPD). Findings on chest X-Ray in patients with Chronic Bronchitis can be quite non-specific. Radiological signs include bronchial wall thickening with increased bronchovascular markings, enlarged vessels and cardiomegaly (abnormal enlargement of the heart). Due to the recurrent nature of infections and inflammation, scarring occurs causing the bronchovascular structures to typically have irregular contours. Findings Chronic Bronchitis.
Chronic bronchitis is part of a large group of lung diseases that are collectively known as Chronic Obstructive Pulmonary Disease (COPD). Chronic Bronchitis together with Emphysema are the two major diseases of the group, these two diseases can occur either separately or concurrently. Bronchitis specifically refers to inflammation of the mucous membrane or lining, of the bronchial tubes. It is the tissue damage to the lining of the airways that attracts the inflammatory cells, these cells then release enzymes that create more damage and stimulate extra production of goblet cells, which in turn produce heavy mucus or phlegm resulting in obstruction of air flow. There are two types of bronchitis, acute and chronic. Acute bronchitis usually occurs following a cold or flu and is a short term condition, whereas chronic bronchitis, as the name implies, is an ongoing and progressive disease. Chronic bronchitis has been clinically defined as ‘a persistant cough that produces sputum (phlegm) and mucus, for at least three months per year in two consecutive years’.(1) Chronic bronchitis is highly associated with smoking. Over 40% of smokers will develop chronic bronchitis with an associated and accelerated decline in lung function.(2)
Images 3 and 4 of Computed tomography (CT) scan in an elderly patient with known chronic bronchitis. The scans demonstrate thickening of the bronchial walls (purple arrows) and bronchi filled with mucus or phlegm (blue arrows).
Chronic Bronchitis is characterized by low oxygen levels in the blood (hypoxia) which can cause constriction of the blood vessels in the right-side of the heart that lead to the lungs. These restrictions in the blood vessels cause an increase in pressure, known as pulmonary hypertension, which can result in right-sided heart failure called Cor Pulmonale. To try and compensate for reduced oxygen levels in the blood there is also an increase in the number of red blood cells made which leads to the blood becoming thicker with a sluggish flow and an increased risk of clot formation. This condition is known as secondary polycythaemia. Pneumothorax and Respiratory failure are also serious complications of Chronic Bronchitis.
Chronic Obstructive Pulmonary Disease is a major health problem on a worldwide scale. In 2010 an estimated 329 million people (4.8% of the total population) were affected by the disease.(3) There has also been a large increase in the developing world between 1970 and the 2000’s which has been linked to an increase in population, an ageing population and an increase in smoking habits in these areas.(4) In 2012 Chronic Obstructive Pulmonary disease was the third leading cause of deaths claiming 3.1 million lives. The disease has higher prevalence in older people, it affects between 34 and 200 out of every 1000 people over 65 years of age.(5) It is also more common in lower socio-economic groups.
1. American Lung Association Epidemiology and Statistics Unit Research and Health Education Division March 2013
2. Pelkonen M. ‘Smoking: relationship to chronic bronchitis, chronic obstructive pulmonary disease and mortality.’ Curr 2008 Mar;14(2):105-9. doi: 10.1097/MCP.0b013e3282f379e9 [PubMed]
3. Vos T, Flaxman AD, Naghavi M, Lozano R, Michaud C, Ezzati M, Shibuya K, Salomon JA, Abdalla S, Aboyans V, et al. (December 2012). ‘Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010’. Lancet 380 (9859): 2163–96.doi:10.1016/S0140-6736(12)61729-2. PMID 23245607.
4. Decramer M, Janssens W, Miravitlles M (April 2012). ‘Chronic obstructive pulmonary disease’. Lancet 379 (9823): 1341–51.doi:10.1016/S0140-6736(11)60968-9. PMID 22314182.
5. ‘Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease’. Global Initiative for Chronic Obstructive Lung Disease. pp. 1–7.