CSIM 1.68: Case 48: A worker with Breathing Problems - Asbestos and Lung Disease Flashcards
What is finger clubbing? What are the potential causes?
Softening of the nail beds, leading to a curvature of the nails because they ‘float’ instead of being firmly attached
LUNG DISEASES
• Lung cancer
• Chronic lung infection
HEART DISEASES
• Infectious endocarditis
• Congenital heart defect
OTHER DISEASES
• Liver disease
• Thyroid disorder
What is groundglass?
A hazy opacity found in the lungs on a CT scan due to thickening of the alveolar interstitium by: • Blood • Water • Tumour • Cells • Fibrous tissue • Any combination of the above
IMG 165 - (left hand image = groundglass)
What are pleural plaques?
A benign condition that shows that a person was exposed to asbestos at some point in their life
Recall what V/Q is in terms of lungs
V = ventilation = the air that reaches the alveoli Q = perfusion = the blood that reaches the alveoli
What is a shunt?
What is ‘dead space’?
What is the V/Q of each?
An area of lung with perfusion but no ventilation (e.g. due to a tumour) - V/Q=0
An area of lung with ventilation but without perfusion - V/Q=infinite
IMG 166
What is a raised JVP indicative of?
High pressure in the right atrium
Where can asbestos bodies be found?
What do they look like histologically?
How does the body respond to foreign asbestos? What does this allow us to do?
Bronchoalveolar lavage fluid (BAL fluid)
Like a rod (IMG 167)
Coats it in iron, this allows you to do iron staining to identify the asbestos body
What is cor pulmonale?
Enlargement and failure of the right ventricle as a response to increased vascular resistance and BP in the lungs
What is honeycomb lung?
A lung riddled in holes due to multiple cystic spaces
What are the two forms of asbestos? How do they differ? Which is more likely to induce lung disease?
- Serpentine
- Amphibole
These differ in the ability to penetrate into the respiratory tract. Serpentine is softer and curled, whereas amphibole are needle shaped and rigid. (IMG 168)
Therefore, amphibole is more likely to be invasive and cause lung disease
What diseases are associated with asbestos exposure?
- Bronchogenic carcinoma
- Malignant mesothelioma
- Asbestosis (severe fibrosis of the lungs)
- Pleural disease
- Pneumoconiosis
What is pneumoconiosis?
Non-neoplastic lung reaction to inhalation of mineral dusts (a type of RESTRICTIVE lung disease):
• Inflammation response to a range of organic and inorganic particles followed by fibrosis
• Inhaled dusts are phagocytosed by macrophages
• Coal workers pneumoconiosis shows pigmentation of the lung tissue
What is interstitial lung disease? What changes are seen in the lung as a result of this process?
Interstitial lung disease
• Decreased volume and compliance of lungs due to inflammation and fibrosis of lungs in response to inhaled toxins or agents
• The repair process goes awry and the tissue around the air sacs (alveoli) becomes scarred and thickened. This produces a barrier to diffusion.
What are the two patterns of damage which can be seen with chronic lung diseases?
How does each effect performance in pulmonary function tests?
Obstructive lung disease
• Increased resistance to flow
• Lung capacity unchanged, but FEV1 decreased
• E.g. COPD
Restrictive lung disease
• Reduced lung expansion
• Lung capacity decreased, but normal FEV1
• E.g. pneumoconiosis
What is hypersensitivity pneymonitis?
Type 3 hypersensitivity reaction due to inhalation of dust or other antigens
