Asbestosis

Question 1

Definition of Asbestosis

Answer 1

Is diffuse interstitial fibrosis of the lung as a result of inhalation of asbestos fibres. Can lead to pleural abnormalities

Question 2

Aetiology of asbestosis

Answer 2

• Caused by the inhalation of asbestos fibres
◦ The more that is inhaled, the greater the risk of developing asbestosis
• Asbestos was commonly used in the building trade

Question 3

Pathophysiology of asbestosis

Answer 3

• The inhaled asbestos would deposit at the alveolar duct bifurcations and cause alveolar macrophage alveolitis
• The activated macrophages would release pro-inflammatory cytokines etc, that would initiate fibrosis
• The initial fibrosis would typically occur in the LOWER LOBES
◦ But can progress to extensive fibrosis and honeycombing
• Plaques may form in the pleural space and the condition can lead to pleural thickening

Question 4

History and examination of asbestosis

Answer 4

• Dyspnoea on exertion: typically first sign, worsens with disease progression
• Cough: dry, non-productive, frequency would increase with progression
• Crackles: May be able to hear fine end inspiratory crackles at the bases
• Clubbing: in more advanced disease

Question 5

Risk factors for asbestosis

Answer 5

• Occupational exposure: can have its effect 10 years down the line
• Longer duration of exposure
• Smoking

Question 6

Investigations for asbestosis

Answer 6

• Chest X ray: can show lower zone linear interstitial fibrosis (ground glass opacities), pleural thickening etc
• High resolution CT: more sensitive than Xray
• Pulmonary function test: Non-specific, but may show restrictive nature (lower FVC, but higher FEV1)

Question 7

Treatment for asbestosis

Answer 7

1) Smoking cessation: would reduce the risk of lung cancer
+ supportive care: antibiotics should be given if evidence of infection (productive cough, fever etc)

CONSIDER pulmonary rehab

Question 8

Prevention and complications of asbestosis

Answer 8

Minimise exposure to asbestos
Patients with asbestosis should receive influenza and pneumococcal vaccines

Prognosis depends on extent of fibrosis. Most patients are likely to die from other causes

Question 9

Complications of asbestosis

Answer 9

• Lung cancer: Increased risk of developing lung cancer (even greater in smokers)
• Cor pulmonale: consequence of hypoxia and development of pulmonary hypertension
• Mesothelioma