Asbestosis_Flashcards
Definition
Asbestosis is a type of pneumoconiosis that presents as diffuse interstitial fibrosis of the lung following exposure to asbestos fibers. It often includes pleural abnormalities such as plaques, diffuse pleural thickening, and benign pleural effusions.
Pathophysiology
Asbestos fibers deposit at alveolar duct bifurcations, leading to macrophage activation, cytokine release, and fibrosis. Fibrosis often starts in the lower lobes and progresses to honeycombing. Pleural scarring may also occur.
Epidemiology
Latency period of ~20 years from exposure to onset. Most cases occur in workers exposed before 1980s. Higher incidence in shipyard, construction, and maintenance workers. 905 cases in the UK in 2019.
History
Patients present with dyspnea, dry cough, and fatigue. History often includes occupational exposure to asbestos. Symptoms develop decades after exposure.
Examination
May show crackles on lung auscultation, clubbing in advanced stages, and cyanosis in severe cases. Physical exam findings may be absent in pleural-only disease.
Investigations - Bedside
Initial clinical assessment focuses on occupational exposure history and symptom review.
Investigations - Bloods
No specific blood tests indicated for asbestosis. Biomarkers like Fibulin-3 may aid in distinguishing related conditions.
Investigations - Imaging
Chest X-ray shows lower lobe fibrosis and pleural plaques. High-resolution CT (HRCT) is more sensitive, showing interstitial and pleural changes with calcification.
Investigations - Special Tests
Pulmonary function tests often reveal restrictive patterns. Lung biopsy or bronchoalveolar lavage may confirm asbestos exposure but are rarely required.
Management - Conservative
Encouragement to cease smoking and workplace safety education.
Management - Medical
Pulmonary rehabilitation, oxygen therapy, and treatment for comorbidities. Antibiotics for infections.
Management - Surgical
Lung transplant or pleural decortication in rare, advanced cases. Generally not needed for pleural thickening.
Risks of Treatments
Corticosteroids have limited use and potential adverse effects. Lung biopsy carries procedural risks.
Benefits of Treatments
Symptom relief and improved quality of life with pulmonary rehabilitation and oxygen therapy.
Medical and Laboratory Sciences
Fibulin-3 as a biomarker. Pulmonary function tests reveal restrictive or mixed patterns. Imaging aids in diagnosis.
