Restrictive Lung Disease Flashcards
What are the clinical symptoms associated with restrictive lung disease?
Symptoms of restrictive lung disease include:
Dyspnea (shortness of breath, especially with exertion).
Non-productive cough.
Fatigue.
Chest discomfort.
Decreased exercise tolerance.
Fine crackles (heard on auscultation).
Hypoxemia (low oxygen levels).
What are the major classes of restrictive lung disease?
The major classes include:
Occupational lung diseases (e.g., asbestosis, silicosis, coal worker’s pneumoconiosis).
Granulomatous lung disease (e.g., sarcoidosis, where granulomas form in the lungs and other organs).
Idiopathic pulmonary fibrosis (IPF), characterized by progressive scarring of lung tissue with no known cause.
What is the natural history of restrictive lung disease?
The natural history varies by type, but typically involves:
Chronic progression of symptoms (dyspnea, cough).
Decreased lung volumes (especially forced vital capacity).
Progressive fibrosis (scarring of lung tissue).
Reduced gas exchange, leading to hypoxemia.
In some cases, disease progression may stabilize, while in others, it can result in respiratory failure and require lung transplantation.
What is the lung interstitium and what are the functional effects of interstitial lung disease?
The lung interstitium refers to the tissue and spaces between the alveoli (air sacs) and blood vessels. Interstitial lung disease (ILD) affects this area, leading to fibrosis and scarring.
The functional effects include:
Impaired gas exchange due to thickening of the interstitial space.
Decreased lung compliance, making it harder for the lungs to expand.
Progressive hypoxemia and reduced oxygen diffusion into the bloodstream.
What is the aetiology and pathogenesis of diffuse alveolar damage syndrome, sarcoidosis, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis?
Diffuse alveolar damage (DAD): Caused by acute lung injury (e.g., due to pneumonia, aspiration, or mechanical ventilation), leading to damage to the alveolar-capillary membrane and inflammation.
Sarcoidosis: An autoimmune or granulomatous condition where immune cells form granulomas, primarily affecting the lungs, leading to inflammation and fibrosis.
Hypersensitivity pneumonitis: An inflammatory response to inhaled organic particles (e.g., mold, bird droppings), causing immune-mediated damage and fibrosis in the lungs.
Idiopathic pulmonary fibrosis (IPF): The cause is unknown, but it involves progressive fibrosis of the interstitial tissue of the lungs, with the formation of scar tissue that disrupts normal lung function.
What are the causes and effects of end-stage lung fibrosis or honeycomb lung?
Causes: Chronic restrictive lung diseases like idiopathic pulmonary fibrosis (IPF) or interstitial lung diseases result in progressive scarring and fibrosis of the lung tissue.
Effects: In end-stage fibrosis, the lung architecture becomes severely distorted, forming cystic spaces or “honeycombing” in the lung tissue. This results in significant reduction in gas exchange, leading to severe hypoxemia and respiratory failure.
How is restrictive lung disease investigated and managed?
Investigation involves:
Pulmonary function tests (to assess lung volumes and forced vital capacity).
Chest X-ray or CT scan (to identify fibrosis and other lung changes).
Bronchoscopy with biopsy (in some cases for diagnosis of sarcoidosis or other granulomatous diseases).
Serological tests (e.g., for sarcoidosis or autoimmune conditions).
6-minute walk test (to assess functional capacity).
Management options include:
For sarcoidosis: Corticosteroids to reduce inflammation.
For occupational lung diseases: Removing the patient from exposure to harmful substances, plus supportive care.
For hypersensitivity pneumonitis: Avoidance of the offending antigen and corticosteroids for inflammation.
For idiopathic pulmonary fibrosis: Antifibrotic agents (e.g., pirfenidone, nintedanib) to slow disease progression, oxygen therapy, and lung transplantation in severe cases.
