Restrictive (Interstitial) Lung Diseases Flashcards
What is the interstinum of the lung?
The connective tissue space around the airways and vessels and the space between the basement membrane of the alveolar walls
What is true of normal alveolar wall?
Most of the alveolar epithelial and interstitial capillary endothelial cell basement membranes are in direct contact
How does restrictive lung diseases affect compliance?
Reduced lung compliance (stiff lungs)
How are FEV1 and FVC values affected by restrictive lung diseases?
- Low FEV1
- Low FVC
- FEV1/FVC ratio remains normal
How is gas transfer affected in restrictive lung disease?
- Reduced gas transfer
- Diffusion abnormality
How is ventilation/perfusion affected by restrictive lung disease?
- Ventilation/perfusion imbalance
- When small airways affected by pathology
How is diffuse lung disease normally discovered?
Discovery of abnormal chest X-ray
What is the main symptom of restrictive lung disease?
- Dyspnoea
- Shortness of breath on exertion progresses to shortness of breath at rest
What do people with restrictive lung disease often develop?
- Type I respiratory failure
- Heart failure
What normally starts the process of restrictive lung disease
Parenchymal lung injury
How can a parenchymal lung injury progress?
- Acute response
- Chronic response
- Acute response which progresses to a chronic response
What are the ‘3’ responses to a chronic response?
- Usual interstitial pneumonitis (UIP)
- Granulomatous responses
- Other patterns
What is an example of an acute response?
Diffuse alveolar damage (DAD)
What are other names for DAD?
- ARDS
- Shock lung
What are the causes of DAD?
- Major trauma
- Chemical injury/toxic inhalation
- Circulatory shock
- Drugs
- infection
- Autoimmune disease
- Radiation
- Idiopathic
What are the histological features of DAD?
- Protein rich oedema
- Fibrin
- Hyaline membranes
- Denuded basement membranes
- Epithelial proliferation
- Fibroblast proliferation
- Scarring- interstitium and airspaces
What are examples of granulomatous responses?
- Sarcoidosis
- Hypersensitivity pneumonitis
What is sarcoidosis?
A multisystem granulomatous disorder of unknown aetiology
What is the histopathology of sarcoidosis?
- Epithelioid and giant cell granulomas
- Necrosis/caseation very unusual
- Little lymphoid infiltrate
- Variable associated fibrosis
Who is commonly affected by sarcoidosis?
- Young adults
- Females more than males
Where are the most common sites of sarcoidosis?
- Inter-thoracic lymph nodes
- Lungs
How does sarcoidosis usually present in a young adult?
- Acute arthralgia
- Erythema nodosum
- Bilateral hilar lymphadenopathy
How is sarcoidosis diagnosed in a patient who is asymptomatic?
Incidental abnormal chest X-ray
How might sarcoidosis present?
- Shortness of breath
- Cough
- Abnormal chest X-ray
How is sarcoidosis normally diagnosed?
- Based on clinical findings
- Image findings
- Serum Ca+ and ACE
- Biopsy
What is hypersensitivity pneumonitis?
Group of immunologically mediated lung diseases in which a hypersensitivity response occurs in a sensitised individual to an inhaled antigen.