Intersticium, Pleura and Chest disease Flashcards
What is the interstitial space
Potential space between alveolar cells and capillary basement membrane
Functions of the interstitial space
Structural support
Immune function
Controls alveolar growth
What structural changes occur in the lungs in interstitial disease
Intersticium becomes apparent as it contains collagen, cells and fluid
Also affects acini, alveoli lumen, bronchioles, epithelia, endothelia, mesenchyme and macrophages
Inflammatory cells are recruited
How does interstitial disease affect lung function
Fibrosis decreases lung compliance, decreases perfusion and increases diffusion distance
It is a restrictive airflow disorder that causes type 2 respiratory failure
Symptoms and signs of interstitial disease
Symptoms: chronic dyspnoea, chronic cough
Signs: tachypnoea, tachycardia, bilateral reduce chest expansion, cyanosis, signs of right sided heart failure and clubbing in idiopathic pulmonary fibrosis
Broad causes of interstitial lung disease
Occupational Treatment related Connective tissue disorders Immunological Idiopathic
What are the occupational causes of interstitial lung disease
Asbestos
Silicosis
Coal workers pneumoconiosis
What can asbestos cause and what look like on a CXR
Mesothelioma
Bronchogenic cancers
Asbestosis
On a CXR - asbestos plaques (benign irregular mass of calcified asbestos)
What drugs can cause interstitial lung disease and what do each treat
Methotrexate - RA Bleomycin - lymphoma Amiadarone - arrhythmias Nitrofurantoin - UTIs Chemotherapy and radiation - cancer
What connective tissue disorders can cause interstitial lung disease
RA Scleroderma Sjogren's syndrome Polymyositis Systemic lupus erythrematosis
What immunological disorders can cause interstitial lung disease
Sarcoidosis
Extrinsic allergic alveolitis
What is sarcoidosis
Non caseating granulomas, usually in the lungs
Alveoli contain macrophages and lymphocytes
What demographics does sarcoidosis occur in
Female
Afro-Caribbean and Asians
How do you confirm sarcoidosis
Biopsy lymph nodes to distinguish sarcoidosis (non caseating) and TB (caseating)
Treatment for sarcoidosis
No treatment
Steroids
What are the types of extrinsic allergic alveolitis
Acute - farmer’s lung
Chronic - bird fancier’s lung
Cause and symptoms of farmer’s lung
Inhalation of actinomycetes in mouldy hay
Symptoms - dry cough, breathlessness on exertion, wheeze, inspiratory crackles
Cause and symptoms of bird fancier’s lung
Long term pigeon exposure
Symptoms - extreme malaise, dry cough, chronic breathlessness, inspiratory crackles
Describe idiopathic pulmonary fibrosis
Increased activation of alveolar macrophages which attracts neutrophils and eosinophils, leading to tissue damage (release of ROS and hydrolytic enzymes)
Fibrosis occurs to repair damage
Symptoms and prognosis of idiopathic pulmonary fibrosis
Progressive SOB
Cough
Clubbing
Poor prognosis - 3 years
Treatment of idiopathic pulmonary fibrosis
High dose oral steroids
Antifibrotics
CXR appearance in idiopathic pulmonary fibrosis
Small lungs
Micro nodular shadowing in lower lobes
Ragged heart borders
CXR appearance in acute extrinsic allergic alveolitis
Diffuse micro nodular infiltrate (denser towards hila)
CXR appearance in chronic extrinsic allergic alveolitis
Almost normal but progresses to fibrosis