Restrictive Lung Diseases Overview Flashcards
What three things can cause muscle weakness - intercostal or diaphragmatic - which causes thoracic restriction due to causes outwith the lungs?
Myopathy
Neuropathy
Myelopathy
What do Myaesthenia gravis, Guillan Barre, Motor neurone disease and poliomyelitis all cause, which leads to thoracic restriction of teh lungs?
Muscle weakness
How can abdominal obesity/ascites cause thoracic restriction to the lungs?
Compression of thoracic contents
What does thoracic restriction due to causes out with the lungs result in?
Chronic alveolar under ventilation with low PaO2 (decreased SaO2) and raised PaCO2 and reduced lung volumes
Name 5 causes within the lungs that cause thoracic restriction?
- Acute DPLD - diffuse parenchymal lung disease
- Episodic DPLP, all of which may present acutely
- Chronic DPLD due to occupational or environmental agents
- Chronic DPLD with evidence of systemic disease
- Chronic DPLD with no evidence of systemic disease
What is lung parenchyma?
Alveolar walls/lumen
What is the pathophysiology of restrictive thoracic disease due to diseases within the lung i.e. DPLD?
Imparied alveolar gas exchange - alveolar barrier to O2 exchange, CO2 exchange umimparied as alveolar ventilation normal
Leads to decreased PaO2 (decreased SaO2) and normal PaCO2
What can cause DPLD?
Fluid in the alveolar air spaces Consolidation of alveolar air spaces Inflammatory infiltrate of alveolar walls (alveolitis) Dust disease Carcinomatosis Eosinophilic
What two conditions can lead to fluid in the alveolar air sacs?
Cardiac pulmonary oedema (in alveolar walls and lumen)
Non-cardiac pulmonary oedema
What causes cardiac pulmonary oedema?
Raised pulmonary venoius pressure i.e. LVF
What causes non-cardiac pulmonary oedema?
Normal pulmonary venous pressure with leaky pulmonary capillaries - due to sepsis or trauma (ARDS aka shock lung) also due to altitude sickness
Give three causes of consolidation of alveolar air spaces?
Infective pneumonia
Infarction - PE/vasculitis
BOOP - Rheumatoid disease
Name an inflammatory infiltrate cause of alveolitis?
Granulomatous alveolitis
Give two granulomatous-alveolitis diseases?
Extrinsic allergic alveolitis
Sarcoidosis
What do Farmer’s lung and avian cause?
Extrinsic-Allergic-Alveolitis aka hypersensitivity pneumonitis- type III reaction
What is the name of a multi-system disease with clinical features such as lymphadenopathy, erythema nodosum, uveitis, myocarditis and neuropathy?
Sarcoidosis
What three drugs can induce alveolitis?
Amiodarone
Bleomycin
Methotrexate
What toxic gas fume can cause DPLD, alveolitis?
Chlorine
Give two features of fibrosing alveolitis?
Rheumatoid, cryptogenic