*Restrictive Airway Disease Flashcards
What is restrictive lung disease?
Patient find it difficult to fully inflate their lungs due to the lungs being restricted from fully expanding
What are some examples of thoracic restriction due to causes out with the lungs (extrinsic causes)?
Skeletal: (thoracic kyphoscoliosis, ankylosing spondylitis, rib trauma)
Muscle weakness: (intercostal or diaphragmatic due to myopathy, neuropathy, ir myelopathy) e.g. Guillan barre, Motor neurone disease)
Abdominal obesity/ ascites
In terms of alveolar ventilation, PaO2, PaCO2, and lung volumes, what effect does thoracic restriction due to causes out with the lungs have (extrinsic causes)?
- chronic alveolar under ventilation
- Low PaO2
- raised PaCO2
- reduced lung volumes
What does DPLD stand for?
Other name for this?
Diffuse Parenchymal Lung Diseases
Interstitial lung diseases
What are interstitial lung diseases?
A group of conditions that primarily affect the lung parenchyma in a diffuse manner
They are characterised by chronic inflammation +/- progressive interstitial fibrosis
They have a restrictive pulmonary spirometry with reduced carbon monoxide diffusing capacity (DLCO)
Clinical features of Diffuse parenchymal lung diseases? (5)
Dyspnoea on exertion
Non-productive paroxysmal cough (with no wheeze)
Finger clubbing
Abnormal breath sounds (inspiraotry lung crackles)
Abnormal chest x-ray or high resolution CT
Restrictive pulmonary spirometry with decreased DLCO
What 3 general groups can interstitial lung diseases be grouped into?
Those with a known cause e.g. drugs, occupation, infection, etc.
Those associated with systemic disorders e.g. sarcoidosis, rheumatoid arthritis, etc.
Idiopathic e.g. lymphocytic interstitial pneumonia, idiopathic pulmonary fibrosis
Spectrum of DPLD - BTS classification?
1) acute DPLD (e.g. infections, allergy, toxins, etc.)
2) episodic DPLD, all of which may present acutely (e.g. extrinsic allergic alveolitis, eosinophilic pneumonia)
3) Chronic DPLD due to occupational or environmental agents or drugs (e.g. aspestosis, silicosis, etc.)
4) Chronic DPLD with evidence of systemic disease (e.g. rheumatoid arthritis)
5) Chronic DPLD with no evidence of systemic disease e.g. idiopathic pulmonary fibrosis
What are the 2 very broad classifications of restrictive lung disease?
Intrinsic (interstitial lung disease)
Extrinsic (due to causes outwith the lungs)
Alveolar gas exchange in restrictive thoracic disease due to disease within he lungs? (PaO2 and PaCO2)
PaO2 = decreased PaCO2 = normal as CO2 exchange unimpaired as alveolar perfusion normal
Aetiology of DPLD? (6)
Fluid in the alveolar air spaces Consolidation of alveolar air spaces Inflammatory infiltrate of alveolar walls Dust disease Carcinomatosis Eosinophilic
What causes fluid in the alveolar spaces?
Cardiac pulmonary oedema (due to raised venous pressure i.e. LVF)
Non-cardiac pulmonary oedema due to leaky capillaries (caused by sepsis or trauma - ARDS aka shock lung) - also due to altitude sickness
What causes consolidation of alveolar air spaces?
Infective pneumonia
Infarction e.g. PE/ vasculitis
Other causes i.e. BOOP, rheumatoid disease, drugs
What is BOOP?
Other name?
Bronchiolitis obliterans with organizing pneumonia (BOOP) is a rare lung condition in which the small airways (bronchioles) and air exchange sac (alveoli) become inflamed with connective tissue
Cryptogenic organising pneumonia
What causes an inflammatory infiltrate of alveolar walls? (5)
Granulomatous alveolitis (extrinsic allergic alveolitis, sarcoidosis)
Drug induced alveolitis
Toxic gas/ fumes
Fibrosing alveolitis (rheumatoid arthritis, idiopathic pulmonary fibrosis)
Autoimmune (Wegeners, Churg-Strauss, etc.)
