Restrictive lung disease Flashcards
What are three causes of thoracic restriction due to causes outwith the lungs? what does this result in?
Skeletal :Vertebrae-eg Thoracic kyphoscoliosis , Ankylosing spondylitis ,Ribs –eg Traumatic multiple rib #s
Muscle Weakness - Intercostal or Diaphragmatic (due to
Myopathy/Neuropathy/Myelopathy) –eg Myaesthenia Gravis ,Guillan Barre,
Motor neurone disease ,Poliomyelitis
Abdominal Obesity/Ascites –compression of thoracic contents
Results in Chronic alveolar under ventilation with low PaO2 ( SaO2) and raised PaCO2 and reduced lung volumes
What is the BTS classification of diffuse parenchymal lung disease? (DPLD)
- Acute DPLD
- Episodic DPLD, all of which may present acutely
- Chronic DPLD due to occupational or environmental agents or drugs.
- Chronic DPLD with evidence of systemic disease
- Chronic DPLD with no evidence of systemic disease .
What causes restrictive lung disease? what does this lead to?
-due to disease within the lung itself i.e. interstitial lung disease i.e. diffuse parenchymal lung disease
Leads to:
- impaired alveolar gas exchange - alveolar barrier to oxygen exchange
- carbon dioxide is unchanged because alveolar ventilation is normal and CO2 is v soluble and is blown off
= type 1 respiratory failure
What are the 6 causes of DPLD?
1 - Fluid in the alveolar spaces:
- cardiac pulmonary oedema (due to raised pulmonary venous pressure i.e. LVF)
- non-cardiac pulmonary oedema (due to leaky pulmonary capillaries e.g. sepsis/trauma)
2 - consolidation of alveolar air spaces:
- infective pneumonia
- infarction e.g. P.E/vasculitis
- other causes i.e. BOOP e.g. rheumatoid disease, drugs, cryptogenic
3 - inflammatory infiltrate of alveolar walls i.e. alveolitis:
- granulomatous alveolitis such as both extrinsic allergic alveolitis AKA hypersensitivity pneumonitis (farmers lung/avian lung) or sarcoidosis
- Drug induced alveolitis e.g. amiodarone, bleomycin, methotrexate, gold
- toxic gas/fumes alveolitis
- fibrosing alveolitis e.g. rheumatoid, cryptogenic (idiopathic pulmonary fibrosis)
- autoimmune e.g. SLE, polyarteritis, wegeners, churg-strauss, bechets
4: dust disease (pneumoconiosis):
- Fibrogenic- asbestosis/silicosis
- Non-fibrogenic e.g. siderosis (iron) stanosis (tin) baritosis (barium)
5: carcinomatosis via lymphatic/blood spread from bronchus, breast, prostate, colon, stomach
6: eosinophilic:
- drugs e.g. nitrofurantoin
- Fungal e.g. aspergillosis
- parasites e.g. toxocara, ascaris, filaria
- autoimmune e.g. churg strauss, polyarteritis
What is the clinical syndrome of DPLD? (6)
- breathless on exertion
- cough but no wheeze
- finger clubbing
- inspiratory lung crackles
- central cyanosis (if hypoxaemic)
- pulmonary fibrosis occurs as end stage response to chronic inflammation
what are the aspects of diagnosis of DPLD? (11)
1: history e.g. occupation/drugs/pets/arthritis
2: reduced lung volumes (reduced FEV1 and FVC, normal FEV1:FVC ratio), peak flow normal
3: reduced gas diffusion (DLCO)
4: arterial oxygen desaturation at rest or on exercis (decreased P02, decreased Sa02)
5: antibodies - avian, fungal, auto-antibodies
6: serum ACE and Ca raised in sarcoid
7: bilateral diffuse alveolar infiltrates on chest x-ray
8: echo to exclude heart failure
9: High resolution CT scan-Inflammatory ground glass
vs Fibrotic nodular component of alveolar infiltrates
10: Bronchoalveolar lavage or induced sputum–to
exclude Pneumocystis, TB or other infection
11: Transbronchial or thoracoscopic lung biopsy-rarely indicated
What does the treatment of DPLD involve? conservative and 1st/2nd line medical treatment and other adjunctive treatments (for interstitial pulmonary fibrosis) and end stage treatment
Remove any trigger factor
- dust, drug, allergen
Treat any inflammation ie ground glass on HRCT -immuno-suppressives
(NB-danger of secondary super-infection due to immune suppression)
1st line treatment
Systemic Corticosteroids- ie oral prednisolone-inhaled corticosteroids not effective
2nd line treatment -oral Azathioprine [steroid sparing]
Anti-fibrotic agents :Pirfenidone ,Nintedanib [For IPF]
Anti-oxidant agents : Acetylcysteine [For IPF]
O2 if hypoxaemic
Lung transplantation –last resort for end stage disease
What is BOOP AKA COP?
Cryptogenic organizing pneumonia (COP) is an idiopathic condition in which granulation tissue obstructs alveolar ducts and alveolar spaces with chronic inflammation occurring in adjacent alveoli.
What is sarcoidosis?
idiopathic:
- Systemic (multi-system) granulomatous inflammatory disease characterized by non-caseating granulomas (small inflammatory nodules) on lung…
- Granulomas most often appear in the lungs or the lymph nodes, but virtually any organ can be affected. Normally the onset is gradual/insidious.
- Sarcoidosis may be asymptomatic or chronic and may cause death.
What clinical features are seen in sarcoidosis?
- bilateral hilar lymphadenopathy
- erythema nodosum
- uveitis
- myocarditis
- neuropathy
