Medicine: Restrictive lung diseases, Pulmonary hypertension and O2 therapy Flashcards
Conditions causing upper zone fibrosis
Fibrosis predominately affecting the upper zones
- hypersensitivity pneumonitis (also known as extrinsic allergic alveolitis)
- coal worker’s pneumoconiosis/progressive massive fibrosis
- silicosis
- sarcoidosis
- ankylosing spondylitis (rare)
- histiocytosis
- tuberculosis
Conditions causing lower zone fibrosis
Fibrosis predominately affecting the lower zones
- idiopathic pulmonary fibrosis
- most connective tissue disorders (except ankylosing spondylitis) e.g. SLE
- drug-induced: amiodarone, bleomycin, methotrexate
- asbestosis
Drugs that can cause lung fibrosis
- amiodarone
- cytotoxic agents: busulphan, bleomycin
- anti-rheumatoid drugs: methotrexate, sulfasalazine
- nitrofurantoin
- ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, pergolide)
Pathophysiology of lung fibrosis
Injury to endothelial cells → inflammatory response (with initiation of growth factors, cytokines etc → repair (cellular re-organization and fibrin formation) → wound contraction
Pathophysiology of Interstitial Pneumonitis
•excessive extracellular
matrix deposition
•fibroblast and myofibroblast
accumulation
•between vascular and alveolar
endothelium
- disrupt normal lung structure
- “honeycomb” appearance
What can be seen in this X-ray?
- Increased interstitial markings
- Reduced lung volumes
What pattern can be seen on spirometry in Pulmonary Fibrosis?
- restrictive
- reduced FEV1 and FVC
- normal FEV1/FVC ratio
- reduced lung volumes
- reduced transfer factor
Features of Idiopathic Pulmonary Fibrosis
IPF is typically seen in patients aged 50-70 years and is twice as common in men.
Features
- progressive exertional dyspnoea
- bibasal fine end-inspiratory crepitations on auscultation
- dry cough
- clubbing
Diagnosis of idiopathic pulmonary fibrosis
- modalities
- what’s seen
- spirometry: classically a restrictive picture (FEV1 normal/decreased, FVC decreased, FEV1/FVC increased)
- impaired gas exchange: reduced transfer factor (TLCO)
- imaging: bilateral interstitial shadowing (typically small, irregular, peripheral opacities - ‘ground-glass’ - later progressing to ‘honeycombing’) may be seen on a chest x-ray but high-resolution CT scanning is the investigation of choice and required to make a diagnosis of IPF
- ANA positive in 30%, rheumatoid factor positive in 10% but this does not necessarily mean that the fibrosis is secondary to a connective tissue disease. Titres are usually low
What can be seen on imaging in idiopathic pulmonary fibrosis ?
- bilateral interstitial shadowing (typically small, irregular, peripheral opacities - ‘ground-glass’ - later progressing to ‘honeycombing’)
- may be seen on a chest x-ray but high-resolution CT scanning is the investigation of choice and required to make a diagnosis of IPF
Management of Pulmonary FIbrosis
- pulmonary rehabilitation
- very few medications have been shown to give any benefit in IPF. There is some evidence that pirfenidone (an antifibrotic agent) may be useful in selected patients
- many patients will require supplementary oxygen and eventually a lung transplant
Prognosis in Pulmonary Fibrosis
poor, average life expectancy is around 3-4 years
What’s seen on this CT?
CT scan showing advanced pulmonary fibrosis including ‘honeycombing’
What’s seen on this imaging?
Chest X-ray and CT scan
- The x-ray shows reitcular opacities predominantly in the bases
- CT demonstrates honeycombing and traction bronchiectasis
Symptoms of pulmonary hypertension
- Breathlessness
- Weakness / lethargy
- Exertional dizziness
- Syncope
- Anginal chest pain
What’s that?
Plexiform lesion
- associated with pulmonary hypertension (thickening of a pulmonary arteriolar wall)
What can be seen on CXR in a patient with pulmonary hypertension?
- CXR
- elevated cardiac apex
- enlarged right atrium
- prominent pulmonary outflow tract
- enlarged pulmonary arteries
- pruning of peripheral pulmonary vessels
Colours of venturi masks and % of oxygen they deliver
