Interstitial Lung Disease Flashcards
describe vesicular breath sounds?
inspiration > expiration
soft intensity
describe bronchovesicular breathing?
inspiration=expiration
intermediate intensity
describe bronchial breathing?
tubular, hollow sounds
louder and higher-pitched than vesicular breath sounds
what other breath sounds may you hear on auscultation?
- fine crackles
- coarse crackles
- high pitched wheeze
- pleural rub
what signs would be present in a patient with consolidation?
- dull percussion
- increased (bronchial) sounds
- crackles
- increased tactile vocal fremitus
what would the signs be in a patient with pneumothorax?
- mediastinual shift and trachea to opposite of affected side
- resonant to percuss
- decreased breath sounds
- decreased tactile vocal fremitus
what would be the signs seen in a patient with pleural effusion?
- no mediastinal shift
- stony dull percussion
- decreased breath sounds
- occasional rub
- decreased vocal fremitus
what would be the signs seen in a patient with lobar collapse?
- mediastinal shift towards the affected side
- dull percussion
- decreased breath sounds
- decreased vocal fremitus
what would be the signs seen in a patient with pleural thickening?
- no mediastinal shift
- dull percussion
- decreased breath sounds
- decreased vocal fremitus
what are interstitial lung diseases?
conditions that affect the parenchyma of the lung (alveoli, alveolar epithelium, capillary endothelium)
what can be seen on CXR in patients with interstitial lung disease?
interstitial opacities on CXR
what symptoms do patients with interstitial lung diseases have?
progressive exertional dyspnoea persistent non productive cough haemoptysis wheezing chest pain
what can interstitial lung diseases be split into?
groupings based on major underlying histopathology;
- those associated with predominant inflammation and fibrosis
- those with predominantly granulomatous reaction in interstitial or vascular areas
what are the most common interstitial lung diseases of unknown aetiology?
sarcoidosis
idiopathic pulmonary fibrosis
pulmonary fibrosis associated with CTDs
Give examples of interstital lung diseases of known cause?
occupational and environmental exposures
inhalation of inorganic dusts and fumes or gases
what is the pathogenesis of interstitial lung diseases?
- nonmalignant disorders not caused by identified infectious agents
- multiple initiating agents of injury, the immunopathogenic responses of lung tissue are limited and mechanisms of repair have similar features
what is the histopatholgic pattern of disease in granulomatous lung disease?
accumulation of T cells, macrophages and epitheloid cells organised into discrete structures in lung parenchyma which can progress to fibrosis
what is the histopatholgic pattern of disease in inflammation and fibrosis ILD?
initial insult is injury to epithelial surface causin inflammation in air spaces and alveolar walls. if becomes chronic the inflammation spreads to adjacent portions of the interstitium and vasculature causing interstitial fibrosis
what developments in ILD can lead to derangement of ventilatory function and gas exchange?
irreversible scarring of alveolar walls, airways or vasculature
what lung conditions can be caused by irritants such as sulphur dioxide, chlorine, ammonia, nitrogen oxides?
acute bronchitis
pulmonary oedema
what is the commonest industrial lung disease in the developed world?
occupational asthma
what lung disease can be caused due to industrial agents such as asbestos, polycyclic hydrocarbons, radon in mines?
bronchial carcinoma
- what substances can cause nodular shadowing on CXR when inhaled?
- and what effect does this have on lung function and symptoms?
- iron (siderosis)
barium (baritosis)
tin (stannosis) - minimal affect
what substance has historically accounted for 90% of all compensated industrial lung diseases?
coal dust
it has an intermediate fibrogenic effect
what does pneumoconiosis mean?
accumulation of the dust in the lungs and the reaction of the tissue to its presence
what causes coal workers pneumoconiosis?
dust particles 2-5um in diameter that are retained in the small airways and alveoli of the lung
incidence of disease is related to total dust exposure
what are the 2 syndromes that result from inhalation of coal?
simple pneumoconiosis
progressive massive fibrosis
describe simple pneumoconiosis?
- reflect deposition of coal dust in lung, it produces fine micronodular shadowing on CXR
- most common type of pneumoconiosis
- graded on CXR according to categories; small round opacities either with or without normal lung markings
- can progress to progressive massive fibrosis
what is progressive massive fibrosis?
- development of fibrosive masses usually in upper lobe and having necrotic central cavities
- fibrogenic promoting factor present leading to formation of immune complexes, analogous to development of large nodules in coal miners with rheumatoid (caplans syndrome)
- patients with PMF usually have rheumatoid factor and anti-nuclear antibodies present
- apical desctruction and disruption leading to emphysema and airway damage
- pulmonary function-restrictive and obstructive with loss of lung volume, irreversible airflow limitation and reduced gas exchange
- effort dyspnoea with cough
- black sputum and can progress after exposure has stopped to respiratory failure
in what occupations does silicosis occur?
stonemasons
sand blasters
pottery
ceramic workers
what causes of silicosis?
inhalation of silica (highly fibrogenic)
3g of silica is sufficient to kill)
what damage does silica cause to the lungs?
toxic to alveolar macrophages and readily initiates fibrogenesis
what would CXR and clinical features be in a patient with silicosis?
similar to PMF
distinctive streaks of calcification around hilar lymph nodes (‘eggshell’ calcification)
what causes byssinosis?
endotoxins from bacteria present in raw cotton causing constriction of airways of the lung
what are CXR findings in a patient with byssinosis?
no changes
what are the symptoms of byssinosis?
tightness in chest, cough and breathlessness within first hour in dusty areas of mill
‘monday sickness’-symptoms start first day back at work
what causes berylliosis?
beryllium copper alloy (used in aerospace industry, atomic reactors and electrical devices)
what effect does berllium have when inhaled?
causes systemic illness with similar clinical picture to sarcoidosis
progressive dyspnoea with pulmonary fibrosis
what is asbestos?
mixture of silicates of iron, magnesium, nickel, cadmium, aluminium
occurs naturally as a fibre
it is resistant to heat, acid, alkali
used for roofing, insulation and fireproofing
describe crocidolite (blue asbestos)?
particularly resistant to chemical destruction and exists in straight fibres. This is the type of asbestos is most likely to produce asbestosis and mesothelioma as it is readily trapped in lung. It is long and thin in shape so can be inhaled but subsequent rotation against the long axis of the smaller airways causes fibres to impact. It is resistant to macrophage and neutrophil enzymatic destruction
what risk is increased in people exposed to asbestos?
primary lung cancer (adenocarcinoma)
what is asbestosis?
fibrosis of the lungs caused by asbestos dust which may or may not be associated with fibrosis of parietal or visceral layers of the pleura. It is a progressive disease characterised by breathlessness and accompanied by finger clubbing and bilateral basal end inspiratory crackles. Minor degrees of fibrosis that are not seen on chest x-ray are often reveals on high resolution CT. no treatment is known to alter progression by corticosteroids often prescribed
what is the most common presentation of mesothelioma?
pleural effusion with chest wall pain
what treatment is given to patients with mesothelioma?
chemotherapy with surgery
what investigations are useful when you suspect a patient has interstitial lung disease?
CT scan
echo
lung tissue analysis
pulmonary function tests
why is CT scanning useful in diagnosis of ILD?
extent of lung damage
shows details of fibrosis to narrow down diagnosis and guide treatment decisions
why is an echo scan useful in diagnosing ILD?
evaluates the amount of pressure in the right side of the heart
what are the methods of lung tissue analysis used in diagnosis of ILD?
bronchoscopy
bronchoalveolar lavage
surgical biopsy
what pulmonary function tests are useful in diagnosis of ILD?
spirometry and diffusion capacity
oximetry
