Resp Flashcards
When has or is the peak of asbestos-related diseases due or did present?
Over the 5-10 years (I.e., around 2019-2024), due to the long latent period between asbestos exposure and disease.Asbestos use was banned in the 1980’s but many people worked with it up until then.
What nations still produce and use lots of asbestos?
Brazil, Russia, China, Kazakhstan. So important to know about asbestos related disease not only for the point of view of uk workers who used to work with it, but migrants from countries that still use it.
What are the two types of asbestos? How widely used are/were they?
White - chrysotile, accounts for more than 95% of use worldwide! serpentine minerals! curly long woven fibres.Blue/brown - corcoidolite, amosite, and others - straighter, brittle, less malleable.
What are the useful properties of asbestos which meant it was and still is used so widely?
Heat, fire, and chemical resistance.Electrical and sound insulation.Medium tensile strength.Therefore very valuable in industry, especially in building and construction.
What are the four grades of asbestos-related lung disease?
1) benign disease (pleural plaques, diffuse pleural thickening, benign pleural effusion).2) asbestososis (a type of interstitial lung disease).3) lung cancer.4) malignant mesothelioma (cancer of the pleural layer, very dangerous).
What is the epidemiology of asbestos-related disease? (Three points)
As mentioned previously, peak onset between now and 2024.Male:female ratio of 4:1 (due to exposure; more men worked with asbestos than women).It is rare under the age of 40 (due to long latent period).
What is the pathophysiology of asbestos related disease? What properties of asbestos molecules make it difficult for the lungs to clear? (Name 3).
The fibres become airborne, are inhaled, and are trapped inside the lungs. They are classified as carcinogens. Mucocilliary clearance gets rid of some, but not all of these fibres, because of their special properties:1) they are long, therefore cannot be completely enclosed by macrophages, and are not effectively cleared.2) they are thin - this mean they can travel deep into the respiratory network, beyond they point where mucucilliary clearance occurs.3) biopersistance - they are not broken down, they accumulate over time.
What are the risk factors for developing asbestos related disease? (name 3).
1) the dose of asbestos that an individual is exposed to; the quantity and duration of that exposure.2) type and size of fibre; it is thought that blue or brown asbestos (amphibole sub types) has a greater propensity for causing mesothelioma than the white (chrysotile). This is due to the structure of the molecule.3) personal factors: smoking, pre-existing lung disease, sex, age, etc.
Is smoking a risk factor for developing mesothelioma?
A sneaky question!Smoking on it’s own is NOT a risk factor for developing mesothelioma.BUT if you are exposed to asbestos AND you are a smoker, you have around twice the risk of developing mesothelioma. Also this population has 50-90% increased risk of developing asbestos-related lung cancer.Weird, huh?
Apart from people who directly handle asbestos, who else is at risk of asbestos exposure. (Name two).
The families of the people exposed - they are exposed to, e.g., asbestos on the clothes of the worker.Also people who live close to sites where asbestos is manufactured, or where asbestos-containing products are manufactured.
What occupation carries the greatest risk of asbestos exposure?
Mining asbestos!Fortunately, the UK never had asbestos mines…but other countries did (and do) and migration means we may see the results of this.
What occupations are at-risk for asbestos exposure? (There are seven named here; name 4).
1) miner of asbestos (not in the uk).
2) shipyard workers. (E.g., insulation of boiler pipes, incinerators, pipes. Fibres build up in poorly ventilated areas of the ship).
3) demolition. (Disturbed fibres become airborne).
4) car manufacturing. (Manufacture or repair of breaks and clutch pads)
5) construction. (Electricians, cement production, insulators, pipe-fitters, steel workers, plumbers, roofers, welders).
6) railway workers. (Especially those involved in carriage insulation).
7) manufacturing. (Specifically manufacturing of asbestos containing products for home and industry).
Ini addiction to occupational exposure, and the families of these workers, and the people who live near sites of asbestos manufacture, who else might be exposed?
Anyone who tampers with products that contain asbestos!Any building built prior to 1980 probably has asbestos in it - which is ok as long as it is not disturbed.Self employed plumbers, electricians, builders and carpenters of today may unwittingly expose themselves.Also, DIY enthusiasts may do the same.
Who should remove asbestos?
By a licensed contractor, as set out by the UK’s HSE. But this is NOT often done!
Who should a GP be most suspicious of asbestos related disease in? What should they do?
Middle aged or elderly men, with a history of asbestos exposure, presenting with respiratory symptoms, especially SOBOE.GP’s should: take a thorough occupational and social history, clinical history, full exposure to asbestos history (if known, the type of asbestos exposed to, and the duration of that exposure), full clinical examination.
According to the 2005 NICE guidelines, what should be done with a patient who has a history of asbestos exposure, presenting with SOB, chest pain, unexplained systemic symptoms, or clinical suspicion of cancer?
They should be referred urgently (2WW) to the lung physicians!Duh!
Other than an CXR which can be order in primary care, what secondary care investigations might be useful if asbestos related disease is suspected?
Lung function testing.High resolution CT scan (v sensitive for detecting early fibrosis and pleural plaques).
Who should you tell to stop smoking?
Everybody, of course!But anyone with a history of asbestos exposure should be told twice, because they have double the risk of lung cancer and mesothelioma.
Who should be offered the annual influenza and pneumococcal vaccinations?
Those who have been diagnosed with asbestososis, mesothelioma, or lung cancer.
COPD patients.
What might be the clinical presentation of someone with benign asbestos related disease?
SOB, chest pain.CXR would show pleural plaques (usually asymptomatic) and diffuse pleural thickening.
What might be the presenting symptoms of asbestososis?
SOBOE, dry cough; later, finger clubbing, cor pulmonale.
What might be the presenting features of asbestos related lung cancer?
Usually none at first! Occasional dry cough.Advanced stage: haemoptysis, cough, loss of weight, chest pain, fatigue, SOB, pleural effusion.
What might be the presenting symptoms of mesothelioma?
Usually none at first; sometimes some chest pain and SOB.Advanced disease: SOB, severe and progressive chest pain, pleuritic chest pain, constitutional symptoms such as loss of weight and fatigue.
What is the most common response to exposure to asbestos? What is the latent period? What does this pathology represent? What symptoms might thee patients have, what is there prognosis, and how should they be treated?
Pleural plaques, which usually occur 20-40 years after exposure.They are usually asymptomatic. They are areas of fibrous thinking that usually become calcified over time, usually affecting the parietal pleura (occasionally the visceral pleura affected too).They do not generally progress to anything nasty - they are benign - and it is important to tell patients this; the treatment is reassurance and monitoring in primary care.However, it would be prudent to advise these patients to report any red flag signs, e.g., haemoptysis, persistent chest pain, or SOB should they develop.
What is asbestos related diffuse pleural thickening?
This refers to fibrosis of the visceral pleura as well as loss of pleural space.On a CXR, usually appears as unilateral or bilateral diffuse pleural thickening, with blunting of costophrenic angles.
What often precedes the development of diffuse pleural thickening (DPT) and can facilitate disease progression?
Benign asbestos related pleural effusion.
What do benign asbestos related pleural effusion and benign diffuse pleural thickening have in common?
They are both diseases of exclusion - other causes must be ruled out first, e.g., TB, malignancy; or mesothelioma in the case of pleural thickening.Some patients with a benign asbestos related pleural effusion will need a pleuritic tap if it is large or symptomatic.
When doe benign asbestos related pleural effusion present? What type of effusions are they?
The lag time is short compared to other forms of asbestos related disease - as short as ten years.They are often small exudative effusions, and may regress spontaneously.They may also herald the onset of benign diffuse pleural thickening.
What investigations are required if benign asbestos-related diffuse pleural thickening is suspected?
Intitially, HRCT is the imagining of choice - it is more sensitive than CXR at assessing DPT and it’s extent.However, as asbestos related DPT is a diagnosis of exclusion, other investigations are then usually performed, possibly including MRI, positron omission tomography, and pleural biopsy (to exclude malignant mesothelioma).
Diffuse pleural thickening (DPT) has many causes other than asbestos exposure, hence asbestos related DPT being a diagnosis of exlusion.What can cause DPT? (Name 5)
1) asbestos exposure2) previous thoracotomy or pleurodesis3) TB4) bacterial infection5) connective tissue disease6) haemothorax
What would be the spirometry of someone with diffuse pleural thickening?
A restrictive ventilators defect.
What treatment is there for diffuse pleural thickening?
Not much - it is generally just supportive. Occasionally, non-invasive ventilation is used when type 2 respiratory failure develops.
What is the definition of asbestososis? What is it the most common of?
Bilateral pulmonary fibrosis secondary to asbestos inhalation. Usually there is a lag time of at least 20 years.It is the most common of all the pneumoconiosis diseases and has similar characteristics to interstitial lung fibrosis.
What is the pathogenesis of asbestososis?
Asbestos is fibrogenic to the lungs. Asbestos deposits in the lung causes collagen deposits in the alveolar epithelium and surrounding tissues.
What is the most common presenting feature of asbestosis?
SOBOE and non productive cough.Advanced features include chest tightness and features related to pulmonary hypertension and cor pulmonale.
What examination findings might there be to be found on someone with asbestososis?
Two thirds of patients have fine bi-basal end-inspiritory crackles.Finger clubbing and reduced chest expansion may also be seen.Note that radiographic or pulmonary function testing suggestive of interstitial lung disease often precedes the development of clinical signs.
As with all forms of interstitial fibrosis, what will be found on lung function testing in asbestososis? How about chest radiography/HRCT findings? And pulse oximetry? If this isn’t sufficient for a diagnosis, what can be done, and what would be seen?
Lung function testing would show restrictive pattern with reduction in total lung capacity, vital capacity, and small airway flow rates.CXR will show reticulonodular shadowing in the lower zones.HRCT will show interstitial infiltrates.Pulse oximetry may give evidence of desaturation on exertion.If this is not enough, or if diagnosis is in doubt, then a tissue sample can be taken - pathology will show fibrosis and presence of ferringous bodies (asbestos fibres with a ferritin coating) in the interstitium.
What are the treatment options for asbestososis?
Unfortunately, asbestososis does not respond to convention treatments for interstitial lung diseases - so no role for steroids or immunosuppressants.So management is initially generally supportive.Supplementary oxygen should be offered for those with those at rest or on exercise.Respiratory physiotherapy also plays an important role, as does palliation in the latter stages.
What type of lung cancer does asbestos exposure increase the risk of?
All types!Though note (again!) that smoking + asbestos exposure increases the risk more than would be expected - about twice as much!Asbestos related small cell and non-small cell lung cancers are clinically identical to other tumours of these types.
Where does mesothelioma arise?
Typically in the pulmonary pleura (80%).BUT can also occur peritoneum, the pericardium, and even the tunica vaginalis of the testes!It develops from the mesothelial cells found in these places.
Mesothelioma usually arises secondary to asbestos exposure, with an average lag time of 32 years. But what else can cause it?
Exposure to other fibrous silicate materials, e.g., erionite. Irradiation. Smoking does not (unless also exposed to asbestos - in which case the risk is doubled!)
What are the typical presenting symptoms of malignant mesothelioma?
Dyspnoea (often secondary to pleural effusion or pleural thickening).Chest pain (often described as progressive and dull).Systemic features such as weight loss and fatigue.If peritoneal mesothelioma, then may get abdominal pain, ascites, or features of bowel obstruction.
Does mesothelioma typically metastasise? If so where to?
No, it is not common to.But when it does, typical sites include bone, liver, and lymphatics.
What radiographical features might alert you to the possibility of mesothelioma in a patient with a history of asbestos exposure?What is required to confirm the diagnosis? How is this done?
Pleural thickenings, chest wall masses, or effusion notes on CXR or HRCT.The diagnosis is confirmed by histological and/or cytological examination (important if money / reparations is an issue!!).Pleural aspiration or US-guided pleural biopsy are the usual methods of obtaining a sample; if the facilities exist, then thoracoscopy can be employed to drain the pleural fluid, get a biopsy of the pleura, and also carry out a pleurodesis.
