Block 3; IPF, sarcoidosis, Pneumoconiosis Flashcards
1
Q
COPD: indications for NIV at home
A
- Ongoing hypercapnia in patients after an acute exacerbation that needed NIV= PaCO2 ≥7kPa following discharge
- Inability to wean off acute NIV as keeps decompensating
- Repeated admissions for decompensated T2RF (generally ≥3)
- Where LTOT is required and is causing hypercapnia.
- Long term ventilation at home: reduces exacerbation frequency and readmission, improves QOL, may have mortality effect
2
Q
Obesity hypoventilation
A
- Obesity (BMI >30)
- Chronic respiratory failure, but can decompensate: Treated with NIV (acutely or long term)
- Often co-exists with other causes of respiratory failure (esp COPD), important to see whats the major cause
- Weight management key, as is managing multimorbidity: Bariatric services have a role to play
3
Q
Neuromuscular weakness
A
- Broad spectrum of diseases
- Development of worsening lung function or symptoms of: Breathlessness (orthopnoea), Poor sleep, Headaches, Weak cough
- Often NIV then indicated at home – life prolonging and improves sleep symptoms/QoL
4
Q
Contraindications for NIV
A
- Absolute: severe facial deformity, facial burns, fixed upper airway obstruction
- Relative: pH <7.15, GCS <8, confusion/agitation, cognitive impairment. Can still give if CO2 is causing cognitive impairment. May need extra monitoring
5
Q
IPF: definition
A
Chronic lung condition caused by progressive fibrosis of the interstitium of the lungs. Also associated with inflammation of the alveoli and interstitium causing a barrier to gas exchange. Tend to get small stiff lungs (restrictive).
6
Q
Interstitial lung disease and bronchiectasis
A
Interstitial lung disease: Idiopathic pulmonary fibrosis, Sarcoid, Hypersensitivity pneumonitis
Bronchiectasis: course crackles with wet productive cough, obstructive physiology
7
Q
IPF: features
A
- progressive exertionaldyspnoea
- bibasal fine end-inspiratory crackles on auscultation
- dry cough
- clubbing
- Peripheral cyanosis and low oxygen sats
- Reduced chest expansion bilaterally
8
Q
Investigations for IPF
A
- spirometry: classically a restrictive picture (FEV1 normal/decreased, FVC decreased, FEV1/FVC increased). Reduced Total lung capacity
- impaired gas exchange: reduced transfer factor (TLCO)
- ABG: often type 1 respiratory failure
9
Q
Imaging for IPF
A
- Imaging: bilateral interstitial shadowing (typically small, irregular, peripheral opacities - ‘ground-glass’ - later progressing to ‘honeycombing’) may be seen on a chest x-ray. Increased interstitial marking bilaterally. Lungs are small and white. Prescence of nodules. Heart borders are shaggy and indistinct.
- High-resolution CT scanning is required to make a diagnosis of IPF: sub-pleural reticulation and honeycombing
- NO LUNG BIOPSY
- 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
10
Q
IPF: history
A
- Ask about environmental/occupational exposures i.e. dust/asbestos/pets
- Drug history i.e. methotrexate, nitrofurantoin
- Remember connective tissue disease i.e. rheumatoid arthritis i.e. autoantibodies
11
Q
IPF: management
A
- pulmonary rehabilitation
- Pirfenidone/Nintedanib (an antifibrotic agent) may be useful in selected patients, slow the rate of deterioration and reduction in vital capacity. Side effects: Gi upset/photosensitive rash
- Supportive care i.e. oxygen/rehabilitation/morphine
- many patients will require supplementary oxygen and eventually a lung transplant if under 65
- Prognosis is very poor life expectancy is around 3-4 years, acute attacks can be fatal
12
Q
Sarcoidosis definition
A
Characterised by formation of non-caseating granulomas which can affect any organ. lungs and intrathoracic lymph nodes most commonly affected. An exaggerated immune response to an unidentified antigen in a genetically susceptible individual.
13
Q
Sarcoidosis causes
A
- Infectious agents: for example mycobacteria and propionibacteria
- Environmental and occupational exposures: inorganic particles, organic antigens, and mould spores. As well as specific occupations with increased exposure to dust, metals or pesticides
- Genetic predisposition:
- Black African ethnicity
14
Q
Syndromes associated with sarcoidosis
A
- Lofgren’s syndrome is an acute form of the disease characterised by bilateral hilar lymphadenopathy (BHL), erythema nodosum, fever and polyarthralgia. It usually carries an excellent prognosis
- Heerfordt’s syndrome (uveoparotid fever) there is parotid enlargement, fever and uveitis secondary to sarcoidosis
15
Q
Sarcoidosis: clinical features
A
- From asymptomatic to life threatening
- Cough, dyspnoea and chest pain
- Fever, fatigue and weight loss
- Can involve other organs causing: uveitis, peripheral neuropathy, cardiac arrhythmias and hepatic dysfunction
- Skin manifestations i.e. erythema nodosum and lupus pernio
16
Q
Staging of sarcoidosis with CXR
A
- stage 0 = normal
- stage 1 = bilateral hilar lymphadenopathy (BHL)
- stage 2 = BHL + pulmonary interstitial infiltrates
- stage 3 = diffuse interstitial infiltrates only
- stage 4 = diffuse fibrosis
17
Q
Sarcoidosis investigations
A
- CXR
- CT scan: multiple tiny nodules in a peri-bronchlier distribution associated with lymphadenopathy. There is fissural beading
- FVC/FEV1 show restrictive pattern with reduced TLCO
- Blood tests: high levels of ACE, hypercalcaemia and hypercalcuria. ACE levels help monitor disease activity
18
Q
Sarcoidosis investigations
A
- Bronchoscopy with transbronchial lung biopsy, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), or mediastinoscopy may be required to obtain tissue samples for histopathological examination.
- Mediastinoscopy: biopsy of lymph nodes from mediastinum, fairly invasive
- EBUS(endobronchial ultrasound): bronchoscope is passed into the lung with an ultrasound on the end, a needle then passes into the lymph node to get a biopsy, US makes it more safe
19
Q
Sarcoidosis management
A
- Asymptomatic/non life threatening: no treatment, spontaneous remission is common
- First line: systemic corticosteroids (prednisolone) 20-40mg daily, symptom control but dont cure. Different from idiopathic pulmonary fibrosis where steroids are harmful
- Second line (corticosteroids not tolerated): immunosuppressive drugs like methotrexate, azathioprine and mycophenolate mofetil
- Severe organ involvement: biologic therapies targeting TNF-α, such as infliximab or adalimumab, may be used. However, increased risk of infection
20
Q
Sarcoidosis specific organ involvementand treatment
A
- Topical or systemic corticosteroids may be used for ocular involvement.
- calcium channel blockers or implantable devices may be necessary for cardiac arrhythmias.
- Pulmonary hypertension may require vasodilator therapy, and in severe cases, lung transplantation might be considered.
21
Q
Sarcoidosis: factors associated with poor prognosis
A
- insidious onset, symptoms > 6 months
- an absence oferythema nodosum
- extrapulmonary manifestations: e.g. lupus pernio, splenomegaly
- CXR: stage III-IV features
- people of Black African ethnicity
22
Q
Hypersensitivity pneumonitis
A
- For example: Farmer’s lung, Saw mill workers lung, Bird fancier’s lung, Malt workers lung
- A Hypersensitivity reaction (type 3/4- delayed) to an inhaled antigen
- Affects alveoli and small airways of the lung
- Presents with cough, breathlessness and sometimes systemic symptoms of fever, weight loss
- CT: ground glass change and mosaicism, areas of air trapping (black bobs). May develop fibrosis
- More in the upper lobes, IPF tends to be in lower lobe
23
Q
Hypersensitivity pneumonitis: history and examination
A
- History: birds, occupation, black lobes, feather is pillows
- Auscultation: high pitched inspiratory squawk/screak typically in upper zones, crackles
- Bird fancier: IgG antibody to pigeons, some stimulants have specific antibody responses
- Lots of cases of Hypersensitivity pneumonitis where you cant identify the antigen
- Treatment: remove antigen exposure or use immunosuppression (steroids, mycophenolate or cyclophosphamide)
- Can use Nintedanib if progressive and with fibrosis
Diagnosis of sarcoidosis on biopsy: non-necrotising granulomas present.
24
Q
COVID-19 ILD
A
- patients with ILD are at high risk of complications from COVID-19, important to give monoclonal antibodies and vaccines.
- COVID-19 can give an organised pneumonia type of disease, dexamethasone is good treatment
- Rare to get progressive fibrotic disease
25
Q
Lung health checks
A
- Offered to 55-75 year olds who have ever smoked
- Will be offered spirometry and low dose CT to detect lung cancer and COPD early
26
Q
Pneumoconiosis definition and treatment
A
Lung disease caused by breathing is dust i.e. coal miners, asbestosis, silicosis
Treatment: trigger removal and pulmonary rehabilitation
27
Q
Pneumoconiosis symptoms
A
- Cough
- Chronic sputum production (may be black in coal miners pneumoconiosis)
- Decreased lung volume
- Progressive dyspnoea
- Rapid shallow breathing
- Weight loss
28
Q
Silicosis
A
A fibrosing lung disease caused by the inhalation of fine particles of crystalline silicon dioxide (silica). It is a risk factor for developing tuberculosis (silica is toxic to macrophages). Silicates are combinations of silica with an oxide or metal. Several silicates are associated with nodular or fibrotic lung disease, e.g. talc, slate and asbestos. Generates O2 radicals that injure pulmonary cells causing cytokine release, inflammation and fibrosis
29
Q
Silicosis: occupations at risk and features
A
Occupations at risk of silicosis:
- mining, slate works, foundries, potteries
- Exposure higher if abrasive blasting with sand
Features: silicosis
- upper zone fibrosing lung disease
- ‘egg-shell’ calcification of the hilar lymph nodes
- Volume loss
30
Q
Silicosis investigations
A
- CXR: symmetrical bilateral opacities, they are irregular and highly radio-opaque. Predominantly in upper/middle zones
- High resolution CT (diagnostic): Innumerable bilateral, pulmonary calcified nodules. Each lesion has a sharp margin (not hazy or indistinct). May have pleural thickening and calcified mass like conglomerates
- Pulmonary function tests: to assess severity i.e. TLCO
- Endobronchial ultrasound: excludes malignancy
- Bronchoscopy: in chronic silicosis there will be reduced macrophages. In acute silicosis there will be an increased cell count and > 70% of macrophages will have visible silica particles.
31
Q
Chronic simple silicosis
A
- After chronic low-dose silica exposure over 15-30 years
- It progresses slowly and often presents in retired workers who have small, rounded nodules on chest X-ray or CT. The nodules are bundles of collagen surrounding macrophages that contain silica dust.
- Even after exposure ends the fibrotic process can continue so the disease is progressive
- Silicosis is normally asymptomatic or only causes exertional dyspnoea. Progresses to more dyspnoea, cough and sputum
- Prognosis worsens with cumulative silica exposure, young age and lower interstitial lung function
32
Q
Complicated silicosis
A
- Occur when the nodules merge together to form masses >1cm in diameter. Called progressive massive fibrosis (PMF)
- Mostly in upper lobes and represent nodules that are united by an active fibrotic process
- Calcification can occur but cavities rarely do
- Growing nodules destroy alveoli, causing secondary emphysema, and extensive pleural thickening
- Worsening breathlessness and hypoxia, eventually develop pulmonary hypertension, cor pulmonale and respiratory failure
33
Q
Acute silicosis
A
- This occurs following very high exposure to inhaled silica and can be fatal.
- High levels of silica prevent macrophages from clearing surfactant, causing it to accumulate in the alveoli.
- Patients become breathless and have a cough. CT typically shows ground-glass opacities and ‘crazy-paving’ patterns.
- Silica nodules do not have time to form, but silica can be seen within macrophages in broncho-alveolar (BAL) lavage fluid.
34
Q
Accelerated silicosis
A
- Represents a mid-ground between chronic and acute silicosis in which PMF (progressive massive fibrosis) develops quickly.
- Rapid progression, so can only be diagnosed after a couple of months
- Presence of PMF within 10 years of exposure to silica.
- Patients will have ground-glass lesions on CT; nodules may have softer, less-defined edges. Fibrosis can occur concurrently.
- Chest X-ray may be entirely normal in early stages of accelerated silicosis.
34
Q
Other disease associated with silica
A
- COPD: increased exposure in silica causes reduction in FEV1
- Silicosis increases the risk of active TB by 3x, risk is greatest in acute and accelerated silicosis
- Similarly increased risk of non-tuberculous mycobacterium (NTM) and fungal infections.
- Known carcinogen and increases risk of lung cancer
- Silica is the particle and silicosis is the condition
34
Q
Silicosis treatment
A
- Lung transplant is the only effective treatment
- Steroids and immunosuppression are ineffective
34
Q
Coal workers pneumoconiosis (CWP)
A
- An occupational lung disease caused by long term exposure to coal dust, severity is linked to extent of exposure
- Diagnosis is usually made 15-20 years after initial exposure
- Diagnosed with a CT
- Can have mixed-dust pneumoconiosis as patients are exposed to silica as well
35
Q
Histology of Coal mine dust lung disease
A
- Represents a spectrum of disease
- Histologically the classic feature of CMDLD is thecoal macule. These are collections of reticulin, collagen and macrophages filled with coal dust and found within the respiratory bronchioles.
- Focal emphysema can surround coal macules, as the disease progresses coal nodules form which contain more collagen and are not localised to bronchioles, progresses to fibrosis
36
Q
Coal workers pneumoconiosis (CWP)
A
- A nodular interstitial disease that occurs 10 years after exposure to coal dust, similar to chronic silicosis
- Nodules normally develop in the upper zone
As these small lesions grow they merge and progressive massive fibrosis (PMF) develops. PMF is typically straight-edged and areas of adjacent emphysema are often seen. Background small opacities should always be visible.
37
Q
Simple pneumoconiosis in CWP
A
- Is the commonest type of pneumoconiosis.
- Patients are often asymptomatic.
- Its presence increases the risk of lung diseases such as COPD.
- Simple pneumoconiosis may lead to Progressive Massive Fibrosis (PMF), occurring in around 30% of those with stage 3 grading.
38
Q
Staging in CWP
A
- The disease is graded on the appearance of the chest X-ray:
- Category 1: some opacities but normal lung markings visible
- Category 2: large number of opacities but normal lung markings visible
- Category 3: large number of opacities with normal lung not visible
39
Q
CWP: progressive massive fibrosis
A
- Dust exposure causes patients to develop round fibrotic masses which can be several centimetres in diameter.
- These are most commonly in the upper lobes.
- The exact pathogenesis is not known.
- Patients are often symptomatic and have both breathlessness on exertion and cough, some may have black sputum.
- Lung function testing shows a mixed obstructive/restrictive picture.
- Can cause structural distortion and loss of lung volume
- Increases with age, cumulative dust exposure and volume of smaller nodules
40
Q
CWP: investigations
A
- Chest x-ray: upper zone fibrosis
- Spirometry: restrictive lung function tests - a normal or slightly reduced FEV1 and a reduced FVC
41
Q
CWP: management
A
- Avoid exposure to coal dust and other respiratory irritants (e.g. Smoking).
- Manage symptoms of chronic bronchitis
- Patients may be eligible for compensation via the Industrial Injuries Act.
42
Q
Coal dust and COPD
A
- More potent cause then cigarette smoke, exposure increases severity of emphysema
- Even without CWP coal mine dust causes reduced lung function
43
Q
Other forms of CMDLD
A
- Coal dust can cause a pulmonary fibrosis pattern called dust related diffuse fibrosis (DDF)
- Caplan’s syndrome is CWP plus Rheumatoid arthritis. Patients have round or oval opacities which are actually rheumatoid nodules rather than typical CWP.
44
Q
Management of CMDLD
A
- Lots of patients are asymptomatic
- Symptoms of dyspnoea may occur so gradually that patients attribute them to ageing. Symptom severity does not correlate with radiological features.
- No specific treatments for CMDLD, so management is aimed at symptoms, e.g. bronchodilators for COPD or oxygen therapy for hypoxia.
- Smoking cessation should be encouraged to prevent additional impairment.
- Lung transplants are an option
45
Q
Asbestosis: investigations
A
- CXR: bilateral reticular opacities worse in the bases, bilaterally reduced lung volumes. There can be calcified pleural plaques but no focal consolidation or pleural effusion
- High resolution CT: honeycombing, tractional bronchial dilation
- Pulmonary function tests: restrictive pattern with reduced FEV1 and FVC. Also reduced TLCO and KCO
46
Q
Asbestosis: quantifying asbestos exposure
A
- Cumulative asbestos exposure is expressed as ‘fibre years’: inhaled fibres/ml x years of exposure
- Delay between exposure and disease is typically 10-20 years
- Fibre concentration in BAL fluid is a reliable marker for exposure but is rarely indicated
- CXR sign pathognomic for asbestosis: pleural plaques
47
Q
Asbestosis
A
- Directly toxic to lung parenchyma cells it also induces cytokine, protease and reactive oxygen release with leads to inflammation.
- Types of asbestos: Amphibole is more fibrogenic than chrysolite
- A slowly progressive diffuse pulmonary fibrosis, affects the sub pleural regions of the lower lobe is central sparing
- Similar pattern to usual interstitial pneumonia (UIP), but there is often associated pleural fibrosis which can help with differentiation.
- Asbestos bodies can be seen: transparent asbestos fibres encased in iron and protein, quantity of fibrosis relates to severity
- Dont need histology
