Restrictive Lung Disease Flashcards
What is the characteristic feature of restrictive lung disease?
Reduced lung volume
What areas does intrinsic restrictive lung disease involve?
Lung parenchyma
What areas does extrinsic restrictive lung disease involve?
- Pleura
- Chest wall (incl. obesity)
- Neuromuscular diseases (respiratory pump)
What do lung function tests show in restrictive lung disease?
1) Reduced vital capacity
2) Preserved airflow (FEV1)
3) Increased FEV1/FVC
4) Gas transfer → reduced in lung parenchymal disease but preserved in other causes of RLD e.g. motor neurone disease
What should expiration be?
Effort independent
What is an example of a chest wall disease that causes RLD?
Kyphoscoliosis
What happens in kyphoscoliosis?
1) Spine is curved so the shape of the chest is wrong
2) This prevents lung expansion bc can’t expand the lungs as much as are supposed to
How can kyphoscoliosis lead to type 2 respiratory failure?
1) Progressively as the lungs are getting more and more squashed, patients can go into type 2 respiratory failure
2) Therefore they are no longer able to compensate → during the day they can breathe normally but when sleeping CO2 rises and in the morning they normally compensate but this eventually goes
What are causes of diffuse pleural thickening leading to RLD?
Infection, asbestos
What happens in diffuse pleural thickening?
- The lining of the lung (pleura) becomes inflamed and solid
- This can happen bc of asbestos exposure years later or infection making pleura thickened and hardened or haemothoraces
- This prevents lung expansion and restricts how you breathe
What are causes of extrinsic restriction?
1) Pleural diseases
2) Chest wall disease/deformity
3) Obesity → increased amount on chest, unable to inflate chest (restriction)
4) Neuromuscular
What is the effect of having obesity-associated hypoventilation?
Survival gets progressively worse as don’t breathe as well as you should overnight
What are features of intrinsic restriction (ILD)?
1) ‘Reduced lung volume’
2) Increased elastic recoil of lung
3) Hypoxia due to VQ mismatch - lung is damaged → hypoxia
What is interstitial lung disease (ILD)?
Fibrotic lung disease causing thickening of lung tissue
What is the main ILD?
Idiopathic pulmonary fibrosis
What are examples of associations in ILD of known association?
1) CTD (chemotherapy drug)
2) Medication
3) Exposure
What are other names for ILD?
1) Pulmonary fibrosis
2) Lung scarring
What are key features of ILD?
1) Interstitial inflammation → fibrosis
2) Impaired gas exchange → VQ mismatch
3) Symptoms → SOB/cough
4) Abnormal CXR (not always) → CT scan better
5) Abnormal lung function → restriction, reduced lung volumes and gas transfer factor decreases
What are symptoms of ILD?
- Breathlessness
- Dry cough
- Wheeze
- Chest pain
- Haemoptysis
- Fever, myalgia → if linked to CT disease
- Weight loss
- Weakness
What might you see on general inspection of someone with ILD?
- Pt might be underweight
- Might have chest/spine deformity e.g. in ankylosing spondylitis
- Rash → in CT disease
- Tachypnoea
- Clubbing
- Accessory muscle use (if later stage)
- Cyanosis (also later stage)
What might you see in a respiratory examination of someone with ILD?
- Tracheal deviation
- Reduced chest expansion
- Altered percussion note
- Inspiratory crepitations (crackles)
- Reduced/absent breath soudns
Why might fibrosis not always be uniform/bilateral?
If patients sleep on one side more likely to get fibrosis on that side e.g. if have severe reflux acid might tip onto that side
What might you see in a cardiovascular examination on someone with ILD?
- Displaced apex beat
- Signs of secondary pulmonary hypertension (hypoxic)
- Signs of cor pulmonale (hypoxic)
- Loud P2, fluid overload
What disease is the pathology of idiopathic similar to?
Interstitial pneumonia
What are the main causes of clubbing and crackles?
- Idiopathic pulmonary fibrosis
- Bronchiectasis
- Cystic fibrosis (bc in CF get bronchiectasis)
What questions might you ask someone with pulmonary fibrosis?
- Occupation
- Drugs
- Previous infections causing damage e.g. TB, whooping cough, pneumonia
- Hobbies/pets (birds) → hypersensitivity pneumonitis (allergy)
- Smoking → respiratory bronchiolitis ILD (RBILD), gets better if stop smoking
- Family history
- Systemic enquiry
- What bedding/pillows made of? e.g. allergy to bird feathers (avian precipitins)
- Radiotherapy for cancer e.g. breast directed to chest → beam can damage lung
Why might you ask someone with PF about their occupation?
- Asbestosis → ship building, pipe work, electricians, building work
- Farmers lung → chemical exposure, compost (allergy)
Why might you ask someone with PF about their drug history?
- Amiodarone (anti-arrhythmic)
- Nitrofurantoin → still given prophylactically for recurrent UTIs
- Drugs only cause the reaction in some people (so also other drugs)
Why might you do a systemic enquiry on someone with PF?
Looking for CT disease
- Eyes
- Pain/swelling of joints incl. fluctuating joint aches
- Rash
- Weakness
- Raynaud’s
What bloods would you do for someone with ILD?
FBC, U+E, autoantibodies (ANA and ENA), rheumatoid factor
Why would you do an FBC on someone with ILD?
To test renal function bc patients get vasculitis and with this renal involvement
- e.g. in goodpasture syndrome (GPS), ANCA positive vasculitis, granulomatosis with polyangiitis (GPA)
What autoantibodies would you test for in someone with ILD?
RF, CCP antibody, myositis antibodies, complement factors
On what are ABGs taken?
Air
What is type 1 respiratory failure?
High pO2, normal pH and pCO2
What is a high FEV1/FVC ratio?
> 75% e.g. 87%
What might you see on a CT of someone with ILD?
- Basal, bilateral sub pleural reticular changes
- Honeycombing → holes punched out, can’t treat, just need to stop progression (also seen in emphysema)
- Traction bronchiectasis
What happens in traction bronchiectasis?
- Airways are bigger than they should be
- Lungs are becoming smaller (shrinking is bad prognostic sign), pulling the airways
- Don’t bring up a lot of phlegm unlike patients with normal bronchiectasis
What are risk factors for idiopathic pulmonary fibrosis?
- Smoking
- Metal/wood dust
- Genetic (familial)
Why is idiopathic pulmonary fibrosis a problem with emphysema?
Bc if have a lot of emphysema as well, lung volumes are quite high and not reduced where you need them to be for the medication
Is IPF more common in men or women?
Men
What is the mean age of IPF?
66
What is the pathogenesis of usual interstitial pneumonia?
- Aetiology unknown
- Proliferation of mesenchymal cells, collagen deposition, fibroblastic foci
- Minimal inflammation, fibrosis predominates
- Abnormal epithelial repair to unknown stimulus (hypothesis)
- IFN, TNF, TGF, oxidants important in pathogenesis
What investigations do you do in someone with IPF?
- Bloods → FBC, AA, RhF
- CXR/HRCT
- Lung function test
- Oxygen saturation (blood gases)
- Lung biopsy in some cases but if they have a complication with these lungs won’t end well
- Bronchoalveolar lavage
Why do you do a lung function test on someone with IPF?
To know if they are hypoxic to give them supportive treatment
Describe bronchoalveolar lavage
- Looking for infection (look at inflammatory profile)
- Put some fluid in a send it off to cytology who report on the number of immune cells
- Get lots of lymphocytes in allergic disease e.g. hypersensitive pneumonitis
What do you do every time you are monitoring someone with IPF?
Lung function and ask how they feel
How do you diagnose IPF?
CT ± lung biopsy
How do you assess severity of IPF?
Lung function - VC, TLCO
How do you work out the prognosis of someone with IPD?
Exercise test/serial VC
What is the aim of IPF treatment?
To reduce disease progression
What two drugs are used to reduce progression of IPF?
- Pirfenidone (antifibrotic)
- Nintedanib (triple tyrosine kinase inhibitor)
What are the effects of pirfenidone and nintedanib?
- Oral
- Slows disease progression (FVC)
- Reduces mortality
What are side effects of drugs used to treat IPF?
GI, diarrhoea
What is used to support patients with IPF when they are hypoxic?
Oxygen
What are other treatments for people with IPF?
Pulmonary rehabilitation
Palliative care
Lung transplant
Describe pulmonary rehabilitation
- Works v well
- Maybe bc coaching lungs into accepting breathlessness better
- Getting people into more psychological frame of mind in how to manage this
- Training respiratory muscles
Why do patients with IPF not really get lung transplants?
Because lung thickening makes lungs harder to transplant
What is the median survival for IPF?
3 years esp. in idiopathic group (poor, not much better than lung cancer)
What does UIP stand for?
Usual interstitial pneumonia
What does NSIP stand for?
Non specific interstitial pneumonia
What is the main cause of death in IPF patients?
Respiratory failure
What are other causes of death in IPF patients?
- Heart failure
- PE
- Pneumonia
- Lung cancer (high incidence)
Describe differences between NSIP (IIP) and UIP
- CT → see ground glass opacities and fibrosis - little holes but also patches with more normal lung around
- More inflammatory
- Treatment responses better
- Prognosis better
What is the drug treatment for NSIP/DIP/AIP/COPD?
Steroids+
What is the treatment for HP (hypersensitivity pneumonitis)?
Steroids
What is the treatment for connective tissue disease?
Immunosuppressants e.g. rituximab (wipes out B cells)
What are systemic effects of ILD?
- Systemic sclerosis (red dots on face?)
- Dermatomyositis (rash under eyes)
- Changes in knuckles → papules, machinist hands, rough
- SLE
- Rheumatoid arthritis → shouldn’t see this now bc patients with suspected diagnosis will be seen within 4-6 weeks and will v quickly be put on DMARDs (disease modifying anti-rheumatic drugs)
- Ankylosing spondylitis
What is sarcoidosis?
A multi-system disease that can affect any organ (genetic in < 5% of cases)
What organs are most commonly affected by sarcoidosis?
Lungs, skin, eyes (uveitis), kidney, heart, liver
What do most people with sarcoidosis die of?
Respiratory failure bc lungs are the most common organ affected
What happens when sarcoid affects the heart?
- Severe disease
- Affects electrical systems leading to arrhythmias, heart block, ventricular tachycardia
- Typical symptos of pre-syncopal episodes, syncopal episodes, breathlessness
What happens when sarcoid affects the neuro system (CNS or PNS)?
Facial nerve palsy, cognitive features
Why is prognosis of sarcoid better than fibrosis?
Bc lots of people have mild disease
What are causes of sarcoidosis?
1) Unknown
2) Inhaled → infection, other antigen
3) Inflammatory disease (T cell)
What is a hallmark lesion of sarcoidosis on a biopsy?
Granuloma (but are other causes e.g. TB which hasn’t necrotised yet)
What is the acute presentation of someone with sarcoidosis?
- Loefgren’s syndrome
- Bilateral hilar lymphadenopathy on CXR
- Erythema nodosum (rash over legs, raised, painful papules)
- Arthralgia
- Good prognosis - no problems usually, hilar lymphadenopathy may or may not be clear
- Don’t usually need a biopsy
What is the chronic presentation of someone with sarcoidosis?
- Can be self limiting
- Can also relapse
- Can become progressive
- Can be v difficult to treat bc lung keeps on getting eroded and destroyed
What are investigations that you should do for sarcoidosis?
- CXR (scadding) but CT is better
- Serum ACE
- Calcium
- Liver FT (sarcoid affects liver)
- Renal
- FBC
- Biopsy
- Lung function test
- CT scan chest
- Heart → baseline 24h ECG and cardiac MRI/PET to look for scarring and cardiac inflammation
Describe the serum ACE test for sarcoidosis
- Used as test but not definitively diagnostic as can be elevated for other reasons and can be normal
- If have proven sarcoid and it goes down in treatment, it can be a useful marker
Describe calcium test for sarcoidosis
- Sarcoid/granulomas interfere with calcium metabolism so patients quite often present with hypercalcaemia
- Bigger risk in summer when patients are exposed to the sun
- Can affect kidneys
Why do you do an FBC for someone with sarcoid?
Some patients can have bone marrow failure
Describe biopsy for sarcoidosis
- Could be something else
- EBUS (endobronchial US to get mediastinal lymph node biopsy)
- Skin lesion
- Lymph node
What is included in treatment for sarcoidosis?
Immunosuppression principles (QoL and threatened organ function)
- Steroids
- Methotrexate and/or hydroxychloroquine if need second line treatment
- Anti-TNF
- Mycophenolate, azathioprine
What happens for many patients with sarcoid?
They don’t require any treatment, just observation/monitoring
What are the outcomes of sarcoidosis?
- Good life expectancy even in progressive disease → however more indirect mortality not captured e.g. effects of steroids or heart attack
- Pulmonary hypertension → poor prognosis
What is a mesothelioma?
A pleural tumour
What happens to pleura in mesothelioma?
Pleura is infiltrated, thick and hardened
What can you see on a CXR in pulmonary fibrosis?
- Reticular nodular shadowing seen in pulmonary fibrosis
- This is where CXR can be useful but if getting CXR at this stage in condition it is useless → something has gone wrong if this is the first CXR you see
