Block 3; IPF, sarcoidosis, Pneumoconiosis Flashcards
COPD: indications for NIV at home
- 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
Obesity hypoventilation
- 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
Neuromuscular weakness
- 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
Contraindications for NIV
- 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
IPF: definition
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).
Interstitial lung disease and bronchiectasis
Interstitial lung disease: Idiopathic pulmonary fibrosis, Sarcoid, Hypersensitivity pneumonitis
Bronchiectasis: course crackles with wet productive cough, obstructive physiology
IPF: features
- progressive exertionaldyspnoea
- bibasal fine end-inspiratory crackles on auscultation
- dry cough
- clubbing
- Peripheral cyanosis and low oxygen sats
- Reduced chest expansion bilaterally
Investigations for IPF
- 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
Imaging for IPF
- 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
IPF: history
- 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
IPF: management
- 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
Sarcoidosis definition
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.
Sarcoidosis causes
- 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
Syndromes associated with sarcoidosis
- 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
Sarcoidosis: clinical features
- 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
Staging of sarcoidosis with CXR
- 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
Sarcoidosis investigations
- 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
Sarcoidosis investigations
- 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
Sarcoidosis management
- 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
Sarcoidosis specific organ involvementand treatment
- 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.