Idiopathic Pulmonary Fibrosis Flashcards
What are interstitial lung diseases (ILDs) ?
A diverse group of over 300 different lung diseases that all affect the lung interstitium
e.g. the space between the alveolar epithelium and capillary endothelium
What can IDLs’ pathology be broadly classified as?
- granulomatous (e.g., sarcoid)
- inflammatory (e.g. hypersensitivty pneumonitis (HP))
- fibrotic (e.g. IPF)
What is the interstitial space?
The space between alveoli, capilaries and airways
Aeitology of ILD?
→ Aetiology varies but all present in a similar fashion, with exertional breathlessness and a nonproductive cough
→ Affect 1/2000 of pop.
→ Outcome varies between patients, but fibrosis represents the common, irreversible end stage of ILD
→ 1/3 of cases have known cause
Does IPF have a known cause?
No
What is idiopathic pulmonary fibrosis?
Progressive chronic pulmonary fibrosis of unknown aetiology.
- 5/100,000 people affected
- Male predominance - median age mid-60s
What process occurs in IPF?
Characterised by scar tissue in the lungs that decreases lung compliance i.e. the lungs become stiffer.
Pathogenesis of PF is complex and not completely understood.
Main features of IPF?
→ A lesion affecting the alveolar-capillary basement membrane
→ Cellular infiltration and thickening of collagen in the interstitium of the alveolar wall
→ Fibroblasts proliferate, leading to further collagen deposition
Stages of IPF
- Repeated epithelial damage
- Fibroblast recruitment - endothelial damage leads to a plasma leak and wound clotting - leads to fibroblasts proliferating
- Fibrotic remodelling - perm. changes happening within the lungs, fibroblasts produce collagen and become smooth muscle actin position myofibroblasts resistant to apoptosis
- Irreversibly scarred lung
Clinical features of IPF?
- Progressive, gradual-onset (9 months) exertional breathlessness and a dry cough
- Bilateral fire end-inspiratory crepitations (may sound like velcro): due to sudden opening of small airways during inspiration, which were held closed during the previous expiration.
- Clubbing is present in 50% of cases - as disease progresses, patient may develop cyanosis, respiratory failure and signs of cor pulmonale.
Diagnosis and investigation of IPF?
→ patients often hypoxic which reduces oxygen saturations, especially on exertion
→ arterial blood gas sampling may demonstrate type 1 respiratory failure
→ lung function tests show a restrictive pattern with reduced gas transfer
What is type 1 respiratory failure?
Involves hypoxaemia (PaO2 <8 kPa /60mmHg) with normocapnia (PaCO2 <6.0 kPa / 45mmHg).
(Type 1 respiratory failure occurs when the respiratory system cannot adequately provide oxygen to the body, leading to hypoxemia. )
What is type 2 respiratory failure?
Type 2 respiratory failure involves hypoxaemia (PaO2 <8 kPa / 60mmHg) with hypercapnia (PaCO2 >6.0 kPa / 45mmHg).
Type 2 respiratory failure occurs when the respiratory system cannot sufficiently remove carbon dioxide from the body, leading to hypercapnia (too much CO2).
Treatment options for IPF?
supportive, medical or lung transplant
Supportive treatments for IPF?
- Oxygen therapy - considered if breathless and pO2 <7.3 or <8 kPa with evidence of pulmonary hypertension
- Pulmonary rehabilitation
- Palliative care support - opioids may be required for symptomatic treatment of severe breathlessness
Medial treatment for IPF?
Treatment w/antifibrotic medications such as pirfenidone and nintendanib can be considered by the ILD MDT and after meeting a specialist respiratory physician.
Have significant gastrointestinal side effects and are not always tolerated well by patients
Surgical treatment for IPF?
Lung transplant - patients should be referred early where appropriate - rare in UK
Prognosis of patient with IPF remains poor, with an average life expectancy of 3 years following diagnosis.
Typical physiotherapy problems?
- reduced exercise tolerance
- increased work of breathing
- dyspnoea
Physiotherapy treatment for IPF?
- pacing
- breathing control (ACBT)
- positions of ease
