Obstructive Lung Disease Flashcards
What are the two types of restrictive lung disease?
What is the pathology behind each type?
Restrictive lung diseases: impaired total lung function: Extrinsic OR Intrisic
Intrinsic: pathology arises from lung parenchyma inflammation and scarring. Causes redued alveolar function & alveolar gas transfer
Extrinsic: pathology arises from abnormal function of chest wall, pleura & neuromuscular apparatus. Causes impaired ventilator function &
respiratory failure
What is intrinsic restrictive lung disease caused by? [1]
Name two pathologies that cause extrinsic restrictive lung disease caused by? [2]
Intrinsic: Interstitial Lung Diseases
Extrinsic: Obesity & Myasthenia Gravis (rare long-term condition that causes muscle weakness)
What are the two major interstitial lung diseases? [2]
Idiopathic Pulmonary Fibrosis
Sarcoidosis
Describe the aetiology of IPF xx
Describe the pathophysiology of IPF
Occurs due to:Unknown cause [1]
Environmental factors, chronic viral infections, smoking, Fx causes scarring and honeycombing of the lungs: airway remodelling. Causes impaired oxygen transfer.
Airway remodelling cccurs due to:
- fibroblast remodelling and activation: causes fibroblast plaques occurring & collagen deposition. Causes Traction bronchiectasis: where there is irreversible dilatation of bronchi and bronchioles within areas of pulmonary fibrosis
- ↓ Epithelial cell integrity
- Accelerated ageing-associated changes
- Exaggerated fibroblast expansion
Describe symptoms of IPF [3]
- exertional dyspnoea
- clubbing
- dry cough
What would the lung sound like on physical examination of a Ptx with IPF? [1]
Fine, high-pitched bibasilar inspiratory crackles (velcro-like sounds
What is the key diagnostic test for identificaiton of IPF?
How do you calculate this?
DLCO (Diffusing capacity of the lungs for CO): measures the quantity of carbon monoxide (CO) transferred per minute from alveolar gas to red blood cells (mL/min/mm Hg)
DLCO = Lung surface area available for gas exchange (Va) X rate of capillary blood CO uptake (Kco)
(Kco is particularly affected by IPF)
Describe the diagnostic pathway for IPF xx
- Suspected ILD
- ID the cause? If yes - not IPF
- If no, conduct Chest High Resolution CT Scan. If you see usual interstitial pneumonia (honeycombing lungs) then v likely to have IPF.
Still unsure? - Lung biopsy
- MDT Diagnosis
- IPF / Not IPF
Which drugs would you use to manage IPF ? [3]
How would you treat IPF via non-pharmacotherapy?
Pharmacotherapy:
- Pirfenidone: anti fibrotic agent, decreases pyhysiological deterioration
- Nintedanib : Tyrosine kinase inhibitor. ↓FVC decline
- Antiacid therapy:IPF with gastro-oesophageal reflux
Non-pharmacotherapy:
- Pulmonary rehab (MDT Team & QoL
- Oxygen therapy
- Lung treatment
Which drugs should you NOT combine to treat IPF?
Prednisone, Azathioprine & NAC = Harmful AEs
Treatment pathway for IPF?
What FVC and DLCO would you continue pharmalogical treatment of IPF?
What drug would you use?
Treat using Pirfenidone if:
FVC less than 10%
and
DLCO less than 15%
IF WORSE - assess Pirfenidone use - use with NAC instead? Clinical trials?
What would a Ptx’s FVC and DLCO be to start pharmalogical treatment of IPF?
Mild - moderate disease:
FVC greater than 50%
DCLO greater than 35%
Define sarcoidosis
Caused by multi system granulomas (is a tiny cluster of white blood cells and other tissue that can be found in the lungs). Inflammation causes multi-system granulomas
Most cases are acute, self-limiting (needs no medicinal treatment)
About 90% of diagnosed cases are deemed to be pulmonary sarcoidosis.
Idea of physiopathology causing sarcoidosis?
Unknown BUT:
Antigen (bacteria?) phagocytosed by antigen-presenting cells
Presentation of antigen to T cells by HLA class II molecules
Formation of sarcoid granuloma
How do you diagnose sarcoidosis? (probably dont need to know)
Clinicoradiographic data / CXR:
- Bilateral hilar adenopathy on the chest radiograph
- Lofgren syndrome (erythema nodosum skin rash + bilateral hilar adenopathy on chest radiograph +/- fever and arthritis)
