Restrictive lung disease Flashcards
What is restrictive lung disease?
- Characterised by ‘reduced lung volume’
- Intrinsic: parenchyma
- Extrinsic: Pleura; chest wall; neuromuscular diseases ‘respiratory pump’
What are the characteristics of intrinsic restrictive lung disease?
- Characterised by ‘reduced lung volume’
- Increased elastic recoil of lung
- Hypoxia due to VQ mismatch
List the different lung function tests
-Reduced total lung capacity
-Reduced forced vital capacity
-Preserved airflow( FEV)
-Increased FEV/FVC (ratio>70 is indicative of a restrictive lung disease)
-Gas transfer:
Reduced in lung parenchymal disease
Preserved in other causes of RLD
What are the characteristics of extrinsic restrictive lung disease?
- Characterised by reduced lung volume
- Decreased compliance of respiratory system
- Hypoxia due to VQ mismatch from areas of atelectasis( collapse/closure of a lung resulting in reduced/absent gas exchange)
Outline chest wall disease
- Kyphoscoliosis
- prevents lung expansion
What disease may result from problems in the interstitum?
Infection: TB, PCP Malignancy: lymphangitis Vascular: Pulmonary oedema ILD: autoimmune/CTD ILD: idiopathic
Define Interstitial lung disease
-Range of disorders characterised by cellular and extracellular matrix deposition within regions of lung distal to terminal bronchiole
Interstitium: area between alveolar epithelium& capillary endothelium
Outline the causes of ILD
- ) Systemic diseases: RA, SLE, CTD, scleroderma, vasculitis
- ) Environmental: Abestosis, coal/silicosis
- ) EAA(extrinsic allergic alveolitis)/ hypersensitivity pneumonitis: bird fancier’s lung; farmer’s lung
- ) Drugs: Amiodarone; Nitrofurantoin; Bleomycin
- ) Idiopathic interstitial pneumonia (ILP)
Outline the characteristics of ILD
- Interstitum inflammation/fibrosis
- Impaired gas exchange
- Symptoms: SOB/cough
- Abnormal CXR
- Abnormal lung function: (restrictive, reduced lung volumes& gas transfer factor)
How can we classify idiopathic interstitial pneumonia
- Usual interstitial pneumonia (UIP) aka interstial pulmonary fibrosis
- Non specific interstitial pneumonia (NSIP): rare disorder that affects the tissues that surrounds& separates tiny air sacs of the lungs
- Acute interstitial pneumonia (AIP): idiopathic ILD that is characterised by sudden onset of dyspnea and rapid development of respiratory failure
- Cryptogenic Organising pneumonia: swelling of the small airways in your lungs
What can clubbing& crackles indicate?
- Idiopathic pulmonary fibrosis
- Bronchiectasis
- Cystic Fibrosis
What is bronchiestasis?
A long-term condition where the airways of the lungs become abnormally widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection
What diagnostic lung function tests exist
-FEV1
-FVC
-FEV1/FVC
TLCO
Outline the characteristics of Usual interstitial pneumonia
- Aetiology unknown
- Proliferation of mesenchymal cells, collagen deposition, fibroblastic foci
- Minimal inflammation, fibrosis predominates
- Hypothesis: abnormal epithelial repair to unknown stimulus
- IFN, TNF, TGF, oxidants- important in pathogenesis
What investigations are used when diagnosing restrictive lung disease?
-Bloods: FBC, AA(antinuclear antibodies),RhF
-CXR/HRCT
-Lung function test
-Oxygen saturation ( blood gases)
-Lung biopsy in some cases
Bronchoalveolar lavage: a diagnostic procedure by which cells and other components from bronchial and alveolar spaces are obtained for various studies.
