Restrictive lung disease Flashcards
what is a restrictive lung disease
Restrictive lung disease is when there is reduced lung volume and thus reduced TLC
- Lung parenchyma
- Pleura, chest wall or neuromuscular apparatus
what are the two major categories of restrictive lung disease
- Intrinsic
- Extrsinic
what is the
- pathology
- outcome
- disease for intrinsic restrictive lung disease
- Pathology – lung parenchyma inflammation and lung scarring
- Outcome – decrease in alveolar; arterial gas transfer, exudate and debris (pneumonitis)
- Disease – interstitial lung disease
what is the
- pathology
- outcome
- disease for extrinsic restrictive lung disease
- Pathology – abnormal function of chest wall, pleura, and neuromuscular apparatus
- Outcome – impaired ventilator function, respiratory failure
- Disease - Myasthenia Gravis, Obesity
Name 3 major interstitial lung diseases
- Idiopathic Pulmonary Fibrosis
- Sarcoidosis -
- pneumoconiosis
what is the survival rate for idiopathic pulmonary fibrosis
- 1 in 3 expected to die within next 12 months
- 50% die within 2 to 3 years after diagnosis
what are some risk factors for idiopathic pulmonary fibrosis
- Smoking
- Environment exposures
- Chronic virla infections
- Abnormal acid reflux
- Family history
what is the result of idiopathic pulmonary fibrosis
- Scarring and honeycombing in the lung restricts breathing and oxygen exchange
Airway remodelling
– leads to impaired oxygenation, it is progressive and incurable
what are the pathophysiology proposed for idiopathic pulmonary fibrosis
- Genetic susceptibility – ageing, telomere attrition, mitochondrial dysfunction, genetic instability, environmental factors
- Epigenetic reprogramming
- These lead to repetitive micro injuries
- These lead to fibroblast migration and proliferation
- These lead to the scarring and are like roadblocks
- As you breath in and out the airways collapse and expand
- Ability to expand is reduced
what are the environmental factors that lead to idiopathic pulmonary fibrosis
- Decreased epithelia cell integrity
- Accelerated ageing associated changes
- Exaggerated fibroblast expansion
- There is dilation of the bronchi
- Alveolar remodelling
- Parenchymal fibrosis – laying down of fibroblast that act as road blocks
what are the symptoms of idiopathic pulmonary fibrosis
- difficult to distinguish
- Extertional dyspneoa
- Clubbing
- Dry cough
how do you diagnose idiopathic pulmonary fibrosis
- Medical history
- Physical examination – fine, high pitched bibasilar inspiratory crackles (Velcro like sounds)
- The volume is significantly less
how do you work out the DLCO and what is it
Lung surface area available for gas exchange (Va) X rate of capillary blood CO uptake (kco)
- Quantity of carbon monoxide transferred per minute form alveolar gas to red blood cells (ml/min/mmHg)
mil of CO transferred per minute for each mmHg of pressure difference across the total available functioning lung gas exchange surface
what does DLCO stand for
Diffusing capacity of the lungs for carbon monoxide
why does the DLCO decrease in interstitial lung disease
↓DLCO primarily due to ↓Kco
what is the DLCO used for
Useful for early stage ILD detection before substantial reduction in lung volumes
what are the concerns for using the DLCO
- Falsely reduced in individuals who fail to inspire to TLC(total lung capacity)
- Significant variation
how do you treat idiopathic pulmonary fibrosis
- Pirfenidone
- Nintedanib
- Antacid therapy
how do you treat idiopathic pulmonary fibrosis non pharmacologically
- Pulmonary rehab increases physical and psychological, increase walk distance, increase QoL
- Long term oxygen – patients with hypoxemia at rest, short burst oxygen therapy; exertional hypoxemia
- Lung transplant – moderate severe disease
how does pirfendione work
- Anti-fibrotic agent
- Mechanism of action unclear
- ↓Physiological deterioration
- ↑Progression-free survival
- AEs = GI, photosensitivity, anorexia, skin rash & liver toxicity
How does nintedanib work
Tyrosine kinase inhibitor
• ↓FVC decline
• AEs: diarrhoea, weight loss & liver toxicity
how does antacid therpay work
- IPF with gastro-oesophageal reflux
* AEs (long-term): Infection, cognitive function & MI
What is sarcoidosis
Sarcoidosis is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomas
- these granulomas can infiltrate and invade any part of the organism
- it is usually acute and self-limiting
what are the symptoms in sarcoidosis
- Eye – dry eyes, blurry vision
- Lymph nodes – enlarged
- Lungs – hacking cough, cough up blood
- Heart – complciations
- -liver and spleen – enlargement
- Joints – pain, arthritis, swelling of the knees
- Skin – rashes, lupus pernio, erythema nodosum, skin lesions on back, subcutaneous nodules
what can cause sarcoidosis
- Antigen (bacteria?) phagocytosed by antigen-presenting cells
- Presentation of antigen to T cells by HLA class II molecules, CD4 positive Cells, leas to activation of TNF leaves to alveolitis – inflammation and clumping around the alveoli region
- Formation of sarcoid granuloma
how to you diagnose sarcoidosis
- Info from the patient and
Clinicoradiographic data: - Bilateral hilar adenopathy on the chest radiograph
- Lofgren syndrome (erythema nodosum skin rash + bilateral hilar adenopathy on chest radiograph +/- fever and arthritis)
- Diagnosis possible versus idiopathic granulomas – for example one organ has granulomas if there is more than one granuloma then diagnosis is more likely
describe how the chest x ray stage of sacoidosis works
stage 0/1
- no symptoms
- no systemic therpay
stage 2-4
- symptomatic
- treat with corticosteroids
steroid sparing alternatives for chronic pulmonary sarcoidosis
- methotrexate
- folic acid
- azathioprine
- leflunomide
- mycophenolate
treatment of refractory sarcoidosis
- infliximab
how do corticosteroids work
- CS binds to GR when bound
- Translates into the nucleus
- Increases gene expression of anti-inflammatory genes
- Or it may recruit genetic machinery that dampens pro-inflammatory genes
