11. Restrictive interstitial Fibrosing Lung Disease - SW

• Interstitial lung disease is diffuse and typically chronic lung injury

  • different degrees of inflammation
• Interstitial lung disease leads to lung fibrosis
• Interstitial lung disease - Pathophysiology

  1. interstitium surrounding the distal part of the alveoli affected
  2. Physiological restrictions
  3. decrease lung volume
  4. Affecting the interstitium surrounding the proximal part of the alveoli
  5. preserved lung volume
  6. physiological obstruction
• Idiopathic pulmonary fibrosis - most common in pts > 60 years old

  • common in men
• Interstitial lung disease symptoms

  • SOB on exertion
  • dry cough
  • constitutional symptoms - fatigue, fever and weight loss
  • non-respiratory symptoms
  • skin thicken
  • ulnar deviation
• Idiopathic pulmonary fibrosis is a chronic condition

  • but with acute exacerbation
• Interstitial lung disease - Past history causes

  • Cryptogenic organizing pneumonia (COP) and sarcoid like reactions.
  • Asthma and allergic rhinitis
  • family history
  • environment
  • smoking
  • asbestos
  • birds
• The strongest risk factor of IPF - family history
• malignancy in dermatomyositis associated Cryptogenic organizing pneumonia (COP) can lead to Interstitial lung disease
• Interstitial lung disease - physical exam

  1. tachypnea
  2. clubbing and cyanosis
  3. crackles
  4. wheezing
  5. signs of cor pulmonale or pulmonary HTN
• There are signs of cor pulmonale or pulmonary HTN in Interstitial lung disease
• Interstitial lung disease causes pulmonary hypertension because

  • blood vessels in lung become thick and narrow --> decrease blood flow in the lung
  • leading to increase blood pressure
• Exams for Interstitial lung disease

  1. pulmonary function test (PFT) - will show restrictive pattern
  2. Total lung capacity = reduced
  3. decrease FRC and RV
  4. normal flow rate
  5. reduce FEV1 and FEV --> increase FEV1/FVC ratio
  6. DLCO - reduced
• DLCO is reduced when alveoli are damaged - common in ILD
• Interstitial lung disease - confirm true restrictive disease

  • FVC will be less than 80%
  • TLC will be less than 80%
• alveolar-arterial (A-a) gradient testing - measures difference between oxygen concentration in alveoli and arterial system
• Interstitial lung diseases (ILD)  - (pulmonary)

  • decrease DLCO
  • increase A-a gradient
• Definitive diagnosis for interstitial lung disease

  • imaging - HRCT
  • Bronchoalveolar lavage (BAL)
  • lung biopsy
• gold standard for lung biopsy is surgical lung biopsy using Video assisted thoracoscopic surgery  (VATS procedure)
• What type of features can you see in interstitial lung disease?

  honeycomb features
•  High resolution CT scan (HRCT) is used for diagnosing?

  Idiopathic Pulmonary Fibrosis (IPF)
• Ground glass opacification opacity is typically seen in Idiopathic Pulmonary Fibrosis (IPF)
• Treatment of Interstitial lung disease - depends on diagnosis

  • if hypoxemia is severe - supplemental oxygen
  • anti-inflammation and immuno-modulator
  • manage cor pulmonale if present
• Interstitial lung disease - try to avoid smoking
• Interstitial lung disease - try to maintain SpO2 (by oximetry) higher than 89%
• Interstitial lung disease - occupational exposure

  • asbestosis
  • coal miner's lung
  • silicosis
  • flock worker's lung
• Pneumoconiosis is any lung disease caused by the inhalation of organic or nonorganic airborne dust and fibers.
• Chronic Hypersensitivity pneumonia (CHP) is a type of interstitial lung disease due to

  • repeated exposure and sensitization to antigen in the air
  • antigen will trigger autoimmune response leading to inflammation
  • eventually leading to fibrosis
• Chronic Hypersensitivity pneumonia (CHP) will cause long term inflammation and lead to fibrosis
• Chronic Hypersensitivity pneumonia (CHP) is diagnosed with

  • surgical lung biopsy after histology
  • bronchoscopy cryobiopsy
  • HRCT will show upper lobe fibrotic changes
• Chronic Hypersensitivity pneumonia (CHP) will look or mimic Nonspecific interstitial pneumonia (NSIP)
• Idiopathic Pulmonary Fibrosis is due to abnormal wound healing
• Idiopathic Pulmonary Fibrosis

  • Early stages - interstitial pneumonia
  • Later stages
  • interstitial fibrosis
  • honeycombing lung
• Idiopathic Pulmonary Fibrosis CXR will show bilateral and diffuse in lower lobes
• Idiopathic Pulmonary Fibrosis gold standard diagnosed by surgical lung biopsy
• Idiopathic Pulmonary Fibrosis - HRCT

  • basal subpleural reticular opacities
  • traction bronchiectasis
  • honeycombing
• Idiopathic Pulmonary Fibrosis treatment

  • steroid
  • immunosuppression
  • anti-fibrotic agents
  • lung transplantation
• Nonspecific Interstitial Pneumonia (NISP)

  • Nonsmoking women
  • uniform interstitial - no honeycomb
• Nonspecific Interstitial Pneumonia (NSIP) - Risk factor

  • connective tissue disorder
  • Viral infection
  • reaction to medication
• Desquamative Interstitial Pneumonia (DIP)

  • smoking men
  • diffuse hazy - ground glass