12. Physiology of Restrictive Lung Disease

• DLCO - diffusion capacity of respiratory membrane
• Obstructive disease with increase diffusion rate is?

  asthma
• Restrictive lung disease is

  • increase elastic recoil
  • decrease lung compliance
• Example of restrictive lung disease

  • ARDS
  • interstitial lung disease - fibrosis
• Restrictive lung disease will have thick respiratory membrane
• FVC - forced vital capacity (amount of air that a person can forcefully exhale from the lungs)
• FEV1 - how much air you can exhale in one second
• Restrictive lung disease - Cannot get air in - restricted from filling
•  Restrictive lung disease

  • TLC is decrease
  • during maximal forced expiration - volume expired is more quick and complete due to decrease in compliance
•  Restrictive lung disease

  • FEV1 is reduced (smaller reduction)
  • FVC is reduced (greater reduction) 
  • FEV1/FVC ratio = normal or increase
•  Restrictive lung disease - diagnose: FEV1/FVC > 0.8 or normal
• Obstructive disease - can't get air out
• Restrictive - can't get air in
•  2 types of restrictive lung disease

  • Intrinsic - within the lung parenchyma itself
  • Pulmonary fibrosis
  • Extrinsic - outside the lung
  • Weak intercostal muscle
  • Wall deformity