Emphysema

• Emphysema:

  • Primarily a disease of the alveoli
  • Permanent enlargement of the air spaces distal to the terminal bronchiole
  • Protein breakdown leads to erosion of alveolar septa, dilation of distal air spaces and destruction of elastic fibres
  • Formation of bullae
  • Destruction of the capillary bed

  
• Emphysema:

  • Airways become floppy due to loss of radial traction
  • Airways collapse on expiration
  • Obstructive disease

  
• Emphysema:

  • Secondary effects of emphysematous changes:
  • airflow obstruction
  • increased resistance to airflow
  • increased work of breath
  • less surface area for gas exchange
  • V/Q mismatch
• Aetiology of Emphysema:

  • Smoking is the major cause
  • Genetic – alpha 1 antitrypsin deficiency (accounts for 2-3% of cases)
  • alpha 1 antitrypsin inhibits the action of neutrophil elastase which destroys elastin
  • develops before 40 yrs of age
  • equal distribution between sexes
• Emphysema - Auscultation:

  • decreased amount of breath sounds
  • due to very hyperinflated lungs theres a lot of gas trapping, so the tissue is quiet as you dont hear as much airflow
• Chest X-ray - Emphysema:

  • Hyperinflated - seen by the lungs looking long
  • Long, thin heart - if the diaphragms are flat due to hyperinflation, the heart also gets pulled down
  • Bullae are present - black lung fields with less lung markings present due to capillaries being destroyed
  • Diaphragm is low and flat due to the lungs being hyperinflated