Crackles

• Crackles:

  • Popping sound, a bit like fireworks
  • Created when air is forced through airways that have been narrowed by oedema, inflammation or secretions
  • Also created when airless alveoli or peripheral airways snap open
  • Mainly heard on inspiration
  • Can be early/late (early – large proximal airways, late – peripheral small airways)
  • Can be fine/coarse
• Crackles

  • Ask patient to cough if crackles heard at the mouth
  • Causes:
  • Early inspiratory crackles often heard in COPD (bronchioles opening)
  • Fine late inspiratory crackles may indicate pulmonary oedema or pulmonary fibrosis
  • Late inspiratory crackles may be heard in areas of bibasal atelectasis