Crackles / Rales / Crepitations

  • Probably represent opening of small airways and alveoli. - They may be normal at the lung bases if they clear on coughing or after taking a few deep breaths. - Basal rales are a classical feature of pulmonary congestion with left ventricular failure. They may be more diffuse in pulmonary fibrosis.
  1. Adventitious sound
  2. Intermittent
  3. Appeared in phase of inspiration or early expiration
  4. Constant in site
  5. Unchanged in character
  6. Medium and fine crackles exist meantime
  7. Less or disappeared after cough

Site of crackles

  1. Local: local lesion
  • Pneumonia, TB, bronchiectasis
  1. Both bases
  • Pulmo. edema, bronchopneumonia, chronic bronchitis
  1. Full fields
  • Acute pulmo. edema, severe bronchopneumonia, chronic bronchitis with severe infection