pulmonary crackles; rales

Etiology

• Late inspiratory crackles:
  • sudden reinflation of previously deflated airways
  • pneumonia
  • dependent regions of lungs
    • congestive heart failure
      • acute aortic insufficiency
    • diffuse pulmonary fibrosis
    • shallow respirations in bedridden & elderly
• Early inspiratory crackles:
  • COPD/bronchitis
  • May be heard at mouth
• Inspiratory & expiratory crackles:
  • bronchiectasis
  • secretions in trachea & large bronchi
    • pulmonary edema
    • patients who cannot cough up secretions

Pathology

• rales are produced by movement of thick exudate or the vibration of inflammed or edematous membranes
• the presence of rales indicates that fluid has permeated the terminal bronchioles & alveoli, which can be due either to heart failure or to primary pulmonary disease, especially pneumonia

Clinical manifestations

• crackling or bubbling sounds heard during auscultation of the lungs

More general terms

• abnormal chest sound

Additional terms

• Randomized ALdactone Evaluation Study (RALES)