Crackles
Crackles,
crepitations, or
rales are the clicking, rattling, or crackling noises that may be made by one or both lungs of a human with a respiratory disease during inhalation. They are often heard only with a stethoscope.
Bilateral crackles refers to the presence of crackles in both lungs.
Basal or
basilar crackles are crackles apparently originating in or near the base of the lung.
Bibasal or
bibasilar crackles refer to crackles at the bases of both the left and right lungs.
Bilateral basal crackles also refers to the presence of
basal crackles in both lungs. Crackles are caused by the "popping open" of small airways and alveoli collapsed by fluid, exudate, or lack of aeration during expiration. The word "rales" derives from the French word
râle meaning "rattle". Crackles can be heard in patients with pneumonia, atelectasis, pulmonary fibrosis, acute bronchitis, bronchiectasis, or post thoracotomy or metastasis ablation. Pulmonary edema secondary to left-sided congestive heart failure can also cause rales.