Crackles (Rales)

Definition

Crackles, also called rales, are discontinuous, non-musical, short popping or crackling sounds heard on auscultation. They are classified as fine or coarse, inspiratory or expiratory, and by location.

Types

• Fine crackles: High-pitched, brief, such as cHF, pulmonary edema, interstitial fibrosis, atelectasis.
• Coarse crackles: Lower-pitched, longer, such as pneumonia, severe pulmonary edema, bronchiectasis.

Mechanism

Sudden opening of small airways or popping of fluid-filled alveoli during inspiration.

Nursing Considerations

Fine crackles at lung bases in a patient with shortness of breath and weight gain suggest heart failure, such as coarse crackles with fever, productive cough, and leukocytosis suggest pneumonia. Elevate head of bed, administer diuretics/antibiotics, perform pulmonary toileting (coughing, deep breathing, incentive spirometry, possibly chest physiotherapy). Monitor SpO2.

NCLEX Relevance

High-yield for CHF case studies: fine bilateral basilar crackles are classic.