Rales

Rattling noises (RG, RGs) are formally considered to be breathing noises. These noises occur in addition to physiological vesicular breathing and usually indicate pathological changes. Pathophysiologically, rales are caused by the presence of secretions or fluids and the resulting altered auscultation properties of the lungs.

Rattling noises can essentially be divided into wet and dry rattling noises. However, this classification is no longer entirely up to date. A more recent classification only refers to breathing noises and divides them into discontinuous and continuous breathing noises. However, this division into wet and dry rales is very present in clinical routine and is often used as a synonym for discontinuous and continuous breath sounds.

Discontinuous respiratory sibilance/formerly moist sibilance/rales:

Originating from thin secretions, especially during inspiration. The character of the noise indicates which part of the respiratory tract is affected by pathological changes. They are divided into fine-bubble, medium-bubble and coarse-bubble breath sounds.

Coarse-bubble breath sounds: lung sections with a large lumen.

Occur in: pulmonary congestion/ pulmonary edema, bronchiectasis.

Occasionally perceptible even without stethoscope.

Medium bubbled breath sounds : Lung sections with medium lumen

Occurrence in: Bronchitis

Fine-bubbled breath sounds: lung sections with small lumen (in the area of the alveoli).

Occurrence in: Pneumonia

Crackling:

A special form is crackling rales (sclerosiphonia): Occurs in pulmonary fibrosis, perceptible by auscultation, especially endinspiratory, in the basal lung segments.

Sound aspect of moist respiratory by-products:

Sounding "near the ear," e.g., in pneumonia.

Non-sounding "far from the ear", inside the lungs, e.g. in pulmonary edema

Metallic pneumothorax

Continuous respiratory sidetone/formerly dry sidetone/rales:

Originating from viscous secretions, usually accompanied by mucosal swelling. Continuous respiratory accessory sounds include stridor, humming, whistling, and wheezing.

Stridor both inspiratory and expiratory occurrence,

Cause: narrowing of the airway, auscultatory: audible flow sound,

Occurrence expiratory: in bronchial asthma, COPD,

occurrence inspiratory: epiglottitis, pseudocroup, foreign body aspiration, bilateral vocal cord paralysis

Hum Cause: mucus threads in the large airways, auscultatory: low-frequency noise, typical occurrence in asthma attacks, among others

Whistling/Giemen Cause: Cause: Narrowing of the airways, e.g. by mucus, giemen can be explained auscultatorily by the narrowing of the smallest airways (bronchioles), typical occurrence in chronic obstructive pulmonary disease (COPD) and bronchial asthma, among others.

• Link to auscultation findings (YouTube link): Lung sounds (respiratory auscultation sounds)