Product Code Database
Respiratory sounds, also known as lung sounds or breath sounds, are the specific sounds generated by the movement of air through the respiratory system. These may be easily audible or identified through auscultation of the respiratory system through the lung fields with a stethoscope as well as from the spectral characteristics of lung sounds. These include normal breath sounds and added sounds such as crackles, , pleural friction rubs, stertor, and stridor.
Description and classification of the sounds usually involve auscultation of the inspiratory and expiratory phases of the breath cycle, noting both the pitch (typically described as low (≤200 Hz), medium or high (≥400 Hz)) and intensity (soft, medium, loud or very loud) of the sounds heard.
| + !Name !Location where heard normally !Quality of sound !Sound duration !Example | ||||
| tracheal | over the trachea | very loud | expiratory sound duration is equivalent to inspiratory sound | |
| bronchial | over the manubrium | loud, high pitched | expiratory sound duration is longer than inspiratory sound | |
| bronchovesicular | anteriorly between the 1st and 2nd intercostal space; posteriorly in-between the scapulae | intermediate | expiratory sound duration is about equivalent to inspiratory sound | |
| vesicular | over most of both lungs | soft, low pitched | expiratory sound duration is shorter than inspiratory sound |
| Wheeze or rhonchi | continuous | high (wheeze) or lower (rhonchi) | expiratory or inspiratory | whistling/sibilant | Caused by narrowing of airways, such as in asthma, chronic obstructive pulmonary disease, foreign body. | |
| Stridor | continuous | high | inspiratory, expiratory, or both | whistling/sibilant | epiglottitis, foreign body, laryngeal oedema, croup | |
| Inspiratory gasp | continuous | high | inspiratory | whoop | pertussis (whooping cough) | see New England Journal of Medicine, Classic Whooping Cough sound file, Supplement to the N Engl J Med 2004; 350:2023-2026 |
| Crackles (rales) | continuous | high (fine) or low (coarse) | inspiratory | cracking/clicking/rattling | pneumonia, pulmonary edema, tuberculosis, bronchitis, heart failure | |
| Pleural friction rub | discontinuous | low | inspiratory and expiratory | many repeated rhythmic sounds | inflammation of lung linings, lung tumors | not available |
| Hamman's sign (or Mediastinal crunch) | discontinuous | neither (heartbeat) | crunching, rasping | pneumomediastinum, pneumopericardium | not available | |
| Grunting | Continuous | low | expiratory | snoring | surfactant deficiency, pneumonia, cardiac abnormalities |
Several sources will also refer to "medium" crackles, as a crackling sound that seems to fall between the coarse and fine crackles. Crackles are defined as discrete sounds that last less than 250 ms, while the continuous sounds (rhonchi and wheezes) last approximately 250 ms. Rhonchi are usually caused by a stricture or blockage in the upper airway. These are different from stridor.
|
|
