Tubular breathing (older term)
In one sentenceA loud, high-pitched sound. Expiration is at least as long as inspiration. It is normal over the manubrium (bronchial breath sound). Heard over the lung periphery, it is called bronchial breathing and is abnormal.
Listen to the same sound in another patient. Breathing rate, chest wall, the pitch of the sound and the number of adventitious sounds vary within realistic limits.
What does it sound like?
Expiration is at least as long and as loud as inspiration. There is a short silent gap between the two phases.
Where is it heard?
Normally over the manubrium and the central airways. In the periphery: consolidation, the upper border of an effusion, compressive atelectasis.
What causes it?
In consolidation, the air in the alveoli is replaced by fluid and cells. The solid lung transmits the sound made in the trachea and large bronchi with much less filtering. No new sound is made. The existing central sound becomes audible in the periphery. This needs an open bronchus.
Quantitative criteria
- In consolidation, higher-frequency components reach the chest wall more clearly.
- Bronchophony, whispered pectoriloquy and sometimes egophony may be present over the same area.
Clinical meaning
Localised bronchial breathing is a strong clue to consolidation when tests show increased voice transmission (bronchophony, egophony) over the same area. Unlike sounds caused by secretions, it does not change with coughing.
Sounds it can be confused with
The tracheal sound is normal over the neck and is more broadband. The bronchial sound matters when it is heard in the periphery.
In the bronchovesicular sound, expiration is fainter and the gap between the phases is less distinct.
Where you hear bronchial breathing, ask the patient to whisper "ninety-nine". If the words become clear (whispered pectoriloquy), transmission is increased.
See the reference list for sources.