Earlier we discussed Respiratory system examination and it’s section- Auscultation of lungs. Today, we are going to explain the normal breath sounds and the related variations and pathological causes of normal breath sounds and abnormal breath sounds.
Vesicular Breath Sounds
Vesicular sounds Definition- These are sounds produced by passage of air, in and out of alveoli (vesicles).
Classical sites for hearing vesicular sounds- Infra-axillary, Infra-mammary, Infra-scapular.
Characteristics of vesicular breath sounds :
- Rusting (leaves blowing)
- Intensity of inspiration is greater than intensity of expiration
- Duration of inspiration is more that duration of expiration
- No gap in between inspiration and expiration
Variations of vesicular breath sounds :
- Decreased vesicular sound- Thick chest wall, obesity, thickened pleura, pleural effusion, pneumothorax, hydropneumothorax, empyema, emphysema, fibrosis.
- Vesicular sounds with prolonged expiration- This can mean asthma or Chronic obstructive pulmonary disease (COPD).
- Harsh vesicular sounds- Intensity of inspiration > Intensity of expiration, usually pathological, seen in compensatory emphysema, forced breathing.
- Puerile (childish/silly)- Intensity of inspiration > Intensity of expiration, normally physiological, in thin built people (usually children).
- Cogwheel or jerky- hysteical, nervous or crying patient.
- Absent vesicular breath sound- It is seen in pneumothorax, massive pleural effusion, hydropneumothorax, collapse with obstructed bronchus, grossly thickened pleura, etc.
Bronchial Breath Sounds
Bronchial breath sounds Definitions- These sounds are produced by passage of air through the tracheo-bronchial tree.
Classical site for hearing bronchial sound- Over the trachea
These sounds are audible in situations where sound generated in central airways is transmitted more or less unchanged through the lung having a pathology such as Consolidation, with a patent bronchus.
Characteristics of bronchial breath sounds :
- Blowing, Hollow tube or Aspirate in character
- Intensity of expiration is more than that of inspiration
- Duration of expiration is usually equal to inspiration
1. Tubular- This is a high-pitched bronchial breath sound which is commonly found in –
- Collapse of lung
- Above level of pleural effusion
- Pulled tracheal syndrome
2. Cavernous- It is a low-pitched bronchial breath sound classically heard over a superficial, big, empty cavity connected with a patent bronchus, eg. tuberous cavity, lung abscess.
3. Amorphic- It is a low-pitched bronchial breath sound with tones and overtones, or with a metallic tone. The sound is similar to whistling sound which one can produce blowing air through mouth into an empty glass bottle. It is classically found in-
- Bronchopleural fistula (open pneumothorax)
- Big cavity connected with a small bronchus
NOTE- CONDITIONS ASSOCIATED WITH BRONCHIAL BREATH SOUNDS WILL PRODUCE QUANTITATIVE INCREASE IN VOCAL RESONANCE (BRONCHOPHONY, AEGOPHONY, WHISPERING PECTORILOQUY).
Bronchovesicular Breath Sounds
Bronchovesicular breath sounds Definition- These are a mixture of Bronchial breath sound during expiration and Vesicular breath sound during inspiration, with no gap in between the inspiration and expiration.
Classical sites for hearing Bronchovesicular breath sounds- Right infra-clavicular area (trachea is in direct contact with lungs on right side) and Inter-scapular area at back (root of lung)
Clinical associations- Consolidation (pneumonia) in resolution stage, Partial collapse of lung, Cavity in lung.