Earlier we discussed Respiratory system examination and its section- Auscultation of lungs. Today, we are going to explain 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 the 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)
- The intensity of inspiration is greater than the intensity of expiration
- The duration of inspiration is more than the duration of expiration
- No gap 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- hysterical, 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 the passage of air through the tracheobronchial tree.
Classical site for hearing the 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
- The intensity of expiration is more than that of inspiration
- The duration of expiration is usually equal to the inspiration
1. Tubular- This is a high-pitched bronchial breath sound that is commonly found in –
- Collapse of lung
- Above the 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 or 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 a whistling sound which one can produce by blowing air through the 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 sounds during expiration and Vesicular breath sound during inspiration, with no gap between the inspiration and expiration.
Classical sites for hearing Bronchovesicular breath sounds- Right infra-clavicular area (trachea is in direct contact with lungs on the right side) and Inter-scapular area at back (the root of the lung)
Clinical associations- Consolidation (pneumonia) in the resolution stage, Partial collapse of the lung, Cavity in the lung.