Auscultation

Breath sound:

• It should be heard using the diaphragm of stethoscope, compare both sides. Use the bell above the clavicle to hear lung apices. Breath sound may be normal (vesicular), bronchial,vesicular with prolonged expiration, diminished or absent.

1. Normal vesicular (similar to wind rustling in leaves): It is louder and longer in inspiration and expiration is short, without any gap. Vesicular sound is produced in large airways. When heard through normal lung, filtering effect through the alveoli produces attenuated and low pitched sound.

2. Bronchial: Harsh, louder, blowing quality, inspiration and expiration are of equal length and intensity. There is a gap between inspiration and expiration. It is produced in large airways, but when the lung between airway and chest wall is airless (e.g., consolidation), loss of filtration effect results in high pitched bronchial sound. 

It is 2 types:

• High pitched (tubular): Found in consolidation and collapse with patent bronchus.

• Low pitched (also called cavernous): Found in cavitation.

Causes of bronchial sound (3 C’s):

• Consolidation.
• Collapse with patent bronchus.
• Cavity (near the chest wall).

• Also fibrosis (low pitched).

3. Causes of vesicular with prolonged expiration:

•  COPD (chronic bronchitis and emphysema).
•  Bronchial asthma.

Vocal Resonance:

This may be normal, increased or decreased. Vocal resonances are 3 types:

• Bronchophony: It appears to be near the ear piece, found in consolidation.
• Aegophony: Nasal quality or goat like (Greek: aix means goat and phony means sound), found in consolidation and above the fluid level of pleural effusion.
• Whispering pectoriloquy: Ask the patient to tell ‘ninety-nine’ or ‘one-one’, as if whisper. When auscultated with stethoscope, it appears as if the patient whispers in the examiner’s ear. It may be found in consolidation, collapse with patent bronchus or cavitation (3 C’s).

Causes of increased vocal resonance (3 C’s):

• Consolidation.
• Collapse with patent bronchus.
• Cavity.

• Also in fibrosis.

Causes of decreased vocal resonance:

• Pleural effusion.
• Thickened pleura.
•  Pneumothorax.
•  Collapse with complete bronchial obstruction.
•  Mass lesion.

Rhonchi:

• It is the musical sound produced by passage of air through narrow airways (due to mucosal oedema or spasm of bronchial musculature). 

It is 2 types:

•  High pitched: Indicates small airway obstruction.
• Low pitched: Indicates large bronchi obstruction.

Causes of rhonchi:

• Bronchial asthma (medium or high pitched, more in expiration).
• Chronic bronchitis (low or medium pitched, both in inspiration and expiration).

Localized rhonchi (indicates partial obstruction of large bronchus). Usually a fixed, low pitched rhonchi. Causes are:

• Neoplasm (bronchial carcinoma, adenoma).
• Foreign body.
• Mucous plugs (disappear after coughing).
• Congenital bronchial stenosis.

Crepitations:

These are bubbling or crackling sounds, occur due to passage of air through fluid in alveoli. Crepitations may be fine or coarse, may be present in inspiration, expiration or both.

• Early inspiratory crepitations: commonly found in chronic bronchitis.
• End or pan-inspiratory crepitations: found in fibrosing alveolitis (DPLD).

Causes of coarse crepitations :

•  Bronchiectasis (may be unilateral or bilateral).
•  Resolution stage of pneumonia.
• DPLD (or ILD).

Crepitations reduce or disappear after coughing in the following diseases:

•  Resolving pneumonia.
•  Bronchiectasis.
•  Lung abscess.
•  Pulmonary oedema.

Crepitation not changed after coughing: Found in DPLD.

Causes of bilateral basal crepitations:

• Bilateral bronchiectasis.
• Pulmonary oedema due to any cause (commonly acute LVF).
•  DPLD.

Pleural Rub:

• It is the localized grating, creaking, rubbing and leathery sound produced by movement of visceral pleura over the parietal pleura.

• Heard both in inspiration and expiration, disappears when breathing is hold (to differentiate from pericardial rub).

• Rub is augmented by pressing the stethoscope.

• May be palpable and associated with local pain.

Presence of pleural rub indicates pleurisy (which may be due to viral or other infections, pneumonia, pulmonary infarction and bronchial carcinoma).

Pleuro-pericardial rub:

• When pleurisy involves the pleura adjacent to pericardium, pleura-pericardial rub is heard (there is no pericarditis).

• It is due to rough pleural surface adjacent to pericardium, which moves one upon another by

cardiac pulsation.