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Chapter 3: Respiratory procedures 93

Table 3.4 Breath sounds A high-pitched expiratory wheeze, often with a mix-
ture of notes ‘polyphonic wheeze’ is caused by ob-
Vesicular This is the normal pattern, a fine rustling
or whispering sound. Inspiration and struction of many smaller airways as occurs in asthma
the first part of expiration are heard and chronic obstructive pulmonary disease (COPD).
with no gap in between. Inspiration is However,theseconditionsmayoccurwithoutwheeze,
slightly louder and longer than despite severe obstruction.
expiration.
Reduced Bilaterally: Chronic obstructive pulmonary Crackles/crepitations: Normally the airways do not col-
disease, severe acute asthma. lapse or obstruct on expiration, but they may due to se-
Asymmetry: Pneumothorax, pleural cretions and oedema or damage by either fibrosis or loss
effusion or lung collapse on the side of elasticity. The re-opening of collapsed small airways
with reduced sounds. and alveoli or the presence of secretions in the larger air-
Bronchial When the lung is solid it conducts the ways cause inspiratory crackles. They are differentiated
sounds from the larger airways better,
so the whole of inspiration and by their timing and nature:
expiration are heard. Expiration is Early inspiratory crackles come from the airways,
louder than inspiration. There is where air reaches them first in inspiration. Late or
often a gap between the two. It occurs pan-inspiratory crackles come from the alveoli.
over consolidated lung, but
‘Fine crackles’ are usually alveolar (late) and are often
may occur in localised pulmonary
fibrosis and at the top of a pleural described as rubbing hair through fingers. They are
effusion. typical of pulmonary fibrosis or alveolar oedema.
Coarse crackles are wet, low-pitched early inspiratory

sounds due to airway secretions, often changed in na-
Added breath sounds ture by coughing.
These are divided into wheezes from the airways, crack- Pleuralfrictionrub:A creaking sound in inspiration and
les, which come from the large airways, the bronchioles expiration, localised over an area of pleural inflamma-
and the alveoli, and friction rubs from the pleura (see tion. Causes include viral or bacterial pneumonia and
Table 3.5) pulmonary infarct/embolus.
Wheezes are musical sounds caused by airway ob-
struction and are usually heard in expiration.
Alow-pitched monophonic wheeze is caused by ob-
Chest signs in respiratory disease
struction of a single large airway (below the trachea). See Table 3.6.
It is caused by bronchial carcinoma or inhaled foreign
body, and is frequently inspiratory.
Respiratory procedures
Table 3.5 Summary of added breath sounds
Sound type Commonest cause Lung function testing
Low-pitched Bronchial carcinoma/foreign The simplest way to assess lung function is from a pa-
monophonic wheeze body
Polyphonic expiratory Asthma tient’s history, i.e. the exercise capacity, how far the pa-
wheeze COPD tient can walk before becoming breathless. However, for
Early inspiratory crackles more repeatable objective assessment various tests are
Medium crackles COPD used:
Coarse crackles Bronchiectasis
Late/pan inspiratory
crackles Bedside testing
Fine crackles Pulmonary fibrosis Peak expiratory flow (PEF): This is quick and simple.
Medium crackles Left ventricular failure
Pleural friction rub Pleurisy It is measured by asking patients (standing where possi-
ble) to take a deep breath to full inspiration, then blow