Lung sounds Flashcards
where do lung sounds come from
- Normal breath sounds are generated turbulent airflow in the trachea and large airways.
- These sounds are comprised of high, medium and low frequencies
what are normal breath sound characteristics
- heard all over chest wall
- quieter at bases than apices
- muffled due to filtering by the air in alveoli
- expiration is shorter and quieter than inspiration with no pause in between
what are abnormal bronchial breath sounds
are tracheal and large airway sounds that have been transmitted though non-aerated (airless) lung tissue which does not attenuate the higher frequencies
-Bronchial Breath sounds (Br Br) are loud and high pitched, with a harsh quality
what are bronchial breath sounds heard
- heard over an area of consolidated or collapsed lung
- are similar to those heard over the trachea itself
what do crackles sound like
Crackles are clicking sounds heard during inspiration
what causes crackles
-caused by the spanning-open of alveoli and small airways during inspiration or by air being forced through airways narrowed by oedema, secretions
what type of crackles would you hear in bronchiectasis
Coarse, early inspiratory crackles are heard in cases like bronchiectasis and bronchitis when bronchioles opens
what type of crackles are heard in pulmonary oedema/fibrosis
Fine, late crackles occur when alveoli and respiratory bronchioles open such as in pulmonary oedema and pulmonary fibrosis
what is a wheeze
- sounds produced by airways on expiration primarily because the pressure gradient causes greater narrowing (inspiration too if more severe)
- sound is made by airflow vibration in a narrow or compressed airway
how does obstruction affect wheeze
- pitch of wheeze is directly proportional to degree of obstruction (higher pitch= more obstruction)
what is a polyphonic wheeze
many different sounds/pitches
What does a polyphonic wheeze indicate
indicates widespread airway narrowing/obstruction
what is a monophonic wheeze
caused by a single obstructed airway
what is whispering pectoriloquy
when you can hear the person’s whisper clearly though auscultation
what is whispering pectoriloquy indicative of
- Associated with bronchial breath sounds
- likely indicates an area of consolidation
- Whispered speech lacks the lower frequencies and is normally not transmitted through the chest wall
what is a percussion note
- elicited by tapping the chest wall
- resonant over normal tissue and dull over solid tissue
what are percussion notes used to evaluate
- density of underlying disease
- Hyper-resonance indicates excess air, a stony, dull sound indicates pleural effusion
what are diminished breath sounds
- Reduced sound generation due to increased attenuation (filtering)
- Localised or global
what could be the reason for globally diminished breath sounds
- could be due to pain
- muscle weakness
- obesity
- accumulation of fluid/air in the pleural space (increase in filtering)
- emphysema
what could be the reason for localised diminished breath sounds
- sputum plugging with distal hyperinflation -
- obstruction of an airway by a tumour or sputum
what is a pleural rub sound
- sound made by inflamed pleural (visceral and parietal) rubbing together with friction
- caused by infection or non-inflammatory via neoplasm
- localised or generalised and ranges in volume
- heard equally during inspiration and expiration, which helps differentiate pleural rub from crackles
what are stridor lung sounds
o Loud, high pitch sound heard on inspiration
-heard on inspiration because the extra-pulmonary airways are subject to opposite pressure gradients than the intrapulmonary airways
what are stridor breath sounds indicative of
- Sign of upper airway obstruction.
- Caused by turbulent airflow through a partially obstructed airway at the level of the supraglottis, glottis, subglottis or trachea
anatomy of auscultation
LOOK AT NOTES FOR DIAGRAM
what are some limitations to auscultation
Inter-and intra-therapist/practitioner interpretation of lung sounds is poor
Needs practise and a good quality stethoscope
Not infallible; sounds may change very quickly
Needs patient co-operation to generate sufficient flow rate
what is the clinical significance of breath sounds/adventitious sounds
- auscultation is one method of pre treatment
- abnormal breath sounds and adventitious sounds (wheeze etc) are indicative of pathology
what sounds can be heard in asthma
• likely to hear expiratory and possibly inspiratory wheeze if severe, stridor
what sounds can be heard in pneumonia
• may hear crackles, diminished breath sounds
what sounds can be heard in pleuritis
-pleural rub
what sounds can be heard in pneumothorax
• diminished breath sounds, bronchial breath sounds, hyper-resonant percussive sound
what sounds can be heard in bronchitis
• crackles, diminished breath sounds, wheeze, occasionally stridor
what sounds can be heard in bronchiectasis
crackles, wheeze
what sounds can be heard in fracture
crunching
Auscultation
READ NOTES
when do you hear gurgling sounds
massive pulmonary oedema
when do you hear crunching sounds
’s or dislocations
causes of large airway noises
- usually mucus in larger airways which clears after coughing
- may be audible without auscultation
- very loud sound heard all over chest
- heard on inspiration and expiration
how might a crackle vary (features of crackles)
pitch–> gives a clue to site and pathology
time–> very early crackles = coarse and loud- originate in large airways and usually clear with an effective cough. late crackles are from small airways and alveoli
number–> proportional to severity of disease (diffuse/widespread/scant)
when might crackles occur
aged patient–> due to loss of elastic recoil and subsequent early airway closure during expiration
normal–> if preson breathes down to RV and airway closure occurs
-pulmonary oedema
-pulmonary fibrosis–> due to increased elastic recoil
-presence of expirations
