2. Auscultation is a simple, non-invasive procedure that involves the
use of a stethoscope to listen to the sounds produced by the
body. A stethoscope amplifies the sounds within the lungs so that
we can hear and have an idea of what’s going on with the patient’s
condition. When performing lung auscultation, the bell or
diaphragm of the stethoscope is placed on the patient’s chest
and/or back. Both sides can be compared with one another and the
sounds of each lung should be compared as well.
3. A stethoscope is a closed acoustic system
where air serves as a transmitting medium for
sounds.Therefore, if the tube is clogged, or
communicates with ambient air, auscultation
becomes impossible.The skin against which
the bell of the stethoscope is pressed acts as a
membrane whose acoustic properties change
under pressure: if the pressure on the skin
increases higher frequencies are better
transmitted, and vice versa. Excess pressure on
the bell damps vibration of the underlying
tissues. A large bell better transmits lower
frequencies.
4. Auscultation techniques
-silence in the room and the absence of any extraneous sounds
-the ambient temperature should provide comfort for the undressed patient
-patient is either sits or stands upright
-the skin to which the bell of the phonendoscope is pressed should be hairless
-bell should be pressed firmly and uniformly to the patient's skin
-in some cases the patient is asked to cough
5.
6. Stethoscope or phonendoscope should be placed in strictly symmetrical points of the right
and left sides of the chest. Auscultation begins with the anterior wall of the chest, from its
upper part, in the supra- and subclavicular regions, and then the stethoscope should be
moved downward and laterally.
7. The lungs are then auscultated in the same order from the posterior wall of the chest and in the axillary
regions. In order to increase the area of auscultation between the scapulae, the patient should be asked
to cross his arms on the chest and in this way to displace his shoulder-blades laterally from the spine,
while for convenience of auscultation of the axillary regions he should place his hands on the back of the
head.
8. Vesicular breathing (vesicular/ alveolar respiration)
Respiratory sounds known as vesicular respiration arise due to vibration of the elastic
elements of the alveolar walls during their filling with air in inspiration.The alveoli are
filled with air in sequence.Therefore, the summation of the great number of sounds
produced during vibration of the alveolar walls gives a long soft (blowing) noise that can
be heard during the entire inspiration phase, its intensity gradually increasing. Alveolar
walls still vibrate at the initial expiration phase to give a shorter second phase of the
vesicular breathing, which is heard only during the first third of the expiration phase,
because vibrations of elastic alveolar walls are quickly dampened by the decreasing
tension of the alveolar walls.
9. Normal vesicular breathing is better heard over the anterior surface of the chest,
below the 2nd rib, laterally of the parasternal line, and also in the axillary regions and
below the scapular angle, i.e. at points where the largest masses of the pulmonary
tissue are located.Vesicular breathing is heard worse at the apices of the lungs and
their lowermost parts, where the masses of the pulmonary tissue are less abundant.
10.
11.
12. Physiological weakening of vesicular respiration occurs in patients with thicker
chest wall due to excessively developed muscles or subcutaneous fat.
Physiological intensification of vesicular respiration may be observed in patients
with underdeveloped muscles or subcutaneous fat. Intensified vesicular
breathing is characteristic of children with a thin chest wall, good elasticity of the
alveoli and the interalveolar septa.This respiration is called “puerile respiration”
(L puer child).Vesicular respiration is intensified during exercise; respiratory
movements become deeper and more frequent. Physiological changes in
vesicular respiration always involve both parts of the chest, and respiratory
sounds are equally intensified or weakened at the symmetrical points of the
chest.
13. Pathologically decreased vesicular respiration can be due to a significantly
diminished number of the alveoli because of atrophy and gradual degradation of
the interalveolar septa and formation of larger vesicles incapable of collapsing
during expiration.This pathological condition is observed in pulmonary
emphysema, at which the remaining alveoli are no longer elastic; their walls
become incapable of quick distention and do not give sufficiently strong
vibrations.
14.
15. Decreased vesicular breathing can be due to inflammation and swelling of the walls
in a part of the lung and decreased amplitude of their vibration during inspiration,
which is characteristic of early acute lobar pneumonia. During the second stage of
this disease, the alveoli of the affected part of the lung become filled with effusion
and vesicular breathing becomes inaudible over this region.Vesicular breathing can
be decreased also in insufficient delivery of air to the alveoli through the air ways
because of their mechanical obstruction (e.g. by a tumour).Air admission to the
alveoli can be decreased in patients with a markedly weakened inspiration phase
(as a result of inflammation of the respiratory muscles, intercostal nerves, rib
fracture, extreme asthenia of the patient and adynamia).
16. Vesicular respiration decreases also due to obstructed conduction of sound
waves from the source of vibration (alveolar walls) to the chest surface, as, for
example, in thickening of the pleural membranes or accumulation of air or
fluid in the pleural cavity. If the amount of fluid or air in the pleural cavity is
great, respiratory sounds are not heard. Conduction of sound to the surface of
the chest may be absent in atelectasis of the lung due to complete obstruction of
the lumen in the large bronchus.
17. Abnormally increased vesicular respiration can be heard during expiration or
during both respiratory phases. Increased expiration depends on obstruction to
the air passage through small bronchi or their contracted lumen
(inflammatory edema of the mucosa, bronchospasm). Expiration becomes
louder and longer.
18. Deeper vesicular respiration during which the inspiration and
expiration phases are intensified, is called harsh (or coarse, rough)
respiration. It occurs in marked and non-uniform narrowing of
the lumen in small bronchi and bronchioles due to inflammatory
edema of their mucosa (bronchitis).
19. Another type of pathological respiration is interrupted or cogwheel respiration. This
vesicular respiration is characterized by short jerky inspiration efforts interrupted by
short pauses between them; the expiration is usually normal. Interrupted breathing
also occurs in non-uniform contraction of the respiratory muscles, e.g. when a patient
is auscultated in a cold room, or when he has nervous trembling, or diseases of the
respiratory muscles, etc. Interrupted breathing over a limited part of the lung
indicates difficult passage of air from small bronchi to the alveoli in this region and
uneven unfolding of the alveoli. Interrupted breathing indicates pathology in fine
bronchi and is more frequently heard at the apices of the lungs during their
tuberculosis infiltration.
20. Bronchial breathing/respiration (laryngotracheal respiration)
Respiratory sounds known as bronchial or tubular breathing arise in the larynx and
the trachea as air passes through the vocal slit. As air is inhaled, it passes through
the vocal slit to enter wider trachea where it is set in vortex-type motion. Sound
waves thus generated propagate along the air column throughout the entire
bronchial tree. Sounds generated by the vibration of these waves are harsh. During
expiration, air also passes through the vocal slit to enter a wider space of the larynx
where it is set in a vortex motion. But since the vocal slit is narrower during
expiration, the respiratory sound becomes louder, harsher and longer.This type of
breathing is called laryngotracheal (by the site of its generation).
21. Bronchial breathing is well heard in physiological cases over the larynx, the
trachea, and at points of projection of the tracheal bifurcation (anteriorly, over
the manubrium sterni, at the point of its junction with the sternum, and
posteriorly in the interscapular space, at the level of the 3rd and 4th thoracic
vertebrae). Bronchial breathing is not heard over the other parts of the chest
because of large masses of the pulmonary tissue found between the bronchi
and the chest wall.
22. Bronchial breathing can be heard instead of vesicular (or in addition to the
vesicular breathing) over the chest in pulmonary pathology.This breathing
is called pathological bronchial respiration. Depending the origin there are
three types of pathological bronchial respiration:
23. 1) Infiltrative type
arises in consolidation of a pulmonary tissue (II stages of acute lobar pneumonia, infarct of lungs,
tuberculosis)
In such cases the alveolar walls do not vibrate, while consolidated airless pulmonary tissue becomes
a good conductor of sound waves in laryngotracheal respiration to the surface of the chest wall.
24. 2) Cavitary type
is auscultated above superficially posed smooth-bore lumen of the big diameter connected with a
bronchus (an abscess, a tubercular cavern, bronchiectasias with an appreciable distention of bronchi)
25. 3) Atelectatic type
it is observed in compression atelectasis (exsudative pleurisy of 1,5-3 litres), is auscultated at a
column on high bound of a dullness where is compressiated lung, rarely passes for lin. axillaries
anterior.
26. Amphoric respiration arises in the presence of a smooth-wall cavity (not less
than 5-6 cm in diameter) communicated with a large bronchus. Sounds of
this kind can be produced by blowing over the mouth of an empty glass or clay
jar.This altered bronchial breathing is there called amphoric (Gk amphoeus jar).
Metallic respiration differs from both bronchial and amphoric. It is loud and
high, and resembles the sound produced when a piece of metal is struck.
Metallic respiration is heard in open pneumothorax when the air of the pleural
cavity communicates with the external air.
Stenotic respiration is exaggerated laryngotracheal breathing which is heard
in cases with narrowed trachea or large bronchus (due to a tumour); it is
heard mainly ay points where physiological bronchial breathing is normally
heard.
