The thorax is delimited at the top by the cervico-thoracic line which, starting
from the jugular and touching the upper edge of the clavicle, while behind touches the
spinous apophysis of the VII cervical vertebra. At the bottom, the thorax is
delimited by the thoraco-abdominal line which, starting from the sternum ensiform
apophysis, reaches the spinous apophysis of the XII thoracic vertebra, following
the lower rib edge. Laterally, the thorax is delimited by the two omobrachial
lines which, at the humeral attachment of the pectoralis major and the great
dorsal, separate the thorax from the upper limbs.
In order to identify with sufficient precision any point placed on the chest wall, it is necessary to use several lines of repere, which are divided vertically and horizontally.
Chest reference lines
1. midsternal
2. lateralsternal
3. midclavear
5. sternal angle
6. submammary
7. xipho-costal
The vertical lines of the anterior wall are: the
midsternal line, which joins the jugular apex to the ensiform apophysis; the
lateral sternal lines, which run along the two edges of the sternum; the
parasternal lines that run at about 2 cm (or a transverse finger) from the margin
of sternum;
the midclavear line, which start from the middle point of the clavicles; the
anterior axillary line, which runs along the anterior pillar of the axillary cavity;
the midaxillary line, which runs at the midpoint of the axillary cavity. The
horizontal lines are: the clavicular line, which runs along the clavicle; the
mammary line, which runs below the VI coast; the xifocostale, which runs along
the lower edge of the costal arch. In the posterior wall the vertical lines are:
the spondyloid line, which passes through the spiny apophysis; the angle-scapulars,
which start from the lower corner of the scapula; the paravertebral lines, which
pass 2-3 cm more medially; the posterior axillaries lines, which run along the
posterior pillar of the axillary cable. The horizontal lines are: the
supraascular, which passes through the upper limit of the scapula; the angle of
the scapula, which passes through the margin of the scapula. The inspection of
the thorax also includes the analysis of the conformation of the same. In fact,
there are some thoracic deformities that do not necessarily have clinical
significance.
Among these the spinal and sternal deformities and the deformations of the column of greatest interest are kyphosis and scoliosis. These conditions may be accompanied by respiratory movement and therefore, in many cases, cause respiratory failure. Among the most frequent sternal deformities is the chestened thorax, caused by the forward protrusion of the sternum, or the funneled thorax, caused by a re-entry of the sternal body. In normal conditions the two thoracic hemisystems must be symmetrical and equally expansive during respiratory acts. A different amplitude of one may be due to increased dilation or retraction of the contralateral hemorrhage. During the inspection, you should also carefully evaluate any discoloration and scarring anomalies present on the thoracic walls.
Allows evaluation of the symmetry and expansibility of the rib cage. The observer poses posteriorly to the patient and rests his hands flatly on the chest wall with his thumbs joined at the level of the midline. During the respiratory acts the symmetrical removal of the two inches must be evaluated. This maneuver must be performed in several points from top to bottom. The most important relief allowed by palpation is the tactile vocal thrill (FVT) which consists of that "vibrational sensation" that is appreciated with the ulnar side of the hand resting on the chest wall when the patient pronounces words full of consonants (for example, thirty-three ). FVT originates from the vibrations of the vocal cords that are transmitted along the air column contained in the trachea and bronchi. For the FVT to be regularly transmitted, the integrity of the vocal cords and the airway patency is required. It can be modified for alterations concerning the vocal cords, the tracheobronchial airway column, the pulmonary parenchyma and the pleurae. Any pathology leading to aphonia is responsible for the abolition of the FVT. A bronchial occlusion (from neoplasm, mucus plug or other) is responsible for the abolition of the FVT in the area of the lung dependent on the occluded bronchus. An expansion of the bronchial wall, as can occur for example in bronchiectasis, can lead to an increase in the FVT. An inflammatory thickening of the pulmonary parenchyma causes an increase in the FVT for better transmissibility of the vibrations.
Back lines
1. spondyloid
2. paravertebral
3. scapular
4. Angle of the scapula
5. spiny
6. basilar chest
Axillary lines:
1. anterior axillary line
2. midaxillary line
3. posterior axillary line
Vice versa, in bronchial obstruction atelectasis, FVT is abolished. A condition of diminished elasticity of the pulmonary parenchyma causes a weakening of the FVT, as for example, in pulmonary emphysema. Under physiological conditions, the pleurae do not modify the transmissibility of the FVT; this is however reduced in the case of pneumothorax or pleural effusion. Percussion By percussion we mean mostly digital-digital percussion, but there is also immediate percussion (performed directly on the surface of the body without the interposition of any vibrating medium).
For digital-digital percussion, the middle finger of a hand (called a plastiometer) is placed on the wall to be explored. With the homologous finger of the other hand (defined flexor), blows are impressed on the plasti- meter, in rapid succession. The percussion of a normal thorax allows to evoke the clear pulmonary sound (SCP) which is the normal relationship between lung parenchyma and air present during normal breathing. The SCP has a fair intensity, a reduced frequency and a rather long duration. We speak of dull or hypophonetic sound when the amplitude of the vibrations is reduced. We speak of hyperphonic sound and the amplitude of vibrations is higher than normal. Qualitative percussion shows resonance abnormalities of the pulmonary parenchyma due to changes in the area or the fact that other means (solid or liquid or gaseous) have interposed between parenchyma and thoracic disease. Hyperphonesis is caused by an increase in air content in vibration-induced structures with percussion: presence of gas in the pleura; increase in air content of the lung parenchyma (emphysema); presence of a cave. Hypophonesis is caused by loss of normal lung air content or by the presence of a pleural effusion, of a solid mass placed between the pulmonary parenchyma and the chest wall. The percussion has a twofold purpose: on the one hand, to delimit the pulmonary parenchyma from the adjacent organs, on the other hand to compare an abnormal finding with the contralateral finding. In the first case, it may be useful to delimit the Kronig fields consisting of two shoulder straps above the shoulders that can be drawn with the percussion proceeding medially and laterally starting from the midpoint of the muscle to be culled. These areas of SCP (as opposed to the obtuseness of the lateral and medially located soft parts) tell the clinician that the apices are normally ventilated. It may also be useful to detect the lower edge of the lung, delimiting the point of transition between SCP and obtuseness of the abdominal organs and inviting the patient to perform a deep inhalation during which the percussion will highlight the transition from the tympanic sound to the PCS.
It is now performed with the help of a phonendoscope. The respiratory noises
perceived by the auscultation are substantially two: the bronchial breath and
the vesicular murmur (MV). The bronchial breath is generated by the passage of
air through the respiratory tree (trachea, bronchi). Under normal conditions it
is covered by the MV that in fact is the only physiologically audible noise at
the thoracic level. MV is perceived more in inspiration than during exhalation.
This is due to the fact that the inhalation can be considered an "active" phase
(with the recall of air in the alveoli) while the exhalation, although it is of
longer duration, can be considered "passive". The reduced distensibility of the
pulmonary parenchyma as in pulmonary fibrosis; the breath is a characteristic of
weakened MV due to reduced alveolar ventilation and no longer able to cover the
underlying bronchial breath. The presence of bronchial breath at the
auscultation shows the permanence of the air passage while the alveolar
ventilation is abolished.
Added noises
Based on the presence or absence of fluid secretions, they can be distinguished
in wet and dry conditions.
Bronchial noises
They are divisible in wet and dry. The wet noises are the rattles, classified as
small, medium and large bubbles, depending on the bronchial caliber in which the
secret is found. The rattle is comparable to the audible noise when blowing with
a straw in a full glass of water. Their characteristic is that of modifying (and
sometimes disappearing) after the patient has emitted a cough (which has also
caused a partial removal of the bronchial secretions). The dry sounds of
bronchial origin are called ronchi and are mainly caused by the passage of air
through the spastic bronchi.
They are distinguished in snoring if they come from the trachea and the big
bronchi and sibilant or groans when they originate from the bronchi of the
smaller sizes.
Lung sounds
The most common are the crackling rattles or rattles mostly perceptible at the
end of exhalation in the most sloping areas of the lung, caused by interstitial
imbibition.
Pleural noises
They are determined by the rubbing of the pleurae, compared to the noise of 2
sheets that rub against each other, due to the fibrin that rubs, and does not
change under coughing.