VESICULAR MURMUR: CHARACTERISTICS, DECREASED AND INCREASED - MEDICINE - 2024

The vesicular murmur is soft low sound is heard at the listening to the chest of a healthy person. It is produced by the passage of air through small airways in the distal regions of the bronchial tree. Although the term is currently in disuse, classical literature and authors continue to use it.

Formally described by René Laënnec, the French physician inventor of the stethoscope, it is one of the four basic breath sounds: pulmonary breath noise or vesicular murmur, bronchial breath noise, cavernous breath noise and wheezing noise and veiled breath.

Vesicular murmur is a fundamental component of pulmonary and thoracic semiology. Its description is mandatory in the physical examination of the patient, especially if the patient has any respiratory pathology.

In addition, it is considered one of the simplest clinical evaluations to carry out and whose alterations provide more information.

characteristics

Normal breath sounds can be heard throughout the chest and should be symmetrical and uniform on both sides. However, its presence and characteristics are best perceived when auscultating below the armpits and clavicles or in the interscapular space just to the sides of the dorsal spine.

On physical examination we can hear the vesicular murmur during the entire inspiration. If the patient is asked to inhale deeply and with her mouth open. its auscultation is facilitated.

In forced expiration, we can hear it during the first half of it, losing itself in the final part as the air flow decreases.

In normal breathing it is a sound of low intensity and tone, like the intermittent breeze that blows past. In forced breathing it becomes more intense and lower in tone, similar to the sound of a deep sigh or a yawn. Some authors compare it to the noise of a bellows without a valve.

Vesicular murmur decreased

Some pathologies or medical conditions can cause a decrease in the perception of vesicular murmur. This phenomenon is produced basically by two causes, as described below:

Decreased respiratory action

Any clinical picture that does not allow the passage of air to the periphery of the lung, can reduce or abolish the murmur. Among the most frequent diseases that have this behavior we have the following:

Asthma

Reduction of the caliber of the airways due to immunological alterations. It usually affects mainly the smaller bronchi or bronchioles.

The vesicular murmur is replaced or masked by wheezing and, in severe cases, by total silence on auscultation.

Emphysema

Abnormal growth with subsequent destruction of the pulmonary alveoli. It is a type of chronic obstructive pulmonary disease.

Deterioration of the terminal section of the airways reduces the passage of air through the airways and compromises normal breath sounds.

COPD

Chronic inflammation of the lungs with airway obstruction that is usually progressive and irreversible. Related to smoking or the presence of other toxins, it causes a reduction in the flow of air through the bronchi and, therefore, a decrease in vesicular murmur.

Strange bodies

Aspiration of foreign bodies from the nose or mouth can cause total or partial obstruction of the airway. Depending on the size, it can affect a main bronchus, a branch of it or distal regions of the bronchial tree.

Partial airway obstruction would be perceived on auscultation as a whistle or wheeze. Total obstruction, by not allowing the entry or exit of air, would cause auscultatory silence.

Depending on the location of the obstruction, changes in the respiratory murmur could affect an entire hemithorax or just a sector of it.

Tumors

The presence of tumor lesions that occupy the airway lumen or press it from the outside, can modify the vesicular murmur.

The characteristics of the picture would be very similar to those of the foreign body, depending on the total or partial involvement of the caliber of the bronchus.

Decrease in noise transmission

In this case, there is no compromise in the passage of air through the airway, but rather in the transmission of respiratory noise through the anatomy of the chest wall.

Semiologically it is expressed under the premise that the vesicular murmur "neither nothing nor flies", understanding that the abnormal presence of air or liquid in the pleural cavity affects the murmur.

Pleural effusion

The presence of fluid in the pleural cavity prevents the transmission of respiratory noise and makes auscultation of the respiratory murmur impossible.

The most important causes of this condition are severe pneumonia, congestive heart failure, paraneoplastic syndromes, and immune diseases.

Bulls

They are produced by the initial destruction and subsequent confluence of the pulmonary alveoli. Of similar etiology, emphysema produces the massive accumulation of air in a sector of the lung, which reduces the transmission of normal respiratory noise and, therefore, its auscultation.

Hemothorax and pneumothorax

The presence of blood or air in the pleural cavity, usually due to trauma, diminishes or extinguishes the vesicular murmur.

Increased vesicular murmur

It is much less common than decreased breath sounds. However, some pathologies -usually severe- can produce an increase in the uptake of respiratory noise. Some examples are cited below:

Lung consolidation

The consolidated lung, as a result of severe pneumonia, can better transmit breath sounds when it is patent.

The bronchi in an area of ​​consolidation look like a rigid tube due to the hardening of their walls; Paradoxically, this facilitates the passage of air and increases the uptake of the respiratory murmur.

This phenomenon is known as a tubal or bronchial murmur and is considered pathognomonic for lobar pneumonia with consolidation.

Once the condition resolves, auscultation can return to normal unless there is permanent damage to the lung parenchyma, which would make this abnormal noise a fixed finding.

Agitation

Exercising or strenuous physical activity increases the air intake to the lungs and, in turn, increases the intensity of the vesicular murmur.

Although this example is not pathological, this situation can occur due to psychomotor agitation in patients with mental illness or in early heart disease.

The type of effort made and the patient's history should be questioned to determine whether this increased respiratory murmur should be considered normal or, on the contrary, associated with a disease that warrants further studies and treatment.

References

1. Easy auscultation (2017). Vesicular Breath Sounds. Recovered from: easyauscultation.com
2. Ecured (sf). Vesicular murmur. Recovered from: ecured.cu
3. EdikaMed (nd). Vesicular murmur. Recovered from: aulaepoc.com
4. Bárány, Ernst (1937). On the origin of the vesicular he murmured. Journal of Internal medicine, volume 91, numbers 1 and 2: 115-120.
5. Empedium (sf). Breathing noises Recovered from: empendium.com
6. Ingianna Acuña, Mario and Suarez Mejido, Alvaro (1991). Pulmonary or respiratory sounds. Costa Rican Medical Act, volume 34, 3: 112-117.
7. Sarkar, Malay and collaborators (2015). Auscultation of the respiratory system. Annals of Thoracic Medicine, 10 (3): 158-168.
8. Wikipedia (last edition 2018). Respiratory sounds. Recovered from: en.wikipedia.org