Respiratory sounds, breath sounds, or lung sounds refer to the specific sounds generated by the movement of air through the respiratory system. These may be easily audible or identified through auscultation of the respiratory system through the lung fields with a stethoscope.
Knowing how to auscultate a thorax is an art, a fundamental practice, for
the physician in general, either a specialist in basic care, or an hospital
doctor or a pulmonologist. In fact an adequate therapy is prescribed to the patient with
a respiratory
and / or cardiac diseases by auscultation of respiratory sounds. In fact, dyspnoea, which we have investigated in our
online medical pages, is not always a symptom of a respiratory problem, since it
can be correlated with cardiac pathologies, in particular related to congestive
heart failure, and to valvular pathologies.
The physiological vesicular murmur is the
sound heard on the whole healthy lung; in the lower parts, however,
it is particularly highlighted for its purity. If it is reduced or abolished we
must think that the lung is not well ventilated.
Breath sounds can be normal or abnormal.
Abnormal breath sounds
can indicate a lung problem, such as:
- obstruction
- inflammation
- infection
- fluid in the lungs
- asthma
A normal breath sound is similar to the sound of air. However, abnormal breath
sounds may include:
- rhonchi (a low-pitched breath sound)
- crackles (a high-pitched breath sound)
-
wheezing (a high-pitched whistling sound caused by narrowing of the bronchial
tubes)
-
stridor (a harsh, vibratory sound caused by narrowing of the upper airway)
example of wet noise large bubbles, it is a patient with mucopurulent catarrh:
example of dry sounds, it is a chronic asthmatic bronchitic patient
The bibasilar crackles are caused by excess fluid in the lungs.
Many conditions may generated crackles such as: pneumonia, bronchitis and
pulmonary edema.
Pneumonia is an infection in your lungs. The infection causes air sacs in
your lungs to become pus-filled and inflamed. This causes a cough, difficulty
breathing, and crackles. Bronchitis occurs when your bronchial tubes
become inflamed. These tubes carry air to your lungs. The symptoms may include
bibasilar crackles, a severe cough which brings up mucus, and wheezing. Viruses,
such as the cold or flu, or lung irritants usually may cause acute bronchitis.
Chronic bronchitis occurs when bronchitis doesn't go away.
Pulmonary edema may cause crackling sounds in lungs. This condition may occur into congestive heart failure (CHF). CHF occurs when the heart cannot pump blood effectively and fluids collect in the air sacs in the lungs.
During the inhalation a deep and intense noise is heard, while during the
exhalation in most cases the noise is almost not perceptible. It has a frequency
of about 150 Hz, however partial vibrations are still demonstrable up to 600 Hz.
The accessory noises, however, are those that come from the bronchial system and
generally auscultate in respiratory diseases:
From the bronchi they generate the rales, distinct in buckets and wet rales;
still there are the non-consonant bollards and the sound rales.
Sounds or consonants can be found where there is infiltrated pulmonary tissue
and therefore the conduction of vibrations is favored on the chest wall;
consonants instead where the pulmonary tissue is not infiltrated.
The rales, expression of the mucus or bronchial catarrh, as in chronic
bronchitis can be:
- small bubbles
- medium bubbles
- large bubbles
Dry rales, ie snoring, sibilant and mixed ronchi (snoring, sibilant and groin)
are an expression of bronchostenosis, present for example in chronic asthmatic
bronchitis and / or pure bronchial asthma.
Chest X-ray: on the right, the lung has a thickening
and pleural effusion, so the respiratory space is at
the apex. In this patient in MV, it is abolished on the
right
Chest X-ray: lung with "boot" heart, cottony
aspect and multiple thickenings some sign of congestion
of the small circle: in this patient we can appreciate
widespread crackles and reduction of MV with poor
ventilation in the lung
From the pleura the rubbings, perceived as sounds of screeching, of rasp.
Now, if the noises are humid, a fluidifying and / or cortisone therapy may be
indicated, to blast the bronchi; if, however, the noises are dry, a therapy with
bronchodilator is indicated, for example the theophylline and beta 2 stimulants.
recordings of thoracic sounds