Auscultation is the part of the clinical examination which is to listen with a stethoscope (mediate auscultation), or simply in the ear, noises produced by different organs of human body, including those issued by the heart, the lungs and bronchi, the intestines, the carotid arteries and the arteries femoral. This method of medical diagnosis has been developed by René Laennec in 1816.
It is a mistake to characterize auscultation a clinical examination that do not appeal to the hearing.
Preferably made on the posterior chest, can also be done earlier. It looks for the presence of normal lung sounds and adventitious sounds (abnormal). The main noise is normal lung breath sounds. It reflects the entry of air into the lungs is decreased in several pulmonary conditions.
- Breath sounds throughout the chest
- Anterior chest: bilaterally in the 2nd intercostal space near the body of the sternum
- Posterior chest: bilaterally on the 2nd, 3rd, 4th intercostal spaces near the junction of the ribs (head, neck) to the backbone
- Tracheobronchial noise level of the sternum
- Noise level of the trachea
- Rhonchi or wheezing or snoring sound
- Tone bass frequencies below 200Hz.
- Emphasis on expiry.
- Noise resembling what one hears when you blow into the neck of a bottle and snoring.
- It may disappear if the person produces an effective cough, or if secretions were aspirated.
Wheeze (audible stethoscope only)
- Have a pitched around 400Hz
- Emphasis on expiry
- Noise that looks like that means that when you deflate a balloon which pinch the hole.
- Sounds sweet, high tone, very brief.
- Audibles especially at the end of inspiration.
- They do not disappear when the person coughs. We can compare the sound of a lock of hair when it is rolled between his fingers.
- Sounds strong, low tone, longer.
- Audibles especially during inspiration and early expiration.
- They can decline if the person coughs, if it changes its position or following a bronchial aspiration.
- They can be compared to a wood fire crackling or corn that explodes. They also resemble the gargoyles.
- Noise very superficial, which resembles the crackling.
- It happens at the end of expiration.
- You can compare the noise made by two pieces of leather rubbing against each other.
- It is especially audible around the left anterior axillary line or lines.