When performing auscultation, you need to be able to characterize four properties of a heart sound:
- Location, where the sound is heard in the chest
- Timing, when the sound occurs
- Grade, or intensity of the sound
- Quality. And shape of the sound
Auscultation should proceed in an orderly manner over four general areas, with the patient typically lying down. These regions should be listened to using the flat diaphragm of the stethoscope.
- The aortic region, between the second and third intercostal spaces at the right sternal border.
- The pulmonic region, between the second and third intercostal spaces at the left sternal border.
- The tricuspid region, between the third, fourth, fifth, and sixth intercostal spaces at the left sternal border.
- Mitral region, near the apex of the heart, between the fifth and sixth intercostal spaces in the midclavicular line.
Auscultation is the most important clinical technique you will ever learn for evaluating a patient’s respiratory function. When listening to the lungs try to find as quiet an environment as possible.
The patient should be in the proper position for auscultation, ideally sitting up in bed or on the examining table.
Always ensure patient comfort and cleanliness. Be sure to clean the stethoscope head with a disinfecting wipe before and after touching the patient. It is considerate to warm the diaphragm of your stethoscope with your hand before auscultation.
Your stethoscope should be touching the patient’s bare skin so that you don’t mistake the rubbing of the patient’s clothes against the stethoscope for abnormal sounds. If needed, wet the patients chest hair with warm water or gel to decrease the sounds of hair against the stethoscope.
As you are auscultating your patient, ask yourself:
- Are the breath sounds increased, normal, or decreased?
- Breath sounds are the noises produced by the lungs as the patient breathes.
- Are there any abnormal or adventitious breath sounds?
- Abnormal, adventitious sounds refers to the extra or additional sounds that might be heard in addition to normal breath sounds such as crackles or wheezes.
Auscultate using the diaphragm of your stethoscope. Ask the patient not to speak and to breath deeply through the mouth. You should listen to at least one full breath in each location. Always compare what you hear on one side of the lungs with what you hear on the corresponding opposite side.
There are 12 and 14 locations for auscultation on the anterior and posterior chest respectively. Generally you should listen to at least six locations on both the anterior and posterior chest. Begin by auscultating the apices of the lungs, moving from side to side and comparing one side to the other. If you hear a suspicious breath sound, listen to a few other nearby locations and try to delineate its extent and character.