History - Pulmonary Exam - Physical Diagnosis Skills - University of Washington School of Medicine

In the late 18th century, physicians began to diagnose patients by listening to the sounds of the body in addition to obtaining subjective history from the patient. Physical examination at this time developed with a strong scientific basis. In 1791 the Italian, Morgagni, published "On the Sites and Origins of Disease," which was widely read. Pathology subsequently was considered a discipline underlying clinical diagnosis. (Warren)

The inventor of percussion was Dr. Leopold Auenbrugger of Austria, who got the idea for examining his patients after observing a wine merchant percussing out a half-full barrel. He used all four fingers striking the chest wall directly to percuss with one hand. At that time patients were examined through clothing. (Warren)

He described the technique of percussion:

"I here present the reader with a new sign, which I have discovered for detecting diseases of the chest. This consists in percussion of the human thorax, whereby according to the character of the particular sounds thence elicited, an opinion is formed of the internal state of the cavity."

By the onset of the 19th century, physicians in Paris, including Napoleon's physician, Corvisart, combined percussion with the knowledge of anatomy to diagnose chest disorders. They also began listening to the chest with "immediate auscultation" by applying the ear directly to the skin.

In 1816 Laennec examined a woman with a new device he created to listen to her chest, since she could not otherwise be carefully examined due to her gender and age. He rolled a "quire of paper into a sort of cylinder" and applied one end to the patient's chest and listened at the other end. Laennec reported that acoustics were the basis for this experiment, as he had previously learned that tapping a pin at one end of the beam could be heard at the other. This technique was described as mediate auscultation. Subsequently, Laennec modified his instrument and developed a cylinder made of hollow wood for auscultation that he called a "stethoscope" (Greek stethos for "breast" and skopein "to view".)

To communicate about the sounds heard through the stethoscope, Laennec initially used the French term rales for any abnormal adventitious sound, including "the death rattle" so often heard in his patients with terminal pulmonary tuberculosis. Later he used the term rhonchus, (Latin word that originated from a Greek word meaning "snoring"). Translations to English led to separate definitions for these terms. Interestingly, Hippocrates is credited with originally using the term rales for a specific lung sound, which he compared to the sound of boiling vinegar (Sapira).

Within ten years of Laennec's discovery, records of ausculatory and percussion findings were commonly recorded in patient notes in some teaching hospitals. References to Laennec were made in journals, including The Lancet in 1823, its first year.

Author note: Why don't we detect sounds to the extent achieved by the great physical diagnosticians? Perhaps there are several reasons, including:

Patient evaluation earlier in the course of disease, when physical signs may be subtle.
Less time for detailed physical examination.
Our ears may be untrained:
- We rely on other diagnostic tests such as chest x-ray in the initial evaluation.
- Many clinicians may not have a strong musical ear, which helps the examiner to detect differences in pitch and tone. (At one time it was suggested that physicians have education in music in order to better appreciate the various sounds of the chest and heart!)