My love of music first led me to develop my ear. From the very womb, I admired the refined technique (although some squares may call it otherwise) of the great James Marshall Hendrix. Years later, on a Colorado evening with friends, I thumped the sides of a keg we were nursing, to check its levels. Little did I know, I was beginning to hone an ancient skill that would help me in my profession.
An 80-year-old retired man was plagued with recurrent right pleural effusions of undetermined etiology. He was admitted to our service after suffering an iatrogenic pneumothorax at the ever-infamous (still curiously operating) Outside Hospital. It was day three. On exam, the right upper back was tympanic to percussion, the right lung base was dull, and both had decreased breath sounds. My findings were stable save one novel discovery: percussive dullness in the posterior mid-lung. Anticlus revealed!
I closed my eyes to envision the Argives hidden within—pneumothorax at the apex, effusion at the base, and consolidation in the superior segment of the lower lobe. A chest X-ray confirmed my exam (see below), which was the first indication that our patient was failing to improve. Thus a simple technique, applied clinically for at least the last 250 years, remains an enlightening component of the physical exam.
Josef Leopold Auenbrugger (1722–1809), the Austrian son of an innkeeper, is credited with describing the clinical art of percussion. Himself a composer, Auenbrugger was a kind and humble man, described in a 1962 article by Smith as “available to all, rich and poor alike, showing a special devotion to the poor.” The story goes that Auenbrugger learned to percuss by observing his father thump the sides of beer barrels to estimate their Dionysian bounty.
While Giovanni Morgagni was focused on correlating postmortem anatomic pathology with clinical history, Auenbrugger had the sagacity to pursue physical examination as a prospective diagnostic technique. After seven years of experimentation, on New Year's Eve of 1760 Auenbrugger published his findings, fully anticipating a good professional flogging. “It has always been the fate of those who have illustrated or improved the arts and sciences by their discoveries, to be beset by envy, malice, hatred, detraction and calumny,” he wrote in his book, referred to in short as “Inventum Novum.” This 95-page opus describes his techniques and findings.
Auenbrugger wrote that “the thorax ought to be struck, slowly and gently, with the points of the fingers, brought closely together and at the same time extended.” Thus his method is “immediate percussion,” wherein the fingers strike the chest directly. He advises us to use a hand gloved in unpolished leather, as “if the naked chest is struck by the naked hand, the contact of the polished surfaces...obscures the natural character of the sound,” which, he says, “resembles the stifled sound of a drum covered with a thick woolen cloth.”
He goes on to describe the morbid sounds of the chest, exempli gratia, “if [the chest] yields only a sound like that of a fleshy limb when struck, disease exists in that region.”
As Auenbrugger presaged, the medical community could not hear what it did not understand, perhaps in part due to adumbration by Morgagni's great “De Sedibus,” which appeared the same year (1761) and made anatomicopathologic correlation inchoate.
One of Auenbrugger's colleagues, Maximilian Stoll, taught the “Inventum” to his student Josef Eyerel, who wrote a paper about the art. Percussion was nearly lost to oblivion until Jean Nicolas Corvisart (1755-1821), whose clinical prowess earned him the role of Napoleon Bonaparte's physician, discovered the article. After 20 years of practice, he published his own observations in 1808 alongside a translation of “Inventum Novum” from Latin to French.
Corvisart's motto for the translation was “resonuere cavae cavernae” (the hollow cavities resounded). This he took from the Aeneid, wherein, at the siege of Troy, Laocoön hurls his spear into the Trojan Horse's chest with the aforementioned effect. Later in the Aeneid, Entellus and Aeneus go fisticuffs and, so writes Dante's escort, “pectore vastos dant sonitus” (“from their chests the blows resound aloud”).
In the Odyssey, Helen of Troy thrice circled the great wooden perissodactyl, thumping its sides searching for the men she suspected were lurking therein. One of Odysseus' men, Anticlus, nearly revealed himself during the investigation. If Virgil knew the principles of percussion (as the good and thorough doctor Buck explicated in the New England Journal of Medicine in 1933), I argue that he had them from Homer. Had Helen known Auenbrugger's methods, or had Laocoön's spear but struck dull rather than resonant, “No Man's” odyssey might have been truncated. But I digress.
Corvisart entrusted Auenbrugger's technique to the great René Laënnec (1781-1826). A spartan among physicians (and a fellow musician), Laënnec was renowned for the inexhaustible enthusiasm that defined his tragically short life. His greatest contribution to mankind, and modern emblem of our profession, was the stethoscope.
On the contrivance of this, according to R.H. Major's “A History of Medicine,” Laënnec's friend Kergerade tells us, “one day walking in the court of the Louvre, [Laënnec] saw some children, who, with their ears glued to the two ends of some long pieces of wood which transmitted the sound of the little blows of the pins, struck at the opposite end ... He conceived instantly the thought of applying this to the study of diseases of the heart. On the morrow...he took a sheet of paper, rolled it up, tied it with a string, making a central canal which he then placed on a diseased heart. This was the first stethoscope.” Laënnec went on to master auscultatory percussion. Unlike Auenbrugger's, Laënnec's book was an instant classic.
Next in the lineage of percussion was Pierre Adolphe Piorry (1794-1879), another devoted pupil of Corvisart. His own Archimedean revelation came by a somewhat less romantic happenstance than Laënnec's: Scratching himself, Piorry noted the sound, which he found enhanced by its performance through a coin. He thereby ungloved the “Inventum” with his novel “pleximeter.”
Known as the “medical Paganini,” Piorry became a virtuoso of mediate percussion, mapping out his patients' organs on their skin with colored crayons. He once paid a visit to the French king, whereupon he was told the monarch was absent. “Piorry then decided to percuss the closed door with his pleximeter, detected a certain dull sound and diagnosed the presence of the King in his chamber!”, according to a 1979 article by Sakula in Thorax.
English and American ingenuity (though our French colleagues might call it indelicacy) led to the use of a finger of the left hand as pleximeter, as practiced today. I first learned of the lineage through a Mayo Clinic mentor, who taught me to percuss the enlarged liver of a patient with hepatic metastases in my first year of medical school. This began my enthusiasm for the physical exam, which can divulge what the history cannot.
Imagine my dismay, in the age of technology, to find myself a physician more often in the company of machine than of man. Perhaps our propensity as internists for beard stroking has drawn us from the bedside toward excessive cogitation, or maybe the demands of documentation have outgrown their place.
What will be the mark of our generation? I fear it may not be devotion to our patients' needs, steadfast equanimity at the bedside, nor our insatiable pursuit of science; but rather the image of a physician stooped over a laptop, occasionally approaching her patients, hands in sanitary slime wringing, to clumsily bonk out a few cacophonous percussive notes upon their chests.
Auenbrugger might ask us instead to develop, with a musician's creativity and discipline, our clinical arts as earnestly as we pursue our USMLE board scores, that we who live in daily contact with the sick might be of some service beyond the multiple-choice world we're pushed toward.
I recall my youthful Colorado night, percussing out the libations of yesteryear. Auenbrugger would be tickled to know his technique had come from beerside to bedside and back. As I strive to master the “Inventum,” I share its odyssey with my patient, telling him “I'm just checking for beer,” as I percuss his chest in search of anomaly.