‘
‘Je
l’ai entendu désigner sous divers noms, tous impropres et quelquefois
barbares … . Je lui ai donné, en conséquence, le nom de stéthoscope, qui
me paraît exprimer le mieux son principal usage.’ Thus Laennec in his book,
Traité de l’auscultation médiate, of 1819
1
named his invention, the instrument that came to symbolize his very
profession and that illuminated the path to an understanding of the
outward signs of disease in pathological terms.
As a medical student in the 1950s, I was confused by the terms used to describe the sounds heard through the stethoscope,
râle and
rhonchus,
which meant little in English and seemed in their original languages to
mean the same thing, a rattle. Yet, they were used apparently to denote
different sounds. It was therefore my good fortune to become a student
of Dr John Robertson in Liverpool who referred me back to the original
text and showed me a copy of his paper with Robert Coope in the Lancet,
Rales, rhonchi and Laënnec.2
It is still well worth reading. My interest in Laënnec and the origins
of clinical examination was fired, and on graduating in 1962 I bought
myself a copy of his most recent biography
3 and hitch-hiked down to Brittany to visit his birthplace in Quimper and his grave near Douarnenez.
René-Théophile-Hyacinthe
Laënnec, named for his grandfather, father and god-mother, did not have
an easy life. Born in 1781, he lost his mother 5 years later and his
father proved to be a feckless if intelligent and charming lawyer who
managed repeatedly to lose all his money. However, Théophile did have
two pieces of good fortune, first being sent to live with his uncle
Guillaume, a physician and a constant support in his endeavours and,
second, being possessed of an intelligence not short of genius. He
played the flute, sang Breton songs and became a scholar of Celtic
tongues and a devoted farmer, but these were secondary to his career in
medicine, relaxations and ways of coping with his chronic ill-health,
asthma, gout and tuberculosis; the last of these eventually killed him
at the age of 46 years. He survived the awfulness of the Revolution and
the terror of 1793 in Nantes. His apprenticeship to his uncle started as
an army surgeon third class at the age of 15 years. With five years of
military surgery behind him, he made his way to Paris in 1801 to enrol
in medical school where he quickly distinguished himself and started
publishing original observations. He does, however, seem to have
attracted the opposition and perhaps enmity of several of his seniors,
notably Dupuytren, and was repeatedly passed over for senior
appointments – it is possible that his brilliance attracted some
jealousy. His financial survival depended on his ability to attract
wealthy patients but his academic work required a hospital base. He
achieved a position first at La Salpêtrière (where he was heavily involved in the care of soldiers returning from the Russian campaign) and then, in 1816, the Hôpital Necker.
It was here that he finally established his international reputation.
He records that in 1816 he was consulted by a plump young woman with
symptoms of heart disease in whom it seemed indelicate and difficult to
listen to the precordium by direct application of the ear, a method
occasionally used though little commented upon at the time. His mind was
prepared, as an advocate of Hippocratic medicine and of the recently
rediscovered studies of Auenbrugger on percussion, and he wrote: ‘ … je
vins à me rappeler un phénomène d’acoustique fort connu: si l’on
applique l’oreille à l’extrémité d’une poutre, on entend très
distinctement un coup d’épingle donnè à l’autre bout.’ Being thus
aware of the acoustic properties of solid material, in this case in
conducting the sound of a pin scratch along a wooden beam, he used as a
substitute readily to hand a tightly rolled bunch of papers and was
convinced that this made the heart sounds more readily audible.
This
single observation led Laënnec to a series of studies both of the
properties of different materials and shapes of device in conducting
sound and also of the pathological correlates of the sounds he heard in
his patients’ chests and hearts. In this he differed from all his
predecessors, relying on combining meticulous clinical and post mortem
observations of patients with lung disease. He made the first
stethoscopes himself, being (inevitably) a skilled wood turner, and the
first editions of his book came with a stethoscope for an additional 3
francs. The publication made an instant impact and within a few years
distinguished physicians from all of Europe and indeed America came to
study under him in his final hospital appointment at La Charité.
His work was translated into English by Forbes, though subsequent
commentaries led to some confusion as to the use of his terminology. In
fact, Laënnec had been quite clear about râles and rhonchi, only using the former term in his book to describe the various added sounds heard in the lung; in his own words: ‘Je
crois devoir engager les médecins qui se livreront à l’auscultation Ã
ne jamais prononcer devant les malades et les personnes étrangères à la
médecine les noms des signes stéthoscopiques. Cela n’est jamais
nécessaire; et déjà je me suis aperçu que la valeur de certains signes
graves était connue de quelques malades, dont les médecins avaient parlé
devant eux avec trop peu de prudence. Par cette même raison, je
substitue habituellement au nom de râle celui de rhonchus, qui n’effraie
person, si par inadvertance on vient à le prononcer.’ Thus he was
clear that the two words were synonymous and that the Latin (a language
in which he commonly lectured) provided a less frightening substitute
for the French with its connotations of the death rattle when speaking
in front of his patients. It is unfortunate that this was misunderstood
in 1876 by Latham, who taught that râle meant a moist sound and rhonchus a dry sound or wheeze. This aberrant usage persisted and confused students until the 1970s.
Laënnec’s
teaching, in spite of misunderstanding and some downright opposition,
formed the basis of pulmonary and, to a somewhat lesser extent, cardiac
diagnosis until the introduction of radiology and the increased
understanding of cardiac physiology in the early 20th century. The
stethoscope was modified as a bi-aural instrument, helping to exclude
extraneous noise,
4
and the use of rubber then plastic tubes substituted, but the sounds we
hear are those described by Laënnec. He was aware of the different
sound frequencies and that different configurations of stethoscope
allowed better conduction of higher and lower frequencies, and this was
incorporated in the use of bell and diaphragm from the mid-20th century.
Laënnec was not of course completely correct in all his suggestions as
to the genesis of the sounds, searching as he was for anatomical
correlates. Only in the late 1960s did the innovative work of Nath,
Capel and Forgacs explain the origin of breath sounds and crackles in
physical and physiological terms
5 (and for discussion of this, see Ref.
6).
But, these modifications aside, what matters is the connection the
instrument makes between the patient and the brain of the listener.
The
retired doctor, chancing inadvertently or from ennui on Holby City or
Casualty on television, or waiting patiently to be seen in the Out
Patient department of his local hospital, will have noticed the
principal use of the stethoscope nowadays seems to be to denote the
trade of the individual who hangs it round his or her neck. Occasionally
we see it removed and applied briefly to the upper chest under the
shirt prior to its owner issuing reassurance or a worried look. Even I
have been examined in this cursory manner. In many cases, it appears
that the mystique of the stethoscope has hypnotised some doctors into
using its application as a substitute for a careful examination
involving observation, palpation, percussion and auscultation as urged
by Laënnec and his followers. Observations of candidates for the MRCP
over several decades has suggested to me that skill in clinical
examination among UK graduates has deteriorated, perhaps a consequence
of over-reliance on more sophisticated methods of examination. This has
coincided with the sad decline of the post mortem examination as a vital component of teaching and as a final audit on our care of our patients.
One
of Laënnec’s pupils, Charles Williams, described him thus: ‘His great
talents are known to the public through the medium of his writings; but
those who attended his
clinique can only appreciate the
wonderful acuteness of his perception, and faculty for observation, that
enabled him to carry his discovery to the degree of perfection in which
he left it; and they above all witnessed, felt, and profited by the
solicitous interest which he showed to make others partake of its
inestimable advantages. They felt in his death the loss of a friend.’
7
Laënnec was the man who taught us to think about what is going on
inside a patient’s chest. Are we forgetting what he taught? Alas, poor
Laënnec!
- ©
The Author 2010. Published by Oxford University Press on behalf of the
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