[Footnote 1: The address in surgery delivered before the Medical
Society of the State of Pennsylvania, June 4, 1890.]
By JOHN B. ROBERTS, A.M., M.D., Professor of Surgery in the Woman's
Medical College and in the Philadelphia Polyclinic.
The revolution which has occurred in practical surgery since the
discovery of the relation of micro-organisms to the complications
occurring in wounds has caused me to select this subject for
discussion. Although many of my hearers are familiar with the germ
theory of disease, it is possible that it may interest some of them to
have put before them in a short address a few points in bacteriology
which are of value to the practical surgeon.
It must be remembered that the groups of symptoms which were formerly
classed under the heads "inflammatory fever," "symptomatic fever,"
"traumatic fever," "hectic fever," and similar terms, varying in name
with the surgeon speaking of them, or with the location of the
disease, are now known to be due to the invasion of the wound by
microscopic plants. These bacteria, after entering the blood current
at the wound, multiply with such prodigious rapidity that the whole
system gives evidence of their existence. Suppuration of wounds is
undoubtedly due to these organisms, as is tubercular disease, whether
of surgical or medical character. Tetanus, erysipelas, and many other
surgical conditions have been almost proved to be the result of
infection by similar microscopic plants, which, though acting in the
same way, have various forms and life histories.
A distinction must be made between the "yeast plants," one of which
produces thrush, and the "mould plants," the existence of which, as
parasites in the skin, gives rise to certain cutaneous diseases. These
two classes of germs are foreign to the present topic, which is
surgery; and I shall, therefore, confine my remarks to that group of
vegetable parasites to which the term bacteria has been given. These
are the micro-organisms whose actions and methods of growth
particularly concern the surgeon. The individual plants are so minute
that it takes in the neighborhood of ten or fifteen hundred of them
grouped together to cover a spot as large as a full stop or period
used in punctuating an ordinary newspaper. This rough estimate applies
to the globular and the egg-shaped bacteria, to which is given the
name "coccus" (plural, cocci). The cane or rod shaped bacteria are
rather larger plants. Fifteen hundred of these placed end to end would
reach across the head of a pin. Because of the resemblance of these
latter to a walking stick they have been termed bacillus (plural,
bacilli).
The bacteria most interesting to the surgeon belong to the cocci and
the bacilli. There are other forms which bacteriologists have dubbed
with similar descriptive names, but they are more interesting to the
physician than to the surgeon. Many micro-organisms, whether cocci,
bacilli, or of other shapes, are harmless, hence they are called
non-pathogenic, to distinguish them from the disease-producing or
pathogenic germs.
As many trees have the same shape and a similar method of growing, but
bear different fruits--in the one case edible and in the other
poisonous--so, too, bacteria may look alike to the microscopist's eye,
and grow much in the same way, but one will cause no disease, while
the other will produce perhaps tuberculosis of the lungs or brain.
Many scores of bacteria have been, by patient study, differentiated
from their fellows and given distinctive names. Their nomenclature
corresponds in classification and arrangement with the nomenclature
adopted in different departments of botany. Thus we have the
pus-causing chain coccus (streptococcus pyogenes), so-called because
it is globular in shape, because it grows with the individual plants
attached to each other, or arranged in a row like a chain of beads on
a string, and because it produces pus. In a similar way we have the
pus-causing grape coccus of a golden color (staphylococcus pyogenes
aureus). It grows with the individual plants arranged somewhat after
the manner of a bunch of grapes, and when millions of them are
collected together, the mass has a golden yellow hue. Again, we have
the bacillus tuberculosis, the rod-shaped plant which is known to
cause tuberculosis of the lungs, joints, brain, etc.
It is hardly astonishing that these fruitful sources of disease have
so long remained undetected, when their microscopic size is borne in
mind. That some of them do cause disease is indisputable, since
bacteriologists have, by their watchful and careful methods, separated
almost a single plant from its surroundings and congeners, planted it
free from all contamination, and observed it produce an infinitesimal
brood of its own kind. Animals and patients inoculated with the plants
thus cultivated have rapidly become subjects of the special disease
which the particular plant was supposed to produce.
The difficulty of such investigation becomes apparent when it is
remembered that under the microscope many of these forms of vegetable
life are identical in appearance, and it is only by observing their
growth when in a proper soil that they can be distinguished from each
other. In certain cases it is quite difficult to distinguish them by
the physical appearances produced during their growth. Then it is only
after an animal has been inoculated with them that the individual
parasite can be accurately recognized and called by name. It is known
then by the results which it is capable of producing.
The various forms of bacteria are recognized, as I have said, by their
method of growth and by their shape. Another means of recognition is
their individual peculiarity of taking certain dyes, so that special
plants can be recognized, under the microscope, by the color which a
dye gives to them, and which they refuse to give up when treated with
chemical substances which remove the stain from, or bleach, all the
other tissues which at first have been similarly stained.
The similarity between bacteria and the ordinary plants with which
florists are familiar is, indeed, remarkable. Bacteria grow in animal
and other albuminous fluids; but it is just as essential for them to
have a suitable soil as it is for the corn or wheat that the farmer
plants in his field. By altering the character of the albuminous fluid
in which the micro-organism finds its subsistence, these small plants
can be given a vigorous growth, or may be actually starved to death.
The farmer knows that it is impossible for him to grow the same crop
year after year in the same field, and he is, therefore, compelled to
rotate his crops. So it is with the microscopic plants which we are
considering.
After a time the culture fluid or soil becomes so exhausted of its
needed constituents, by the immense number of plants living in it,
that it is unfit for their life and development. Then this particular
form will no longer thrive; but some other form of bacterium may find
in it the properties required for functional activity, and may grow
vigorously. It is probable that exhaustion or absence of proper soil
is an important agent in protecting man from sickness due to infection
from bacteria. The ever-present bacteria often gain access to man's
blood through external wounds, or through the lungs and digestive
tracts; but unless a soil suited for their development is found in its
fluids, the plants will not grow. If they do not grow and increase in
numbers, they can do little harm.
Again, there are certain bacteria which are so antagonistic to each
other that it is impossible to make them grow in company, or to
co-exist in the blood of the same individual. For example, an animal
inoculated with erysipelas germs cannot be successfully inoculated
immediately afterward with the germs of malignant pustule. This
antagonism is illustrated by the impossibility of having a good crop
of grain in a field overrun with daisies.
On the other hand, however, there are some micro-organisms which
flourish luxuriantly when planted together in the same fluid, somewhat
after the manner of pumpkins and Indian corn growing between the same
fence rails. Others seem unwilling to grow alone, and only flourish
when planted along with other germs. It is very evident, therefore,
that bacteriology is a branch of botany, and that nature shows the
same tendencies in these minute plants as it does in the larger
vegetable world visible to our unaided eyes.
As the horticulturist is able to alter the character of his plants by
changing the circumstances under which they live, so can the
bacteriologist change the vital properties and activities of bacteria
by chemical and other manipulations of the culture substances in which
these organisms grow. The power of bacteria to cause pathological
changes may thus be weakened and attenuated; in other words, their
functional power for evil is taken from them by alterations in the
soil. The pathogenic, or disease producing, power may be increased by
similar, though not identical, alterations. The rapidity of their
multiplication may be accelerated, or they may be compelled to lie
dormant and inactive for a time; and, on the other hand, by exhausting
the constituents of the soil upon which they depend for life, they may
be killed.
It is a most curious fact, also, that it is possible by selecting and
cultivating only the lighter colored specimens of a certain purple
bacterium for the bacteriologist to obtain finally a plant which is
nearly white, but which has the essential characteristics of the
original purple fungus. In this we see the same power which the
florist has to alter the color of the petals of his flowers by various
methods of selective breeding.
The destruction of bacteria by means of heat and antiseptics is the
essence of modern surgery. It is, then, by preventing access of these
parasitic plants to the human organism (aseptic surgery), or the
destruction of them by chemical agents and heat (antiseptic surgery),
that we are enabled to invade by operative attack regions of the body
which a few years ago were sacred.
When the disease-producing bacteria gain access to the tissues and
blood of human and other animals by means of wounds, or through an
inflamed pulmonary or alimentary mucous membrane, they produce
pathological effects, provided there is not sufficient resistance and
health power in the animal's tissues to antagonize successfully the
deleterious influence of the invading parasitic fungus. It is the
rapid multiplication of the germs which furnishes a _continuous_
irritation that enables them to have such a disastrous effect upon the
tissues of the animal. If the tissues had only the original dose of
microbes to deal with, the warfare between health and disease would be
less uncertain in outcome. Victory would usually be on the side of the
tissues and health. The immediate cause of the pathogenic influence is
probably the chemical excretions which are given out by these
microscopic organisms. All plants and animals require a certain number
of substances to be taken into their organisms for preservation of
their vital activities. After these substances have been utilized
there occurs a sort of excretion of other chemical products. It is
probably the excretions of many millions of micro-organisms,
circulating in the blood, which give rise to the disease
characteristic of the fungus with which the animal has been infected.
The condition called sapræmia, or septic intoxication, for example, is
undoubtedly due to the entrance of the excretory products of
putrefaction bacteria into the circulation. This can be proved by
injecting into an animal a small portion of these products obtained
from cultures of germs of putrefaction. Characteristic symptoms will
at once be exhibited.
Septicæmia is a similar condition due to the presence of the
putrefactive organisms themselves, and hence of their products, or
ptomaines, also in the blood. The rapidity of their multiplication in
this albuminous soil and the great amount of excretion from these
numerous fungi make the condition more serious than sapræmia.
Clinically, the two conditions occur together.
The rapidity with which symptoms may arise after inoculation of small
wounds with a very few germs will be apparent, when it is stated that
one parasitic plant of this kind may, by its rapidity of
multiplication, give rise to fifteen or sixteen million individuals
within twenty-four hours. The enormous increase which takes place
within three or four days is almost incalculable. It has been
estimated that a certain bacillus, only about one thousandth of an
inch in length, could, under favorable conditions, develop a brood of
progeny in less than four days which would make a mass of fungi
sufficient to fill all the oceans of the world, if they each had a
depth of one mile.
Bacteria are present everywhere. They exist in the water, earth, air,
and within our respiratory and digestive tracts. Our skin is covered
with millions of them, as is every article about us. They can
circulate in the lymph and blood and reach every tissue and part of
our organisms by passing through the walls of the capillaries.
Fortunately, they require certain conditions of temperature, moisture,
air, and organic food for existence and for the preservation of their
vital activities.
If the surroundings are too hot, too cold, or too dry, or if they are
not supplied with a proper quantity and quality of food, the bacterium
becomes inactive until the surrounding circumstances change; or it may
die absolutely. The spores, which finally become full-fledged
bacteria, are able to stand a more unfavorable environment than the
adult bacteria. Many spores and adults, however, perish. Each kind of
bacterium requires its own special environment to permit it to grow
and flourish. The frequency with which an unfavorable combination of
circumstances occurs limits greatly the disease-producing power of the
pathogenic bacteria.
Many bacteria, moreover, are harmless and do not produce disease, even
when present in the blood and tissues. Besides this, the white blood
cells are perpetually waging war against the bacteria in our bodies.
They take the bacteria into their interiors and render them harmless
by eating them up, so to speak. They crowd together and form a wall of
white blood cells around the place where the bacteria enter the
tissue, thus forming a barrier to cut off the blood supply to the
germs and, perhaps, to prevent them from entering the general blood
current.
The war between the white blood cells and the bacteria is a bitter
one. Many bacteria are killed; but, on the other hand, the life of
many blood cells is sacrificed by the bacteria poisoning them with
ptomaines. The tissue cells, if healthy, offer great resistance to the
attacks of the army of bacteria. Hence, if the white cells are
vigorous and abundant at the site of the battle, defeat may come to
the bacteria; and the patient suffer nothing from the attempt of these
vegetable parasites to harm him. If, on the other hand, the tissues
have a low resistive power, because of general debility of the
patient, or of a local debility of the tissues themselves, and the
white cells be weak and not abundant, the bacteria will gain the
victory, get access to the general blood current, and invade every
portion of the organism. Thus, a general or a local disease will be
caused; varying with the species of bacteria with which the patient
has been affected, and the degree of resistance on the part of the
tissues.
From what has been stated it must be evident that the bacterial origin
of disease depends upon the presence of a disease-producing fungus and
a diminution of the normal healthy tissue resistance to bacterial
invasion. If there is no fungus present, the disease caused by such
fungus cannot develop. If the fungus be present and the normal or
healthy tissue resistance be undiminished, it is probable that disease
will not occur. As soon, however, as overwork, injury of a mechanical
kind, or any other cause diminishes the local or general resistance of
the tissues and individual, the bacteria get the upper hand, and are
liable to produce their malign effect.
Many conditions favor the bacterial attack. The patient's tissues may
have an inherited peculiarity, which renders it easy for the bacteria
to find a good soil for development; an old injury or inflammation may
render the tissues less resistant than usual; the point, at which
inoculation has occurred may have certain anatomical peculiarities
which make it a good place in which bacteria may multiply; the blood
may have undergone certain chemical changes which render it better
soil than usual for the rapid growth of these parasitic plants.
The number of bacteria originally present makes a difference also. It
is readily understood that the tissues and white blood cells would
find it more difficult to repel the invasion of an army of a million
microbes than the attack of a squad of ten similar fungi. I have said
that the experimenter can weaken and augment the virulence of bacteria
by manipulating their surroundings in the laboratory. It is probable
that such a change occurs in nature. If so, some bacteria are more
virulent than others of the same species; some less virulent. A few of
the less virulent disposition would be more readily killed by the
white cells and tissues than would a larger number of the more
virulent ones. At other times the danger from microbic infection is
greater because there are two species introduced at the same time; and
these two multiply more vigorously when together than when separated.
There are, in fact, two allied hosts trying to destroy the blood cells
and tissues. This occurs when the bacteria of putrefaction and the
bacteria of suppuration are introduced into the tissues at the same
time. The former cause sapræmia and septicæmia, the latter cause
suppuration. The bacteria of tuberculosis are said to act more
viciously if accompanied by the bacteria of putrefaction.
Osteomyelitis is of greater severity, it is believed, if due to a
mixed infection with both the white and golden grape-coccus of
suppuration.
I have previously mentioned that the bacteria of malignant pustule are
powerless to do harm when the germs of erysipelas are present in the
tissues and blood. This is an example of the way in which one species
of bacteria may actually aid the white cells, or leucocytes, and the
tissues in repelling an invasion of disease-producing microbes.
Having occupied a portion of the time allotted to me in giving a crude
and hurried account of the characteristics of bacteria, let me
conclude my address by discussing the relation of bacteria to the
diseases most frequently met with by the surgeon.
Mechanical irritations produce a very temporary and slight
inflammation, which rapidly subsides, because of the tendency of
nature to restore the parts to health. Severe injuries, therefore,
will soon become healed and cured if no germs enter the wound.
Suppuration of operative and accidental wounds was, until recently,
supposed to be essential. We now know, however, that wounds will not
suppurate if kept perfectly free from one of the dozen forms of
bacteria that are known to give rise to the formation of pus.
The doctrine of present surgical pathology is that suppuration will
not take place if pus-forming bacteria are kept out of the wound,
which will heal by first intention without inflammation and without
inflammatory fever.
In making this statement I am not unaware that there is a certain
amount of fever following various severe wounds within twenty-four
hours, even when no suppuration occurs. This wound fever, however, is
transitory; not high; and entirely different from the prolonged
condition of high temperature formerly observed nearly always after
operations and injuries. The occurrence of this "inflammatory,"
"traumatic," "surgical," or "symptomatic" fever, as it was formerly
called, means that the patient has been subjected to the poisonous
influence of putrefactive germs, the germs of suppuration, or both.
We now know why it is that certain cases of suppuration are not
circumscribed but diffuse, so that the pus dissects up the fascias and
muscles and destroys with great rapidity the cellular tissue. This
form of suppuration is due to a particular form of bacterium called
the pus-causing "chain coccus." Circumscribed abscesses, however, are
due to one or more of the other pus-causing micro-organisms.
How much more intelligent is this explanation than the old one that
diffuse abscesses depended upon some curious characteristic of the
patient. It is a satisfaction to know that the two forms of abscess
differ because they are the result of inoculation with different
germs. It is practically a fact that wherever there is found a diffuse
abscess there will be discovered the streptococcus pyogenes, which is
the name of the chain coccus above mentioned.
So, also, is it easy now to understand the formation of what the old
surgeons called "cold" abscesses, and to account for the difference in
appearance of its puriform secretion from the pus of acute abscesses.
Careful search in the fluid coming from such "cold" abscesses reveals
the presence of the bacillus of tuberculosis, and proves that a "cold"
abscess is not a true abscess, but a lesion of local tuberculosis.
Easy is it now to understand the similarity between the "cold abscess"
of the cervical region and the "cold abscess" of the lung in a
phthisical patient. Both of them are, in fact, simply the result of
invasion of the tissues with the ubiquitous tubercle bacillus; and are
not due to pus-forming bacteria.
Formerly it was common to speak of the scrofulous diathesis, and
attempts were made to describe the characteristic appearance of the
skin and hair pertaining to persons supposed to be of scrofulous
tendencies. The attempt was unsuccessful and unsatisfactory. The
reason is now clear, because it is known that the brunette or the
blond, the old or the young, may become infected with the tubercle
bacillus. Since the condition depends upon whether one or the other
become infected with the generally present bacillus of tubercle, it is
evident that there can be no distinctive diathesis. It is more than
probable, moreover, that the cutaneous disease so long described as
lupus vulgaris is simply a tubercular ulcer of the skin, and not a
special disease of unknown causation.
The metastatic abscesses of pyæmia are clearly explained when the
surgeon remembers that they are simply due to a softened blood clot
containing pus-causing germs being carried through the circulation and
lodged in some of the small capillaries.
A patient suffering with numerous boils upon his skin has often been a
puzzle to his physician, who has in vain attempted to find some cause
for the trouble in the general health alone. Had he known that every
boil owed its origin to pus bacteria, which had infected a sweat gland
or hair follicle, the treatment would probably have been more
efficacious. The suppuration is due to pus germs either lodged upon
the surface of the skin from the exterior or deposited from the
current of blood in which they have been carried to the spot.
I have not taken time to go into a discussion of the methods by which
the relationship of micro-organisms to surgical affections has been
established; but the absolute necessity for every surgeon to be fully
alive to the inestimable value of aseptic and antiseptic surgery has
led me to make the foregoing statements as a sort of _résumé_ of the
relation of the germ theory of disease to surgical practice. It is
clearly the duty of every man who attempts to practice surgery to
prevent, by every means in his power, the access of germs, whether of
suppuration, putrefaction, erysipelas, tubercle, tetanus, or any other
disease, to the wounds of a patient. This, as we all know, can be done
by absolute bacteriological cleanliness. It is best, however, not to
rely solely upon absolute cleanliness, which is almost unattainable,
but to secure further protection by the use of heat and antiseptic
solutions. I am fully of the opinion that chemical antiseptics would
be needless if absolute freedom from germs was easily obtained. When I
know that even such an enthusiast as I myself is continually liable to
forget or neglect some step in this direction, I feel that the
additional security of chemical antisepsis is of great value. It is
difficult to convince the majority of physicians, and even ourselves,
that to touch a finger to a door knob, to an assistant's clothing, or
to one's own body, may vitiate the entire operation by introducing one
or two microbic germs into the wound.
An illustration of how carefully the various steps of an operation
should be guarded is afforded by the appended rules, which I have
adopted at the Woman's Hospital of Philadelphia for the guidance of
the assistants and nurses. If such rules were taught every medical
student and every physician entering practice as earnestly as the
paragraphs of the catechism are taught the Sunday school pupil (and
they certainly ought to be so taught) the occurrence of suppuration,
hectic fever, septicæmia, pyæmia, and surgical erysipelas would be
practically unknown. Death, then, would seldom occur after surgical
operations, except from hemorrhage, shock, or exhaustion.
I have taken the liberty of bringing here a number of culture tubes
containing beautiful specimens of some of the more common and
interesting bacteria. The slimy masses seen on the surfaces of jelly
contained in the tubes are many millions of individual plants, which
have aggregated themselves in various forms as they have been
developed as the progeny of the few parent cells planted in the jelly
as a nutrient medium or soil.
With this feeble plea, Mr. President and members of the Society, I
hope to create a realization of the necessity for knowledge and
interest in the direction of bacteriology; for this is the foundation
of modern surgery. There is, unfortunately, a good deal of abominable
work done under the names of antiseptic and aseptic surgery, because
the simplest facts of bacteriology are not known to the operator.
_Rules to be observed in Operations at Dr. Roberts' Clinic at the
Woman's Hospital of Philadelphia._--After wounds or operations high
temperature usually, and suppuration always, is due to blood
poisoning, which is caused by infection with vegetable parasites
called bacteria.
These parasites ordinarily gain access to the wound from the skin of
the patient, the finger nails or hands of the operator or his
assistants, the ligatures, sutures, or dressings.
Suppuration and high temperature should not occur after operation
wounds if no suppuration has existed previously.
Bacteria exist almost everywhere as invisible particles in the dust;
hence, everything that touches or comes into even momentary contact
with the wound must be germ-free--technically called "sterile."
A sterilized condition of the operator, the assistant, the wound,
instruments, etc., is obtained by removing all bacteria by means of
absolute surgical cleanliness (asepsis), and by the use of those
chemical agents which destroy the bacteria not removed by cleanliness
itself (antisepsis).
Surgical cleanliness differs from the housewife's idea of cleanliness
in that its details seem frivolous, because it aims at the removal of
microscopic particles. Stains, such as housewives abhor, if germ-free,
are not objected to in surgery.
The hands and arms, and especially the finger nails, of the surgeon,
assistants, and nurses should be well scrubbed with hot water and
soap, by means of a nail brush, immediately before the operation. The
patient's body about the site of the proposed operation should be
similarly scrubbed with a brush and cleanly shaved. Subsequently the
hands of the operator, assistants, and nurses, and the field of
operation should be immersed in, or thoroughly washed with, corrosive
sublimate solution (1:1,000 or 1:2,000). Finger rings, bracelets,
bangles, and cuffs worn by the surgeon, assistants, or nurses must be
removed before the cleansing is begun; and the clothing covered by a
clean white apron, large enough to extend from neck to ankles and
provided with sleeves.
The instruments should be similarly scrubbed with hot water and soap,
and all particles of blood and pus from any previous operation removed
from the joints. After this they should be immersed for at least
fifteen minutes in a solution of beta-naphthol (1:2,500), which must
be sufficiently deep to cover every portion of the instruments. After
cleansing the instruments with soap and water, baking in a temperature
a little above the boiling point of water is the best sterilizer.
During the operation the sterilized instruments should be kept in a
beta-naphthol solution and returned to it when the operator is not
using them.
[The antiseptic solutions mentioned here are too irritating for use in
operations within the abdomen and pelvis. Water made sterile by
boiling is usually the best agent for irrigating these cavities, and
for use on instruments and sponges. The instruments and sponges must
be previously well sterilized.]
Sponges should be kept in a beta-naphthol or a corrosive sublimate
solution during the operation. After the blood from the wound has been
sponged away, they should be put in another basin containing the
antiseptic solution, and cleansed anew before being used again. The
antiseptic sutures and ligatures should be similarly soaked in
beta-naphthol solution during the progress of the operation.
No one should touch the wound but the operator and his first
assistant. No one should touch the sponges but the operator, his first
assistant, and the nurse having charge of them. No one should touch
the already prepared ligatures or instruments except the surgeon and
his first or second assistants.
None but those assigned to the work are expected to handle
instruments, sponges, dressings, etc., during the operation.
When any one taking part in the operation touches an object not
sterilized, such as a table, a tray, or the ether towel, he should not
be allowed to touch the instruments, the dressings, or the ligatures
until his hands have been again sterilized. It is important that the
hands of the surgeon, his assistants, and nurses should not touch any
part of his own body, nor of the patient's body, except at the
sterilized seat of operation, because infection may be carried to the
wound. Rubbing the head or beard or wiping the nose requires immediate
disinfection of the hands to be practiced.
The trailing ends of ligatures and sutures should never be allowed to
touch the surgeon's clothing or to drag upon the operating table,
because such contact may occasionally, though not always, pick up
bacteria which may cause suppuration in the wound.
Instruments which fall upon the floor should not be again used until
thoroughly disinfected.
The clothing of the patient, in the vicinity of the part to be
operated upon, and the blanket and sheets used there to keep him warm,
should be covered with dry sublimate towels. All dressings should be
kept safe from infection by being stored in glass jars, or wrapped in
dry sublimate towels.
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