certain peculiarities of both septicæmia and pyæmia, and it is
supposed to arise from the absorption of both poisons; the term pyæmia
simplex is applied to a pyæmic condition in which there is no
metastasis; while the name pyæmia multiplex is given to that form of
disease which is characterized by the existence of metastatic
abscesses. It may be well to add here that this nomenclature is not
intended to cover all cases of septic poisoning, but to be applied to
those cases only in which the morbid changes give to the terms a
certain degree of appropriateness.
Septic poisoning may be justly regarded as a single chain composed of
many links. Take, for example, a case of amputation of the thigh,
followed within a few hours by traumatic fever, later by septicæmia;
afterward there may be developed secondary fever; formation of
ichorous pus, with absorption and its concomitants; pyæmia,
accompanied by embolism, thrombosis, abscess in the lungs, liver, etc.
To these may also occasionally be added phlebitis and inflammation of
the joints, terminating speedily in suppuration. This chain may in
this case be further lengthened or varied with traumatic erysipelas or
with hospital gangrene. In fact, the variations in these cases are
very numerous, and all these conditions, together with many others,
are due to septic blood-poisoning.
ETIOLOGY OF PYÆMIA.--Four theories have been advanced at different
times to explain the etiology of pyæmia, and they have been designated
as follows: the mechanical, the nervous, the chemical, and the germ
theories respectively; and their action is based on the following
hypotheses: 1, that pus enters the blood, circulates in it, and acts
as a poison; 2, that an irritation is excited in certain visceral
organs in sympathy with inflammation of the fibrous membranes of the
cranium or the bones of the upper or lower extremity, and there is
thus produced a metastasis to these organs of an ichorous miasm or of
a fluid which is more or less acrid; 3, that a chemical poison is
generated from the pus in the wound, and when it is absorbed produces
pyæmic manifestations; 4, that the putrefaction of pus in wounds is
caused by a microscopic organism which enters the circulation and
produces pyæmia.
The first hypothesis was somewhat modified, as we have already
mentioned, by John Hunter and others, who advanced the idea that
pyæmia consisted essentially of a phlebitis, and that the pus found in
the circulation had its origin within the veins. However, it has since
been shown conclusively that pyæmia cannot be produced by the
injection of healthy pus into the cellular tissue or veins. This fact
having been generally admitted by the profession, it is thought
unnecessary to adduce here either the experiments or the arguments
which have been accepted as conclusive on this important point. It is
not even necessary to bring forward the disputed question of the
possibility of the entrance of pus into the blood, since laudable pus
does not produce pyæmia. In fact, we have reached a point in the {956}
progress of medicine when the discussion of either the first or second
hypothesis ceases to be interesting to medical men. Consequently, our
chief interest in the study of the etiology of pyæmia centres in the
third and fourth hypotheses; and we believe that it may be safely
asserted that the origin of this disease has been fully demonstrated
by an almost unlimited number of experiments.
The injection of pus into living animals produces local, remote, and
constitutional symptoms. The character of these symptoms depends
principally on the kind of pus, laudable or ichorous, the quantity
injected, and the site of the injection. It will be readily perceived
that in cases where the pus is thrown directly into a vein the local
symptoms would be unimportant, while the danger of remote
trouble--metastatic abscesses in the lungs, liver, etc.--would be very
great; but should the injection be made into the connective tissue,
then the relations would be reversed. Constitutional symptoms may
exist in both cases, but will differ in character and degree.
In regard to the character of the pus, and its agency in the
production of this disease, Billroth says: "The old view, that pyæmia
is only induced when decomposed pus (ichor) is reabsorbed, is entirely
erroneous. There are cases where decomposed, putrid pus enters the
blood, and which present a combination of the symptoms of septicæmia
and pyæmia (septo-pyæmia of Hueter)."[25] Dupuytren failed to produce
metastasis by injections of pus into the veins of dogs; these results
were confirmed by Boyer, who only obtained metastasis when he used
ichorous pus in his experiments. The same results are recorded in the
works of Günther and Sedillot, based on numerous experiments. Beck
made fourteen experiments very carefully, but did not succeed in
producing metastasis in a single case. The same results are recorded
by a commission of the Physiological Society of Edinburgh. O. Weber
has recently shown by extended experiments that carefully filtered pus
will not produce metastatic abscesses in the lungs. Therefore, it may
be considered as proved that fluid pus injected into the veins of an
animal produces no metastatic points of inflammation.
[Footnote 25: _Surgical Pathology_, p. 344.]
It should not be supposed, however, that because injection of fresh
(non-ichorous) pus failed to produce metastatic abscesses, it was
therefore without results, as the earlier experimenters thought.
Billroth and O. Weber have shown by their recent experiments that
these injections are uniformly followed by fever, and, if
subcutaneous, by abscess; and further, that injections of fresh pus
produce even a higher temperature than do those of ichorous pus; but
the pus taken from cold abscesses has apparently very slight effect.
The fresh non-ichorous dried pus was found to possess in a similar
degree the power to excite inflammation and suppuration; even the
removal of the albumen did not change its character or power. It will
be observed that these injections caused not only local inflammations,
but severe constitutional symptoms, as high temperature, etc.
Experiments have thus far completely failed to show the agent that
excites the inflammation, although it is generally admitted that it at
least exists in the molecular bodies.
Virchow and Panum have shown conclusively by their experiments on
living animals that the introduction of foreign bodies into the {957}
veins--as powdered coal, wax balls, and quicksilver--fail in all cases
to produce metastatic abscesses in the visceral organs or symptoms of
pyæmia. These foreign bodies were frequently found blocking up the
terminal branches of the pulmonary artery, in some cases encapsulated,
frequently resembling miliary tubercles, and occasionally surrounded
by evidences of slight local inflammation, but in every instance
without suppuration. The same experimenters, however, observed that
the introduction of ichorous pus and decomposing animal tissue into
the veins was attended with the formation of metastatic abscesses and
other symptoms of pyæmia. They therefore conclude that the
introduction of putrid animal substances into the veins, and the
further transport of the same to the branches of the pulmonary artery,
produce metastatic abscesses, and that the origin of these deposits is
independent of the mere stopping up of the branches of this artery.
The occlusion of the blood-vessels in this diseased condition is a
subject which has given rise to much discussion. Some of the earlier
writers supposed this phenomenon constituted the disease pyæmia, while
others believed it to be the essential cause. Roser says: "But the
thrombus is, as can be easily proved, not the cause, but only a
symptom, of pyæmia. If a surgical patient--_e.g._ one suffering with
an injury of the head--is attacked by inflammation, and occlusion of a
large vein, as of the common iliac vein, for instance, then there are
three different theories for the inflammation of the occluded
vessel--viz. Hunter's, Rokitansky's, and Virchow's. According to the
old Hunterian phlebitic theory, the coagulation of the blood should be
the result of the inflammation of the vein. On account of the
circumstances under which the coagulation of the blood in the vein has
occurred, one might suppose that the cause must be the oozing of
coagulable exudation from the inflamed wall of the vein, but
pathological dissections, especially Rokitansky's, would not accord
with it. Large veins were found plugged up without the existence of
corresponding indications of inflammation, and perfectly clear
indications were often present that occlusion had preceded the
inflammation. Consequently, the occlusion of the vein was the primary
condition, and this must be explained in some other way than by its
inflammation. Rokitansky in his theory recognized an independent
disease of the blood. Yet it does not appear, on examination of the
morbid conditions, that this theory can account for them. If it is
recognized as correct that a primary disease of the blood is to be
admitted, yet the coagulation of the blood in a large vein has not
been traced back to it. It remained wholly unexplained why a single
vein, especially one so large and strong as the common iliac, should
become the seat of the local coagulation. The necessity of finding a
local basis for the local coagulation could not be denied. For that
reason it was greeted as a highly desirable advance when Virchow
pointed out that the occlusion of such large veins could be dependent
on the coagulation of the blood in the concave spaces behind the
valves of the veins, or through the coagulation in the small
branches--_e.g._ the hypogastric veins, which is gradually carried
forward until it reaches the common iliac, and by continual increase
this vein may also be filled up. At the same time, it was demonstrated
that not infrequently, much oftener than {958} was formerly supposed,
the coagulated masses of blood are broken up and carried farther on in
the circulation, in this manner producing occlusion of the pulmonary
artery or its branches."[26]
[Footnote 26: _Archiv der Heilkunde_, Erst. Jahrg., Erst. Heft, S. 4.]
The examination of this subject finally brings Roser to this
conclusion: "Contamination of the blood is essentially the primary
cause of pyæmia; thrombosis is only a result of this morbid
contamination, and cannot, therefore, be regarded as the cause of
pyæmia, but only as an apparent part, as one of the symptoms of the
same."[27] The opinion here expressed by Roser I believe to be the one
generally entertained by the profession at this time.
[Footnote 27: _Ibid._, S. 43.]
In cases of pyæmia there are recognized two principal sources of
contamination of the blood--viz. the wound itself, and the vitiated
condition of the atmosphere surrounding the patient--contamination, in
the first place, directly from the wound through the blood-vessels;
and in the second, by the passage of disease-germs or of the poisonous
elements into the blood along the respiratory tract. E. Wagner says:
"The latest examinations in regard to the vegetable parasites have
made it very probable not only that these are the active agents, but
also--what has been clinically quite generally accepted--that
septicæmia and pyæmia owe their origin to different plants (the first
to rod bacteria, the latter to globular bacteria); and, finally, that
both may combine."[28] These germs may be generated in the wound or be
received into it from the surrounding atmosphere. The character of the
wound and the conditions surrounding the patient thus become important
subjects for the consideration of the surgeon.
[Footnote 28: _Manual of General Pathology_, p. 593.]
It has been observed, and is now generally admitted, that wounds
complicated with a fracture of the long bones of the extremities,
opening large medullary cavities and accompanied by extensive
laceration of the soft parts, always increase the danger of
blood-poisoning. This fact may be more thoroughly understood by a
brief consideration of the condition of the parts. Frequently in open
fractures large quantities of pus constantly remain in contact with
the surface of the wound, while detached fragments of bone, which
become speedily necrosed, move about with every motion of the injured
limb, lacerating more or less the surrounding tissues, and thus
exciting inflammation and suppuration. The periosteum becomes
inflamed; a widespread suppurative periostitis is the result; necrosis
of the bone from insufficient nutrition follows, while mechanical
pressure on the pus aids in its absorption. The medulla frequently
takes on suppurative inflammation, and here the surgeon fails to
receive prompt warning of danger; slowly the suppuration progresses,
without pain or other symptoms unless the disease has extended to the
other tissues; the medullary cavity at the fractured end of the bone
may be completely or partially occluded by a new osseous formation;
and in such cases the absorption of pus by the comparatively large
venous vessels of this cavity is greatly facilitated.
The soft parts may also be the seat of dangerous trouble. The same
force that produced the wound and fracture may have also contused the
soft parts, destroying in a greater or less degree their nutrition,
thus giving rise to gangrenous sloughs, or in other cases to the
formation of abscesses, etc. I will also call attention to the fact
that the laudable pus {959} in these cases is most favorably situated
for a rapid change into that commonly called ichorous. The heat of the
parts and the contact of the pus with the atmosphere will not fail to
effect its rapid decomposition.
ETIOLOGY OF SPONTANEOUS PYÆMIA.--It is unquestionable that cases of
true pyæmia have been observed in which the etiology was not traceable
to a wound; and it is equally certain that this failure to discover
such a source of contamination in the majority of cases is no proof
that it did not exist. When it is remembered that a large portion of
the alimentary canal, the respiratory and the genito-urinary tracts,
are so situated that the existence of a contaminating wound might be
absolutely undiscoverable, we are compelled to admit the possibility
of a local centre of contamination in all these cases. But the
question may be asked here with propriety, "Is fatal pyæmia,
independent of a wound, ever produced by breathing vitiated air?" The
answers to this question must generally be a negative, although it is
certainly true that poisoning of the blood does take place to a
certain degree, as is abundantly shown by the different symptoms
arising in patients thus exposed who are not suffering with wounds. It
is said that dogs exposed in this way are found to rapidly emaciate
and suffer from severe and constant diarrhoea. The various symptoms
arising in patients confined in overcrowded and pus-infected wards,
among which may be mentioned loss of appetite, with diarrhoea and
emaciation, are too well known to require an enumeration here.
Therefore it appears highly probable that living in and breathing a
vitiated atmosphere may act as a strongly predisposing cause, only
requiring a slight scratch or abrasion of the skin, in which the
infection may be said to act as an exciting cause of pyæmia.
In reference to such complications the following questions are asked
by Roser: "Is it a specific deleterious material, a miasmatic or
contagious disease-poison, or, as it is generally expressed, a zymotic
agent? Must we regard each particular typhus-like fever, with its
remarkable changes of blood, with its various localizations in all the
organs and membranes, with its chills, furred tongue, petechiæ,
delirium, etc., as we regard typhus, scarlatina, variola, etc.? or, as
Virchow teaches us, is this pyæmia, so greatly feared by all surgeons,
only an ontological idea? Is the word pyæmia only a general name for
three different conditions--viz. leucocythæmia, thrombosis, and
embolism, or ichorrhæmia and septicæmia? or are there, as many have
supposed, two ways in which pyæmia may originate? Is there one primary
miasmatic pyæmia analogous to the other epidemic, so-called zymotic
diseases? and again, a secondary pyæmia arising from suppurative
inflammation, wherein the poison is formed in the patient's own body,
which is infected by a single organ?"[29]
[Footnote 29: _Loc. cit._, S. 39.]
That this disease is caused by a specific deleterious material in the
large majority of cases is no longer a question for discussion. The
only question to consider is, whether it always arises from the same
cause. Is it possible for pyæmia to originate spontaneously? Are there
any cases of sporadic origin, or are they always due to endemic or
contagious influences? No definite answer can be given to these
questions, although, undeniably, the weight of the argument is
strongly opposed to a sporadic origin. The term miasmatic, as {960}
used by Roser, probably refers to the vitiated condition of the
atmosphere, as seen in the overcrowded surgical and obstetrical wards
of hospitals. In no other sense can the word be appropriately used in
connection with the subject of pyæmia. It is true, pyæmic diseases are
found to prevail at certain seasons and in certain localities much
more extensively than under other circumstances. The same, however, is
true of cholera, typhus fever, scarlatina, variola, and other
contagious diseases. That pyæmia is contagious has been frequently
demonstrated. I therefore conclude that the prevalence and spread of
this disease must be explained by the same rules as are applied to the
existence and propagation of these allied affections.
This inquiry into the etiology of pyæmia brings before us again the
four hypotheses which have been given in explanation of the same
number of theories. The first and second have been already abandoned
by the medical profession, after it was satisfactorily demonstrated
that they were based on false theories, and consequently there remain
for our consideration only the third and fourth.
The third hypothesis assumes that a chemical poison is developed in
the wound-secretions, which when absorbed produces pyæmia. An
examination of the subject does not justify us in asserting that this
proposition has been proved, although it is certain that the results
of experimental inquiry demand for it a more extended investigation.
In all the analyses which have thus far been made the investigators
have entirely failed to give us an adequate knowledge of this poison,
and not a word has ever been said in regard to the agency by which it
is produced, although it is universally admitted to have been only
obtained from decomposing animal substances. It is therefore pertinent
to the continuation of this inquiry to ask, By what agency is the
putrefaction of animal substances produced? It has now been fully
shown that there can be but one answer given to this question--viz.
the putrefaction of albuminoid substances can only be effected by
living organisms. We therefore conclude that the fourth hypothesis
brings us at least one step nearer the correct explanation of the
etiology of pyæmia than the third, since we justly assume that if
there is a chemical poison in decomposing albuminoid substances, it is
produced through the agency of living organisms.
ETIOLOGY OF SEPTICÆMIA.--The first question which arises in the
discussion of the etiology of this morbid condition is entirely
dependent on the scope which we give to the word septicæmia. Sternberg
says: "The view which is entertained by high authorities, upon
clinical and experimental evidence, is that there are two forms of
septicæmia--the one a septic toxæmia due to the effects of a chemical
poison or poisons evolved during the putrefactive decomposition of
certain organic substances, especially of nitrogenous animal products;
the other an infective disease produced by the rapid multiplication in
the body of the infected animal of a parasitic organism. The
best-studied and most widely known form of septicæmia, due to the
presence of a parasitic organism, is the disease known as
anthrax--charbon of the French, milzbrand of the Germans--but several
other varieties are now well established, in which similar symptoms
and pathological results are produced by organisms morphologically
different from the bacillus anthracis. Among these may {961} be
mentioned the form of septicæmia in the mouse, so well studied by
Koch, which is due to a minute bacillus, and the form of septicæmia in
the rabbit, produced by the subcutaneous injections of human saliva,
due to micrococci, which has been studied by Pasteur, Vulpian, and
myself independently."[30]
[Footnote 30: _Amer. Jour. Med. Sci._, July, 1882, p. 70.]
The terms septic toxæmia and septic intoxication are applied
indiscriminately to the same disease, and the committee appointed by
the London Pathological Society to investigate the nature and cause of
those infectious diseases known as septicæmia, etc. further report
that "ordinary wound-fever is merely septic intoxication in a very
mild form, and it is only necessary for the dose absorbed to be
sufficient in quantity for fatal consequences to ensue. Septic
intoxication is, therefore, of the commonest possible occurrence as a
complication of severe surgical injuries, but it is in so mild a form
as to bear but little resemblance to that experimentally produced on
animals."[31] The question which now arises is, Shall septic
intoxication be classified with septicæmia?
[Footnote 31: _Trans. Pathological Soc. of London_, vol. xxx. p. 14.]
We have been long accustomed to speak of this complication as a
surgical or traumatic fever; and consequently any change in this
classification must necessarily lead to confusion. Furthermore, it is
now generally supposed there is much difference in the etiology of
these morbid conditions. It is claimed that septic intoxication arises
from the absorption of a chemical poison evolved through the agency of
living organisms during the process of putrefaction in a wound, and
that the conditions are unfavorable for their development within the
blood or tissues of a living animal; but in true septicæmia the
organisms are developed in the wound during putrefaction, and then
find their way into the blood and tissues of the body, where they
rapidly multiply. Consequently, the former condition tends to a rapid
recovery--unless the quantity of poison primarily admitted to the
system has been excessive--while the latter tends to a fatal
termination.
Septic intoxication is regarded as a non-infective disease, and true
septicæmia as an infective malady. The only etiological similarity
between these morbid conditions is found in the fact that they take
their origin in putrefaction, which is effected by the action of
different organisms possessing marked morphological differences and
requiring essentially different surroundings for the maintenance of
life and reproduction. Thus, it is supposed that in cases of septic
intoxication the organism by which putrefaction is caused in the
wound-secretions can only live in the open air, and that its life is
commonly only of a few hours' duration. The brevity of bacterial
action in this instance may be due to a failure of the absorptive
power or to a changed condition in the wound-fluids, rendering them
unfit to support the organism.