Chapter LIX: Part II: , Showing Predominance of Malarial Element . . . . 617 (58)

The French definition and nomenclature of pyæmia, according to Guérin, is as follows: "Purulent infection, or pyohæmia, purulent fever, surgical typhus." The purulent infection is a poisoning of the blood, which terminates by the formation of multiple abscesses, which have been improperly known under the name of metastatic abscesses.

From 1820 to 1870 surgeons admitted that these abscesses were the result of a phlebitis having its origin in a wound exposed to the air. Therefore, this disease was variously designated under the name of phlebitis, pyohæmia, or purulent infection. Tessier called it purulent diathesis; "in 1847, I compared it to the typhus, and, as the poison is absorbed from the surface of the wound in the purulent infection, I gave it the name of surgical typhus or purulent fever."[19]

[Footnote 19: _Nouveau Dict. de Méd. et de Chir. pratiques_, t. xxx. p. 222.]

Having given enough on this subject to answer our purpose, we will consider the nomenclature of another septic complication.

NOMENCLATURE OF SEPTICÆMIA. The term septicæmia was first employed by Piorry, and was applied for a considerable time to all those diseases in which the blood was submitted to a septic influence. Therefore, the term was made applicable to the morbid conditions existing in anthrax, glanders, typhus and typhoid fevers, variola, and also all forms of purulent and putrid infections. Guérin now adds: "Fortunately, for several years the most competent authors seem to have wished to {954} reserve the name of septicæmia for what surgeons call putrid infection, and for the morbid state that the experimenters produce by the injection of putrid material into healthy animal tissues; it is consequently the experimental septicæmia which we aim at first and foremost."[20]

[Footnote 20: _Nouveau Dict. de Méd. et de Chir. pratiques_, t. xxx.]

Dunglison defines septicæmia with a single word, septæmia. The same authority gives the following derivation and definition to septæmia: "From [Greek: sêptos], 'rotten,' and [Greek: haema], 'blood.' A morbid condition of the blood produced by septic or putrid matters."

Sanderson says: "What I mean by septicæmia is a constitutional disorder of limited duration, produced by the entrance into the blood-stream of a certain quantity of septic material. It must, therefore, be regarded less as a disease than as a complication, differing from pyæmia not only in the fact that it has no necessary connection with any local process, either primary or secondary, but also in the important particular that it has no development."[21]

[Footnote 21: _British Medical Journal_, Dec. 22, 1877.]

Both Davine and Koch designate as septicæmic all cases of general infection from wounds in which no metastatic changes occur. "Birch-Hirschfeld limits the term septicæmia much in the same way as Sanderson. He describes as septicæmia those cases in which the disease results merely from the absorption of the products of putrefaction, and regards it merely as a process of poisoning, such as might arise from the injection of any other noxious chemical substance into the blood. Pyæmia, on the other hand, he considers a truly infective process, probably due to the entrance of specific organisms into the body. He would therefore include many of the cases described by Koch as septicæmia under pyæmia."[22]

[Footnote 22: _Trans. Pathological Soc. of London_, vol. xxx. p. 9.]

Billroth defines septicæmia as an "acute general affection which arises from the taking up of various kinds of putrid substances into the blood, and it is believed that these putrid substances so change the quality of the blood that it can no longer fulfil its physiological functions."[23]

[Footnote 23: _Lectures on Surgical Pathology and Therapeutics_ (trans. from 8th ed.), vol. ii. p. 41.]

Heuter defines septicæmia as a fever caused by the entrance into the circulation of the products of putrefaction from local centres of decomposition. He draws no clear distinction between an infective and a non-infective form, but the affection he describes as pyæmia simplex or pyæmia without metastasis seems to include many cases which Davine, Koch, and others would include under septicæmia.[24]

[Footnote 24: _Trans. Path. Soc. of London_, vol. xxx. p. 9, 1879.]

Having before us the views of some of the prominent authors who have written upon the nomenclature of pyæmia and septicæmia, we observe that the use of these terms is based either on known or imaginary morbid conditions of the body, more especially of the blood. It therefore seems that the first step toward determining the proper limit within which these terms can be employed consists in learning their accurate meaning, which is fortunately clearly shown by their derivation. The next step consists in the application of these terms to the morbid conditions which are described more or less completely by these words. It may be here added that there will be frequently required for a full and definite expression certain modifying words, and consequently we may {955} properly employ such phrases as puerperal septicæmia, spontaneous pyæmia, etc.

Having carefully examined the terms employed by various authors in connection with the morbid changes which are known to occur in certain cases of septic contamination, we give our preference to the following nomenclature: Septicæmia, septo-pyæmia, pyæmia simplex, and pyæmia multiplex.

The term septo-pyæmia is applied to a morbid condition possessing 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.

It is now a well-recognized fact that all septic absorption ends so soon as the wound-surfaces are covered with healthy granulations, but that septic absorption, which produces septic intoxication, is most commonly of a much shorter duration, and, consequently, that the wound complication, which I prefer to designate traumatic fever, is essentially an acute disease, and can only be lengthened out by unusually favorable circumstances for the continuance of the absorption of the poison by which it is produced. {962} The severity and danger of the disease will necessarily depend on the amount of poison absorbed and the resisting power of the patient; but since there is no multiplication of the materies morbi within the body, a rapid elimination by the natural emunctories may be reasonably expected under favorable circumstances.

It should be observed here that the etiology of septicæmia differs from that of traumatic fever, since the organisms in the former condition are first formed in the wound-secretions, but quickly enter the body, where they rapidly multiply; consequently, Chauvel has defined surgical septicæmia as follows: "The particular intoxication which results from the penetration and multiplication in the body of a specific microbe designated by Pasteur under the name of septic vibrio." The bacterial origin of this disease is now generally accepted, and the only question in the professional mind seems to be whether the organisms are the direct or indirect cause of the malady.

There are also some other interesting questions which have arisen in connection with the study of this subject, and are thought to be of sufficient importance to merit mention here. It has long been known that dissecting wounds are most dangerous when made while examining the body very soon after the death of the subject. Recent observations seem to justify the conclusion that the greatest activity of the septic agent is often, if not always, attained before the odor of putrefaction has become fairly perceptible; and even before this odor has reached its maximum degree of offensiveness the danger from septic poisoning has generally disappeared. In some cases septic intoxication is promptly followed by a slight inflammation in and about the wound, which may entirely disappear within a few hours, but only to reappear after a lapse of eight to fifteen days, with the first vigorous physical exercise of the patient. Two cases of this kind have recently come under my observation. In both instances the wounds were located in the hands, and the exercise which developed the septicæmia consisted in rowing a boat, and while thus engaged the local symptoms reappeared with such severity as to cause the patients to quickly discontinue the labor. The reappearance of the local inflammation in both these instances was quickly followed by a rigor and the rapid development of other constitutional symptoms, although prior to the recurrence there was no pus, nor even marked inflammatory action, in any part of the hands.

Professional attention was first called to the above-stated facts by Panum in 1855, who discovered that the maximum toxic action of putrid substances is generally developed during the first hours of bodily activity. In this stage of incubation in cases of surgical septicæmia, if we admit the bodily action as an etiological factor, we observe a striking resemblance to one of the leading characteristics of all the infectious diseases, which unquestionably depend on some sort of septic poison. Furthermore, this analogy becomes most striking if we contrast the effects arising from dissecting wounds with those of the bites of poisonous serpents and rabid animals.

Further investigation is required to settle the perplexing questions of etiological and pathological differences in these allied morbid conditions, for although much has been accomplished during the last two decades, still much more remains to be done. It has only recently been discovered {963} that the septic material in septicæmia is absorbed by the lymphatics, while in pyæmia the poison enters the body through the veins.

ETIOLOGY OF SEPTO-PYÆMIA.--It is now generally admitted that remittent fever and typhoid may be associated, and this morbid condition is commonly designated by the term typho-malarial fever. The etiology is unquestionably dependent upon the action of the two distinct and entirely dissimilar poisons. Scarlatina is likewise frequently complicated by diphtheria, and here we have the combined action of two poisons, each commonly designated as septic and supposed by many physicians to be similar.

In a like manner, it is believed that septicæmia and pyæmia may be associated, and take their origin in dual poisons; but since the etiology of both these morbid conditions has been already described, it is not deemed necessary to dwell longer on septo-pyæmia under this division of our subject.

PATHOLOGY OF PYÆMIA.--The study of the pathology of pyæmia is advanced by adopting the following classification, which is based on recognized post-mortem lesions. The pathological appearances in these forms of the disease differ widely, although the clinical symptoms are often similar. In pyæmia simplex the pathological conditions are essentially more negative. This variety of the disease can only destroy life by the height and duration of the fever which is maintained in connection with the continued existence of ichorous pus. There is found, as an essential basis of this form of disease, extensive suppuration in the subcutaneous tissues.

The arguments in favor of the admission of pus-corpuscles into the blood are as follows: 1. The blood in pyæmia is known to contain more white granular spherical bodies than are normal. The question has been raised, Are they pus-cells or white blood-corpuscles? The answer is difficult, and has not yet been attained. Virchow, in the mean time, has proved that we cannot differentiate, morphologically, between the blood- and pus-corpuscles. 2. Cohnheim has demonstrated the existence of the wandering corpuscles in cases of inflammation. Therefore it appears probable that in cases of pyæmia the blood may contain the pus-corpuscles, but further investigation is needed to establish this fact. However, the establishment of this point would still leave the more important undetermined.

There are often important changes observed in the blood of patients dead of pyæmia, to which I now desire to direct attention. The red corpuscles of the blood, even in the early stage of the disease, in many cases show signs of disintegrating into molecules, and are observed to be accumulated in masses without showing the slightest tendency to form rouleaux. There is a steady increase in the number of pus- or white corpuscles in the blood of pyæmic patients during the whole course of the disease in fatal cases. The condition of the red corpuscles, already mentioned, becomes more and more marked toward the fatal termination.

In all cases of pyæmia multiplex the increased coagulability of the blood may be observed in the early stages of the disease, and steadily increases as the disease progresses.

In pyæmia simplex this condition is less marked, although generally present, "while we know septicæmia diminishes or destroys the {964} coagulability of the blood. Hereby the possibility is given, at least on the cadaver, to differentiate between pyæmia simplex and septicæmia, although cases occur of the more fatal septic infection in which the post-mortem condition is a complete or almost complete negative. Therefore, in these cases the differential diagnosis on the cadaver must be limited to this, that we are able to demonstrate the existence of a purulent or ichorous deposit." It will be readily observed that the difference in diagnosis mentioned above relates to pyæmia and septicæmia, and not to the different varieties of the former disease.

The following facts should be constantly kept in mind by the surgeon to enable him to differentiate between the two forms of pyæmia: In pure cases of purulent infection, without metastasis, the disease is called pyæmia simplex, and in cases with metastasis, pyæmia multiplex. The various conditions on which the metastasis may depend are shown by Hueter, who says: "The metastatic abscesses of pyæmia multiplex met with in the lungs, liver, spleen, and other internal organs are regarded, with the greatest probability, as a result of the embolic process. The metastatic inflammation of the serous membranes, of the cellular tissues, and of the parotid glands, and probably also a few metastatic inflammations of the internal organs, are at present supposed to arise from a general inflammatory diathesis."[32] It has already been shown by numerous experiments on animals that metastatic abscesses in the lungs, liver, and other visceral organs only arise after the introduction of ichorous pus, while healthy pus has uniformly failed to produce these results.

[Footnote 33: Billroth's _Handbuch der Chirurgie_, S. 88.]

It now remains to be shown how the introduction of ichorous pus acts in the production of pyæmia multiplex. The ichorous pus, having found its way into the venous circulation, gives rise to the formation of thrombi in the veins; these clots become more or less broken up, and are carried forward by the blood to the right auricle; from this auricle to the right ventricle; from this ventricle to the pulmonary artery, and through its ramifications to every part of the lungs. In the minute ramifications of this vessel are found wedge-shaped clots of various sizes in different conditions, some softened and others still firm. The possibility of these clots ever passing through the lungs, and afterward being arrested in other visceral organs, has been demonstrated on animals. It has been shown that fine particles of foreign matter injected into the veins have passed through the lungs and subsequently lodged in the liver. This theory enables us to account, upon a mechanical basis, for the existence of the metastatic abscesses in the liver which have apparently originated as the result of primary infection.

In other cases these abscesses are supposed to arise from secondary infection. Thus, ichorous pus, having found its way into the venous circulation, produces primarily venous thrombi, which, as in other instances, break up, the clots being carried in the same manner into the terminal branches of the pulmonary artery, where they are designated as emboli. The first action of the emboli is the mechanical closure of these vessels, thus depriving the surrounding parts of nutrition to a greater or less extent. It will be proper now to recall the fact that the composition of these emboli is such as to favor rapid suppuration; this commonly commences {965} in the clot and surrounding tissues, having been preceded by a brief stage of congestion and inflammation. There is also occasionally found around these points more or less extravasation. The metastatic abscess thus formed in the lungs is favorably situated for the production of secondary infection. From this abscess thrombi arise in the pulmonary veins, which become disintegrated, and are carried to the auricle, thence to the left ventricle, and finally through the aorta, and find lodgment in the terminal branches of the arteries of the various organs, where they produce the characteristic lesions.

The organs which most frequently become the seat of this secondary infection are the liver, spleen, kidneys, brain, and eyes.

Let us now briefly examine this mechanical theory. Do metastatic abscesses arise from a single cause or from a combination of causes? I am inclined to the opinion that the proximal cause of metastatic abscesses in the visceral organs is the existence of emboli in the terminal branches. The vitiated atmosphere surrounding the patient, the existence of a wound, and the formation of ichorous pus are conditions which should not be lost sight of. These are the elements acting on the blood, producing in it morbid changes, and may therefore be regarded as predisposing causes. The morbid conditions of the blood, the increased number of white blood-corpuscles (possibly pus), the disintegration and other changes in the red corpuscles, may be regarded as the exciting causes of metastatic abscesses. It is thus readily observed that emboli may form in the lungs and liver at the same time, or the origin of those in the lungs may precede the formation in other organs.

Is the formation of emboli in the terminal branches of arteries always dependent on the disintegration of thrombi? The answer to this question must, I think, be a negative, although in surgical practice it rarely happens that the emboli take their origin from any other cause. In the large majority of cases, unquestionably, the thrombi primarily exist in the vicinity of the wound in which ichorous pus is generated; but it not infrequently happens during the process of disintegration that broken-up clots are carried forward by the current of blood, receiving accretions on the way, until finally they fill a large venous trunk. In confirmation of these facts relating to the primary origin of thrombi, it is said to have been observed in epidemics of puerperal fever, which were complicated with metastatic abscesses of the visceral organs, that the thrombi occurred in the pelvic veins. In case of wounds of the lower extremity the clot is frequently found in the common iliac vein, although probably it should always be regarded as a secondary formation. In rare cases the only thrombi discovered at the autopsy are found situated far away from the injury.

Observation fully establishes the fact that, after death from pyæmia, pathological changes are much more frequently met with in the lungs than in any of the other organs. This certainly strengthens the embolic theory. Billroth mentions eighty-three cases of true pyæmia multiplex, in which the metastatic abscesses occurred as follows: seventy-five times in the lungs, seventeen times in the spleen, eight times in the liver, and four times in the kidneys. Sedillot remarks that in one hundred cases of pyæmia we find the lungs affected in ninety-nine, the liver and spleen in eight, the muscles in seven, and the heart and peripheric {966} cellular tissue in five cases. The brain and kidneys are comparatively seldom involved.

The theory previously mentioned as the embolic relates to the aggregation of fibrin into clots; but another theory has been recently advanced by E. Wagner, who found in many cases the capillaries in the lungs filled with fat, and was inclined, from the direction it extended in these vessels, to explain a certain number of the pyæmic cases by the fat emboli; but it has been shown that the existence of the fat emboli in pyæmia is purely accidental and possesses no significance. Pyæmia multiplex very frequently occurs without fat emboli, and vice versâ; either process may complicate the other, and so the fat emboli may acquire special importance by obstructing the respiration, and probably also in their way the embolic fat may serve as a carrier of putrid material.

MORBID ANATOMY.--The external appearance of the body varies greatly. The skin, in those cases in which the patient was jaundiced before death, will be found in every part of the body to be of a dark orange or dirty icteric tinge, but in other cases it may present a pale or anæmic appearance. There are also sometimes found circumscribed ecchymoses or purpuric patches, while the edges of ulcers or open wounds are generally of a blackish or dirty yellow color. The lips and finger-nails present a livid appearance; epithelial defects are observed in the cornea, but these had their origin there before the death of the patient.

The eyes in some cases are sunken deeply in their sockets, and where the disease has been protracted there is often very great emaciation. Rigor mortis is commonly well marked after a few hours. When death occurs from puerperal pyæmia there are generally found some indications of the recent parturition, although the principal lacerations or injuries may be confined to the womb. All fluids disappear from external wounds before the death of the patient, and they remain dry afterward.

In some cases the cellular tissue is the seat of diffuse suppuration. The pus formed is thin, fetid, and unhealthy. This suppuration is limited to certain parts of the body, as an injured extremity, or, as frequently happens, it may be found on the trunk and limbs at the same time. The pus in this form of suppuration is exceedingly apt to burrow, on account of the peculiarities of the tissue in which it occurs, and also the condition of the surrounding structures, especially the relaxed and flabby condition of the skin. These abscesses in some instances are superficial, in others deep-seated.

There are few changes which occur in the muscles, and these are not uniform or constant. They are occasionally the seat of abscesses, which have been observed in the heart, tongue, and other organs. The muscles may be of a light-brown or greenish color when they have been covered a considerable time with pus, and are sometimes softened and pultaceous. Suppuration may also take place beneath the fascia of the tendons.

The brain and its membranes are frequently found in a perfectly healthy state after death from pyæmia, although when the diseased process has extended during the life of the patient to the lungs and pleura, giving rise to great dyspnoea, there will generally be observed some congestion of the membranes, an increased quantity of fluid in the brain-substance and ventricles, and also an increased fulness of the meningeal veins and sinuses. Occasionally there have been observed suppurative {967} meningitis, blood extravasations on the surface of the brain, lymph-deposits on the membranes, softening of the cerebral tissues, and circumscribed abscesses in the substance of the brain, which in some cases have been traceable to embolism of its vessels. The changes in the spinal cord and its membranes are probably similar to those found in the brain, but these parts appear to have been rarely examined.

Virchow found emboli of the retinal and choroidal vessels. Heiberg found these vessels occluded with colonies of micrococci. There have also been observed opacity of the cornea, sloughing of the conjunctival epithelium, suppurative infiltration into the periphery of the vitreous body, and deposits of pus in Petit's canal and in the anterior and posterior chambers. Pyæmic ophthalmia has been observed somewhat frequently in puerperal cases, especially when preceded by endocarditis, with deposits on the semilunar or mitral valves. In surgical cases it is rarely seen.

Toynbee "relates several cases of purulent infection following suppuration of the ear. Cases of disease in the mastoid cells terminate fatally, he says, from two different causes: first, from purulent infection, arising from the introduction of pus into the circulation through the lateral sinus; second, from disease of the cerebellum or its membranes. Cases of purulent infection, he further remarks, have not been met with where the disease occurs in the tympanic cavity."[34]

[Footnote 34: Braidwood on _Pyæmia_, pp. 168, 169.]

Numerous lesions of the osseous system have been noted in pyæmia, probably from the fact that this disease results very frequently in cases of bone-lesions, but these changes have very little diagnostic importance. The following have been observed: thickening or infiltration of the periosteum, which may be found to separate readily from the bone after the death of the patient, or there may be pus found between the periosteum and the bone. In the bone-structure there were found caries and necrosis, "while in other cases the whole thickness of the compact tissue is perforated in a honeycomb-like manner by minute cavities filled with thickish pus or caseous matter of a pinkish-white color."[35] "To sum up, the chief morbid alterations met with in the bones are congestion, dilatation of the Haversian canals and cancellated tissue, tending to abscess formation, and the excavation of the cavities by the unhealthy pus."[36]

[Footnote 35: _Ibid._, p. 192.]

[Footnote 36: _Ibid._, p. 194.]

The pathological lesions of the joints commence with marked congestion of the synovial membranes and increase in the synovial fluids, and afterward the fluid is mixed with pus; these conditions are followed by erosion of the cartilage and ligaments, the former thus becoming separated from the bone. Both the small and large joints are occasionally the seat of morbid changes.

The parotid gland is occasionally the seat of a secondary inflammation during the progress of pyæmia, and this may endanger life by interfering with respiration and deglutition. The lymphatic glands are only secondarily affected, and even this takes place very rarely. The changes in the glandular system, when observed, are similar to those which happen in other tissues of the body--viz. congestion, inflammation, and suppuration.

The arteries are usually found empty after death from this disease, and the coats are sometimes apparently thickened. The veins, on the contrary, are commonly found filled, or even distended, with firm fibrinous clots. They are sometimes also found inflamed or altered, although more {968} commonly healthy. The distended condition of the veins gives rise to the cord-like feeling often mentioned by different observers. In some cases of phlebitis there may be pus deposited between the coats of these veins. The most important pathological changes are found in the blood. These changes occur early in the disease, become more marked toward its fatal termination, and may be always studied after death. It is generally admitted that pus is frequently found in the blood of these patients; but it has been shown by numerous experiments that healthy pus never produces the pathological changes which characterize this disease. Pyæmia is only produced by the presence in the blood of ichorous pus or some other decomposing animal substance, or some material having its origin in the decomposition of the same, and no decomposition in these substances is ever effected except through the agency of living organisms. It therefore follows that the discovery of living organisms in the blood of those sick and dead of this disease has given a renewed interest to the study of its pathology. The recent investigations made by Pasteur, Koch, Birch-Hirschfeld, and the London Pathological Society show conclusively that in all cases of pyæmia and septicæmia organisms are present in the blood during the entire course of the disease, and that in the former there is found the globular, and in the latter the rod bacteria. It has further been observed in each morbid condition that the severity of the disease is always increased in proportion to the increase of the organisms in the blood, and that the bacteria found within the body are of the same species as those in the wound from which they have gained admission. The micrococci found in the blood of pyæmic patients are surrounded by the decomposed products of the red and white corpuscles, which appear in the blood-plasma in the form of pale granular bodies. There is likewise in this disease an increased coagulability of the blood, and it steadily increases as the disease progresses. In this condition there may be found in the blood-vessels both thrombi and emboli. The thrombi are occasionally observed as firm fibrinous clots, but they may be likewise found in the rapidly fatal cases to have undergone suppurative changes. These changes begin in the centre of the clots, which often contain true pus or a greenish or puriform fluid.

The pericardium may contain a small amount of serum tinged with blood, but it is seldom covered with recent lymph. Both the lung-tissue and pleuræ are commonly inflamed in this disease. The costal and visceral layers may be agglutinated by old adhesions, but are more commonly united together by recently formed lymph. The pleural cavities often contain some opaque, muddy, sero-purulent fluid, mixed with blood and having masses of lymph floating in it.

The lungs are more frequently the seat of metastatic abscesses and other morbid changes in pyæmia multiplex than any other organs of the body. There may be found emboli in the branches of the pulmonary veins, and in the lung-tissue metastatic abscesses surrounded with capillary congestion and other evidences of inflammation; "The smaller vessels, trying to overcome this afflux of blood, may produce ecchymosis or extravasation beneath the lining membrane of the air-vesicles, but the minute capillary congestions are generally observed as red points studded over the pulmonary surface, which by and by exhibit yellowish-white or bluish-white centres. While one part, generally the lower half of the {969} lung, is thus hepatized, solid, and of a dark greenish color, the remainder of the lung is emphysematous and more or less oedematous. A section of the former presents the same appearance as is observed in the lungs of pneumonic patients. Whether these incipient abscesses are developed from the minute points of congestion before mentioned, by the breaking down of the thrombic clots in their centres, or whether the pus is developed out of the serum exuded by the walls of the engorged capillaries, cannot be easily determined, and has as yet not been decided. These secondary abscesses vary in size from that of a hemp-seed to that of a hen's egg."[37] These are generally situated on the periphery of the lungs and in the lower lobe, although in some cases they are found imbedded deeply in the pulmonary tissue. The contents of these abscesses are similar to those found in other parts of the body in this disease. The bronchial mucous membrane is commonly of a bright pink color, while its secretion is increased in quantity, and may be clear and frothy. These changes are the result of acute bronchial catarrh. Lobular pneumonia has been frequently observed as a complication of pyæmia, and is supposed by some authors to be caused by the vitiated condition of the blood; but probably it is more frequently occasioned by infarctions and embolic abscesses, which have been previously mentioned in this connection.

[Footnote 37: Braidwood, _op. cit._, p. 173 _et seq._]