The principles and practice of modern surgery

D. The Micrococcus Tetragenus.

—Suppurations produced by these organisms are prolonged, mild in character, not painful, but accompanied by much brawny induration of tissues.

E. The Micrococcus GonorrhϾ.

—The micrococcus gonorrhœæ, or gonococcus, is found constantly in the pus of true gonorrhea, in many cases the pus being a pure culture of this organism. These cocci are generally seen in pairs (biscuit-shaped), while their inclusion within the leukocytes or their attachment in or to epithelial cells is characteristic. Unlike other pyogenic cocci, they do not stain by Gram’s method, being decolorized by iodine, by which fact they may be distinguished. They are cultivated with difficulty, and are known rather by their clinical effects than by their laboratory characteristics; are human parasites, other animals, so far as known, being practically immune. The gonococcus may also produce abscesses, and may be carried to distant parts of the body, where its effects are commonly noted as pyarthrosis, although endocarditis, pericarditis, pleurisy, etc., are known to be due to it, and fatal pyemia has been produced in consequence. In some way it is probably the explanation of the post gonorrheal arthritis, wrongly spoken of as gonorrheal rheumatism.

F. The Bacillus Coli Communis or Colon Bacillus.

—This is an inhabitant of the intestinal canal; varies extremely in virulence and somewhat in morphological appearances; coagulates milk; is often associated with other organisms; migrates easily both along the alimentary canal and from it into the surrounding tissues or channels. It is a disturbing element in the production of kidney and hepatic disease, also in the production of appendicitis and peritonitis. Ordinarily its pyogenic properties are not virulent; occasionally, however, it becomes extremely virulent.

G. The Bacillus Pyocyaneus.

—The bacillus pyocyaneus, a widely distributed organism, often observed in the skin and outside of the body; a motile, liquefying bacillus, growing at ordinary temperatures, seldom seen alone, but occasionally producing pus without association with other organisms; it stains the discharges and dressings a bluish-green and imparts sometimes an offensive odor. Suppuration caused by this bacillus is usually prolonged, but characterized by little constitutional disturbance.

Facultative Pyogenic Organisms

—i. e., those which have the power of provoking suppuration, but which have other and more distinct pathogenic activities as well.

A. Bacillus Typhi Abdominalis.

—This is found in many pus foci, developing during or after typhoid fever. It is occasionally met with alone, though most of these abscesses are really mixed infections. It is generally found in the bone or beneath the periosteum. Such abscesses are frequently seen in the ribs, and may not be noticed until months after convalescence from the fever. The pus contained within them is not always typical in appearance, but may be unduly thin or unduly thick.

B. Bacillus Proteus.

—Under this name are included three distinct forms, which were originally described by Hauser as distinct species, but which are now regarded as pleomorphic forms of the same organism. It is a motile bacillus, met with in decomposing animal and vegetable material, and occasionally found in the alimentary canal. It has been known to produce pus, especially in the peritoneal cavity and about the appendix. It may even cause general infection and peritonitis.

C. Bacillus Diphtheriæ.

—A non-motile bacillus, varying considerably in size and shape, changing the reaction in sweet bouillon from acid to alkaline; produces a dangerous infective inflammation of exposed surfaces, with tenacious exudate amounting to a distinct membrane. As a part of its life history it also produces a toxalbumin, which is one of the most powerful cell poisons known, the disintegration of the cell constituents due to its action being rapid and pronounced. This accounts for the heart failures which are often reported in connection with the disease.

D. Bacillus Tetani.

—More will be said about this organism when considering tetanus, and to that subject the reader is referred. The tetanus bacillus is occasionally found in pus which comes from the area through which the original infection was produced. But these bacilli do not travel to any distance in the human body, and are seldom found away from the area involved. Under most circumstances the pus is the product of a mixed infection.

E. Bacillus Œdematis Maligni.

—This organism will be more fully considered under a different heading. (See Malignant Edema.) It is a long, anaërobic bacillus, widely distributed in the soil and the feces of animals. It is believed that this, like the tetanus bacillus, may occasionally lead to formation of pus.

F. Bacillus Tuberculosis.

—This organism likewise will receive fuller description in an ensuing chapter. (See Tuberculosis.) The pus of old cold abscesses in which the more obligate pyogenic organisms have long since died usually contains this organism in mildly virulent form. On the other hand, fresh suppurations occurring in connection with tuberculous disease are mixed infections. There is reason to believe, however, that this organism is capable of producing pus even when none of these are present; for example, in that form of acute miliary tuberculosis which is occasionally met with as bone abscess it may be found.

G. Bacillus Anthracis.

—This is one of the most malignant and resistant organisms known, being in the highest degree poisonous for the smaller animals, man being less susceptible. One of its characteristic lesions in the human body is a form of pustule commonly known as malignant pustule, the pus in which is usually a pure culture of this organism. (See Anthrax.)

H. Bacillus Mallei.

—This is the organism which produces glanders in the lower animals and in man. That form of the disease known as farcy, in which the infected nodules rapidly break down, is likely to contain pus which will be more or less a pure culture of this organism.

I. Bacillus Lepræ.

—This is the microörganism which produces leprosy, closely resembling the tubercle bacillus. It is constantly and exclusively present in the lesions of leprosy, which are often of the suppurative type, the bacilli being enclosed within pus cells; it is also found in the fluid surrounding them. Although suppuration in these cases may be in a large measure due to secondary infection, it is positive that the leprous bacilli deserve to be grouped in this place.

J. The Bacillus Pneumoniæ of Friedlander.

—The bacillus pneumoniæ of Friedländer was at one time regarded as the cause of croupous pneumonia, which is now known to be due to the micrococcus lanceolatus. The Friedländer bacillus, however, is capable of producing bronchopneumonia, and is occasionally met with in empyema, suppurative meningitis, and inflammations about the nasopharyngeal cavity, of which it is known to be an occasional inhabitant.

K. The Bacillus of Rhinoscleroma.

—A distinctive organism has been described for this disease and given this name. It has such wide morphological differences, however, that it is possible that it is only the bacillus of Friedländer above mentioned. At all events, an organism of this general character is constantly found in this disease in the thickened tissues from the nose (Fig. 8).

L. The Bacillus of Bubonic Plague.

—This was recently discovered by Kitasato, and, in view of the recent ravages of the disease in the Orient, has assumed considerable importance. It grows upon most media, and is found in the blood, in buboes, and in all internal organs of patients suffering from this disease. The smaller animals are susceptible upon inoculation. Animals fed with inoculated foods die also, showing the possibility of infection through the intestine. When exposed to direct sunlight for a few hours the bacillus dies. The general symptoms of the disease are those of hemorrhagic septicemia and its consequences.

M. The Bacillus of Rauschbrand.

—This is seldom, if ever, seen in this country. It is known in England as “the black-leg” or “quarter-evil.” It is an anaërobic organism, frequently met with in cattle, which causes a peculiar emphysema of subcutaneous tissue, spreads deeply, and is followed by a copious exudate of dark serum with gas formation. The smaller animals are not ordinarily inoculable; but if to the culture material there is added 20 per cent. of lactic acid, their insusceptibility is overcome and they succumb to the disease. So, also, as in the case of the tetanus bacillus, by addition of the bacillus prodigiosus or of proteus vulgaris the disease may be produced in otherwise insusceptible animals.

N. The Bacillus Aerogenes Capsulatus.

—The bacillus aërogenes capsulatus seems capable sometimes of causing pyogenic and even fatal infection. Its presence is associated with gas formation. It grows as an anaërobe.

O. The Bacillus of Chancroid.

—The bacillus of chancroid identified by Ducrey, and briefly described in the chapter on that subject.

YEASTS.

Busse was the first to call attention of clinicians and pathologists to the role played by yeasts in certain infections. Since the original observations of Busse in a case in which the organism produced a general infection, the lesions of which were a combination of tumor and abscess formation, various observers have noted the presence of pathogenic yeasts, usually in skin lesions. Gilchrist and Stokes were the first in this country to determine the nature of these organisms, and their observations have been followed by the detection of a large number of similar cases. In the skin lesions the organisms are found in minute abscesses; in the subcutaneous tissue and in the infections similar to those of Busse large abscesses surrounded by extensive masses of granulation tissue characterize the infection. The organisms can be detected in the pus by means of an examination of the fresh unstained fluid (Fig. 9).

FUNGI.

Besides the micro-organisms everywhere grouped as bacteria, there are other minute organisms which have also the power of engendering pus. One of these is the ray fungus, known as the actinomycis, which causes the disease known as lumpy jaw or actinomycosis. Suppuration is always a concomitant of the advanced lesions of this disease, and, while it may be in many instances a mixed infection, it is not necessarily so. Moreover, the pus produced under these circumstances contains minute calcareous particles which are pathognomonic, by which a diagnosis can sometimes be made off-hand.

Besides these fungi, others, belonging rather to the class of vegetable molds, which are yet pathogenic for human beings, may be occasionally met with under these circumstances—e. g., the fungus of Madura foot, the leptothrix, and other molds from the mouth, while the different varieties of aspergillus may be found in pus about the ear or even in that from the brain.

PROTOZOA.

The protozoa have the power of producing, if not absolute ideal pus, something so nearly resembling it that we may include them among the facultative pyogenic organisms. The best known of these protozoa are the amebæ, which are met with in the intestinal canal in some countries, occasionally in the United States, especially as the exciting causes of a peculiar type of dysentery often accompanied by abscess of the liver. In these abscesses the amebæ are found, and no other organisms. Another group of the protozoa, known to biologists as the coccidia, are also capable of causing pus formation, more particularly in some of the lower animals. Numerous other parasites, belonging higher in the animal kingdom, are undoubted exciters of pus formation, though it is not necessary to lengthen the list beyond those already mentioned.

Protozoa have recently been established as the active agents in the production of smallpox and probably also of scarlatina. They have been seen so generally in and around cancer cells as to make it extremely probable that cancer is a protozoan infection. In syphilis also they are found as the spirochetæ, now regarded as its cause.

Protozoa are as ubiquitous as bacteria, but their recognition is as yet more difficult, as but little is known of them. The numerous stages through which they pass in completing their life cycles only complicate the subject, while the difficulties encountered in cultivating them are still to be overcome. As we become more familiar with them we shall more frequently find them to be pathogenic organisms.

CLINICAL CHARACTERISTICS OF PUS FROM DIFFERENT AGENCIES.

Staphylococcus.—Dirty white, moderately thick, with sour-paste odor.

Streptococcus.—Thin, white, often with shreds of tissue.

Colon Bacillus.—Thick, brownish, with fetid odor, or thin, dirty white, with thicker masses.

Micrococcus Lanceolatus.—Thin, watery, greenish, often copious.

Bacillus Pyocyaneus.—Distinctly green or blue in tint.

Bacillus Tuberculosis.—Thick, curdy, white paste, or thin, greenish, with small, cheesy lumps or even with bone spicules.

Actinomycis.—Thick, brownish white, with small, firm, gritty or chalky nodules of yellow color.

Ameba Coli.—Thick, brownish red.

BACTERIAL DETERMINATION AS AN INDICATION IN TREATMENT.

There is a practical side of great importance pertaining to the recognition of the nature of the infectious organism in many cases of suppuration and abscess. For instance, pus which is due to streptococcus invasion indicates a collection which should be freely evacuated and carefully drained. This is also true in essential respects of staphylococcus pus, particularly that due to the streptococcus aureus. Putrid pus from any source requires disinfection and free drainage, the former preferably perhaps by hydrogen dioxide. Pus which is due to the colon bacillus is not often extremely virulent, which accounts for so many cases of appendicitis recovering with or without operation. A collection of this pus needs little more than mere drainage and opportunity for escape. Pus from a recognizable tuberculous source may still contain living tubercle bacilli. This means either that the cavity whence it came should be completely destroyed and eradicated, or else that the margins of the incision or opening through which it has escaped should be so cauterized that infection of a fresh surface is impossible. The same is true of abscesses due to glanders bacilli and to certain cases of suppurating bubo following chancroid, where the whole course of events shows the virulent character of the organisms at fault.

SUPPURATION.

Although it may be possible to produce in certain laboratory experiments metamorphosed material which very closely simulates pus, or, in fact, by injection of chemical irritants, to sometimes imitate the suppurative processes, nevertheless, the student should be brought face to face with the statement, to which for surgical purposes there is no practical exception, that suppuration, i. e., formation of pus, is due to the presence in the tissues of the specific irritants already catalogued and described, and of the peculiar peptonizing or other biochemical changes which bacteria exert upon living animal cells.

Coagulation Necrosis.

—Coagulation necrosis is the term applied to the characteristic changes occurring in the tissue cells when thus attacked, which may be summarized as a fading away of cell outlines, diminution in reaction to reagents, and a merging of cells and intercellular substance. Coagulation necrosis is not the only result of bacterial activity, but may be produced by other causes. Nevertheless, pyogenic bacteria do not exert their deleterious action upon the tissues without occasioning changes included under this term. In an area thus infected, as already described, leukocytes, i. e., phagocytes, are present in increased number for purposes already mentioned. As we approach the centre of activity phagocytes are more numerous than cells, and intercellular barriers completely break down. When bacteria are found in greatest number, there also occurs the greatest phagocytic activity, and there also will be found the evidence of suppuration, i. e., pus. As already indicated, the polynuclear leukocytes are most active in the process of defence. Where coagulation necrosis is most marked there has been the greatest activity of conflict with the greatest death of cells. Around these areas bacteria and cells are found in indiscriminate arrangement. Tissue vitality is impaired by intoxication of the cells by the excretory products of the bacteria, i. e., the so-called ptomains, toxins, etc., and their power of resistance is thus weakened. From the mechanical results of pressure tension around the centre of activity is increased, by which tension vitality is still more impaired and more rapid tissue death occurs. Thus there occurs migration or burrowing of pus; or, to state it more clearly, the tissues break down in front of the advancing destruction, and in the direction of least resistance. This is known as the pointing of pus, which brings it many times to the surface, and often in other and less desirable directions.

Abscess.

—An abscess is a circumscribed collection of pus. The term is used in contradistinction to purulent infiltration, in which the collection is not circumscribed, but is exceedingly diffuse and extends itself in various directions, the amount at any spot being almost inappreciable. Purulent infiltration is regarded as the more serious of the two conditions, as it is more difficult for pus to escape under these circumstances than when it can be evacuated through a single opening. The term phlegmon is one now generally used to indicate a suppurative process, usually of the general character of purulent infiltration rather than of abrupt abscess, but generally employed to include both conditions. The adjective phlegmonous is coupled with the names of other surgical infectious diseases to indicate that it is complicated by suppuration, e. g., phlegmonous erysipelas. Pus is a product of bacterial activity usually formed rapidly rather than otherwise, and abscess formation or phlegmonous activity of any kind is a question of but a few days. Empyema means a collection of pus in a preëxisting cavity.

The significance of this condition is well described in the story of inflammation and suppuration, to paraphrase Sutton, read zoölogically, as though it were the story of a battle: The leukocytes (phagocytes) are the defending army, the vessels its lines of communication, the leukocytes being, in effect, the standing army maintained by every composite organism. When this body is invaded by bacteria or other irritants, information of the invasion is telegraphed by means of the vasomotor nerves, and leukocytes are pushed to the front, reinforcements being rapidly furnished, so that the standing army of white corpuscles may be increased to thirty or forty times the normal standard. In this conflict cells die, and often are eaten by their companions. Frequently the slaughter is so great that the tissues become burdened by the dead bodies of the soldiers in the form of pus, the activity of the cells being proved by the fact that their protoplasm often contains bacilli in various stages of destruction. These dead cells, like the corpses of soldiers who fall in battle, later become hurtful to the organism which, during their lives, it was their duty to protect, for they are fertile sources of septicemia and pyemia. This illustration may seem romantic, but is warranted by the facts.

Around the margin of the site of an acute abscess a barrier is formed by condensation and cell infiltration of the surrounding tissues. This is not a distinct wall nor membrane, yet, nevertheless, serves as a sanitary cordon to confine the mimic conflict within reasonable bounds. This is the zone of real inflammation; within it there are tissue destruction and coagulation necrosis. By virtue of the peptonizing power of the pyogenic organisms the parts involved in this necrosis gradually liquefy the intercellular substance dissolving first. It is this which in the main forms the fluid portion of the pus. Various tissues show widely differing resistance to this softening process. In true glands the interlobular septa seem to break down first, and in this way suppuration extends around the acini or gland lobules, and thus pus may contain masses of easily recognizable size. These masses are ordinarily known as sloughs.

It is by virtue of the so-called lymphoid cells, which are those principally involved in producing the barrier or boundary of the acute abscess as above described, that granulation tissue is formed, which takes up the effort of repair as soon as pus is evacuated. This boundary has no sharp limit, but shades off into healthy surrounding tissues.

Under the term “abscess” is meant that which is described as acute abscess. Under certain circumstances, especially when they are produced by the facultative pyogenic organisms rather than the obligate, abscesses form more slowly, and may be spoken of as subacute. These are terms used in contradistinction to the so-called cold abscesses, which, although clinically bearing a certain resemblance to the acute, are in almost every pathological respect different from it. Cold abscesses will be considered under the head of Tuberculosis. It is possible to have an acute pyogenic infection of a cold abscess; in such case we have acute manifestations. Gravitation abscesses are those where pus forming in one part tends to migrate, usually in the direction in which gravity would take it, extending into portions deeper or lower. Perhaps the best illustration of this is the pointing of a psoas abscess below Poupart’s ligament. Metastatic abscesses are those which are formed as the result of embolic processes, each one being in miniature a repetition of a lesion which has occurred at some other part of the body. The underlying fact concerning metastatic abscesses is that the primary process has occurred in some other portion of the body, whence it has been distributed as above. These will be considered in the chapter treating of Pyemia.

The product of all acute suppurative lesions is pus. This is an opaque fluid of creamy consistence and whitish or grayish appearance, varying in density, met with in amounts from a minute drop to half a gallon or more. Under ordinary circumstances it is odorless, and its reaction, either acid or alkaline, is very faint. It is, like the blood, composed of a fluid and a solid portion. The solid portion consists of so-called pus corpuscles and other debris of tissue, which vary with the site of the disease and the parts involved. The source of the pus corpuscles has been cited and the statement made that they are in effect the bodies of phagocytes which have perished in the biochemical fight for existence of the parent organism. Cocci or bacilli are found in pus corpuscles and also in the surrounding fluid.

Pus should be without odor, but under certain circumstances it possesses an odor which will vary in character according to the source of the pus or the nature of its principal bacterial excitant. Pus from the upper end of the alimentary canal frequently has the sour smell of gastric contents; that from the neighborhood of the lower end, the fetid odor which is for the most part due to the action of the colon bacillus. Inasmuch as colon bacilli are found in widely distant parts of the body, they may also give an unpleasant odor to pus even from a brain abscess. When the pus has become contaminated with the ordinary saprophytic organisms, it may smell like any other decomposing material. The older writers called it ichorous pus, while sanious pus was supposed to be that more or less mixed with blood, undergoing ammoniacal decomposition or else strongly acid. Pus sometimes has a well-marked blue or bluish-green tint. This is due to the presence of the bacillus pyocyaneus, already described. An orange tint is sometimes given by the presence of hematoidin crystals, due to the original hemorrhagic character of the infected exudate. The former appearance indicates usually a slow course to the suppurative lesion, while the latter has been regarded by some as affording an unfavorable prognosis. Distinctly red pus, whose tint is due to the presence of a bacillus giving bright-red cultures on blood serum, has been noted in other instances. This can readily be distinguished from blood, because upon dressings it does not change color.

Pus may form superficially, when it is called subcutaneous suppuration, in which case there is a minimum of pain, because tension is not great and the distance to the surface is short. Collections which form beneath the fasciæ, especially the deeper fasciæ of the limbs and trunk, give rise to much more extensive disturbance, both locally and generally, and frequently do not point for many days; or, instead of pointing, burrow deeply and find their outlet at some undesirable point. These are known as subfascial collections. Subperiosteal abscesses give rise to still more pain, because of the unyielding character of their limiting structures, and the symptoms caused by them are acute and distressing.

An illustration of the pain which may follow deep suppuration may also be seen in the ordinary panaritium, or bone felon, where the path of infection is from without, but the destructive lesion is confined within absolutely unyielding tissues, at least at first. Along certain tissues infection spreads with rapidity. This is particularly true of the delicate areolar tissue seen between tendons and tendon sheaths, and the infectious process may follow this tissue wherever it shall lead, even along complex courses.

The question often arises, Can pus be resorbed? There is no question but that small amounts of pus are disposed of by phagocytic activity, and the disappearance of purulent infiltration, under the influence of favoring remedies, or even when let alone, is not infrequently noted. True pus resorption is a question of phagocytic possibilities, and can occur only in very limited degree, as a result upon which it is not safe to count, and which is capable of encouragement only up to a certain point.

One inevitable law seems to govern collections of pus, that when they advance or migrate in any direction it is in that of least resistance. This causes them to take peculiar and sometimes disastrous courses, but it is a law which is never violated. It leads to the bursting of abscesses into the brain, into the pleural cavity, into the peritoneal cavity, the bowel, and elsewhere; it leads to a condition where pus may travel along a path even a foot or more in length, rather than come to the surface, a distance of perhaps an inch, and affords one of the best reasons for early operative interference so that the disastrous effects of burrowing may be obviated. When the pus is limited to a drop or fraction thereof the abscess is called a furuncle, especially when in the skin. The average “boil” of the layman is a subcutaneous or subfascial abscess. When the infiltration is pronounced, and when there has been more or less extensive destruction of tissue, with perhaps formation of numerous outlets for the escape of pus and detritus, it is known as a carbuncle. (See Chapter XXVI.) In certain conditions small superficial furuncles or boils form, sometimes in great number and almost synchronously, or, as it were, in crops. This condition is known as general furunculosis.

Signs and Symptoms of Abscesses.

—The appearances by which pus may be suspected or detected are those of congestion and hyperemia, more or less abruptly circumscribed and markedly accentuated. Along with these there is more or less edema or edematous infiltration of the skin and overlying tissue, which permits of that peculiar appearance known as “pitting on pressure.” Often, too, there is a distinctly edematous swelling of the parts, especially around the margin, with brawny infiltration of the centre of the infected area. Numerous vesicles occasionally are noted upon the skin, which may be filled with reddish serum. When softening and pus formation occur, there is a condition which to the palpating fingers gives the characteristic sensation known as fluctuation. Fluctuation simply points out the presence of fluid beneath; but when in an area marked as thus described fluctuation is noted, it means the presence of pus. It is detected by manipulating in a direction parallel to and concentric with the axis of the limb or part. The pain is also in most instances significant; patients speak of it as having an intense and throbbing character. With these local signs occur symptoms indicating some degree of septic intoxication, i. e., pyrexia, chills, malaise, sweats, etc., which are corroborative indications, their intensity being a reasonably correct index of the severity and gravity of the local infection.

When a deep-seated abscess is suspected a careful blood count will often permit a diagnosis to be made. This is conspicuously true of cases of appendicitis. If leukocytosis is established there should be immediate operation. (See Chapter II.)

It is seldom that a superficial collection of pus can be mistaken for anything else. In small and superficial abscesses (boils, furuncles) as pus approaches the superficial layer (epidermis) of the skin it may be discovered through its thin covering. In deep lesions there is often a doubt, even on the part of the most experienced. The measure now usually resorted to for purposes of diagnosis and exact recognition is the exploring or aspirating needle. The old exploring needle was one of good size, having a groove along which, after introduction, pus might pass. Since the almost universal use of the hypodermic syringe, a small aspirating needle attached to the ordinary syringe is the measure commonly adopted. Such a needle may be introduced into the brain, into the liver, or into almost any and every soft tissue without danger, and if properly manipulated is almost sure to facilitate detection of pus. Exploration done with either of these means and for this purpose should always be conducted as an aseptic, even if a minor operation, in order that no extra infection may be added from without. The skin should be carefully washed, the needle sterilized, etc.

It is good surgery to resort to the knife either for the above purpose or in order that by a longer incision or by opening the cavity deep exploration may be made. Such explorations are of benefit even though a circumscribed collection of pus is not found, since by relief of tension and local abstraction of blood they act in a revulsive way and do much good. Acting upon the same principle the trephine or the bone chisel may be used for the purpose of opening the cranium and exploring for pus, or of opening into the medullary canal of the long bones and hunting there for that which is suspected.

Treatment.

—As soon as suppuration threatens speedy measures should be adopted, either for the purpose of bringing about resorption, or of favoring and hastening suppuration. In theory antiseptic applications are demanded; in practice they are sometimes of benefit. These may consist of mere soothing applications, as a lead and opium wash, or some other wet or dry astringent applied upon the surface; or they may consist of cold applications, which by their astringent action will limit the amount of exudate and prevent its further infection. Or advantage may be taken of the properties of moist heat, and the application of hot poultices or fomentations may encourage exudation, but particularly quicken superficial breaking down, and thus hasten the time when the phlegmon shall point, or come sufficiently close to the surface to show that its contents are pus and permit of evacuation. Such local applications, therefore, give relief from pain and hasten favorably the suppurative process. In cases of phlegmonous infiltration, the application of an ointment composed of resorcin 5, ichthyol 10, mercurial ointment 35, and lanolin 50 parts, or else the Credé silver ointment, is beneficial. Under the influence of these antiseptic and sorbefacient preparations, and of moist heat, many phlegmonous infiltrations assume a kindlier type, and may secure the actual resorption of pus.

Finally in almost every case pus must be evacuated. Here the universal rule may be applied, to which there are practically no exceptions, and which should be stamped on the mind of every student and young practitioner. It is—that pus left to itself will do more harm than will the knife of the surgeon if judiciously used for its evacuation. Action taken in accordance with this rule may be considered wise and timely. The operation of evacuation may at one time be a mere puncture, or possibly the aspirating needle alone will be enough; at other times it requires extensive and careful dissection and entails no little responsibility. This is particularly true in such deep-seated suppurations as those around the appendix and in the brain, while in the deep-seated bone lesions of this character the use of the bone chisel or the cutting forceps may be of use. But the rule holds good, no matter where the pus may be, and as long as good judgment is shown in the operative procedure nothing but good can come from recognition of this law. After the evacuation of pus the cavity should be cleansed and disinfected with hydrogen dioxide, perhaps even with caustic pyrozone, or, if these are not at hand, with other suitable antiseptic solutions.

Ordinary judgment should be exercised in evacuating every abscess, in order that opening be made at that point which in the common position of the body shall be most favorable to drainage by mere gravity alone. If circumstances compel opening when advantage cannot be taken of gravity, then one or more counteropenings should be made at points selected where drainage may be best effected, and where anatomical conditions do not make it injudicious to incise. Drainage should be favored by the introduction of a drainage tube or of other aids, such as gauze, strands of catgut, bundles of horse-hair, etc. Finally, a dressing should be applied which is both protective and absorbent, and in quantity sufficient to make compression of the walls of the abscess cavity—not sufficient to obstruct drainage, but enough to favor prompt adhesion of surfaces, which by speedy granulation shall ensure prompt healing.

Abscesses are found in proximity to large vessels or dangerous anatomical regions, when care must be exercised in opening them. Here careful dissection should be made under an anesthetic. This is true of abscesses in the neck and of those around the appendix, for example, where the general peritoneal cavity is shut off only by more or less delicate adhesions, and where the surgeon must literally feel his way with great precaution lest adhesions be torn and the previously protected cavity infected. At other times, especially in abdominal abscesses, it is necessary to pack sponges or absorbent gauze in and about the parts, so that any fluid which may escape may be absorbed by these dressings.

Accompanying Disturbances.

—The disturbance of function which accompanies all congestion and exudation, whether provoked by specific irritants or not, has been alluded to; but in cases of surgical infections, especially those which produce local suppuration, disturbance of function is much greater, while there are other disturbances which sometimes constitute the worst feature of these cases. The presence of pus is often indicated, especially when deeply seated, by one or more chills, and the occurrence of a chill is always marked to varying degree by pyrexia. It is conceded that the chill is an expression of a general septic disturbance; but it is necessary also not to forget that general septic disturbance is a frequent accompaniment of pus which is not evacuated as soon as formed. Moreover in certain cases suppuration and septic infection seem to occur synchronously, one being local, the other general.

Pus may also be suspected beneath a surface which is red, tender, swollen, edematous, and pitting on pressure. When fluctuation is added to these indications any element of doubt is thereby dissipated.

Other indications of the presence of pus are a well-marked leukocytosis, coupled with the iodine reaction indicating the existence of glycogen in the blood, the presence of indican in the urine, and the positive results frequently obtained by making cultures from the blood. When pyogenic bacteria are found in the blood the inference is very plain, and both treatment and prognosis are influenced. In such a case the introduction into the blood of an antiseptic such as Credé’s soluble metallic silver or of the antistreptococcus serum, is plainly indicated. The absence of bacteria from the blood, under these circumstances, does not disprove the presence of pus, but their presence gives a very serious character to the disease, and should lead to a most guarded prognosis. Invasion of the blood by staphylococci is nearly twice as serious as when streptococci gain entrance. Suppuration of the bones and of the tendon sheaths is liable to produce such invasion.

The other disturbance with which suppuration is so often complicated is septic infection. In fact it may be questioned whether pyrexia is not an expression of this condition. Any collection of pus, no matter how small, may show signs of septic infection; and, on the other hand, large collections may be formed without serious septic symptoms—in other words, suppuration and expressions of septic infection may be blended in almost every conceivable way. Sepsis as a distinct condition will be described in another chapter.

It is important to summarize what may become of pus when once it has formed and is not promptly evacuated. Pus when long present may be—

• A. Absorbed;
• B. Encapsulated; and
• C. Undergo various degenerations or chemical alterations.

A. The possibility of the absorption of pus, or, what is equivalent to it, its spontaneous disappearance, has been mentioned. While it does not usually take this course, it may thus disappear; as, for instance, in the anterior chamber of the eye in cases of hypopyon, or in various other localities, particularly when present only in small amounts. The absorption of pus is purely a matter, as far as we know, of phagocytic activity plus the power of the tissues to take up various fluids.

B. Encapsulation.—This occurs only when pus has been present for some time and when the virulence of the pyogenic organisms is not intense. We may get encapsulation of pus in any part of the body, the most typical illustration naturally being within the bones. Around the purulent focus, as around any other irritating foreign body, the capsule is formed by condensation of surrounding tissue. This is the way in which most cold abscesses with their limiting membranes are produced, those produced by tubercle bacilli having slight irritating properties. Inasmuch, then, as the biological activity in such a focus is small, there is time for such encapsulation; while by the membrane thus formed, or the sanitary cordon, already referred to, protection is afforded to the surrounding tissues. In such a collection fresh infection may incite acute disturbances again, and many abscesses which thus lie latent for a considerable length of time are fanned, as it were, into a conflagration, when a new and acute inflammation is produced.

C. Of the various metamorphoses and chemical changes that occur in that which was originally pus, the caseous and the calcific are the most common. These also are connected largely with the tuberculous process, although calcareous particles are found in the pus of actinomycosis. Under their respective heads these degenerations will be more particularly described.

Certain names have been given to collections of pus in different localities or under peculiar circumstances. A collection of pus in the anterior chamber of the eye is known as hypopyon; when in any preëxisting cavity, it is known as empyema of that cavity, the distinction between empyema and abscess being that “abscess” means a circumscribed collection where previously there was no cavity, while “empyema” implies a normal cavity, without respect to size or location, filled with this abnormal fluid. The term empyema, when not used in connection with some particular cavity, is understood to refer to a collection of pus in the pleural cavity. Other names also are used which are particulate and distinctive; in these the prefix pyo is used while the suffix indicates the part involved; thus we have pyothorax, pyopericardium, pyarthrosis, etc.

SINUS AND FISTULA.

These are terms applied to more or less tubular channels abnormally connecting various parts of the body, or connecting some cavity with the surface of the body in a way anatomically quite abnormal. Or they may be regarded as tubular ulcers, or ulcerated tunnels, connecting as above. A more exact distinction between the two terms would imply that a sinus connects the surface with some deeper portion where a cavity is not normally present—i. e., with a focus of disease—whereas a fistula properly refers to a tubular passage connecting natural or preëxisting cavities in an abnormal manner. Thus we speak of buccal, rectal, vesicovaginal fistulas, etc., whereas a passage leading down to an old abscess or to a focus of disease in bone, for instance, is properly referred to as a sinus. It is possible for the margins of a fistula to become more or less cicatrized and cease to be ulcerous, whereas the entire track of a sinus is practically a continuous ulcer, only tubular in arrangement.

Causes.

A. Congenital.

—There are numerous points about the body where, as the result of arrest of development or failure to grow, fistulous passages which are comprised within the normal fetal arrangements, but which should close later, either before or at birth, fail to do so. Thus we have congenital fistulas of the neck, persistent urachus, persistent omphalomesenteric duct, etc. These are in no sense primarily connected with diseased conditions, but may become so secondarily.

B. Pre-existing Abscess with Unhealed Channel of Escape

—e. g., rectal, fecal, and other fistulas and sinuses which connect with tuberculous foci in any part of the body.

C. Previous Traumatic or other Destruction of Normal Tissues

—e. g., vesicovaginal fistulas due to tissue death from pressure, buccal fistulas from gangrene of the cheek, as in noma.

D. Foreign Bodies

—bullets, ligatures, etc.—which prove irritating or infectious enough to prevent absolute healing. More or less tortuous sinuses will generally be found leading down to the irritating material.

E. The Presence of Necrosed or Necrotic Material

—e. g., a sequestrum in bone, which is usually evidenced by the presence of one or more sinuses.

Treatment.

—If the determining cause is still acting, the treatment is to remove the cause. Consequently, when the sinus leads down to diseased bone or other dead or dying tissue, the complete evacuation of the cavity is necessary before the sinus may heal. If the cause is a foreign body, its removal should be at once insisted upon.

An excellent suggestion is to stain all fistulous tracks with methylene-blue; the blue trail after doing this may be followed, no matter how irregular its course (Fergusson). If the color is mixed with a little hydrogen dioxide, and this forced into a sinus mouth or a fistulous opening, it will carry the dye to all parts of the cavity. This may be used even in dealing with fecal fistulas or those extending deeply into the interior of the body or among the viscera.

Fistulas of congenital origin and those which connect two normal cavities of the human body are usually due to a cause which has ceased to act. Consequently we should endeavor solely to atone for the result. The direction and the course of a sinus may be learned by the use of a probe curved to suit and manipulated by a gentle hand, force never being required. Or sometimes, when the silver instrument fails to pass, a flexible bougie or catheter may be introduced. The character of the passage can be judged for the most part by the appearance of the discharges. With sinuses of recent origin leading down to recent suppurative foci it may be sufficient to enlarge the opening and to wash the cavity thoroughly. If a particle of gauze, tube, or sponge has been left therein, its removal is necessary to secure prompt healing. In cases of long standing antiseptic and stimulating substances should be injected or the interior should be cauterized with strong solutions of zinc chloride or silver nitrate, or with these melted upon the end of a probe. The chronic sinus, as well as the chronic rectal fistula, is usually an expression of local tuberculous disease. Accordingly these passages may be found lined with the same dense, fungating membrane which lines a cold abscess cavity—the membrane, protective in its purpose, to which I have given the name pyophylactic. Whenever such tissue and such membrane are met with they should both be extirpated thoroughly, since in this way only can absolute eradication of the tuberculous infection be relied upon. After such complete excision—which means usually laying open the entire sinus—the parts may be brought together with sutures (this, at least, is usually possible about the rectum) to secure primary union; otherwise, the whole sinus, as well as the cavity to which it has led, must heal by the granulating process, both being kept packed with gauze or some other desirable foreign body acting as an irritant, thereby provoking more rapid formation of granulation tissue. When it is necessary thus to pack a cavity, or when it is desired to keep its upper exit open lest it heal before the lower part, ordinary white beeswax, as suggested by Gunn, makes a serviceable material. This can be molded in hot water to fit the cavity; can be tunnelled or bored for drainage; can be diminished in size as the cavity heals, and is absolutely non-absorbent.

Finally there are numerous plastic methods which have been resorted to in various parts of the body, most of which are made to comprise, first, the absolute eradication of the diseased tract, and, later, the closure of the wound thus made by transplantation or sliding of flaps, or any other plastic expedient which may be considered best. These, as well as the special treatment made necessary for particular forms of sinus and fistula, will be dealt with under their proper headings.