Pyæmia does not supervene at once upon a trauma as may septicæmia, but only after a variable number of days, (3 to 8), a peculiarity which is explained by the temporary protection of the clot. By the constant accretions on its exterior, of the new layers of hæmatoblasts and fibrin, the microbes are at first imprisoned, and it is only when softening has taken place, or when the coagulum has extended into the free flowing current passing into a colateral trunk, that the infection is liable to be washed on in dangerous amount.
The mere presence of pus microbes or their toxins in the blood, does not determine pyæmia: a modification of the intima of the vessels leading to local infections with thrombosis or embolism and abscess is an essential condition. This lesion of the vessels may be a trauma, as from bruise, puncture, operation, ligature, or it may be the extension of a disease process as in arteritis, phlebitis, atheroma, the growth of a tumor from adjacent tissues, or parasitism. The seat of the secondary abscess depends primarily on the location of the original suppurating centre. As such centres are most commonly in the systemic circulation (osteomyelitis, omphalitis, wounds, traumas) the lungs are most commonly attacked, the pulmonary capillaries acting as a sieve and arresting the floating infective coagula. When the primary infection comes from the chylo-poietic viscera, the liver is likely to show the first crop of secondary abscesses. When, on the other hand, the primary abscess is in the lungs, the great flow of blood through the kidney renders it especially subject to secondary suppurating foci, though these may form in any part of the body.
Lesions. Pyæmia may result from a wound or abscess in connection with which will usually be found a vein containing a thrombus more or less softened or liquefied. If from a deep seated injury or from osteomyelitis, the same condition is met with. The thrombus and circulating blood furnish abundance of the infective microbes, and at distant points, in the complimentary circulation, most commonly in the lungs the arteries are found to be the seats of embolism from arrested clots. The arrest always takes place where the vessels are diminished by bifurcation, or the giving off of a considerable colateral trunk, and the appearances will depend on the duration of the embolism. If quite recent, a wedge-shaped mass of tissue supplied by the vessel is ischæmic and pale, its blood passing on into the veins without further arterial supply; if later, this tissue forms an infarct being gorged with deep red or black blood which has filtered in from adjacent anostomosing capillaries and distended those of the exsanguine area. This area becomes of a deep red or black color, consolidated by an exudate of lymph, and rapidly invaded by suppuration. The microbes determine suppuration and softening, first in the clot and intima, and next in the outer coats of the vessel and the surrounding exudate, so that an abscess of variable size may result. Abscesses are usually smaller and more numerous in the acute forms of the disease, and larger and less numerous in the more chronic.
Ulcerative endocarditis with coagula on the valves is not uncommon. The spleen is often the seat of small abscesses in the centre of solid exudates, with in many cases softening and enlargement of the organ. The blood tends to retain its normal bright red color, and clots firmly, contrary to the usual condition in septicæmia.
Symptoms. The formation of emboli and secondary abscess is usually marked by a violent rigor, lasting from a few minutes to an hour and which may be repeated at irregular intervals, serving, in some measure, to distinguish pyæmia from septicæmia. The temperature rises with the rigor, (102° to 105°) but shows marked remissions especially in the morning, when it may not exceed the normal, and rising again with the recurrence of chill or staring coat. The pulse is usually encreased in frequency even during the remissions and is soft and compressible. Remissions may be attended by profuse perspirations or even, in the advanced stages, by fœtid diarrhœa. The breath has a peculiar sweetish or mawkish odor. Blood passed with the fæces may indicate intestinal abscess, and albumen or pus in the acid urine, bespeaks suppurating foci in the kidney. The cloudy mucus from the pelvis of the kidney in the horse must not be mistaken for this. Cough or dyspnœa will indicate abscess of the lungs, and intercostal tenderness, pleurisy.
The buccal mucosa may be dry and cracked, and the tongue coated. From the first the animal is dull, and prostrate, and the visible mucosæ become dusky brown or even yellowish from the liberated hæmatin. Blood abstracted, will show the microörganism, an excess of leucocytes and diminution of the red globules. The poison determines hæmolysis. A cardiac murmur, usually with the first sound, betrays endocarditis. This is especially characteristic of chronic pyæmia. Again multiple suppurating arthritis may appear. Stupor, coma or paralysis will indicate cerebral or meningeal lesions.
In pyæmia following trauma there is drying up of the pus which becomes serous or bloody, a puffy condition of the granulations, and the evidence of a thrombus in one or more veins leading out from the wound.
In other cases the occurrence of pyæmic symptoms, consequent on parturition, metritis, omphalitis, bone-abscess or osteomyelitis, on suppurating internal inflammations, ulcerative endocarditis, or infective fevers like strangles, influenza, contagious pneumonia, cattle plague, distemper, rouget, hog cholera, etc., serves to identify the disease.
The prognosis of pyæmia is always grave, and death may be expected in six to fourteen days in acute cases. Chronic forms last much longer.
Prevention is the great object in regard to surgical cases, and this means the prevention of suppuration in the wound. As far as possible, however, this is to be sought by asepsis, or the use of weak non-caustic antiseptics only, as cauterized tissues form favorable culture media, when the action of the antiseptic is spent, there being no longer any living and resistant leucocytes present. The early excision of veins, the seat of thrombosis, has proven successful.
In purely medical cases, the seat of the primary suppuration is not always obvious and one is thrown back on medical treatment which is rarely satisfactory in severe cases.
Treatment. When accessible even the secondary abscesses may be opened, washed out with a weak antiseptic (3 per cent. carbolic acid solution), and covered with antiseptic dressing. Antipyretics are worse than useless, because of the resulting depression of the vital powers, and the reduction of the natural powers of resistance. Calomel in small and repeated doses tends to assist in elimination, and to counteract complications through sepsis of the contents of the bowels. Quinine and chloride of iron continued in large doses have been especially relied on as antiseptic tonics. Liberal feeding, if the appetite will admit, is all important, to tide the patient over the period of depression. In the chronic cases tepid bathing is of great value (Senn). Senn has great confidence in the stimulating and supporting action of alcoholic liquors—beer, ale, porter and even whisky, and in human beings accustomed to the daily use of these beverages they are more imperative than in the lower animals.
=Septicæmia.= The micro-organisms causing septicæmia are the same as those of pyæmia, but they differ somewhat in activity, and act upon a system with a modified susceptibility, and above all one void of lesions in the internal membrane of the vascular system. The symptoms can be developed by the introduction of the ptomaines and toxins alone, which hypothetical condition has been named septic-intoxication. In case of excessive doses of septic material, death occurs so early as to indicate simple narcosis. If, as is usually the case, the microbes also gain access to the blood and multiply there, the condition has been known as septic infection. In any prolonged case of septicæmia, the tendency is to the formation of suppurating foci (septico-pyæmia), so that the two affections may be looked upon as probably the same, with modifications of the earlier phenomena.
In connection with septicæmia must be mentioned the fermentation fever of Bergmann, (aseptic or resorption fever) which follows on extensive wounds, even if aseptic, on the intravenous injection of the blood of healthy animals or even of fine foreign particles (charcoal, flour), of a normal salt solution, or of well water, or of pancreatin, pepsin or trypsin. It has been attributed to the introduction and metabolism of fibrine and other elements, but manifestly arises also from the solution of blood globules, (hæmolysis). It comes on within a few hours after a severe operation or other cause and lasts from one to three days, terminating in recovery, unless complicated by some intercurrent infection.
The sapræmic fever, of Mathews Duncan (sapros—putrid, haima—blood) may also be named in this connection. It is associated with one or more of the common saprophytes (Bacillus saprogenes 1–2 and 3 of Rosenbach, Proteus Vulgaris, Proteus Zenkeri, Proteus mirable, etc.) These are propagated with difficulty in the blood, but grow readily in pus or necrotic tissue from which their toxic products can pass into the blood.
Again the observations of Brieger and Maas, Ruine, Vaughan, Bourget and others show that the isolated toxins from putrefactive fermentation of animal matters, apart from the living bacteria are capable of producing the characteristic symptoms of septicæmia.
It is now generally concluded that the septicæmic phenomena can be produced by the introduction of such poisons, whether they are the product of septic fermentations outside the animal poisoned, or of fermentation in dead matter in the economy of such animal.
Lesions. In fermentation fever no tissue lesions are known. In septicæmia gross lesions are usually lacking unless the case has been prolonged to allow of secondary abscesses (septico-pyæmia). The blood however is dark and coagulates feebly if at all. The spleen is enlarged, softened, dark in color and gorged with blood. There are petechial hæmorrhages into the serosæ and mucosæ, and the solid organs; cloudy swelling of internal organs from coagulation necrosis; a parboiled appearance of heart, liver, kidneys and voluntary muscles; congestion of the lymph glands and usually the presence of the specific microbes in the blood and local lesions. The kidneys are always congested, and their epithelia granular and swollen, and there may be exudation between the glomeruli and their capsules.
Symptoms. Septic intoxication or septic infection may be ushered in by a staring coat or slight chill, but it rarely shows a violent rigor, such as inaugurates pyæmia. There is a rapid rise of temperature (102° to 104°), which persists for three to seven days without the marked remissions of pyæmia; weak, compressible pulse; great muscular debility; hurried, shallow breathing, usually without cough; anorexia; emesis in vomiting animals; dusky or yellow mucosæ from dissolved hæmoglobin; scanty, high colored urine, rarely albuminous; dulness, sometimes nervous twitching, delirium, apathy, stupor or paraplegia; and either constipation or, later, diarrhœa. When such symptoms supervene on a gangrenous sore, septic abscess or fistula, retained placenta, blood clot in the uterus or elsewhere, suppurating tubercle, or other morbid product, gangrenous lung or other internal organ, purulent pericarditis, pleuritis or peritonitis, or any febrile affection which is complicated by necrosis, septicæmia is to be suspected. “Septicæmia should always be suspected during the course of any disorder the lesions of which afford an opportunity for the growth and development of septic microörganisms, when the symptoms of that disorder depart from the usual type and an elevated temperature continues beyond the usual duration.” (Atkinson). “The final diagnosis of septic infection must be based on the existence of an infection atrium, through which pus microbes have entered the tissues, and from which they have reached the general circulation.” (Senn).
Prognosis is always grave. A slight infection, overcome by the leucocytes or a simple septic intoxication may get well in two or three days, but an acute progressive septic infection will usually prove fatal in from one to seven days.
Prevention does not differ from that recommended for pyæmia.
Treatment is virtually hopeless unless it can secure the removal of the necrotic tissue or fermenting material from which the poison is derived. When the poisoning is due to the absorption of septic products only, with little or no introduction of microbes (septic intoxication) the removal of their source of supply may bring about a speedy and permanent improvement. The removal of a putrid placenta, or liquid from the womb, followed by irrigation with an antiseptic lotion, the evacuation of a putrid abscess, empyema, or ascites, followed by a similar disinfection, or indeed the extirpation of a sloughing and putrid mass of any kind may be followed by a lowering of temperature within a few hours, and a steady improvement in the general symptoms. The antiseptic agents employed must be sufficiently potent, and persistently applied to render the surface sterile and yet not so caustic as to destroy more tissue to become a future culture medium for the septic microbes. Mercuric chloride (1:2000), aluminium acetate (1:100), powdered iodoform, or aristol will often serve a good purpose, to be followed, when necessary, by efficient drainage and a covering of antiseptic gauze. When the primary source of infection is in the intestinal canal, calomel, naphthalin or B. napthol may be tried.
For the weak heart strychnine is the most safe and reliable agent. Quinia in large doses acts as an antipyretic, without the attendant dangers of the coal tar products. It may be advantageously combined with tincture of chloride of iron.
Ammoniacal and alcoholic stimulants are largely resorted to to tide the patient over the period of depression, and nourishing and easily digested food should be given so far as the stomach can make use of it. Skim milk, eggs, and beef tea may be given even to the herbivorous patient.
The thirst should be met by plenty of pure water to favor elimination of the toxins, and the surface frequently sponged with tepid water, not only on the ground of cleanliness and disinfection, but also as calculated to lower the febrile temperature.
MALIGNANT ŒDEMA.
Definition. Causes. Bacillus septicæmiæ gangrenosa, anærobic, rarely in living blood. Source of germ in soils. Pathogenic to man and domestic animals except cattle. First attack immunizes. Infects deep wound, exudates, dropsical and gangrenous parts, womb, intestine, debilitated parts, large dose intravenously. Lesions and symptoms: excess of exudate, boggy swelling, watery discharge, fœtid gas bubbles, œdema of lungs and bowels. Complex infection. Minimum dose—abscess. Diagnosis: from black quarter and anthrax. Treatment: free incisions, hydrogen peroxide. Prevention: disinfection of skin and wounds. Immunity.
Definition. An acute bacteridian disease of domestic and wild mammals, and of man, manifested by doughy, painful and often crepitating swelling in the vicinity of the affected part, and proving fatal in many cases in twenty-four to forty-eight hours.
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