We have here to consider under the terms Sapræmia, Septicæmia, and Pyæmia certain general effects of pyogenic infection, which, although their clinical manifestations may vary, are all associated with the action of the same forms of bacteria. They may occur separately or in combination, or one may follow on and merge into another.
Sapræmia, or septic intoxication, is the name applied to a form of poisoning resulting from the absorption into the blood of the toxic products of pyogenic bacteria. These products, which are of the nature of alkaloids, act immediately on their entrance into the circulation, and produce effects in direct proportion to the amount absorbed. As the toxins are gradually eliminated from the body the symptoms abate, and if no more are introduced they disappear. Sapræmia in these respects, therefore, is comparable to poisoning by any other form of alkaloid, such as strychnin or morphin.
Clinical Features.—The symptoms of sapræmia seldom manifest themselves within twenty-four hours of an operation or injury, because it takes some time for the bacteria to produce a sufficient dose of their poisons. The onset of the condition is marked by a feeling of chilliness, sometimes amounting to a rigor, and a rise of temperature to 102°, 103°, or 104° F., with morning remissions (Fig. 10). The heart's action is markedly depressed, and the pulse is soft and compressible. The appetite is lost, the tongue dry and covered with a thin brownish-red fur, so that it has the appearance of “dried beef.” The urine is scanty and loaded with urates. In severe cases diarrhœa and vomiting of dark coffee-ground material are often prominent features. Death is usually impending when the skin becomes cold and clammy, the mucous membranes livid, the pulse feeble and fluttering, the discharges involuntary, and when a low form of muttering delirium is present.
A local form of septic infection is always present—it may be an abscess, an infected compound fracture, or an infection of the cavity of the uterus, for example, from a retained portion of placenta.
Treatment.—The first indication is the immediate and complete removal of the infected material. The wound must be freely opened, all blood-clot, discharge, or necrosed tissue removed, and the area disinfected by washing with sterilised salt solution, peroxide of hydrogen, or eusol. Stronger lotions are to be avoided as being likely to depress the tissues, and so interfere with protective phagocytosis. On account of its power of neutralising toxins, iodoform is useful in these cases, and is best employed by packing the wound with iodoform gauze, and treating it by the open method, if this is possible.
The general treatment is carried out on the same lines as for other infective conditions.
Chronic sapræmia or Hectic Fever.—Hectic fever differs from acute sapræmia merely in degree. It usually occurs in connection with tuberculous conditions, such as bone or joint disease, psoas abscess, or empyema, which have opened externally, and have thereby become infected with pyogenic organisms. It is gradual in its development, and is of a mild type throughout.
The pulse is small, feeble, and compressible, and the temperature rises in the afternoon or evening to 102° or 103° F. (Fig. 11), the cheeks becoming characteristically flushed. In the early morning the temperature falls to normal or below it, and the patient breaks into a profuse perspiration, which leaves him pale, weak, and exhausted. He becomes rapidly and markedly emaciated, even although in some cases the appetite remains good and is even voracious.
The poisons circulating in the blood produce waxy degeneration in certain viscera, notably the liver, spleen, kidneys, and intestines. The process begins in the arterial walls, and spreads thence to the connective-tissue structures, causing marked enlargement of the affected organs. Albuminuria, ascites, œdema of the lower limbs, clubbing of the fingers, and diarrhœa are among the most prominent symptoms of this condition.
The prognosis in hectic fever depends on the completeness with which the further absorption of toxins can be prevented. In many cases this can only be effected by an operation which provides for free drainage, and, if possible, the removal of infected tissues. The resulting wound is best treated by the open method. Even advanced waxy degeneration does not contra-indicate this line of treatment, as the diseased organs usually recover if the focus from which absorption of toxic material is taking place is completely eradicated.
Septicæmia.—This form of blood-poisoning is the result of the action of pyogenic bacteria, which not only produce their toxins at the primary seat of infection, but themselves enter the blood-stream and are carried to other parts, where they settle and produce further effects.
Clinical Features.—There may be an incubation period of some hours between the infection and the first manifestation of acute septicæmia. In such conditions as acute osteomyelitis or acute peritonitis, we see the most typical clinical pictures of this condition. The onset is marked by a chill, or a rigor, which may be repeated, while the temperature rises to 103° or 104° F., although in very severe cases the temperature may remain subnormal throughout, the virulence of the toxins preventing reaction. It is in the general appearance of the patient and in the condition of the pulse that we have our best guides as to the severity of the condition. If the pulse remains firm, full, and regular, and does not exceed 110 or even 120, while the temperature is moderately raised, the outlook is hopeful; but when the pulse becomes small and compressible, and reaches 130 or more, especially if at the same time the temperature is low, a grave prognosis is indicated. The tongue is often dry and coated with a black crust down the centre, while the sides are red. It is a good omen when the tongue becomes moist again. Thirst is most distressing, especially in septicæmia of intestinal origin. Persistent vomiting of dark-brown material is often present, and diarrhœa with blood-stained stools is not uncommon. The urine is small in amount, and contains a large proportion of urates. As the poisons accumulate, the respiration becomes shallow and laboured, the face of a dull ashy grey, the nose pinched, and the skin cold and clammy. Capillary hæmorrhages sometimes take place in the skin or mucous membranes; and in a certain proportion of cases cutaneous eruptions simulating those of scarlet fever or measles appear, and are apt to lead to errors in diagnosis. In other cases there is slight jaundice. The mental state is often one of complete apathy, the patient failing to realise the gravity of his condition; sometimes there is delirium.
The prognosis is always grave, and depends on the possibility of completely eradicating the focus of infection, and on the reserve force the patient has to carry him over the period during which he is eliminating the poison already circulating in his blood.
The treatment is carried out on the same lines as in sapræmia, but it is less likely to be successful owing to the organisms having entered the circulation. When possible, the primary focus of infection should be dealt with.
Pyæmia is a form of blood-poisoning characterised by the development of secondary foci of suppuration in different parts of the body. Toxins are thus introduced into the blood, not only at the primary seat of infection, but also from each of these metastatic collections. Like septicæmia, this condition is due to pyogenic bacteria, the streptococcus pyogenes being the commonest organism found. The primary infection is usually in a wound—for example, a compound fracture—but cases occur in which the point of entrance of the bacteria is not discoverable. The dissemination of the organisms takes place through the medium of infected emboli which form in a thrombosed vein in the vicinity of the original lesion, and, breaking loose, are carried thence in the blood-stream. These emboli lodge in the minute vessels of the lungs, spleen, liver, kidneys, pleura, brain, synovial membranes, or cellular tissue, and the bacteria they contain give rise to secondary foci of suppuration. Secondary abscesses are thus formed in those parts, and these in turn may be the starting-point of new emboli which give rise to fresh areas of pus formation. The organs above named are the commonest situations of pyæmic abscesses, but these may also occur in the bone marrow, the substance of muscles, the heart and pericardium, lymph glands, subcutaneous tissue, or, in fact, in any tissue of the body. Organisms circulating in the blood are prone to lodge on the valves of the heart and give rise to endocarditis.
Clinical Features.—Before antiseptic surgery was practised, pyæmia was a common complication of wounds. In the present day it is not only infinitely less common, but appears also to be of a less severe type. Its rarity and its mildness may be related as cause and effect, because it was formerly found that pyæmia contracted from a pyæmic patient was more virulent than that from other sources.
In contrast with sapræmia and septicæmia, pyæmia is late of developing, and it seldom begins within a week of the primary infection. The first sign is a feeling of chilliness, or a violent rigor lasting for perhaps half an hour, during which time the temperature rises to 103°, 104°, or 105° F. In the course of an hour it begins to fall again, and the patient breaks into a profuse sweat. The temperature may fall several degrees, but seldom reaches the normal. In a few days there is a second rigor with rise of temperature, and another remission, and such attacks may be repeated at diminishing intervals during the course of the illness (Figs. 12 and 13). The pulse is soft, and tends to remain abnormally rapid even when the temperature falls nearly to normal.
The face is flushed, and wears a drawn, anxious expression, and the eyes are bright. A characteristic sweetish odour, which has been compared to that of new-mown hay, can be detected in the breath and may pervade the patient. The appetite is lost; there may be sickness and vomiting and profuse diarrhœa; and the patient emaciates rapidly. The skin is continuously hot, and has often a peculiar pungent feel. Patches of erythema sometimes appear scattered over the body. The skin may assume a dull sallow or earthy hue, or a bright yellow icteric tint may appear. The conjunctivæ also may be yellow. In the latter stages of the disease the pulse becomes small and fluttering; the tongue becomes dry and brown; sordes collect on the teeth; and a low muttering form of delirium supervenes.
Secondary infection of the parotid gland frequently occurs, and gives rise to a suppurative parotitis. This condition is associated with severe pain, gradually extending from behind the angle of the jaw on to the face. There is also swelling over the gland, and eventually suppuration and sloughing of the gland tissue and overlying skin.
Secondary abscesses in the lymph glands, subcutaneous tissue, or joints are often so insidious and painless in their development that they are only discovered accidentally. When the abscess is evacuated, healing often takes place with remarkable rapidity, and with little impairment of function.
The general symptoms may be simulated by an attack of malaria.
Prognosis.—The prognosis in acute pyæmia is much less hopeless than it once was, a considerable proportion of the patients recovering. In acute cases the disease proves fatal in ten days or a fortnight, death being due to toxæmia. Chronic cases often run a long course, lasting for weeks or even months, and prove fatal from exhaustion and waxy disease following on prolonged suppuration.
Treatment.—In such conditions as compound fractures and severe lacerated wounds, much can be done to avert the conditions which lead to pyæmia, by applying a Bier's constricting bandage as soon as there is evidence of infection having taken place, or even if there is reason to suspect that the wound is not aseptic.
If sepsis is already established, and evidence of general infection is present, the wound should be opened up sufficiently to admit of thorough disinfection and drainage, and the constricting bandage applied to aid the defensive processes going on in the tissues. If these measures fail, amputation of the limb may be the only means of preventing further dissemination of infective material from the primary source of infection.
Attempts have been made to interrupt the channel along which the infective emboli spread, by ligating or resecting the main vein of the affected part, but this is seldom feasible except in the case of the internal jugular vein for infection of the transverse sinus.
Secondary abscesses must be aspirated or opened and drained whenever possible.
The general treatment is conducted on the same lines as on other forms of pyogenic infection.