Dusting powders and poultice dressings are best avoided in the treatment of healing sores.

In extensive ulcers resulting from recent burns, if the granulations are healthy and aseptic, skin-grafts may safely be placed on them directly. If, however, their asepticity cannot be relied upon, it is necessary to scrape away the superficial layer of the granulations, the young fibrous tissue underneath being conserved, as it is sufficiently vascular to nourish the grafts placed on it.

Treatment of Special Varieties of Ulcers.—Before beginning to treat a given ulcer, two questions have to be answered—first, What are the causative conditions present? and second, In what condition do I find the ulcer?—in other words, In what particulars does it differ from a healthy healing sore?

If the cause is a local one, it must be removed; if a constitutional one, means must be taken to counteract it. This done, the condition of the ulcer must be so modified as to bring it into the state of a healing sore, after which it will be managed on the lines already laid down.

Treatment in relation to the Cause of the Ulcer.—Traumatic Group.—The prophylaxis of these ulcers consists in excluding bacteria, by cleansing crushed or bruised parts, and applying sterilised dressings and properly adjusted splints. If there is reason to fear that the disinfection has not been complete, a Bier's constricting bandage should be applied for some hours each day. These measures will often prevent a grossly injured portion of skin dying, and will ensure asepticity should it do so. In the event of the skin giving way, the same form of dressing should be continued till the slough has separated and a healthy granulating surface is formed. The protective dressing appropriate to a healing sore is then substituted. Pressure sores are treated on the same lines.

The treatment of ulcers caused by burns and scalds will be described later.

In ulcers of the leg due to interference with the venous return, the primary indication is to elevate the limb in order to facilitate the flow of the blood in the veins, and so admit of fresh blood reaching the part. The limb may be placed on pillows, or the foot of the bed raised on blocks, so that the ulcer lies on a higher level than the heart. Should varicose veins be present, the question of operative treatment must be considered.

When an imperfect nerve supply is the main factor underlying ulcer formation, prophylaxis is the chief consideration. In patients suffering from spinal injuries or diseases, cerebral paralysis, or affections of the peripheral nerves, all sources of irritation, such as ill-fitting splints, tight bandages, moist applications, and hot bottles, should be avoided. Any part liable to pressure, from the position of the patient or otherwise, must be carefully protected by pads of wool, air-cushions, or water-bags, and must be kept absolutely dry. The skin should be hardened by daily applications of methylated spirit.

Should an ulcer form in spite of these precautions, the mildest antiseptics must be employed for bathing and dressing it, and as far as possible all dressings should be dry.

The perforating ulcer of the foot calls for special treatment. To avoid pressure on the sole of the foot, the patient must be confined to bed. As the main local obstacle to healing is the down-growth of epithelium along the sides of the ulcer, this must be removed by the knife or sharp spoon. The base also should be excised, and any bone which may have become involved should be gouged away, so as to leave a healthy and vascular surface. The cavity thus formed is stuffed with bismuth or iodoform gauze and encouraged to heal from the bottom. As the parts are insensitive an anaesthetic is not required. After the ulcer has healed, the patient should wear in his boot a thick felt sole with a hole cut out opposite the situation of the cicatrix. When a joint has been opened into, the difficulty of thoroughly getting rid of all unhealthy and infected granulations is so great that amputation may be advisable, but it is to be remembered that ulceration may recur in the stump if pressure is put upon it. The treatment of any nervous disease or glycosuria which may coexist is, of course, indicated.

Exposure of the plantar nerves by an incision behind the medial malleolus, and subjecting them to forcible stretching, has been employed by Chipault and others in the treatment of perforating ulcers of the foot.

The ulcer that forms in relation to callosities on the sole of the foot is treated by paring away all the thickened skin, after softening it with soda fomentations, removing the unhealthy granulations, and applying stimulating dressings.

Treatment of Ulcers due to Constitutional Causes.—When ulcers are associated with such diseases as tuberculosis, syphilis, diabetes, Bright's disease, scurvy, or gout, these must receive appropriate treatment.

The local treatment of the tuberculous ulcer calls for special mention. If the ulcer is of limited extent and situated on an exposed part of the body, the most satisfactory method is complete removal, by means of the knife, scissors, or sharp spoon, of the ulcerated surface and of all the infected area around it, so as to leave a healthy surface from which granulations may spring up. Should the raw surface left be likely to result in an unsightly scar or in cicatricial contraction, skin-grafting should be employed.

For extensive ulcers on the limbs, the chest wall, or on other covered parts, or when operative treatment is contra-indicated, the use of tuberculin and exposure to the Rontgen rays have proved beneficial. The induction of passive hyperaemia, by Bier's or by Klapp's apparatus, should also be used, either alone or supplementary to other measures.

No ulcerative process responds so readily to medicinal treatment as the syphilitic ulcer does to the intra-venous administration of arsenical preparations of the "606" or "914" groups or to full doses of iodide of potassium and mercury, and the local application of black wash. When the ulceration has lasted for a long time, however, and is widespread and deep, the duration of treatment is materially shortened by a thorough scraping with the sharp spoon.

Treatment in relation to the Condition of the Ulcer.—Ulcers in a weak condition.—If the weak condition of the ulcer is due to anaemia or kidney disease, these affections must first be treated. Locally, the imperfect granulations should be scraped away, and some stimulating agent applied to the raw surface to promote the growth of healthy granulations. For this purpose the sore may be covered with gauze smeared with a 6 to 8 per cent. ointment of scarlet-red, the surrounding parts being protected from the irritant action of the scarlet-red by a layer of vaseline. A dressing of gauze moistened with eusol or of boracic lint wrung out of red lotion (2 grains of sulphate of zinc, and 10 minims of compound tincture of lavender, to an ounce of water), and covered with a layer of gutta-percha tissue, is also useful.

When the condition has resulted from the prolonged use of moist dressings, these must be stopped, the redundant granulations clipped away with scissors, the surface rubbed with silver nitrate or sulphate of copper (blue-stone), and dry dressings applied.

When the ulcer has assumed the characters of a healing sore, skin-grafts may be applied to hasten cicatrisation.

Ulcers in a callous condition call for treatment in three directions—(1) The infective element must be eliminated. When the ulcer is foul, relays of charcoal poultices (three parts of linseed meal to one of charcoal), maintained for thirty-six to forty-eight hours, are useful as a preliminary step. The base of the ulcer and the thickened edges should then be freely scraped with a sharp spoon, and the resulting raw surface sponged over with undiluted carbolic acid or iodine, after which an antiseptic dressing is applied, and changed daily till healthy granulations appear. (2) The venous return must be facilitated by elevation of the limb and massage. (3) The induration of the surrounding parts must be got rid of before contraction of the sore is possible. For this purpose the free application of blisters, as first recommended by Syme, leaves little to be desired. Liquor epispasticus painted over the parts, or a large fly-blister (emplastrum cantharidis) applied all round the ulcer, speedily disperses the inflammatory products which cause the induration. The use of elastic pressure or of strapping, of hot-air baths, or the making of multiple incisions in the skin around the ulcer, fulfils the same object.

As soon as the ulcer assumes the characters of a healing sore, it should be covered with skin-grafts, which furnish a much better cicatrix than that which forms when the ulcer is allowed to heal without such aid.

A more radical method of treatment consists in excising the whole ulcer, including its edges and about a quarter of an inch of the surrounding tissue, as well as the underlying fibrous tissue, and grafting the raw surface.

Ambulatory Treatment.—When the circumstances of the patient forbid his lying up in bed, the healing of the ulcer is much delayed. He should be instructed to take every possible opportunity of placing the limb in an elevated position, and must constantly wear a firm bandage of elastic webbing. This webbing is porous and admits of evaporation of the skin and wound secretions—an advantage it has over Martin's rubber bandage. The bandage should extend from the toes to well above the knee, and should always be applied while the patient is in the recumbent position with the leg elevated, preferably before getting out of bed in the morning. Additional support is given to the veins if the bandage is applied as a figure of eight.

We have found the following method satisfactory in out-patient practice. The patient lying on a couch, the limb is raised about eighteen inches and kept in this position for five minutes—till the excess of blood has left it. With the limb still raised, the ulcer with the surrounding skin is covered with a layer, about half an inch thick, of finely powdered boracic acid, and the leg, from foot to knee, excluding the sole, is enveloped in a thick layer of wood-wool wadding. This is held in position by ordinary cotton bandages, painted over with liquid starch; while the starch is drying the limb is kept elevated. With this appliance the patient may continue to work, and the dressing does not require to be changed oftener than once in three or four weeks (W. G. Richardson).

When an ulcer becomes acutely inflamed as a result of superadded infection, antiseptic measures are employed to overcome the infection, and ichthyol or other soothing applications may be used to allay the pain.

The phagedaenic ulcer calls for more energetic means of disinfection; the whole of the affected surface is touched with the actual cautery at a white heat, or is painted with pure carbolic acid. Relays of charcoal poultices are then applied until the spread of the disease is arrested.

For the irritable ulcer the most satisfactory treatment is complete excision and subsequent skin-grafting.



CHAPTER VI

GANGRENE

Definition—Types: Dry, Moist—Varieties—Gangrene primarily due to interference with circulation: Senile gangrene; Embolic gangrene; Gangrene following ligation of arteries; Gangrene from mechanical causes; Gangrene from heat, chemical agents, and cold; Diabetic gangrene; Gangrene associated with spasm of blood vessels; Raynaud's disease; Angio-sclerotic gangrene; Gangrene from ergot. Bacterial varieties of gangrene. Pathology—clinical varieties—Acute infective gangrene; Malignant oedema; Acute emphysematous or gas gangrene; Cancrum oris, etc. Bed-sores: Acute; chronic.

Gangrene or mortification is the process by which a portion of tissue dies en masse, as distinguished from the molecular or cellular death which constitutes ulceration. The dead portion is known as a slough.

In this chapter we shall confine our attention to the process as it affects the limbs and superficial parts, leaving gangrene of the viscera to be described in regional surgery.

TYPES OF GANGRENE

Two distinct types of gangrene are met with, which, from their most obvious point of difference, are known respectively as dry and moist, and there are several clinical varieties of each type.

Speaking generally, it may be said that dry gangrene is essentially due to a simple interference with the blood supply of a part; while the main factor in the production of moist gangrene is bacterial infection.

The cardinal signs of gangrene are: change in the colour of the part, coldness, loss of sensation and motor power, and, lastly, loss of pulsation in the arteries.

Dry Gangrene or Mummification is a comparatively slow form of local death due, as a rule, to a diminution in the arterial blood supply of the affected part, resulting from such causes as the gradual narrowing of the lumen of the arteries by disease of their coats, or the blocking of the main vessel by an embolus.

As the fluids in the tissues are lost by evaporation the part becomes dry and shrivelled, and as the skin is usually intact, infection does not take place, or if it does, the want of moisture renders the part an unsuitable soil, and the organisms do not readily find a footing. Any spread of the process that may take place is chiefly influenced by the anatomical distribution of the blocked arteries, and is arrested as soon as it reaches an area rich in anastomotic vessels. The dead portion is then cast off, the irritation resulting from the contact of the dead with the still living tissue inducing the formation of granulations on the proximal side of the junction, and these by slowly eating into the dead portion produce a furrow—the line of demarcation—which gradually deepens until complete separation is effected. As the muscles and bones have a richer blood supply than the integument, the death of skin and subcutaneous tissues extends higher than that of muscles and bone, with the result that the stump left after spontaneous separation is conical, the end of the bone projecting beyond the soft parts.

Clinical Features.—The part undergoing mortification becomes colder than normal, the temperature falling to that of the surrounding atmosphere. In many instances, but not in all, the onset of the process is accompanied by severe neuralgic pain in the part, probably due to anaemia of the nerves, to neuritis, or to the irritation of the exposed axis cylinders by the dead and dying tissues around them. This pain soon ceases and gives place to a complete loss of sensation. The dead part becomes dry, horny, shrivelled, and semi-transparent—at first of a dark brown, but finally of a black colour, from the dissemination of blood pigment throughout the tissues. There is no putrefaction, and therefore no putrid odour; and the condition being non-infective, there is not necessarily any constitutional disturbance. In itself, therefore, dry gangrene does not involve immediate risk to life; the danger lies in the fact that the breach of surface at the line of demarcation furnishes a possible means of entrance for bacteria, which may lead to infective complications.

Moist Gangrene is an acute process, the dead part retaining its fluids and so affording a favourable soil for the development of bacteria. The action of the organisms and their toxins on the adjacent tissues leads to a rapid and wide spread of the process. The skin becomes moist and macerated, and bullae, containing dark-coloured fluid or gases, form under the epidermis. The putrefactive gases evolved cause the skin to become emphysematous and crepitant and produce an offensive odour. The tissues assume a greenish-black colour from the formation in them of a sulphide of iron resulting from decomposition of the blood pigment. Under certain conditions the dead part may undergo changes resembling more closely those of ordinary post-mortem decomposition. Owing to its nature the spread of the gangrene is seldom arrested by the natural protective processes, and it usually continues until the condition proves fatal from the absorption of toxins into the circulation.

The clinical features vary in the different varieties of moist gangrene, but the local results of bacterial action and the constitutional disturbance associated with toxin absorption are present in all; the prognosis therefore is grave in the extreme.

From what has been said, it will be gathered that in dry gangrene there is no urgent call for operation to save the patient's life, the primary indication being to prevent the access of bacteria to the dead part, and especially to the surface exposed at the line of demarcation. In moist gangrene, on the contrary, organisms having already obtained a footing, immediate removal of the dead and dying tissues, as a rule, offers the only hope of saving life.

VARIETIES OF GANGRENE

Varieties of Gangrene essentially due to Interference with the Circulation

While the varieties of gangrene included in this group depend primarily on interference with the circulation, it is to be borne in mind that the clinical course of the affection may be profoundly influenced by superadded infection with micro-organisms. Although the bacteria do not play the most important part in producing tissue necrosis, their subsequent introduction is an accident of such importance that it may change the whole aspect of affairs and convert a dry form of gangrene into one of the moist type. Moreover, the low state of vitality of the tissues, and the extreme difficulty of securing and maintaining asepsis, make it a sequel of great frequency.

Senile Gangrene.—Senile gangrene is the commonest example of local death produced by a gradual diminution in the quantity of blood passing through the parts, as a result of arterio-sclerosis or other chronic disease of the arteries leading to diminution of their calibre. It is the most characteristic example of the dry type of gangrene. As the term indicates, it occurs in old persons, but the patient's age is to be reckoned by the condition of his arteries rather than by the number of his years. Thus the vessels of a comparatively young man who has suffered from syphilis and been addicted to alcohol are more liable to atheromatous degeneration leading to this form of gangrene than are those of a much older man who has lived a regular and abstemious life. This form of gangrene is much more common in men than in women. While it usually attacks only one foot, it is not uncommon for the other foot to be affected after an interval, and in some cases it is bilateral from the outset. It must clearly be understood that any form of gangrene may occur in old persons, the term senile being here restricted to that variety which results from arterio-sclerosis.



Clinical Features.—The commonest seat of the disease is in the toes, especially the great toe, whence it spreads up the foot to the heel, or even to the leg (Fig. 20). There is often a history of some slight injury preceding its onset. The vitality of the tissues is so low that the balance between life and death may be turned by the most trivial injury, such as a cut while paring a toe-nail or a corn, a blister caused by an ill-fitting shoe or the contact of a hot-bottle. In some cases the actual gangrene is determined by thrombosis of the popliteal or tibial arteries, which are already narrowed by obliterating endarteritis.

It is common to find that the patient has been troubled for a long time before the onset of definite signs of gangrene, with cold feet, with tingling and loss of feeling, or a peculiar sensation as if walking on cotton wool.

The first evidence of the death of the part varies in different cases. Sometimes a dark-blue spot appears on the medial side of the great toe and gradually increases in size; or a blister containing blood-stained fluid may form. Streaks or patches of dark-blue mottling appear higher up on the foot or leg. In other cases a small sore surrounded by a congested areola forms in relation to the nail and refuses to heal. Such sores on the toes of old persons are always to be looked upon with suspicion and treated with the greatest care; and the urine should be examined for sugar. There is often severe, deep-seated pain of a neuralgic character, with cramps in the limb, and these may persist long after a line of demarcation has formed. The dying part loses sensibility to touch and becomes cold and shrivelled.

All the physical appearances and clinical symptoms associated with dry gangrene supervene, and the dead portion is delimited by a line of demarcation. If this forms slowly and irregularly it indicates a very unsatisfactory condition of the circulation; while, if it forms quickly and decidedly, the presumption is that the circulation in the parts above is fairly good. The separation of the dead part is always attended with the risk of infection taking place, and should this occur, the temperature rises and other evidences of toxaemia appear.

Prophylaxis.—The toes and feet of old people, the condition of whose circulation predisposes them to gangrene, should be protected from slight injuries such as may be received while paring nails, cutting corns, or wearing ill-fitting boots. The patient should also be warned of the risk of exposure to cold, the use of hot-bottles, and of placing the feet near a fire. Attempts have been made to improve the peripheral circulation by establishing an anastomosis between the main artery of a limb and its companion vein, so that arterial blood may reach the peripheral capillaries—reversal of the circulation—but the clinical results have proved disappointing. (See Op. Surg., p. 29.)

Treatment.—When there is evidence that gangrene has occurred, the first indication is to prevent infection by purifying the part, and after careful drying to wrap it in a thick layer of absorbent and antiseptic wool, retained in place by a loosely applied bandage. A slight degree of elevation of the limb is an advantage, but it must not be sufficient to diminish the amount of blood entering the part. Hot-bottles are to be used with the utmost caution. As absolute dryness is essential, ointments or other greasy dressings are to be avoided, as they tend to prevent evaporation from the skin. Opium should be given freely to alleviate pain. Stimulation is to be avoided, and the patient should be carefully dieted.

When the gangrene is limited to the toes in old and feeble patients, some surgeons advocate the expectant method of treatment, waiting for a line of demarcation to form and allowing the dead part to be separated. This takes place so slowly, however, that it necessitates the patient being laid up for many weeks, or even months; and we agree with the majority in advising early amputation.

In this connection it is worthy of note that there are certain points at which gangrene naturally tends to become arrested—namely, at the highly vascular areas in the neighbourhood of joints. Thus gangrene of the great toe often stops when it reaches the metatarso-phalangeal joint; or if it trespasses this limit it may be arrested either at the tarso-metatarsal or at the ankle joint. If these be passed, it usually spreads up the leg to just below the knee before signs of arrestment appear. Further, it is seen from pathological specimens that the spread is greater on the dorsal than on the plantar aspect, and that the death of skin and subcutaneous tissues extends higher than that of bone and muscle.

These facts furnish us with indications as to the seat and method of amputation. Experience has proved that in senile gangrene of the lower extremity the most reliable and satisfactory results are obtained by amputating in the region of the knee, care being taken to perform the operation so as to leave the prepatellar anastomosis intact by retaining the patella in the anterior flap. The most satisfactory operation in these cases is Gritti's supra-condylar amputation. Haemorrhage is easily controlled by digital pressure, and the use of a tourniquet should be dispensed with, as the constriction of the limb is liable to interfere with the vitality of the flaps.

When the tibial vessels can be felt pulsating at the ankle it may be justifiable, if the patient urgently desires it, to amputate lower than the knee; but there is considerable risk of gangrene recurring in the stump and necessitating a second operation.

That amputation for senile gangrene performed between the ankle and the knee seldom succeeds, is explained by the fact that the vascular obstruction is usually in the upper part of the posterior tibial artery, and the operation is therefore performed through tissues with an inadequate blood supply. It is not uncommon, indeed, on amputating above the knee, to find even the popliteal artery plugged by a clot. This should be removed at the amputation by squeezing the vessel from above downward by a "milking" movement, or by "catheterising the artery" with the aid of a cannula with a terminal aperture.

It is to be borne in mind that the object of amputation in these cases is merely to remove the gangrenous part, and so relieve the patient of the discomfort and the risks from infection which its presence involves. While it is true that in many of these patients the operation is borne remarkably well, it must be borne in mind that those who suffer from senile gangrene are of necessity bad lives, and a guarded opinion should be expressed as to the prospects of survival. The possibility of the disease developing in the other limb has already been referred to.



Embolic Gangrene (Fig. 21).—This is the most typical form of gangrene resulting from the sudden occlusion of the main artery of a part, whether by the impaction of an embolus or the formation of a thrombus in its lumen, when the collateral circulation is not sufficiently free to maintain the vitality of the tissues.

There is sudden pain at the site of impaction of the embolus, and the pulses beyond are lost. The limb becomes cold, numb, insensitive, and powerless. It is often pale at first—hence the term "white gangrene" sometimes applicable to the early appearances, which closely resemble those presented by the limb of a corpse.

If the part is aseptic it shrivels, and presents the ordinary features of dry gangrene. It is liable, however, especially in the lower extremity and when the veins also are obstructed, to become infected and to assume the characters of the moist type.

The extent of the gangrene depends upon the site of impaction of the embolus, thus if the abdominal aorta becomes suddenly occluded by an embolus at its bifurcation, the obstruction of the iliacs and femorals induces symmetrical gangrene of both extremities as high as the inguinal ligaments. When gangrene follows occlusion of the external iliac or of the femoral artery above the origin of its deep branch, the death of the limb extends as high as the middle or upper third of the thigh. When the femoral below the origin of its deep branch or the popliteal artery is obstructed, the veins remaining pervious, the anastomosis through the profunda is sufficient to maintain the vascular supply, and gangrene does not necessarily follow. The rupture of a popliteal aneurysm, however, by compressing the vein and the articular branches, usually determines gangrene. When an embolus becomes impacted at the bifurcation of the popliteal, if gangrene ensues it usually spreads well up the leg.

When the axillary artery is the seat of embolic impaction, and gangrene ensues, the process usually reaches the middle of the upper arm. Gangrene following the blocking of the brachial at its bifurcation usually extends as far as the junction of the lower and middle thirds of the forearm.

Gangrene due to thrombosis or embolism is sometimes met with in patients recovering from typhus, typhoid, or other fevers, such as that associated with child-bed. It occurs in peripheral parts, such as the toes, fingers, nose, or ears.

Treatment.—The general treatment of embolic gangrene is the same as that for the senile form. Success has followed opening the artery and removing the embolus. The artery is exposed at the seat of impaction and, having been clamped above and below, a longitudinal opening is made and the clot carefully extracted with the aid of forceps; it is sometimes unexpectedly long (one recorded from the femoral artery measured nearly 34 inches); the wound in the artery is then sewn up with fine silk soaked in paraffin. When amputation is indicated, it must be performed sufficiently high to ensure a free vascular supply to the flaps.

Gangrene following Ligation of Arteries.—After the ligation of an artery in its continuity—for example, in the treatment of aneurysm—the limb may for some days remain in a condition verging on gangrene, the distal parts being cold, devoid of sensation, and powerless. As the collateral circulation is established, the vitality of the tissues is gradually restored and these symptoms pass off. In some cases, however,—and especially in the lower extremity—gangrene ensues and presents the same characters as those resulting from embolism. It tends to be of the dry type. The occlusion of the vein as well as the artery is not found to increase the risk of gangrene.

Gangrene from Mechanical Constriction of the Vessels of the part.—The application of a bandage or plaster-of-Paris case too tightly, or of a tourniquet for too long a time, has been known to lead to death of the part beyond; but such cases are rare, as are also those due to the pressure of a fractured bone or of a tumour on a large artery or vein. When gangrene occurs from such causes, it tends to be of the moist type.

Much commoner is it to meet with localised areas of necrosis due to the excessive pressure of splints over bony prominences, such as the lateral malleolus, the medial condyle of the humerus, or femur, or over the dorsum of the foot. This is especially liable to occur when the nutrition of the skin is depressed by any interference with its nerve-supply, such as follows injuries to the spine or peripheral nerves, disease of the brain, or acute anterior poliomyelitis. When the splint is removed the skin pressed upon is found to be of a pale yellow or grey colour, and is surrounded by a ring of hyperaemia. If protected from infection, the clinical course is that of dry gangrene.

Bed-sores, which are closely allied to pressure sores, will be described at the end of this chapter.

When a localised portion of tissue, for example, a piece of skin, is so severely crushed or bruised that its blood vessels are occluded and its structure destroyed, it dies, and, if not infected with bacteria, dries up, and the shrivelled brown skin is slowly separated by the growth of granulation tissue beneath and around it.

Fingers, toes, or even considerable portions of limbs may in the same way be suddenly destroyed by severe trauma, and undergo mummification. If organisms gain access, typical moist gangrene may ensue, or changes similar to those of ordinary post-mortem decomposition may take place.

Treatment.—The first indication is to exclude bacteria by purifying the damaged part and its surroundings, and applying dry, non-irritating dressings.

When these measures are successful, dry gangrene ensues. The raw surface left after the separation of the dead skin may be allowed to heal by granulation, or may be covered by skin-grafts. In the case of a finger or a limb it is not necessary to wait until spontaneous separation takes place, as this is often a slow process. When a well-marked line of demarcation has formed, amputation may be performed just sufficiently far above it to enable suitable flaps to be made.

The end of a stump, after spontaneous separation of the gangrenous portion, requires to be trimmed, sufficient bone being removed to permit of the soft parts coming together.

If moist gangrene supervenes, amputation must be performed without delay, and at a higher level.

Gangrene from Heat, Chemical Agents, and Cold.—Severe burns and scalds may be followed by necrosis of tissue. So long as the parts are kept absolutely dry—as, for example, by the picric acid method of treatment—the grossly damaged portions of tissue undergo dry gangrene; but when wet or oily dressings are applied and organisms gain access, moist gangrene follows.

Strong chemical agents, such as caustic potash, nitric or sulphuric acid, may also induce local tissue necrosis, the general appearances of the lesions produced being like those of severe burns. The resulting sloughs are slow to separate, and leave deep punched-out cavities which are long of healing.

Carbolic Gangrene.—Carbolic acid, even in comparatively weak solution, is liable to induce dry gangrene when applied as a fomentation to a finger, especially in women and children. Thrombosis occurs in the blood vessels of the part, which at first is pale and soft, but later becomes dark and leathery. On account of the anaesthetic action of carbolic acid, the onset of the process is painless, and the patient does not realise his danger. A line of demarcation soon forms, but the dead part separates very slowly.

Gangrene from Frost-bite.—It is difficult to draw the line between the third degree of chilblain and the milder forms of true frost-bite; the difference is merely one of degree. Frost-bite affects chiefly the toes and fingers—especially the great toe and the little finger—the ears, and the nose. In this country it is seldom seen except in members of the tramp class, who, in addition to being exposed to cold by sleeping in the open air, are ill-fed and generally debilitated. The condition usually manifests itself after the parts, having been subjected to extreme cold, are brought into warm surroundings. The first symptom is numbness in the part, followed by a sense of weight, tingling, and finally by complete loss of sensation. The part attacked becomes white and bleached-looking, feels icy cold, and is insensitive to touch. Either immediately, or, it may be, not for several days, it becomes discoloured and swollen, and finally contracts and shrivels. Above the dead area the limb may be the seat of excruciating pain. The dead portion is cast off, as in other forms of dry gangrene, by the formation of a line of demarcation.

To prevent the occurrence of gangrene from frost-bite it is necessary to avoid the sudden application of heat. The patient should be placed in a cold room, and the part rubbed with snow, or put in a cold bath, and have light friction applied to it. As the circulation is restored the general surroundings and the local applications are gradually made warmer. Elevation of the part, wrapping it in cotton wool, and removal to a warmer room, are then permissible, and stimulants and warm drinks may be given with caution. When by these means the occurrence of gangrene is averted, recovery ensues, its onset being indicated by the white parts assuming a livid red hue and becoming the seat of an acute burning sensation.

A condition known as Trench feet was widely prevalent amongst the troops in France during the European War. Although allied to frost-bite, cold appears to play a less important part in its causation than humidity and constriction of the limbs producing ischaemia of the feet. Changes were found in the endothelium of the blood vessels, the axis cylinders of nerves, and the muscles. The condition does not occur in civil life.

Diabetic Gangrene.—This form of gangrene is prone to occur in persons over fifty years of age who suffer from glycosuria. The arteries are often markedly diseased. In some cases the existence of the glycosuria is unsuspected before the onset of the gangrene, and it is only on examining the urine that the cause of the condition is discovered. The gangrenous process seldom begins as suddenly as that associated with embolism, and, like senile gangrene, which it may closely simulate in its early stages, it not infrequently begins after a slight injury to one of the toes. It but rarely, however, assumes the dry, shrivelling type, as a rule being attended with swelling, oedema, and dusky redness of the foot, and severe pain. According to Paget, the dead part remains warm longer than in other forms of senile gangrene; there is a greater tendency for patches of skin at some distance from the primary seat of disease to become gangrenous, and for the death of tissue to extend upwards in the subcutaneous planes, leaving the overlying skin unaffected. The low vitality of the tissues favours the growth of bacteria, and if these gain access, the gangrene assumes the characters of the moist type and spreads rapidly.

The rules for amputation are the same as those governing the treatment of senile gangrene, the level at which the limb is removed depending upon whether the gangrene is of the dry or moist type. The general treatment for diabetes must, of course, be employed whether amputation is performed or not. Paget recommended that the dietetic treatment should not be so rigid as in uncomplicated diabetes, and that opium should be given freely.

The prognosis even after amputation is unfavourable. In many cases the patient dies with symptoms of diabetic coma within a few days of the operation; or, if he survives this, he may eventually succumb to diabetes. In others there is sloughing of the flaps and death results from toxaemia. Occasionally the other limb becomes gangrenous. On the other hand, the glycosuria may diminish or may even disappear after amputation.

Gangrene associated with Spasm of Blood Vessels.—Raynaud's Disease, or symmetrical gangrene, is supposed to be due to spasm of the arterioles, resulting from peripheral neuritis. It occurs oftenest in women, between the ages of eighteen and thirty, who are the subjects of uterine disorders, anaemia, or chlorosis. Cold is an aggravating factor, as the disease is commonest during the winter months. The digits of both hands or the toes of both feet are simultaneously attacked, and the disease seldom spreads beyond the phalanges or deeper than the skin.

The first evidence is that the fingers become cold, white, and insensitive to touch and pain. These attacks of local syncope recur at varying intervals for months or even years. They last for a few minutes or even for some hours, and as they pass off the parts become hyperaemic and painful.

A more advanced stage of the disease is known as local asphyxia. The circulation through the fingers becomes exceedingly sluggish, and the parts assume a dull, livid hue. There is swelling and burning or shooting pain. This may pass off in a few days, or may increase in severity, with the formation of bullae, and end in dry gangrene. As a rule, the slough which forms is comparatively small and superficial, but it may take some months to separate. The condition tends to recur in successive winters.

The treatment consists in remedying any nervous or uterine disorder that may be present, keeping the parts warm by wrapping them in cotton wool, and in the use of hot-air or electric baths, the parts being immersed in water through which a constant current is passed. When gangrene occurs, it is treated on the same lines as other forms of dry gangrene, but if amputation is called for it is only with a view to removing the dead part.

Angio-sclerotic Gangrene.—A form of gangrene due to angio-sclerosis is occasionally met with in young persons, even in children. It bears certain analogies to Raynaud's disease in that spasm of the vessels plays a part in determining the local death.

The main arteries are narrowed by hyperplastic endarteritis followed by thrombosis, and similar changes are found in the veins. The condition is usually met with in the feet, but the upper extremity may be affected, and is attended with very severe pain, rendering sleep impossible.

The patient is liable to sudden attacks of numbness, tingling and weakness of the limbs which pass off with rest—intermittent claudication. During these attacks the large arteries—femoral, brachial, and subclavian—can be felt as firm cords, while pulsation is lost in the peripheral vessels. Gangrene eventually ensues, is attended with great pain and runs a slow course. It is treated on the same lines as Raynaud's disease.

Gangrene from Ergot.—Gangrene may occur from interference with blood supply, the result of tetanic contraction of the minute vessels, such as results in ill-nourished persons who eat large quantities of coarse rye bread contaminated with the claviceps purpurea and containing the ergot of rye. It has also occurred in the fingers of patients who have taken ergot medicinally over long periods. The gangrene, which attacks the toes, fingers, ears, or nose, is preceded by formication, numbness, and pains in the parts to be affected, and is of the dry variety.

In this country it is usually met with in sailors off foreign ships, whose dietary largely consists of rye bread. Trivial injuries may be the starting-point, the anaesthesia produced by the ergotin preventing the patient taking notice of them. Alcoholism is a potent predisposing cause.

As it is impossible to predict how far the process will spread, it is advisable to wait for the formation of a line of demarcation before operating, and then to amputate immediately above the dead part.

BACTERIAL VARIETIES OF GANGRENE

The acute bacillary forms of gangrene all assume the moist type from the first, and, spreading rapidly, result in extensive necrosis of tissue, and often end fatally.

The infection is usually a mixed one in which anaerobic bacteria predominate. The anaerobe most constantly present is the bacillus aerogenes capsulatus, usually in association with other anaerobes, and sometimes with pyogenic diplo- and streptococci. According to the mode of action of the associated organisms and the combined effects of their toxins on the tissues, the gangrenous process presents different pathological and clinical features. Some combinations, for example, result in a rapidly spreading cellulitis with early necrosis of connective tissue accompanied by thrombosis throughout the capillary and venous circulation of the parts implicated; other combinations cause great oedema of the part, and others again lead to the formation of gases in the tissues, particularly in the muscles.

These different effects do not appear to be due to a specific action of any one of the organisms present, but to the combined effect of a particular group living in symbiosis.

According as the cellulitic, the oedematous, or the gaseous characteristics predominate, the clinical varieties of bacillary gangrene may be separately described, but it must be clearly understood that they frequently overlap and cannot always be distinguished from one another.

Clinical Varieties of Bacillary Gangrene.—Acute infective gangrene is the form most commonly met with in civil practice. It may follow such trivial injuries as a pin-prick or a scratch, the signs of acute cellulitis rapidly giving place to those of a spreading gangrene. Or it may ensue on a severe railway, machinery, or street accident, when lacerated and bruised tissues are contaminated with gross dirt. Often within a few hours of the injury the whole part rapidly becomes painful, swollen, oedematous, and tense. The skin is at first glazed, and perhaps paler than normal, but soon assumes a dull red or purplish hue, and bullae form on the surface. Putrefactive gases may be evolved in the tissues, and their presence is indicated by emphysematous crackling when the part is handled. The spread of the disease is so rapid that its progress is quite visible from hour to hour, and may be traced by the occurrence of red lines along the course of the lymphatics of the limb. In the most acute cases the death of the affected part takes place so rapidly that the local changes indicative of gangrene have not time to occur, and the fact that the part is dead may be overlooked.



Rigors may occur, but the temperature is not necessarily raised—indeed, it is sometimes subnormal. The pulse is small, feeble, rapid, and irregular. Unless amputation is promptly performed, death usually follows within thirty-six or forty-eight hours. Even early operation does not always avert the fatal issue, because the quantity of toxin absorbed and its extreme virulence are often more than even a robust subject can outlive.

Treatment.—Every effort must be made to purify all such wounds as are contaminated by earth, street dust, stable refuse, or other forms of gross dirt. Devitalised and contaminated tissue is removed with the knife or scissors and the wound purified with antiseptics of the chlorine group or with hydrogen peroxide. If there is a reasonable prospect that infection has been overcome, the wound may be at once sutured, but if this is doubtful it is left open and packed or irrigated.

When acute gangrene has set in no treatment short of amputation is of any avail, and the sooner this is done, the greater is the hope of saving the patient. The limb must be amputated well beyond the apparent limits of the infected area, and stringent precautions must be taken to avoid discharge from the already gangrenous area reaching the operation wound. An assistant or nurse, who is to take no other part in the operation, is told off to carry out the preliminary purification, and to hold the limb during the operation.

Malignant Oedema.—This form of acute gangrene has been defined as "a spreading inflammatory oedema attended with emphysema, and ultimately followed by gangrene of the skin and adjacent parts." The predominant organism is the bacillus of malignant oedema or vibrion septique of Pasteur, which is found in garden soil, dung, and various putrefying substances. It is anaerobic, and occurs as long, thick rods with somewhat rounded ends and several laterally placed flagella. Spores, which have a high power of resistance, form in the centre of the rods, and bulge out the sides so as to give the organisms a spindle-shaped outline. Other pathogenic organisms are also present and aid the specific bacillus in its action.

At the bedside it is difficult, if not impossible, to distinguish it from acute infective gangrene. Both follow on the same kinds of injury and run an exceedingly rapid course. In malignant oedema, however, the incidence of the disease is mainly on the superficial parts, which become oedematous and emphysematous, and acquire a marbled appearance with the veins clearly outlined. Early disappearance of sensation is a particularly grave symptom. Bullae form on the skin, and the tissues have "a peculiar heavy but not putrid odour." The constitutional effects are extremely severe, and death may ensue within a few hours.

Acute Emphysematous or Gas Gangrene was prevalent in certain areas at various periods during the European War. It follows infection of lacerated wounds with the bacillus aerogenes capsulatus, usually in combination with other anaerobes, and its main incidence is on the muscles, which rapidly become infiltrated with gas that spreads throughout the whole extent of the muscle, disintegrating its fibres and leading to necrosis. The gangrenous process spreads with appalling rapidity, the limb becoming enormously swollen, painful, and crepitant or even tympanitic. Patches of coppery or purple colour appear on the skin, and bullae containing blood-stained serum form on the surface. The toxaemia is profound, and the face and lips assume a characteristic cyanosis. The condition is attended with a high mortality. Only in the early stages and when the infection is limited are local measures successful in arresting the spread; in more severe cases amputation is the only means of saving life.

Cancrum Oris or Noma.—This disease is believed to be due to a specific bacillus, which occurs in long delicate rods, and is chiefly found at the margin of the gangrenous area. It is prone to attack unhealthy children from two to five years of age, especially during their convalescence from such diseases as measles, scarlet fever, or typhoid, but may attack adults when they are debilitated. It is most common in the mouth, but sometimes occurs on the vulva. In the mouth it begins as an ulcerative stomatitis, more especially affecting the gums or inner aspect of the cheek. The child lies prostrated, and from the open mouth foul-smelling saliva, streaked with blood, escapes; the face is of an ashy-grey colour, the lips dark and swollen. On the inner aspect of the cheek is a deeply ulcerated surface, with sloughy shreds of dark-brown or black tissue covering its base; the edges are irregular, firm, and swollen, and the surrounding mucous membrane is infiltrated and oedematous. In the course of a few hours a dark spot appears on the outer aspect of the cheek, and rapidly increases in size; towards the centre it is black, shading off through blue and grey into a dark-red area which extends over the cheek (Fig. 23). The tissue implicated is at first firm and indurated, but as it loses its vitality it becomes doughy and sodden. Finally a slough forms, and, when it separates, the cheek is perforated.

Meanwhile the process spreads inside the mouth, and the gums, the floor of the mouth, or even the jaws, may become gangrenous and the teeth fall out. The constitutional disturbance is severe, the temperature raised, and the pulse feeble and rapid.

The extremely foetid odour which pervades the room or even the house the patient occupies, is usually sufficient to suggest the diagnosis of cancrum oris. The odour must not be mistaken for that due to decomposition of sordes on the teeth and gums of a debilitated patient.

The prognosis is always grave in the extreme, the main risks being general toxaemia and septic pneumonia. When recovery takes place there is serious deformity, and considerable portions of the jaws may be lost by necrosis.



Treatment.—The only satisfactory treatment is thorough removal under an anaesthetic of all the sloughy tissue, with the surrounding zone in which the organisms are active. This is most efficiently accomplished by the knife or scissors, cutting until the tissue bleeds freely, after which the raw surface is painted with undiluted carbolic acid and dressed with iodoform gauze. It may be necessary to remove large pieces of bone when the necrotic process has implicated the jaws. The mouth must be constantly sprayed with peroxide of hydrogen, and washed out with a disinfectant and deodorant lotion, such as Condy's fluid. The patient's general condition calls for free stimulation.

The deformity resulting from these necessarily heroic measures is not so great as might be expected, and can be further diminished by plastic operations, which should be undertaken before cicatricial contraction has occurred.

BED-SORES

Bed-sores are most frequently met with in old and debilitated patients, or in those whose tissues are devitalised by acute or chronic diseases associated with stagnation of blood in the peripheral veins. Any interference with the nerve-supply of the skin, whether from injury or disease of the central nervous system or of the peripheral nerves, strongly predisposes to the formation of bed-sores. Prolonged and excessive pressure over a bony prominence, especially if the parts be moist with skin secretions, urine, or wound discharges, determines the formation of a sore. Excoriations, which may develop into true bed-sores, sometimes form where two skin surfaces remain constantly apposed, as in the region of the scrotum or labium, under pendulous mammae, or between fingers or toes confined in a splint.



Clinical Features.—Two clinical varieties are met with—the acute and the chronic bed-sore.

The acute bed-sore usually occurs over the sacrum or buttock. It develops rapidly after spinal injuries and in the course of certain brain diseases. The part affected becomes red and congested, while the surrounding parts are oedematous and swollen, blisters form, and the skin loses its vitality (Fig. 24).

In advanced cases of general paralysis of the insane, a peculiar form of acute bed-sore beginning as a blister, and passing on to the formation of a black, dry eschar, which slowly separates, occurs on such parts as the medial side of the knee, the angle of the scapula, and the heel.

The chronic bed-sore begins as a dusky reddish purple patch, which gradually becomes darker till it is almost black. The parts around are oedematous, and a blister may form. This bursts and exposes the papillae of the skin, which are of a greenish hue. A tough greyish-black slough forms, and is slowly separated. It is not uncommon for the gangrenous area to continue to spread both in width and in depth till it reaches the periosteum or bone. Bed-sores over the sacrum sometimes implicate the vertebral canal and lead to spinal meningitis, which usually proves fatal.

In old and debilitated patients the septic absorption taking place from a bed-sore often proves a serious complication of other surgical conditions. From this cause, for example, old people may succumb during the treatment of a fractured thigh.

The granulating surface left on the separation of the slough tends to heal comparatively rapidly.

Prevention of Bed-sores.—The first essential in the prevention of bed-sores is the regular changing of the patient's position, so that no one part of the body is continuously pressed upon for any length of time. Ring-pads of wool, air-cushions, or water-beds are necessary to remove pressure from prominent parts. Absolute dryness of the skin is all-important. At least once a day, the sacrum, buttocks, shoulder-blades, heels, elbows, malleoli, or other parts exposed to pressure, must be sponged with soap and water, thoroughly dried, and then rubbed with methylated spirit, which is allowed to dry on the skin. Dusting the part with boracic acid powder not only keeps it dry, but prevents the development of bacteria in the skin secretions.

In operation cases, care must be taken that irritating chemicals used to purify the skin do not collect under the patient and remain in contact with the skin of the sacrum and buttocks during the time he is on the operating-table. There is reason to believe that the so-called "post-operation bed-sore" may be due to such causes. A similar result has been known to follow soiling of the sheets by the escape of a turpentine enema.

Treatment.—Once a bed-sore has formed, every effort must be made to prevent its spread. Alcohol is used to cleanse the broken surface, and dry absorbent dressings are applied and frequently changed. It is sometimes found necessary to employ moist or oily substances, such as boracic poultices, eucalyptus ointment, or balsam of Peru, to facilitate the separation of sloughs, or to promote the growth of granulations. In patients who are not extremely debilitated the slough may be excised, the raw surface scraped, and then painted with iodine.

Skin-grafting is sometimes useful in covering in the large raw surface left after separation or removal of sloughs.



CHAPTER VII

BACTERIAL AND OTHER WOUND INFECTIONS

Erysipelas—Diphtheria—Tetanus—Hydrophobia—Anthrax— Glanders—Actinomycosis—Mycetoma—Delhi boil—Chigoe—Poisoning by insects—Snake-bites.

ERYSIPELAS

Erysipelas, popularly known as "rose," is an acute spreading infective disease of the skin or of a mucous membrane due to the action of a streptococcus. Infection invariably takes place through an abrasion of the surface, although this may be so slight that it escapes observation even when sought for. The streptococci are found most abundantly in the lymph spaces just beyond the swollen margin of the inflammatory area, and in the serous blebs which sometimes form on the surface.

Clinical Features.—Facial erysipelas is the commonest clinical variety, infection usually occurring through some slight abrasion in the region of the mouth or nose, or from an operation wound in this area. From this point of origin the inflammation may spread all over the face and scalp as far back as the nape of the neck. It stops, however, at the chin, and never extends on to the front of the neck. There is great oedema of the face, the eyes becoming closed up, and the features unrecognisable. The inflammation may spread to the meninges, the intracranial venous sinuses, the eye, or the ear. In some cases the erysipelas invades the mucous membrane of the mouth, and spreads to the fauces and larynx, setting up an oedema of the glottis which may prove dangerous to life.

Erysipelas occasionally attacks an operation wound that has become septic; and it may accompany septic infection of the genital tract in puerperal women, or the separation of the umbilical cord in infants (erysipelas neonatorum). After an incubation period, which varies from fifteen to sixty hours, the patient complains of headache, pains in the back and limbs, loss of appetite, nausea, and frequently there is vomiting. He has a chill or slight rigor, initiating a rise of temperature to 103, 104, or 105 F.; and a full bounding pulse of about 100 (Fig. 25). The tongue is foul, the breath heavy, and, as a rule, the bowels are constipated. There is frequently albuminuria, and occasionally nocturnal delirium. A moderate degree of leucocytosis (15,000 to 20,000) is usually present.

Around the seat of inoculation a diffuse red patch forms, varying in hue from a bright scarlet to a dull brick-red. The edges are slightly raised above the level of the surrounding skin, as may readily be recognised by gently stroking the part from the healthy towards the affected area. The skin is smooth, tense, and glossy, and presents here and there blisters filled with serous fluid. The local temperature is raised, and the part is the seat of a burning sensation and is tender to the touch, the most tender area being the actively spreading zone which lies about half an inch beyond the red margin.



The disease tends to spread spasmodically and irregularly, and the direction and extent of its progress may be recognised by mapping out the peripheral zone of tenderness. Red streaks appear along the lines of the superficial lymph vessels, and the deep lymphatics may sometimes be palpated as firm, tender cords. The neighbouring glands, also, are generally enlarged and tender.

The disease lasts for from two or three days to as many weeks, and relapses are frequent. Spontaneous resolution usually takes place, but the disease may prove fatal from absorption of toxins, involvement of the brain or meninges, or from general streptococcal infection.

Complications.—Diffuse suppurative cellulitis is the most serious local complication, and results from a mixed infection with other pyogenic bacteria. Small localised superficial abscesses may form during the convalescent stage. They are doubtless due to the action of skin bacteria, which attack the tissues devitalised by the erysipelas. A persistent form of oedema sometimes remains after recurrent attacks of erysipelas, especially when they affect the face or the lower extremity, a condition which is referred to with elephantiasis.

Treatment.—The first indication is to endeavour to arrest the spread of the process. We have found that by painting with linimentum iodi, a ring half an inch broad, about an inch in front of the peripheral tender zone—not the red margin—an artificial leucocytosis is produced, and the advancing streptococci are thereby arrested. Several coats of the iodine are applied, one after the other, and this is repeated daily for several days, even although the erysipelas has not overstepped the ring. Success depends upon using the liniment of iodine (the tincture is not strong enough), and in applying it well in front of the disease. To allay pain the most useful local applications are ichthyol ointment (1 in 6), or lead and opium fomentations.

The general treatment consists in attending to the emunctories, in administrating quinine in small—two-grain—doses every four hours, or salicylate of iron (2-5 gr. every three hours), and in giving plenty of fluid nourishment. It is worthy of note that the anti-streptococcic serum has proved of less value in the treatment of erysipelas than might have been expected, probably because the serum is not made from the proper strain of streptococcus.

It is not necessary to isolate cases of erysipelas, provided the usual precautions against carrying infection from one patient to another are rigidly carried out.

DIPHTHERIA

Diphtheria is an acute infective disease due to the action of a specific bacterium, the bacillus diphtheriae or Klebs-Loffler bacillus. The disease is usually transmitted from one patient to another, but it may be contracted from cats, fowls, or through the milk of infected cows. Cases have occurred in which the surgeon has carried the infection from one patient to another through neglect of antiseptic precautions. The incubation period varies from two to seven days.

Clinical Features.—In pharyngeal diphtheria, on the first or second day of the disease, redness and swelling of the mucous membrane of the pharynx, tonsils, and palate are well marked, and small, circular greenish or grey patches of false membrane, composed of necrosed epithelium, fibrin, leucocytes, and red blood corpuscles, begin to appear. These rapidly increase in area and thickness, till they coalesce and form a complete covering to the parts. In the pharynx the false membrane is less adherent to the surface than it is when the disease affects the air-passages. The diphtheritic process may spread from the pharynx to the nasal cavities, causing blocking of the nares, with a profuse ichorous discharge from the nostrils, and sometimes severe epistaxis. The infection may spread along the nasal duct to the conjunctiva. The middle ear also may become involved by spread along the auditory (Eustachian) tube.

The lymph glands behind the angle of the jaw enlarge and become tender, and may suppurate from superadded infection. There is pain on swallowing, and often earache; and the patient speaks with a nasal accent. He becomes weak and anaemic, and loses his appetite. There is often albuminuria. Leucocytosis is usually well marked before the injection of antitoxin; after the injection there is usually a diminution in the number of leucocytes. The false membrane may separate and be cast off, after which the patient gradually recovers. Death may take place from gradual failure of the heart's action or from syncope during some slight exertion.

Laryngeal Diphtheria.—The disease may arise in the larynx, although, as a rule, it spreads thence from the pharynx. It first manifests itself by a short, dry, croupy cough, and hoarseness of the voice. The first difficulty in breathing usually takes place during the night, and once it begins, it rapidly gets worse. Inspiration becomes noisy, sometimes stridulous or metallic or sibilant, and there is marked indrawing of the epigastrium and lower intercostal spaces. The hoarseness becomes more marked, the cough more severe, and the patient restless. The difficulty of breathing occurs in paroxysms, which gradually increase in frequency and severity, until at length the patient becomes asphyxiated. The duration of the disease varies from a few hours to four or five days.

After the acute symptoms have passed off, various localised paralyses may develop, affecting particularly the nerves of the palatal and orbital muscles, less frequently the lower limbs.

Diagnosis.—The finding of the Klebs-Loffler bacillus is the only conclusive evidence of the disease. The bacillus may be obtained by swabbing the throat with a piece of aseptic—not antiseptic—cotton wool or clean linen rag held in a pair of forceps, and rotated so as to entangle portions of the false membrane or exudate. The swab thus obtained is placed in a test-tube, previously sterilised by having had some water boiled in it, and sent to a laboratory for investigation. To identify the bacillus a piece of the membrane from the swab is rubbed on a cover glass, dried, and stained with methylene blue or other basic stain; or cultures may be made on agar or other suitable medium. When a bacteriological examination is impossible, or when the clinical features do not coincide with the results obtained, the patient should always be treated on the assumption that he suffers from diphtheria. So much doubt exists as to the real nature of membranous croup and its relationship to true diphtheria, that when the diagnosis between the two is uncertain the safest plan is to treat the case as one of diphtheria.

In children, diphtheria may occur on the vulva, vagina, prepuce, or glans penis, and give rise to difficulty in diagnosis, which is only cleared up by demonstration of the bacillus.

Treatment.—An attempt may be made to destroy or to counteract the organisms by swabbing the throat with strong antiseptic solutions, such as 1 in 1000 corrosive sublimate or 1 in 30 carbolic acid, or by spraying with peroxide of hydrogen.

The antitoxic serum is our sheet-anchor in the treatment of diphtheria, and recourse should be had to its use as early as possible.

Difficulty of swallowing may be met by the use of a stomach tube passed either through the mouth or nose. When this is impracticable, nutrient enemata are called for.

In laryngeal diphtheria, the interference with respiration may call for intubation of the larynx, or tracheotomy, but the antitoxin treatment has greatly diminished the number of cases in which it becomes necessary to have recourse to these measures.

Intubation consists in introducing through the mouth into the larynx a tube which allows the patient to breathe freely during the period while the membrane is becoming separated and thrown off. This is best done with the apparatus of O'Dwyer; but when this instrument is not available, a simple gum-elastic catheter with a terminal opening (as suggested by Macewen and Annandale) may be employed.

When intubation is impracticable, the operation of tracheotomy is called for if the patient's life is endangered by embarrassment of respiration. Unless the patient is in hospital with skilled assistance available, tracheotomy is the safer of the two procedures.

TETANUS

Tetanus is a disease resulting from infection of a wound by a specific micro-organism, the bacillus tetani, and characterised by increased reflex excitability, hypertonus, and spasm of one or more groups of voluntary muscles.

Etiology and Morbid Anatomy.—The tetanus bacillus, which is a perfect anaerobe, is widely distributed in nature and can be isolated from garden earth, dung-heaps, and stable refuse. It is a slender rod-shaped bacillus, with a single large spore at one end giving it the shape of a drum-stick (Fig. 26). The spores, which are the active agents in producing tetanus, are highly resistant to chemical agents, retain their vitality in a dry condition, and even survive boiling for five minutes.

The organism does not readily establish itself in the human body, and seems to flourish best when it finds a nidus in necrotic tissue and is accompanied by aerobic organisms, which, by using up the oxygen in the tissues, provide for it a suitable environment. The presence of a foreign body in the wound seems to favour its action. The infection is for all practical purposes a local one, the symptoms of the disease being due to the toxins produced in the wound of infection acting upon the central nervous system.

The toxin acts principally on the nerve centres in the spinal medulla, to which it travels from the focus of infection by way of the nerve fibres supplying the voluntary muscles. Its first effect on the motor ganglia of the cord is to render them hypersensitive, so that they are excited by mild stimuli, which under ordinary conditions would produce no reaction. As the toxin accumulates the reflex arc is affected, with the result that when a stimulus reaches the ganglia a motor discharge takes place, which spreads by ascending and descending collaterals to the reflex apparatus of the whole cord. As the toxin spreads it causes both motor hyper-tonus and hyper-excitability, which accounts for the tonic contraction and the clonic spasms characteristic of tetanus.



Clinical Varieties of Tetanus.—Acute or Fulminating Tetanus.—This variety is characterised by the shortness of the incubation period, the rapidity of its progress, the severity of its symptoms, and its all but universally fatal issue in spite of treatment, death taking place in from one to four days. The characteristic symptoms may appear within three or four days of the infliction of the wound, but the incubation period may extend to three weeks, and the wound may be quite healed before the disease declares itself—delayed tetanus. Usually, however, the wound is inflamed and suppurating, with ragged and sloughy edges. A slight feverish attack may mark the onset of the tetanic condition, or the patient may feel perfectly well until the spasms begin. If careful observations be made, it may be found that the muscles in the immediate neighbourhood of the wound are the first to become contracted; but in the majority of instances the patient's first complaint is of pain and stiffness in the muscles of mastication, notably the masseter, so that he has difficulty in opening the mouth—hence the popular name "lock-jaw." The muscles of expression soon share in the rigidity, and the face assumes a taut, mask-like aspect. The angles of the mouth may be retracted, producing a grinning expression known as the risus sardonicus.

The next muscles to become stiff and painful are those of the neck, especially the sterno-mastoid and trapezius. The patient is inclined to attribute the pain and stiffness to exposure to cold or rheumatism. At an early stage the diaphragm and the muscles of the anterior abdominal wall become contracted; later the muscles of the back and thorax are involved; and lastly those of the limbs. Although this is the typical order of involvement of the different groups of muscles, it is not always adhered to.

To this permanent tonic contraction of the muscles there are soon added clonic spasms. These spasms are at first slight and transient, with prolonged intervals between the attacks, but rapidly tend to become more frequent, more severe, and of longer duration, until eventually the patient simply passes out of one seizure into another.

The distribution of the spasms varies in different cases: in some it is confined to particular groups of muscles, such as those of the neck, back, abdominal walls, or limbs; in others all these groups are simultaneously involved.

When the muscles of the back become spasmodically contracted, the body is raised from the bed, sometimes to such an extent that the patient rests only on his heels and occiput—the position of opisthotonos. Lateral arching of the body from excessive action of the muscles on one side—pleurosthotonos—is not uncommon, the arching usually taking place towards the side on which the wound of infection exists. Less frequently the body is bent forward so that the knees and chin almost meet (emprosthotonos). Sometimes all the muscles simultaneously become rigid, so that the body assumes a statuesque attitude (orthotonos). When the thoracic muscles, including the diaphragm, are thrown into spasm, the patient experiences a distressing sensation as if he were gripped in a vice, and has extreme difficulty in getting breath. Between the attacks the limbs are kept rigidly extended. The clonic spasms may be so severe as to rupture muscles or even to fracture one of the long bones.

As time goes on, the clonic exacerbations become more and more frequent, and the slightest external stimulus, such as the feeling of the pulse, a whisper in the room, a noise in the street, a draught of cold air, the effort to swallow, a question addressed to the patient or his attempt to answer, is sufficient to determine an attack. The movements are so forcible and so continuous that the nurse has great difficulty in keeping the bedclothes on the patient, or even in keeping him in bed.

The general condition of the patient is pitiful in the extreme. He is fully conscious of the gravity of the disease, and his mind remains clear to the end. The suffering induced by the cramp-like spasms of the muscles keeps him in a constant state of fearful apprehension of the next seizure, and he is unable to sleep until he becomes utterly exhausted.

The temperature is moderately raised (100 to 102 F.), or may remain normal throughout. Shortly before death very high temperatures (110 F.) have been recorded, and it has been observed that the thermometer sometimes continues to rise after death, and may reach as high as 112 F. or more.

The pulse corresponds with the febrile condition. It is accelerated during the spasms, and may become exceedingly rapid and feeble before death, probably from paralysis of the vagus. Sudden death from cardiac paralysis or from cardiac spasm is not uncommon.

The respiration is affected in so far as the spasms of the respiratory muscles produce dyspnoea, and a feeling of impending suffocation which adds to the horrors of the disease.

One of the most constant symptoms is a copious perspiration, the patient being literally bathed in sweat. The urine is diminished in quantity, but as a rule is normal in composition; as in other acute infective conditions, albumen and blood may be present. Retention of urine may result from spasm of the urethral muscles, and necessitate the use of the catheter.

The fits may cease some time before death, or, on the other hand, death may occur during a paroxysm from fixation of the diaphragm and arrest of respiration.

Differential Diagnosis.—There is little difficulty, as a rule, in diagnosing a case of fulminating tetanus, but there are several conditions with which it may occasionally be confused. In strychnin poisoning, for example, the spasms come on immediately after the patient has taken a toxic dose of the drug; they are clonic in character, but the muscles are relaxed between the fits. If the dose is not lethal, the spasms soon cease. In hydrophobia a history of having been bitten by a rabid animal is usually forthcoming; the spasms, which are clonic in character, affect chiefly the muscles of respiration and deglutition, and pass off entirely in the intervals between attacks. Certain cases of haemorrhage into the lateral ventricles of the brain also simulate tetanus, but an analysis of the symptoms will prevent errors in diagnosis. Cerebro-spinal meningitis and basal meningitis present certain superficial resemblances to tetanus, but there is no trismus, and the spasms chiefly affect the muscles of the neck and back. Hysteria and catalepsy may assume characters resembling those of tetanus, but there is little difficulty in distinguishing between these diseases. Lastly, in the tetany of children, or that following operations on the thyreoid gland, the spasms are of a jerking character, affect chiefly the hands and fingers, and yield to medicinal treatment.

Chronic Tetanus.—The difference between this and acute tetanus is mainly one of degree. Its incubation period is longer, it is more slow and insidious in its progress, and it never reaches the same degree of severity. Trismus is the most marked and constant form of spasm; and while the trunk muscles may be involved, those of respiration as a rule escape. Every additional day the patient lives adds to the probability of his ultimate recovery. When the disease does prove fatal, it is from exhaustion, and not from respiratory or cardiac spasm. The usual duration is from six to ten weeks.

Delayed Tetanus.—During the European War acute tetanus occasionally developed many weeks or even months after a patient had been injured, and when the original wound had completely healed. It usually followed some secondary operation, e.g., for the removal of a foreign body, or the breaking down of adhesions, which aroused latent organisms.

Local Tetanus.—This term is applied to a form of the disease in which the hypertonus and spasms are localised to the muscles in the vicinity of the wound. It usually occurs in patients who have had prophylactic injections of anti-tetanic serum, the toxins entering the blood being probably neutralised by the antibodies in circulation, while those passing along the motor nerves are unaffected.

When it occurs in the limbs, attention is usually directed to the fact by pain accompanying the spasms; the muscles are found to be hard and there are frequent twitchings of the limb. A characteristic reflex is present in the lower extremity, namely, extension of the foot and leg when the sole is tickled.

Cephalic Tetanus is another localised variety which follows injury in the distribution of the facial nerve. It is characterised by the occurrence on the same side as the injury, of facial spasm, rapidly followed by more or less complete paralysis of the muscles of expression, with unilateral trismus and difficulty in swallowing. Other cranial nerves, particularly the oculomotor and the hypoglossal, may also be implicated. A remarkable feature of this condition is that although the muscles are irresponsive to ordinary physiological stimuli, they are thrown into spasm by the abnormal impulses of tetanus.

Trismus.—This term is used to denote a form of tetanic spasm limited to the muscles of mastication. It is really a mild form of chronic tetanus, and the prognosis is favourable. It must not be confused with the fixation of the jaw sometimes associated with a wisdom-tooth gumboil, with tonsillitis, or with affections of the temporo-mandibular articulation.

Tetanus neonatorum is a form of tetanus occurring in infants of about a week old. Infection takes place through the umbilicus, and manifests itself clinically by spasms of the muscles of mastication. It is almost invariably fatal within a few days.

Prophylaxis.—Experience in the European War has established the fact that the routine injection of anti-tetanic serum to all patients with lacerated and contaminated wounds greatly reduces the frequency of tetanus. The sooner the serum is given after the injury, the more certain is its effect; within twenty-four hours 1500 units injected subcutaneously is sufficient for the initial dose; if a longer period has elapsed, 2000 to 3000 units should be given intra-muscularly, as this ensures more rapid absorption. A second injection is given a week after the first.

The wound must be purified in the usual way, and all instruments and appliances used for operations on tetanic patients must be immediately sterilised by prolonged boiling.

Treatment.—When tetanus has developed the main indications are to prevent the further production of toxins in the wound, and to neutralise those that have been absorbed into the nervous system. Thorough purification with antiseptics, excision of devitalised tissues, and drainage of the wound are first carried out. To arrest the absorption of toxins intra-muscular injections of 10,000 units of serum are given daily into the muscles of the affected limb, or directly into the nerve trunks leading from the focus of infection, in the hope of "blocking" the nerves with antitoxin and so preventing the passage of toxins towards the spinal cord.

To neutralise the toxins that have already reached the spinal cord, 5000 units should be injected intra-thecally daily for four or five days, the foot of the bed being raised to enable the serum to reach the upper parts of the cord.

The quantity of toxin circulating in the blood is so small as to be practically negligible, and the risk of anaphylactic shock attending intra-venous injection outweighs any benefit likely to follow this procedure.

Baccelli recommends the injection of 20 c.c. of a 1 in 100 solution of carbolic acid into the subcutaneous tissues every four hours during the period that the contractions persist. Opinions vary as to the efficiency of this treatment. The intra-thecal injection of 10 c.c. of a 15 per cent. solution of magnesium sulphate has proved beneficial in alleviating the severity of the spasms, but does not appear to have a curative effect.

To conserve the patient's strength by preventing or diminishing the severity of the spasms, he should be placed in a quiet room, and every form of disturbance avoided. Sedatives, such as bromides, paraldehyde, or opium, must be given in large doses. Chloral is perhaps the best, and the patient should rarely have less than 150 grains in twenty-four hours. When he is unable to swallow, it should be given by the rectum. The administration of chloroform is of value in conserving the strength of the patient, by abolishing the spasms, and enabling the attendants to administer nourishment or drugs either through a stomach tube or by the rectum. Extreme elevation of temperature is met by tepid sponging. It is necessary to use the catheter if retention of urine occurs.

HYDROPHOBIA

Hydrophobia is an acute infective disease following on the bite of a rabid animal. It most commonly follows the bite or lick of a rabid dog or cat. The virus appears to be communicated through the saliva of the animal, and to show a marked affinity for nerve tissues; and the disease is most likely to develop when the patient is infected on the face or other uncovered part, or in a part richly endowed with nerves.

A dog which has bitten a person should on no account be killed until its condition has been proved one way or the other. Should rabies develop and its destruction become necessary, the head and spinal cord should be retained and forwarded, packed in ice, to a competent observer. Much anxiety to the person bitten and to his friends would be avoided if these rules were observed, because in many cases it will be shown that the animal did not after all suffer from rabies, and that the patient consequently runs no risk. If, on the other hand, rabies is proved to be present, the patient should be submitted to the Pasteur treatment.

Clinical Features.—There is almost always a history of the patient having been bitten or licked by an animal supposed to suffer from rabies. The incubation period averages about forty days, but varies from a fortnight to seven or eight months, and is shorter in young than in old persons. The original wound has long since healed, and beyond a slight itchiness or pain shooting along the nerves of the part, shows no sign of disturbance. A few days of general malaise, with chills and giddiness precede the onset of the acute manifestations, which affect chiefly the muscles of deglutition and respiration. One of the earliest signs is that the patient has periodically a sudden catch in his breathing "resembling what often occurs when a person goes into a cold bath." This is due to spasm of the diaphragm, and is frequently accompanied by a loud-sounding hiccough, likened by the laity to the barking of a dog. Difficulty in swallowing fluids may be the first symptom.

The spasms rapidly spread to all the muscles of deglutition and respiration, so that the patient not only has the greatest difficulty in swallowing, but has a constant sense of impending suffocation. To add to his distress, a copious secretion of viscid saliva fills his mouth. Any voluntary effort, as well as all forms of external stimuli, only serve to aggravate the spasms which are always induced by the attempt to swallow fluid, or even by the sound of running water.

The temperature is raised; the pulse is small, rapid, and intermittent; and the urine may contain sugar and albumen.

The mind may remain clear to the end, or the patient may have delusions, supposing himself to be surrounded by terrifying forms. There is always extreme mental agitation and despair, and the sufferer is in constant fear of his impending fate. Happily the inevitable issue is not long delayed, death usually occurring in from two to four days from the onset. The symptoms of the disease are so characteristic that there is no difficulty in diagnosis. The only condition with which it is liable to be confused is the variety of cephalic tetanus in which the muscles of deglutition are specially involved—the so-called tetanus hydrophobicus.

Prophylaxis.—The bite of an animal suspected of being rabid should be cauterised at once by means of the actual or Paquelin cautery, or by a strong chemical escharotic such as pure carbolic acid, after which antiseptic dressings are applied.

It is, however, to Pasteur's preventive inoculation that we must look for our best hope of averting the onset of symptoms. "It may now be taken as established that a grave responsibility rests on those concerned if a person bitten by a mad animal is not subjected to the Pasteur treatment" (Muir and Ritchie).

This method is based on the fact that the long incubation period of the disease admits of the patient being inoculated with a modified virus producing a mild attack, which protects him from the natural disease.

Treatment.—When the symptoms have once developed they can only be palliated. The patient must be kept absolutely quiet and free from all sources of irritation. The spasms may be diminished by means of chloral and bromides, or by chloroform inhalation.

ANTHRAX

Anthrax is a comparatively rare disease, communicable to man from certain of the lower animals, such as sheep, oxen, horses, deer, and other herbivora. In animals it is characterised by symptoms of acute general poisoning, and, from the fact that it produces a marked enlargement of the spleen, is known in veterinary surgery as "splenic fever."

The bacillus anthracis (Fig. 27), the largest of the known pathogenic bacteria, occurs in groups or in chains made up of numerous bacilli, each bacillus measuring from 6 to 8 [micron] in length. The organisms are found in enormous numbers throughout the bodies of animals that have died of anthrax, and are readily recognised and cultivated. Sporulation only takes place outside the body, probably because free oxygen is necessary to the process. In the spore-free condition, the organisms are readily destroyed by ordinary germicides, and by the gastric juice. The spores, on the other hand, have a high degree of resistance. Not only do they remain viable in the dry state for long periods, even up to a year, but they survive boiling for five minutes, and must be subjected to dry heat at 140 C. for several hours before they are destroyed.



Clinical Varieties of Anthrax.—In man, anthrax may manifest itself in one of three clinical forms.

It may be transmitted by means of spores or bacilli directly from a diseased animal to those who, by their occupation or otherwise, are brought into contact with it—for example, shepherds, butchers, veterinary surgeons, or hide-porters. Infection may occur on the face by the use of a shaving-brush contaminated by spores. The path of infection is usually through an abrasion of the skin, and the primary manifestations are local, constituting what is known as the malignant pustule.

In other cases the disease is contracted through the inhalation of the dried spores into the respiratory passages. This occurs oftenest in those who work amongst wool, fur, and rags, and a form of acute pneumonia of great virulence ensues. This affection is known as wool-sorter's disease, and is almost universally fatal.

There is reason to believe that infection may also take place by means of spores ingested into the alimentary canal in meat or milk derived from diseased animals, or in infected water.

Clinical Features of Malignant Pustule.—We shall here confine ourselves to the consideration of the local lesion as it occurs in the skin—the malignant pustule.

The point of infection is usually on an uncovered part of the body, such as the face, hands, arms, or back of the neck, and the wound may be exceedingly minute. After an incubation period varying from a few hours to several days, a reddish nodule resembling a small boil appears at the seat of inoculation, the immediately surrounding skin becomes swollen and indurated, and over the indurated area there appear a number of small vesicles containing serum, which at first is clear but soon becomes blood-stained (Fig. 28). Coincidently the subcutaneous tissue for a considerable distance around becomes markedly oedematous, and the skin red and tense. Within a few hours, blood is extravasated in the centre of the indurated area, the blisters burst, and a dark brown or black eschar, composed of necrosed skin and subcutaneous tissue and altered blood, forms (Fig. 29). Meanwhile the induration extends, fresh vesicles form and in turn burst, and the eschar increases in size. The neighbouring lymph glands soon become swollen and tender. The affected part is hot and itchy, but the patient does not complain of great pain. There is a moderate degree of constitutional disturbance, with headache, nausea, and sometimes shivering.

If the infection becomes generalised—anthracaemia—the temperature rises to 103 or 104 F., the pulse becomes feeble and rapid, and other signs of severe blood-poisoning appear: vomiting, diarrhoea, pains in the limbs, headache and delirium, and the condition proves fatal in from five to eight days.

Differential Diagnosis.—When the malignant pustule is fully developed, the central slough with the surrounding vesicles and the widespread oedema are characteristic. The bacillus can be obtained from the peripheral portion of the slough, from the blisters, and from the adjacent lymph vessels and glands. The occupation of the patient may suggest the possibility of anthrax infection.



Prophylaxis.—Any wound suspected of being infected with anthrax should at once be cauterised with caustic potash, the actual cautery, or pure carbolic acid.

Treatment.—The best results hitherto obtained have followed the use of the anti-anthrax serum introduced by Sclavo. The initial dose is 40 c.c., and if the serum is given early in the disease, the beneficial effects are manifest in a few hours. Favourable results have also followed the use of pyocyanase, a vaccine prepared from the bacillus pyocyaneus.

By some it is recommended that the local lesion should be freely excised; others advocate cauterisation of the affected part with solid caustic potash till all the indurated area is softened. Graf has had excellent results by the latter method in a large series of cases, the oedema subsiding in about twenty-four hours and the constitutional symptoms rapidly improving. Wolff and Wiewiorowski, on the other hand, have had equally good results by simply protecting the local lesion with a mild antiseptic dressing, and relying upon general treatment.

The general treatment consists in feeding and stimulating the patient as freely as possible. Quinine, in 5 to 10 grain doses every four hours, and powdered ipecacuanha, in 40 to 60 grain doses every four hours, have also been employed with apparent benefit.

GLANDERS

Glanders is due to the action of a specific bacterium, the bacillus mallei, which resembles the tubercle bacillus, save that it is somewhat shorter and broader, and does not stain by Gram's method. It requires higher temperatures for its cultivation than the tubercle bacillus, and its growth on potato is of a characteristic chocolate-brown colour, with a greenish-yellow ring at the margin of the growth. The bacillus mallei retains its vitality for long periods under ordinary conditions, but is readily killed by heat and chemical agents. It does not form spores.

Clinical Features.—Both in the lower animals and in man the bacillus gives rise to two distinct types of disease—acute glanders, and chronic glanders or farcy.

Acute Glanders is most commonly met with in the horse and in other equine animals, horned cattle being immune. It affects the septum of the nose and adjacent parts, firm, translucent, greyish nodules containing lymphoid and epithelioid cells appearing in the mucous membrane. These nodules subsequently break down in the centre, forming irregular ulcers, which are attended with profuse discharge, and marked inflammatory swelling. The cervical lymph glands, as well as the lungs, spleen, and liver, may be the seat of secondary nodules.