When the charge impinges over one of the large cavities of the body, the shot may scatter widely through the contained viscera, and there is often no exit wound. In the thorax, for example, if a rib is struck, the charge and possibly fragments of bone, will penetrate the pleura, and be dispersed throughout the lung; in the head, the skull may be shattered and the brain torn up; and in the abdomen, the hollow viscera may be perforated in many places and the solid organs lacerated.
On covered parts the clothing, by deflecting the shot, influences the size and shape of the wound; the entrance wound is increased in size and more ragged, and portions of the clothes may be driven into the tissues.
[Ill.u.s.tration: FIG. 62.--Radiogram showing Pellets embedded in Arm.
(Mr. J. W. Dowden"s case.)]
A charge of small shot is much more destructive to blood vessels, tendons, and ligaments than a single bullet, which in many cases pushes such structures aside without dividing them. In the abdomen and chest, also, the damage done by a full charge of shot is much more extensive than that inflicted by a single bullet, the deflection of the pellets leading to a greater number of perforations of the intestine and more widespread laceration of solid viscera.
When the charge impinges on one of the extremities at close range, we often have the opportunity of observing that the exit wound is larger, more ragged than that of entrance, and that its edges are everted; the extensive tearing and bruising of all the tissues, including the bones, and the marked tendency to early and progressive septic infection, render amputation compulsory in the majority of such cases.
At a range of from twenty to thirty feet, although the scatter is complete, the pellets are still close together, so that if they encounter the shaft of a long bone, even the femur, they fracture the bone across, often along with some longitudinal splintering.
Individual pellets striking the shafts of long bones become flattened or distorted, and when cancellated bone is struck they become embedded in it (Fig. 62).
The skin, when it is closely peppered with shot, is liable to lose its vitality, and with the addition of a little sepsis, readily necroses and comes away as a slough.
When the shot have diverged so as to strike singly, they seldom do much harm, but fatal damage may be done to the brain or to the aorta, or the eye may be seriously injured by a single pellet.
Small shot fired at longer ranges--over about a hundred and fifty feet--usually go through the skin, but seldom pierce the fascia, and lie embedded in the subcutaneous tissue, from which they can readily be extracted.
The wad of the cartridge behaves erratically: so long as it remains flat it goes off with the rest of the charge, and is often buried in the wound; but if it curls up or turns on its side, it is usually deflected and flies clear of the shot. It may make a separate wound.
Wounds from sporting guns are to be _treated_ on the usual lines, the early efforts being directed to the alleviation of shock and the prevention of septic infection. There is rarely any urgency in the removal of pellets from the tissues.
#Wounds by Rifle Bullets.#--The vast majority of wounds inflicted by rifle bullets are met with in the field during active warfare, and fall to be treated by military surgeons. They occasionally occur accidentally, however, during range practice for example, and may then come under the notice of the civil surgeon.
It is only necessary here to consider the effects of modern small-bore rifle or machine-gun bullets.
The trajectory is practically flat up to 675 yards. In destructive effect there is not much difference between the various high velocity bullets used in different armies; they will kill up to a distance of two miles. The hard covering is employed to enable the bullet to take the grooves in the rifle, and to prevent it stripping as it pa.s.ses through the barrel. It also increases the penetrating power of the missile, but diminishes its "stopping" power, unless a vital part or a long bone is struck. By removing the covering from the point of the bullet, as is done in the Dum-Dum bullet, or by splitting the end, the bullet is made to expand or "mushroom" when it strikes the body, and its stopping power is thereby greatly increased, the resulting wound being much more severe. These "soft-nosed" expanding bullets are to be distinguished from "explosive" bullets which contain substances which detonate on impact. High velocity bullets are unlikely to lodge in the body unless spent, or pulled up by a sandbag, or metal buckle on a belt, or a book in the pocket, or the core and the case separating--"stripping" of the bullet. Spent shot may merely cause bruising of the surface, or they may pa.s.s through the skin and lodge in the subcutaneous tissue, or may even damage some deeper structure such as a nerve trunk.
A blank cartridge fired at close range may cause a severe wound, and, if charged with black powder, may leave a permanent bluish-black pigmentation of the skin.
The lesions of individual tissues--bones, nerves, blood vessels--are considered with these.
#Treatment of Gunshot Wounds under War Conditions.#--It is only necessary to indicate briefly the method of dealing with gunshot wounds in warfare as practised in the European War.
1. _On the Field._--Haemorrhage is arrested in the limbs by an improvised tourniquet; in the head by a pad and bandage; in the thorax or abdomen by packing if necessary, but this should be avoided if possible, as it favours septic infection. If a limb is all but detached it should be completely severed. A full dose of morphin is given hypodermically. The ampoule of iodine carried by the wounded man is broken, and its contents are poured over and around the wound, after which the field dressing is applied. In extensive wounds, the "sh.e.l.l-dressing" carried by the stretcher bearers is preferred. All bandages are applied loosely to allow for subsequent swelling. The fragments of fractured bones are immobilised by some form of emergency splint.
2. _At the Advanced Dressing Station_, after the patient has had a liberal allowance of warm fluid nourishment, such as soup or tea, a full dose of anti-tetanic serum is injected. The tourniquet is removed and the wound inspected. Urgent amputations are performed. Moribund patients are detained lest they die _en route_.
3. _In the Field Ambulance or Casualty Clearing Station_ further measures are employed for the relief of shock, and urgent operations are performed, such as amputation for gangrene, tracheotomy for dyspna, or laparotomy for perforated or lacerated intestine. In the majority of cases the main object is to guard against infection; the skin is disinfected over a wide area and surrounded with towels; damaged tissue, especially muscle, is removed with the knife or scissors, and foreign bodies are extracted. Torn blood vessels, and, if possible, nerves and tendons are repaired. The wound is then partly closed, provision being made for free drainage, or some special method of irrigation, such as that of Carrel, is adopted. Sometimes the wound is treated with bis.m.u.th, iodoform, and paraffin paste (B.I.P.P.) and sutured.
4. _In the Base Hospital or Hospital Ship_ various measures may be called for according to the progress of the wound and the condition of the patient.
#Sh.e.l.l Wounds and Wounds produced by Explosions.#--It is convenient to consider together the effects of the bursting of sh.e.l.ls fired from heavy ordnance and those resulting in the course of blasting operations from the discharge of dynamite or other explosives, or from the bursting of steam boilers or pipes, the breaking of machinery, and similar accidents met with in civil practice.
Wounds inflicted by sh.e.l.l fragments and shrapnel bullets tend to be extensive in area, and show great contusion, laceration, and destruction of the tissues. The missiles frequently lodge and carry portions of the clothing and, it may be, articles from the man"s pocket, with them.
Sh.e.l.l wounds are attended with a considerable degree of shock. On account of the wide area of contusion which surrounds the actual wound produced by sh.e.l.l fragments, amputation, when called for, should be performed some distance above the torn tissues, as there is considerable risk of sloughing of the flaps.
Wounds produced by dynamite explosions and the bursting of boilers have the same general characters as sh.e.l.l wounds. Fragments of stone, coal, or metal may lodge in the tissues, and favour the occurrence of infective complications.
All such injuries are to be treated on the general principles governing contused and lacerated wounds.
EMBEDDED FOREIGN BODIES
In the course of many operations foreign substances are introduced into the tissues and intentionally left there, for example, suture and ligature materials, steel or aluminium plates, silver wire or ivory pegs used to secure the fixation of bones, or solid paraffin employed to correct deformities. Other substances, such as gauze, drainage tubes, or metal instruments, may be unintentionally left in a wound.
Foreign bodies may also lodge in accidentally inflicted wounds, for example, bullets, needles, splinters of wood, or fragments of clothing.
The needles of hypodermic syringes sometimes break and a portion remains embedded in the tissues. As a result of explosions, particles of carbon, in the form of coal-dust or gunpowder, or portions of shale, may lodge in a wound.
The embedded foreign body at first acts as an irritant, and induces a reaction in the tissues in which it lodges, in the form of hyperaemia, local leucocytosis, proliferation of fibroblasts, and the formation of granulation tissue. The subsequent changes depend upon whether or not the wound is infected with pyogenic bacteria. If it is so infected, suppuration ensues, a sinus forms, and persists until the foreign body is either cast out or removed.
If the wound is aseptic, the fate of the foreign body varies with its character. A substance that is absorbable, such as catgut or fine silk, is surrounded and permeated by the phagocytes, which soften and disintegrate it, the debris being gradually absorbed in much the same manner as a fibrinous exudate. Minute bodies that are not capable of being absorbed, such as particles of carbon, or of pigment used in tattooing, are taken up by the phagocytes, and in course of time removed. Larger bodies, such as needles or bullets, which are not capable of being destroyed by the phagocytes, become encapsulated. In the granulation tissue by which they are surrounded large multinuclear giant-cells appear ("_foreign-body giant-cells_") and attach themselves to the foreign body, the fibroblasts proliferate and a capsule of scar tissue is eventually formed around the body. The tissues of the capsule may show evidence of iron pigmentation. Sometimes fluid acc.u.mulates around a foreign body within its capsule, const.i.tuting a cyst.
Substances like paraffin, strands of silk used to bridge a gap in a tendon, or portions of calcined bone, instead of being encapsulated, are gradually permeated and eventually replaced by new connective tissue.
Embedded bodies may remain in the tissues for an indefinite period without giving rise to inconvenience. At any time, however, they may cause trouble, either as a result of infective complications, or by inducing the formation of a ma.s.s of inflammatory tissue around them, which may simulate a gumma, a tuberculous focus, or a sarcoma. This latter condition may give rise to difficulties in diagnosis, particularly if there is no history forthcoming of the entrance of the foreign body. The ignorance of patients regarding the possible lodgment in the tissues of a foreign body--even of considerable size--is remarkable. In such cases the X-rays will reveal the presence of the foreign body if it is sufficiently opaque to cast a shadow. The heavy, lead-containing varieties of gla.s.s throw very definite shadows little inferior in sharpness and definition to those of metal; almost all the ordinary forms of commercial gla.s.s also may be shown up by the X-rays.
Foreign bodies encapsulated in the peritoneal cavity are specially dangerous, as the proximity of the intestine furnishes a constant possibility of infection.
The question of removal of the foreign body must be decided according to the conditions present in individual cases; in searching for a foreign body in the tissues, unless it has been accurately located, a general anaesthetic is to be preferred.
BURNS AND SCALDS
The distinction between a burn which results from the action of dry heat on the tissues of the body and a scald which results from the action of moist heat, has no clinical significance.
In young and debilitated subjects hot poultices may produce injuries of the nature of burns. In old people with enfeebled circulation mere exposure to a strong fire may cause severe degrees of burning, the clothes covering the part being uninjured. This may also occur about the feet, legs, or knees of persons while intoxicated who have fallen asleep before the fire.
The damage done to the tissues by strong caustics, such as fuming nitric acid, sulphuric acid, caustic potash, nitrate of silver, or a.r.s.enical paste, presents pathological and clinical features almost identical with those resulting from heat. Electricity and the Rontgen rays also produce lesions of the nature of burns.
_Pathology of Burns._--Much discussion has taken place regarding the explanation of the rapidly fatal issue in extensive superficial burns.
On post-mortem examination the lesions found in these cases are: (1) general hyperaemia of all the organs of the abdominal, thoracic, and cerebro-spinal cavities; (2) marked leucocytosis, with destruction of red corpuscles, setting free haemoglobin which lodges in the epithelial cells of the tubules of the kidneys; (3) minute thrombi and extravasations throughout the tissues of the body; (4) degeneration of the ganglion cells of the solar plexus; (5) dema and degeneration of the lymphoid tissue throughout the body; (6) cloudy swelling of the liver and kidneys, and softening and enlargement of the spleen. Bardeen suggests that these morbid phenomena correspond so closely to those met with where the presence of a toxin is known to produce them, that in all probability death is similarly due to the action of some poison produced by the action of heat on the skin and on the proteins of the blood.
#Clinical Features--Local Phenomena.#--The most generally accepted cla.s.sification of burns is that of Dupuytren, which is based upon the depth of the lesion. Six degrees are thus, recognised: (1) hyperaemia or erythema; (2) vesication; (3) partial destruction of the true skin; (4) total destruction of the true skin; (5) charring of muscles; (6) charring of bones.
It must be observed, however, that burns met with at the bedside always ill.u.s.trate more than one of these degrees, the deeper forms always being a.s.sociated with those less deep, and the clinical picture is made up of the combined characters of all. A burn is cla.s.sified in terms of its most severe portion. It is also to be remarked that the extent and severity of a burn usually prove to be greater than at first sight appears.
_Burns of the first degree_ are a.s.sociated with erythema of the skin, due to hyperaemia of its blood vessels, and result from scorching by flame, from contact with solids or fluids below 212 F., or from exposure to the sun"s rays. They are characterised clinically by acute pain, redness, transitory swelling from dema, and subsequent desquamation of the surface layers of the epidermis. A special form of pigmentation of the skin is seen on the front of the legs of women from exposure to the heat of the fire.
_Burns of Second Degree--Vesication of the Skin._--These are characterised by the occurrence of vesicles or blisters which are scattered over the hyperaemic area, and contain a clear yellowish or brownish fluid. On removing the raised epidermis, the congested and highly sensitive papillae of the skin are exposed. Unna has found that pyogenic bacteria are invariably present in these blisters. Burns of the second degree leave no scar but frequently a persistent discoloration.
In rare instances the burned area becomes the seat of a peculiar overgrowth of fibrous tissue of the nature of keloid (p 401).
_Burns of Third Degree--Partial Destruction of the Skin._--The epidermis and papillae are destroyed in patches, leaving hard, dry, and insensitive sloughs of a yellow or black colour. The pain in these burns is intense, but pa.s.ses off during the first or second day, to return again, however, when, about the end of a week, the sloughs separate and expose the nerve filaments of the underlying skin. Granulations spring up to fill the gap, and are rapidly covered by epithelium, derived partly from the margins and partly from the remains of skin glands which have not been completely destroyed. These latter appear on the surface of the granulations as small bluish islets which gradually increase in size, become of a greyish-white colour, and ultimately blend with one another and with the edges. The resulting cicatrix may be slightly depressed, but otherwise exhibits little tendency to contract and cause deformity.
_Burns of Fourth Degree--Total Destruction of the Skin._--These follow the more prolonged action of any form of intense heat. Large, black, dry eschars are formed, surrounded by a zone of intense congestion. Pain is less severe, and is referred to the parts that have been burned to a less degree. Infection is liable to occur and to lead to wide destruction of the surrounding skin. The amount of granulation tissue necessary to fill the gap is therefore great; and as the epithelial covering can only be derived from the margins--the skin glands being completely destroyed--the healing process is slow. The resulting scars are irregular, deep and puckered, and show a great tendency to contract.
Keloid frequently develops in such cicatrices. When situated in the region of the face, neck, or flexures of joints, much deformity and impairment of function may result (Fig. 63).