#Sterilisation by Chemical Agents.#--For the purification of the skin of the patient, the hands of the surgeon, and knives and other instruments that are damaged by heat, recourse must be had to chemical agents.
These, however, are less reliable than heat, and are open to certain other objections.
#Disinfection of the Hands.#--It is now generally recognised that one of the most likely sources of wound infection is the hands of the surgeon and his a.s.sistants. It is only by carefully studying to avoid all contact with infective matter that the hands can be kept surgically pure, and that this source of wound infection can be reduced to a minimum. The risk of infection from this source has further been greatly reduced by the systematic use of rubber gloves by house-surgeons, dressers, and nurses. The habitual use of gloves has also been adopted by the great majority of surgeons; the minority, who find they are handicapped by wearing gloves as a routine measure, are obliged to do so when operating in infective cases or dressing infected wounds, and in making rectal and v.a.g.i.n.al examinations.
The gloves may be sterilised by steam, and are then put on dry, or by boiling, in which case they are put on wet. The gauntlet of the glove should overlap and confine the end of the sleeve of the sterilised overall, and the gloved hands are rinsed in lotion before and at frequent intervals during the operation. The hands are sterilised before putting on the gloves, preferably by a method which dehydrates the skin.
Cotton gloves may be worn by the surgeon when tying ligatures, or between operations, and by the anaesthetist during operations on the head, neck, and chest.
The first step in the disinfection of the hands is the mechanical removal of gross surface dirt and loose epithelium by soap, a stream of running water as hot as can be borne, and a loofah or nail-brush, that has been previously sterilised by heat. The nails should be cut down till there is no sulcus between the nail edge and the pulp of the finger in which organisms may lodge. They are next washed for three minutes in methylated spirit to dehydrate the skin, and then for two or three minutes in 70 per cent. sublimate or biniodide alcohol (1 in 1000).
Finally, the hands are rubbed with dry sterilised gauze.
#Preparation of the Skin of the Patient.#--In the purification of the skin of the patient before operation, reliance is to be placed chiefly in the mechanical removal of dirt and grease by the same means as are taken for the cleansing of the surgeon"s hands. Hair-covered parts should be shaved. The skin is then dehydrated by washing with methylated spirit, followed by 70 per cent. sublimate or biniodide alcohol (1 in 1000). This is done some hours before the operation, and the part is then covered with pads of dry sterilised gauze or a sterilised towel.
Immediately before the operation the skin is again purified in the same way.
The _iodine method_ of disinfecting the skin introduced by Grossich is simple, and equally efficient. The day before operation the skin, after being washed with soap and water, is shaved, dehydrated by means of methylated spirit, and then painted with a 5 per cent. solution of iodine in rectified spirit. The painting with iodine is repeated just before the operation commences, and again after it is completed. The final application is omitted in the case of children. In emergency operations the skin is shaved dry and dehydrated with spirit, after which the iodine is applied as described above. The staining of the skin is an advantage, as it enables the operator to recognise the area that has been prepared.
If any acne pustules or infected sinuses are present, they should be destroyed or purified by means of the thermo-cautery or pure carbolic acid, after the patient is anaesthetised.
#Appliances used at Operation.#--_Instruments_ that are not damaged by heat must be boiled in a fish-kettle or other suitable steriliser for fifteen minutes in a 1 per cent. solution of cresol or washing soda.
Just before the operation begins they are removed in the tray of the steriliser and placed on a sterilised towel within reach of the surgeon or his a.s.sistant. Knives and instruments that are liable to be damaged by heat should be purified by being soaked in pure cresol for a few minutes, or in 1 in 20 carbolic for at least an hour.
_Pads of Gauze_ sterilised by compressed circulating steam have almost entirely superseded marine sponges for operative purposes. To avoid the risk of leaving swabs in the peritoneal cavity, large square pads of gauze, to one corner of which a piece of strong tape about a foot long is securely st.i.tched, should be employed. They should be removed from the caskets in which they are sterilised by means of sterilised forceps, and handed direct to the surgeon. The a.s.sistant who attends to the swabs should wear sterilised gloves.
_Ligatures and Sutures._--To avoid the risk of implanting infective matter in a wound by means of the materials used for ligatures and sutures, great care must be taken in their preparation.
_Catgut._--The following methods of preparing catgut have proved satisfactory: (1) The gut is soaked in juniper oil for at least a month; the juniper oil is then removed by ether and alcohol, and the gut preserved in 1 in 1000 solution of corrosive sublimate in alcohol (Kocher). (2) The gut is placed in a bra.s.s receiver and boiled for three-quarters of an hour in a solution consisting of 85 per cent.
absolute alcohol, 10 per cent. water, and 5 per cent. carbolic acid, and is then stored in 90 per cent. alcohol. (3) Cladius recommends that the catgut, just as it is bought from the dealers, be loosely rolled on a spool, and then immersed in a solution of--iodine, 1 part; iodide of pota.s.sium, 1 part; distilled water, 100 parts. At the end of eight days it is ready for use. Moschcowitz has found that the tensile strength of catgut so prepared is increased if it is kept dry in a sterile vessel, instead of being left indefinitely in the iodine solution. If Salkindsohn"s formula is used--tincture of iodine, 1 part; proof spirit, 15 parts--the gut can be kept permanently in the solution without becoming brittle. To avoid contamination from the hands, catgut should be removed from the bottle with aseptic forceps and pa.s.sed direct to the surgeon. Any portion unused should be thrown away.
_Silk_ is prepared by being soaked for twelve hours in ether, for other twelve in alcohol, and then boiled for ten minutes in 1 in 1000 sublimate solution. It is then wound on spools with purified hands protected by sterilised gloves, and kept in absolute alcohol. Before an operation the silk is again boiled for ten minutes in the same solution, and is used directly from this (Kocher). Linen thread is sterilised in the same way as silk.
Fishing-gut and silver wire, as well as the needles, should be boiled along with the instruments. Horse-hair and fishing-gut may be sterilised by prolonged immersion in 1 in 20 carbolic, or in the iodine solutions employed to sterilise catgut.
The field of operation is surrounded by sterilised towels, clipped to the edges of the wound, and securely fixed in position so that no contamination may take place from the surroundings.
The surgeon and his a.s.sistants, including the anaesthetist, wear overalls sterilised by steam. To avoid the risk of infection from dust, scurf, or drops of perspiration falling from the head, the surgeon and his a.s.sistants may wear sterilised cotton caps. To obviate the risk of infection taking place by drops of saliva projected from the mouth in talking or coughing in the vicinity of a wound, a simple mask may be worn.
The risk of infection from the _air_ is now known to be very small, so long as there is no excess of floating dust. All sweeping, dusting, and disturbing of curtains, blinds, or furniture must therefore be avoided before or during an operation.
It has been shown that the presence of spectators increases the number of organisms in the atmosphere. In teaching clinics, therefore, the risk from air infection is greater than in private practice.
To facilitate primary union, all haemorrhage should be arrested, and the acc.u.mulation of fluid in the wound prevented. When much oozing is antic.i.p.ated, a gla.s.s or rubber drainage-tube is inserted through a small opening specially made for the purpose. In aseptic wounds the tube may be removed in from twenty-four to forty-eight hours, and where it is important to avoid a scar, the opening should be closed with a Michel"s clip; in infected wounds the tube must remain as long as the discharge continues.
The fascia and skin should be brought into accurate apposition by sutures. If any cavity exists in the deeper part of the wound it should be obliterated by buried sutures, or by so adjusting the dressing as to bring its walls into apposition.
If these precautions have been successful, the wound will heal under the original dressing, which need not be interfered with for from seven to ten days, according to the nature of the case.
#Dressings.#--_Gauze_, sterilised by heat, is almost universally employed for the dressing of wounds. _Double cyanide gauze_ may be used in such regions as the neck, axilla, or groin, where complete sterilisation of the skin is difficult to attain, and where it is desirable to leave the dressing undisturbed for ten days or more.
_Iodoform_ or _bis.m.u.th gauze_ is of special value for the packing of wounds treated by the open method.
One variety or another of _wool_, rendered absorbent by the extraction of its fat, and sterilised by heat, forms a part of almost every surgical dressing, and various antiseptic agents may be added to it. Of these, corrosive sublimate is the most generally used. Wood-wool dressings are more highly and more uniformly absorbent than cotton wools. As evaporation takes place through wool dressings, the discharge becomes dried, and so forms an unfavourable medium for bacterial growth.
Pads of _sphagnum moss_, sterilised by heat, are highly absorbent, and being economical are used when there is much discharge, and in cases where a leakage of urine has to be soaked up.
#Means adopted to combat Infection.#--As has already been indicated, the same antiseptic precautions are to be taken in dealing with infected as with aseptic wounds.
In _recent injuries_ such as result from railway or machinery accidents, with bruising and crushing of the tissues and grinding of gross dirt into the wounds, the scissors must be freely used to remove the tissues that have been devitalised or impregnated with foreign material.
Hair-covered parts should be shaved and the surrounding skin painted with iodine. Crushed and contaminated portions of bone should be chiselled away. Opinions differ as to the benefit derived from washing such wounds with chemical antiseptics, which are liable to devitalise the tissues with which they come in contact, and so render them less able to resist the action of any organisms that may remain in them. All are agreed, however, that free washing with normal salt solution is useful in mechanically cleansing the injured parts. Peroxide of hydrogen sprayed over such wounds is also beneficial in virtue of its oxidising properties. Efficient drainage must be provided, and st.i.tches should be used sparingly, if at all.
The best way in which to treat such wounds is by the _open method_. This consists in packing the wound with iodoform or bis.m.u.th gauze, which is left in position as long as it adheres to the raw surface. The packing may be renewed at intervals until the wound is filled by granulations; or, in the course of a few days when it becomes evident that the infection has been overcome, _secondary_ sutures may be introduced and the edges drawn together, provision being made at the ends for further packing or for drainage-tubes.
If earth or street dirt has entered the wound, the surface may with advantage be painted over with pure carbolic acid, as virulent organisms, such as those of teta.n.u.s or spreading gangrene, are liable to be present. Prophylactic injection of teta.n.u.s ant.i.toxin may be indicated.
CHAPTER XIII
CONSt.i.tUTIONAL EFFECTS OF INJURIES
SYNCOPE--SHOCK--COLLAPSE--FAT EMBOLISM--TRAUMATIC ASPHYXIA--DELIRIUM IN SURGICAL PATIENTS: _Delirium in general_; _Delirium tremens_; _Traumatic delirium_.
SYNCOPE, SHOCK, AND COLLAPSE
Syncope, shock, and collapse are clinical conditions which, although depending on different causes, bear a superficial resemblance to one another.
#Syncope or Fainting.#--Syncope is the result of a suddenly produced anaemia of the brain from temporary weakening or arrest of the heart"s action. In surgical practice, this condition is usually observed in nervous persons who have been subjected to pain, as in the reduction of a dislocation or the incision of a whitlow; or in those who have rapidly lost a considerable quant.i.ty of blood. It may also follow the sudden withdrawal of fluid from a large cavity, as in tapping an abdomen for ascites, or withdrawing fluid from the pleural cavity. Syncope sometimes occurs also during the administration of a general anaesthetic, especially if there is a tendency to sickness and the patient is not completely under. During an operation the onset of syncope is often recognised by the cessation of oozing from the divided vessels before the general symptoms become manifest.
_Clinical Features._--When a person is about to faint he feels giddy, has surging sounds in his ears, and haziness of vision; he yawns, becomes pale and sick, and a free flow of saliva takes place into the mouth. The pupils dilate; the pulse becomes small and almost imperceptible; the respirations shallow and hurried; consciousness gradually fades away, and he falls in a heap on the floor.
Sometimes vomiting ensues before the patient completely loses consciousness, and the muscular exertion entailed may ward off the actual faint. This is frequently seen in threatened syncopal attacks during chloroform administration.
Recovery begins in a few seconds, the patient sighing or gasping, or, it may be, vomiting; the strength of the pulse gradually increases, and consciousness slowly returns. In some cases, however, syncope is fatal.
_Treatment._--The head should at once be lowered--in imitation of nature"s method--to encourage the flow of blood to the brain, the patient, if necessary, being held up by the heels. All tight clothing, especially round the neck or chest, must be loosened. The heart may be stimulated reflexly by dashing cold water over the face or chest, or by rubbing the face vigorously with a rough towel. The application of volatile substances, such as ammonia or smelling-salts, to the nose; the administration by the mouth of sal-volatile, whisky or brandy, and the intra-muscular injection of ether, are the most speedily efficacious remedies. In severe cases the application of hot cloths over the heart, or of the faradic current over the line of the phrenic nerve, just above the clavicle, may be called for.
#Surgical Shock.#--The condition known as surgical shock may be looked upon as a state of profound exhaustion of the mechanism that exists in the body for the transformation of energy. This mechanism consists of (1) the _brain_, which, through certain special centres, regulates all vital activity; (2) the _adrenal glands_, the secretion of which--adrenalin--acting as a stimulant of the sympathetic system, so controls the tone of the blood vessels as to maintain efficient oxidation of the tissues; and (3) _the liver_, which stores and delivers glycogen as it is required by the muscles, and in addition, deals with the by-products of metabolism.
Crile and his co-workers have shown that in surgical shock histological changes occur in the cells of the brain, the adrenals, and the liver, and that these are identical, whatever be the cause that leads to the exhaustion of the energy-transforming mechanism. These changes vary in degree, and range from slight alterations in the structure of the protoplasm to complete disorganisation of the cell elements.
The influences which contribute to bring about this form of exhaustion that we call shock are varied, and include such emotional states as fear, anxiety, or worry, physical injury and toxic infection, and the effects of these factors are augmented by anything that tends to lower the vitality, such as loss of blood, exposure, insufficient food, loss of sleep or antecedent illness.
Any one or any combination of these influences may cause shock, but the most potent, and the one which most concerns the surgeon, is physical injury, _e.g._, a severe accident or an operation (_traumatic shock_).
This is usually a.s.sociated with some emotional disturbance, such as fear or anxiety (_emotional shock_), or with haemorrhage; and may be followed by septic infection (_toxic shock_).
The exaggerated afferent impulses reaching the brain as a result of trauma, inhibit the action of the nuclei in the region of the fourth ventricle and cerebellum which maintain the muscular tone, with the result that the muscular tone is diminished and there is a marked fall in the arterial blood pressure. The capillaries dilate--the blood stagnating in them and giving off its oxygen and transuding its fluid elements into the tissues--with the result that an insufficient quant.i.ty of oxygenated blood reaches the heart to enable it to maintain an efficient circulation. As the sarco-lactic acid liberated in the muscles is not oxygenated a condition of acidosis ensues.
The more highly the injured part is endowed with sensory nerves the more marked is the shock; a crush of the hand, for example, is attended with a more intense degree of shock than a correspondingly severe crush of the foot; and injuries of such specially innervated parts as the testis, the urethra, the face, or the spinal cord, are a.s.sociated with severe degrees, as are also those of parts innervated from the sympathetic system, such as the abdominal or thoracic viscera. It is to be borne in mind that a state of general anaesthesia does not prevent injurious impulses reaching the brain and causing shock during an operation. If the main nerves of the part are "blocked" by injection of a local anaesthetic, however, the central nervous system is protected from these impulses.