METHODS OF WOUND TREATMENT
Varieties of wounds--Modes of infection--Lister's work--Means taken to
prevent infection of wounds: _heat_; _chemical antiseptics_;
_disinfection of hands_; _preparation of skin of patient_;
_instruments_; _ligatures_; _dressings_--Means taken to combat
infection: _purification_; _open-wound method_.
The surgeon is called upon to treat two distinct classes of wounds: (1)
those resulting from injury or disease in which _the skin is already
broken_, or in which a communication with a mucous surface exists; and
(2) those that he himself makes _through intact skin_, no infected
mucous surface being involved.
Infection by bacteria must be assumed to have taken place in all wounds
made in any other way than by the knife of the surgeon operating through
unbroken skin. On this assumption the modern system of wound treatment
is based. Pathogenic bacteria are so widely distributed, that in the
ordinary circumstances of everyday life, no matter how trivial a wound
may be, or how short a time it may remain exposed, the access of
organisms to it is almost certain unless preventive measures are
employed.
It cannot be emphasised too strongly that rigid precautions are to be
taken to exclude fresh infection, not only in dealing with wounds that
are free of organisms, but equally in the management of wounds and other
lesions that are already infected. Any laxity in our methods which
admits of fresh organisms reaching an infected wound adds materially to
the severity of the infective process and consequently to the patient's
risk.
There are many ways in which accidental infection may occur. Take, for
example, the case of a person who receives a cut on the face by being
knocked down in a carriage accident on the street. Organisms may be
introduced to such a wound from the shaft or wheel by which he was
struck, from the ground on which he lay, from any portion of his
clothing that may have come in contact with the wound, or from his own
skin. Or, again, the hands of those who render first aid, the water used
to bathe the wound, the handkerchief or other extemporised dressing
applied to it, may be the means of conveying bacterial infection. Should
the wound open on a mucous surface, such as the mouth or nasal cavity,
the organisms constantly present in such situations are liable to prove
agents of infection.
Even after the patient has come under professional care the risks of his
wound becoming infected are not past, because the hands of the doctor,
his instruments, dressings, or other appliances may all, unless
purified, become the sources of infection.
In the case of an operation carried out through unbroken skin, organisms
may be introduced into the wound from the patient's own skin, from the
hands of the surgeon or his assistants, through the medium of
contaminated instruments, swabs, ligature or suture materials, or other
things used in the course of the operation, or from the dressings
applied to the wound.
Further, bacteria may gain access to devitalised tissues by way of the
blood-stream, being carried hither from some infected area elsewhere in
the body.
_The Antiseptic System of Surgery._--Those who only know the surgical
conditions of to-day can scarcely realise the state of matters which
existed before the introduction of the antiseptic system by Joseph
Lister in 1867. In those days few wounds escaped the ravages of pyogenic
and other bacteria, with the result that suppuration ensued after most
operations, and such diseases as erysipelas, pyæmia, and "hospital
gangrene" were of everyday occurrence. The mortality after compound
fractures, amputations, and many other operations was appalling, and
death from blood-poisoning frequently followed even the most trivial
operations. An operation was looked upon as a last resource, and the
inherent risk from blood-poisoning seemed to have set an impassable
barrier to the further progress of surgery. To the genius of Lister we
owe it that this barrier was removed. Having satisfied himself that the
septic process was due to bacterial infection, he devised a means of
preventing the access of organisms to wounds or of counteracting their
effects. Carbolic acid was the first antiseptic agent he employed, and
by its use in compound fractures he soon obtained results such as had
never before been attained. The principle was applied to other
conditions with like success, and so profoundly has it affected the
whole aspect of surgical pathology, that many of the infective diseases
with which surgeons formerly had to deal are now all but unknown. The
broad principles upon which Lister founded his system remain unchanged,
although the methods employed to put them into practice have been
modified.
#Means taken to Prevent Infection of Wounds.#--The avenues by which
infective agents may gain access to surgical wounds are so numerous and
so wide, that it requires the greatest care and the most watchful
attention on the part of the surgeon to guard them all. It is only by
constant practice and patient attention to technical details in the
operating room and at the bedside, that the carrying out of surgical
manipulations in such a way as to avoid bacterial infection will become
an instinctive act and a second nature. It is only possible here to
indicate the chief directions in which danger lies, and to describe the
means most generally adopted to avoid it.
To prevent infection, it is essential that everything which comes into
contact with a wound should be sterilised or disinfected, and to ensure
the best results it is necessary that the efficiency of our methods of
sterilisation should be periodically tested. The two chief agencies at
our disposal are heat and chemical antiseptics.
#Sterilisation by Heat.#--The most reliable, and at the same time the
most convenient and generally applicable, means of sterilisation is by
heat. All bacteria and spores are completely destroyed by being
subjected for fifteen minutes to _saturated circulating steam_ at a
temperature of 130° to 145° C. (= 266° to 293° F.). The articles to be
sterilised are enclosed in a perforated tin casket, which is placed in a
specially constructed steriliser, such as that of Schimmelbusch. This
apparatus is so arranged that the steam circulates under a pressure of
from two to three atmospheres, and permeates everything contained in it.
Objects so sterilised are dry when removed from the steriliser. This
method is specially suitable for appliances which are not damaged by
steam, such, for example, as gauze swabs, towels, aprons, gloves, and
metal instruments; it is essential that the efficiency of the steriliser
be tested from time to time by a self-registering thermometer or other
means.
The best substitute for circulating steam is _boiling_. The articles are
placed in a "fish-kettle steriliser" and boiled for fifteen minutes in a
1 per cent. solution of washing soda.
To prevent contamination of objects that have been sterilised they must
on no account be touched by any one whose hands have not been
disinfected and protected by sterilised gloves.
#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 assistants. 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 vaginal 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 anæsthetist 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 anæsthetised.
#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 assistant. 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 stitched, 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 assistant 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 brass 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
potassium, 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 passed 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 assistants, including the anæsthetist, 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 assistants 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 hæmorrhage should be arrested, and the
accumulation of fluid in the wound prevented. When much oozing is
anticipated, a glass 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 _bismuth 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 stitches 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 bismuth 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 tetanus or spreading gangrene, are liable to
be present. Prophylactic injection of tetanus antitoxin may be
indicated.