Читать книгу Surgery, with Special Reference to Podiatry - Maximilian Stern - Страница 12
ASEPSIS AND ANTISEPSIS
ОглавлениеBefore the introduction of Lister’s methods of treating wounds, it was considered proper, in accidental and operative wounds, to have profuse suppuration, pyemia, erysipelas, etc., and it was not remarkable, therefore, that the mortality following accidental and operative wounds was very high. Lister’s method of wound treatment was largely based upon the conception that the infection of wounds occurred from contact with the air which contained spores and germs, and his method of treatment therefore, was directed chiefly to their destruction. The air can be a medium of wound infection to a certain extent, and dry air contains more spores and bacteria than moist air, but Koch demonstrated the fact that atmospheric microbes were chiefly of innocuous character, and wound infection usually could be traced to bacteria or spores being brought into direct contact with wounds, by the clothing, or by the skin of the patient, or by the hands of the surgeon, or by unclean surgical instruments and dressings. The antiseptic qualities of the blood serum and cell activities in healthy tissues, are sufficient to destroy or remove a certain number of microorganisms, and suppuration occurs only when the tissues are completely overwhelmed by the number of these organisms or when their power of resistance is lessened by injury or disease.
Sepsis. Sepsis is due to the entrance and multiplication of microbes, or to the absorption of their products in the body. Local inflammation and marked constitutional symptoms characterize sepsis.
Asepsis. Asepsis aims at thorough sterilization of the parts and of all the objects brought into contact with the wounds, and the exclusion of germs by the use of occlusive bandages and dressings.
Antisepsis is that method of wound treatment which keeps germicidal agents continuously in direct contact with the wound. Its object, therefore, is to produce asepsis. It is the duty of the surgeon to guard against the contact of microorganisms in the wound and to employ whatever means science has evolved for their destruction. He must, however, be careful to employ means of disinfection or destruction that will not have an injurious effect upon the normal tissues.
Mechanical disinfection does not apply to wounds but is employed as a preventive measure by the operator and his assistants for instruments and for the skin surrounding the wounds. Mechanical disinfection is accomplished by the use of soap and water and a friction brush; germicidal solutions of one kind or another are also employed.
In the modern aseptic operating room germicides and antiseptics do not play so important a part as they formerly did. This is largely due to the fact that heat is used wherever possible in the preparation of sutures, ligatures, dressings and instruments, and to the farther fact that in uninfected tissues no antiseptic solutions are employed. It must also be remembered that the germicidal agents possess the disadvantage of exercising a more or less destructive action on the body cells, and consequently their use is not warranted in clean wounds. We still, however, sufficiently often meet with infected wounds that render the use of these agents necessary.
Heat is the most valuable of all sterilizing agents, its only drawback being that it is not universally applicable. Wherever possible it should be employed in preference to chemical agents. It can be employed either dry or moist. Moist heat is a much more efficacious germicide than dry heat, for it destroys the organisms at a much lower temperature. Boiling water at a temperature of 212°F. will destroy nearly instantaneously all pus-producing organisms. Spores, however, require a moist heat of 284°F. kept up for at least a half-hour. A dry heat of 212°F. will not destroy pus-producing organisms under an hour and a half of treatment, and spores will live for three hours at a dry temperature of 284°F.
Although moist heat is very much quicker and more satisfactory in its action, yet it is often inconvenient to employ it in the sterilization of gowns, towels, operating suits, etc. However, sterilization by heat has been greatly facilitated by the introduction of the autoclave, by means of which a very high temperature under pressure can be obtained. This is the most satisfactory method of sterilizing dressings, towels, sheets, operating suits and aprons. A similar and less expensive method of sterilizing these articles is by the use of one of the simple steam sterilizers which are sold by all dealers. In an emergency, an ordinary bake oven can be employed as a sterilizer. It is best, however, where the temperature cannot be estimated, to boil the articles and dry them between sheets moistened with bichloride solution.
Disinfection or Sterilization. Sterilization of a wound, or of the substances coming in contact with it, may be accomplished by using the aseptic or antiseptic method; by combining these two methods we obtain the best results. The aseptic method, which employs antiseptic substances for the purpose of sterilization of objects coming in contact with the wound when their disinfection by heat is impossible, is the method perhaps most generally favored by modern surgeons.
Antiseptic Method. In the antiseptic method, the field of operation, the hands of the operator and of his assistants, and the instruments, must be treated in germicidal solution and, in addition, the wound should be frequently irrigated during the operation with a solution that has germicidal properties.
Recent investigations show that many germicidal substances have not the power that was formerly attributed to them. Furthermore, substances which are really active germicides very often produce a marked toxic effect upon the patient and produce a very decided irritation of the skin with which they come in contact.
Aseptic Methods. The aseptic method for the treatment of wounds admits of the use of germicidal solutions and heat upon the field of operation, upon the hands of the operator and of his assistants, and upon the instruments employed. After this has been accomplished, placing absolute dependence upon this sterilization, no germicidal or antiseptic substances are brought into contact with the wound, sterilized salt solution or plain sterilized water being used, if necessary, to flush the wound, the dressings employed having been sterilized by dry heat or moist heat.
Sterilization of the Hands. Experimental investigation has shown that the failure of the surgeon’s efforts to render his hands absolutely aseptic, has been the productive cause of infection in many wounds.
The hands and finger nails may be best sterilized by first rubbing them with spirits of turpentine; then scrubbing them with soap and water; and then using a sterilized nail brush freely. The scrubbing should be done for several minutes. The hands should then be rinsed to remove the soap, and then soaked for about ten minutes in a solution of bichloride, strength, 1 to 2500. If turpentine has not been used before washing with the soap, strong alcohol or ether should be well rubbed over the hands before they are immersed in the bichloride solution. Perhaps the best way of rendering the hands sterile is to scrub them with green soap and water, then mix a tablespoonful of commercial chloride of lime and half a tablespoonful of carbonate of soda with enough water to make a paste. When this has assumed a thick creamy consistency, it should be rubbed into the hands until the grains of lime disappear and the skin feels cool; then rinse the hands in sterile water.
Sterilization of Instruments. Instruments may be sterilized by boiling them for fifteen minutes in water in which a tablespoonful of washing soda has been added for each quart. This prevents rusting of the instruments and also makes the water a better solvent for any fatty matter which may be upon the instruments, thus increasing the sterilizing effect of the heat.
Sterilization of the Feet. As most patients do not apply water as freely or as frequently to the feet as to other portions of the body, there is usually present an excessive amount of thickened epidermis, which is very difficult to render sterile. For operations in chiropody the feet should be thoroughly moistened with soap and water, scrubbed vigorously with a brush, then soaked in a solution of bichloride of mercury of 1 to 1000 strength, and then wrapped up in a towel soaked in the same solution while waiting for the operator.