Antisepsis and Asepsis

ANTISEPSIS AND ASEPSIS (from Greek anti- against, a- negative particle, and sepsis- decay), anti-decay and non-decay methods of fighting infection in wounds. Both methods have the aim of disinfecting everything that comes into contact with the wound, and if possible, the wound itself. It is now strictly impossible to draw a clear line between them, as they complement each other and are combined by various surgeons in the most diverse combinations. Therefore, new terms are beginning to come into use, replacing and uniting the previous ones, namely- germ-free, anti-parasitic, amicrobic. Antisepsis is generally understood to mean chemical methods of fighting infection with the help of various chemical disinfecting substances, both in the wound itself and outside it, while asepsis refers to physical methods of disinfection- boiling, sterilization with steam, high temperature, washing, filtering. The aseptic method is thus preventive, not allowing microbes into the wound, acting on all inanimate objects that come into contact with the wound. With the aseptic method, the effect on an infected wound is reduced to creating conditions unfavorable for the development of microbes- elimination of tissue trauma and stagnation of discharge, correct position, a well-drying dressing made of hygroscopic material, etc. In the late 1850s and early 1860s of the 19th century, Pasteur's research clarified the role of microbes in the processes of fermentation and decay of protein substances. The enormous role of so-called pathogenic pus-forming microorganisms was also clarified. This discovery made understandable the usual then terrifying complications in the course of wounds, observed by all surgeons, clarified what those 'miasmas' were, about the infectiousness of which much was said and written. The English surgeon Lister, having become acquainted with Pasteur's discovery, began to study and develop methods of combating wound infection. In 1867, he already presented in a number of articles his observations and the brilliant results achieved by the use of carbolic acid. Chemical substances were used in the treatment of wounds even earlier. One of those who came closest to solving the problem was Semmelweiss, who in 1848 proposed washing hands with chloride of lime and thereby achieved a significant reduction in postpartum complications. The work of Pasteur and Lister laid the foundation for antiseptic treatment of wounds and the entire modern state of surgery, which gained the opportunity to fight infection. Lister's method consisted in the use of a carbolic solution (5%): for washing hands, the skin of the operative field, instruments, constant spraying (spray) over the operative field, a special multi-layer dressing on the wound- with the aim of not allowing microbes into the wound or killing them in it. Lister's method, giving excellent results for that time, slowly acquired many supporters, but as observations accumulated, it became clear that carbolic acid was not indifferent to wounds, and to patients, and to surgeons; adverse effects on tissues (up to necrosis) and cases of poisoning were observed. The search and testing of various other chemical substances less harmful to the body and tissues to replace carbolic acid began. At the same time, the possibility of achieving good operative results by using thorough cleanliness, the possibility of killing microbes with high temperature (dry heat, boiling) gave impetus to the development of the so-called aseptic method, physical antisepsis. Already in the 1880s of the 19th century, some surgeons sharply limited the use of chemical anti-parasitic substances in operations, for the treatment of wounds, etc., trying to use the developed aseptic techniques. This method and the results achieved in many cases, in the treatment of clean wounds, in clean operations, were excellent. Surgery in peacetime was satisfied with asepsis, but during the imperialist war (1914-18) the huge number of infected wounds with very severe course and consequences prompted some to again seek salvation in chemical anti-parasitic means, both old and newly proposed, while others- to pay increased attention to the study of the protective properties of the body and ways to enhance these properties and promote their manifestation (so to speak, biological antisepsis). Antiseptic substances. Antiseptic chemical substances are used in the form of wound irrigation, compresses, lubrications, powders, ointments, etc. These chemical substances act 1) on the plasma of bacteria, penetrating inside them, and 2) on the environment surrounding the bacteria (coagulation, change in reaction, etc.), changing the favorable conditions for the growth and reproduction of bacteria. Bacterial spores more strongly resist the action of all kinds of chemical and physical agents. Chemical substances have a stronger effect on microbes in solutions, in dry form their action is weaker. Many potent antiseptics (sublimate, carbolic acid, etc.), due to their toxicity, can only be used in solutions. Chemical substances, especially those used to affect the wound, must satisfy several conditions: 1) they must act sufficiently bactericidal, 2) they must not suppress the vital activity of tissues (and even more so kill them) and poison the body, 3) be stable in storage in solutions, 4) not decompose upon contact with wound discharge.-It is impossible to list the huge number of proposed antiseptics. None of them satisfies all the above requirements, and therefore at present they have a limited range of application, especially for affecting the wound itself. More strongly attracted and attract the attention of surgeons the following antiseptics: 1. Carbolic acid (in 2-5% aqueous solutions), a fairly strong bactericidal agent, but undoubtedly harmful to tissues even in weak solutions (with longer use); paralyzes white blood cells, volatile, causes poisoning. In surgery, it is usually not used.- 2. Creolin (0.5 - 2% aqueous emulsion) and 3. Lysol (0.5-2% aqueous solution) are sometimes used for irrigating wounds, purulent cavities, storing instruments (lysol); less toxic than carbolic acid, but more bactericidal.-4. Boric acid (1-4% aqueous solution) is very little bactericidal, does not harm tissues, but can cause poisoning with abundant use (for example, washing some large cavity).-5. Of mercury preparations, sublimate (in solutions 1:1,000-5,000) was for a long time widely used for irrigating wounds, washing hands, the operative field, etc. Sublimate has a significant anti-parasitic force, but this force decreases when the sublimate solution comes into contact with living tissues, because sublimate combines with the protein substances of tissues and wound discharge into an inactive and insoluble mercury albuminate. Sublimate solutions easily decompose under the influence of light, heat, alkalinity of water; to give greater stability to solutions, NaCl (0.1%) is added to them, but this addition reduces the bactericidal properties of the solution, although, on the other hand, it makes the mentioned mercury albuminate soluble. Sublimate solutions stronger than 0.1% are usually not used, as they are harmful to tissues, and stronger solutions (1-3%) cauterize tissues. Sublimate is easily absorbed even through the skin, which can lead to symptoms of more or less severe mercury poisoning. Instruments turn black from sublimate. The toxicity of sublimate, the instability of its solutions and the decrease in bactericidal properties upon contact with proteins led to the abandonment of its widespread use. At present, a sublimate solution in the operating room and dressing room is used for washing dishes, washbasins, floors, storing sterilized drainage tubes, etc.-6. Silver nitrate in solutions and per se has significant bactericidal properties; its solutions easily decompose in the light and upon contact with tissues and wound discharge. On tissues, silver salts have an astringent and cauterizing effect; a superficial crust of silver albuminate, insoluble and not allowing the solution to penetrate inward, is formed.-7. Thymol (in aqueous solution 1:1,000) is a strong bactericidal agent, but has a strong smell not always tolerated by patients; does not cauterize tissues, is slightly toxic (for internal use up to 2.0-4.0 per day). Easily soluble in alcohol.-8. Potassium permanganate (0.1-0.5% solutions) in the presence of organic substances releases oxygen, which acts bactericidal at that moment. The preparation (solution) is used as a means of effectively destroying bad odor in foul-smelling wounds.-9. Similarly, hydrogen peroxide (3% solution) acts, i.e., both bactericidal and deodorizing; in addition, it perfectly cleans the wound, since the foam formed when introduced into the wound easily removes blood clots, pus, tissue fragments, particles of dirt, etc. Tissues are not irritated by hydrogen peroxide.-10. No less famous than sublimate was iodine form, which was used in the form of powder on the wound, ointments (5-10%), sticks, 'emulsions' (10%) with glycerin, in an ether-alcohol solution (10%), in the form of iodine form gauze. Iodine form is not bactericidal, either in dry or in dissolved form. Bacteria can live perfectly in iodine form powder.

Animal tissues, wound exudate, and products of bacterial vital activity decompose iodoform into iodine, hydrogen iodide, and other compounds, which act bactericidally. The instability of the decomposition products of iodoform, its sharp odor, the occasional poisonings that occur, and the possibility of introducing infection into the wound along with the iodoform itself with a large excess cover up its few merits, and its application is now very limited. A large number of substitutes for iodoform have been proposed, mainly bismuth preparations, but their merits are relative. Xeroform is used more than others. A 40% aqueous solution of formaldehyde—formalin—possesses strong antiparasitic properties, but it coagulates proteins, does not penetrate deeply into tissues, and cauterizes and hardens them. The vapors of formaldehyde can be used to disinfect instruments that cannot be boiled (for example, cystoscopes); complete sterilization is achieved in 5-6 hours, but before use, instruments sterilized in formaldehyde vapors must be thoroughly washed with sterile water or a saline solution, since the formalin vapors condensed on the surface of the instrument can strongly irritate the mucous membranes. Alcohol (wine spirit) is widely used, although its bactericidal properties are small. 90-96° alcohol acts weakly, because the protein that coagulates on the periphery of the microorganism's plasma under its influence serves as a barrier to the further action of the alcohol on the plasma. 50-70° alcohol acts much more strongly, because dense coagulation of protein on the surface of the plasma does not occur, and the alcohol has the opportunity to act on the entire plasma of the microorganism. Alcohol is now mainly used for disinfecting hands, the operative field, for storing silk, etc. Iodine is of great importance, being a strong bactericidal agent. It is used in the form of a 10% tincture of iodine (with 96° alcohol), now mainly for disinfecting the operative field (Grossich's method). The tincture of iodine irritates and cauterizes tissues and is rarely used for smearing wounds themselves. The addition of water increases the bactericidal properties of the tincture of iodine (Brunn), while at the same time decreasing its penetrating ability and harmful effect on tissues. Sapezhko proposed using an alcohol-water solution of iodine (30-40° alcohol with 0.25-0.5% iodine) to combat infection by systematically pouring it into infected wounds through inserted drains. The vapors of iodine have the ability to penetrate into the thickness of tissues; this, among other things, is the basis for the sterilization of catgut in iodine vapors (Sitkovsky's method). During the imperialist war, Dakin's solution received fairly widespread use (14 parts sodium carbonate, sice, or 40 g sodium carbonate crystallis., 100 parts water, 20 g calcium chloride; after half an hour of settling, the sediment is poured off, the liquid is filtered through cotton wool, and 25-40 g boric acid is added to it until a neutral or slightly acidic reaction is obtained; the solution is unstable). This solution was used according to Carrel's method in the form of constant irrigation of wounds through drains. The aim is the abortive disinfection of a fresh wound, previously widely opened and thoroughly cleansed of foreign bodies and of crushed, non-viable tissues. The solution promotes the rapid rejection and removal of necrotized tissues, but its bactericidal capacity, as research has shown, is relatively weak. It also turned out that Dakin's solution is not entirely indifferent to tissues, it reduces the phagocytic properties of leukocytes (like some other antiseptic substances, for example, carbolic acid, mercuric chloride). In already developed infection, the Carrel-Dakin method helps little. Among the harmless to tissues antiseptic substances, Peruvian balsam must be noted. It is little poisonous, has low bactericidal properties, but has the ability to envelop bacteria and, thus, makes them harmless to the body; besides, it possesses chemotactic properties, which to a large extent explains the favorable effect on infected wounds. Collargol, colloidal silver proposed by Credé, possesses very weak bactericidal properties, but increases leukocytosis and promotes the destruction of bacterial toxins by accelerating and increasing oxidative processes in tissues. Collargol is used in a 1-2% solution (enema 50.0-100.0 solution, intravenously-5-10 cubic cm), in ointments for rubbing in (15%-2.0-3.0), for washing wounds, cavities (0.2-1% solution). In recent years, derivatives of quinine—optochin, euquin, vuquin, derivatives of aniline (from the group of acridine compounds)—trypaflavin, rivanol—have been proposed. The derivatives of quinine have been abandoned because they turned out to be harmful to tissues; trypaflavin turned out to be poisonous; rivanol is retained in practice the longest (solutions 1:500, 1:1,000), because according to observations it, as it were, does not harm tissues and the body. It is even used for so-called deep antisepsis, i.e., it is introduced directly into the tissues around the inflammatory focus to prevent the development and spread of infection, it is introduced into clean wounds, intravenously (20-10 cubic cm of 0.1% solution), not to mention pouring into purulent cavities, infected wounds, etc. Its drawbacks include easy decomposability (fresh solutions must be used) and its varying action in different patients, perhaps due to different degrees of acidity of the tissues. To obtain an enhanced outflow of lymph from the tissue spaces into the wound, in order to wash out bacteria from there, a hypertonic solution of table salt (5-10%) is also used, which is applied either in the form of pouring into the wound several times a day (through drains) or for moistening drains. According to observations, the course of infected wounds improves significantly with this, and tissues suffer little. Asepsis. Despite the numerous chemical antiseptic agents used to eliminate infection from wounds, it must be admitted that this issue is still far from resolution. In suitable cases, a more reliable method is the operative method of cleansing a fresh contaminated wound—excision of the entire wound surface, if anatomical conditions do not interfere, with removal of all crushed, non-viable, infected tissues, followed by a tight suture (Augier's method, 1882). It is much easier to prevent the contamination of a clean wound, although it has gradually become clear that there is no such thing as an ideally germ-free wound. Infection can penetrate into a clean wound through the air, through contact, and by autoinfection through the lymphatic or blood vessels. Infection from the air is now feared much less: there are relatively few pathogenic microorganisms in the air, and few of them get into the wound. Microorganisms in the air are in a dry state, are not adapted and do not immediately adapt to the conditions of life in the wound, and cannot immediately begin to grow. All this gives the body the opportunity to cope with the infection that has entered a clean wound from the air, provided that this infection does not quantitatively and qualitatively exceed the body's protective forces, and if there are no particularly favorable conditions for the growth of microbes—crushed, non-viable tissues, hemorrhages, etc. The practice of everyday surgery, operations in random conditions, confirm the minor danger of wound infection from the air. Of course, this does not mean that one can not care about the cleanliness of operating rooms, dressing rooms, and the air in them. Operating rooms must be arranged without unnecessary corners, projections, dead spaces; the flooring, walls, and ceiling must be made of material that is easily washable and cleanable; heating and ventilation must be arranged so that no dust gets into the room; one should not overload with unnecessary items, not allow people into the operating room in untidy clothes, even if covered with gowns, etc. To maintain the cleanliness of the operating room, dressing room, and the air in them, frequent washing of the entire room (including walls and ceiling) is necessary, sometimes filling with steam, which carries away dust particles as it settles. Many surgeons divide operating rooms into clean and purulent; abroad there are even special operating rooms for clean operations on bones, but this is not a necessity, as shown by observations in many surgical institutions. With trained, disciplined personnel who have well mastered the basic rules and requirements of asepsis, the combination of clean and purulent operating rooms may not lead to any harmful consequences. Participants in the operation should speak as little as possible and not over the wound, not to operate with a runny nose, sore throat, bronchitis, etc. A sufficiently radical measure against this route of wound infection is various types of masks, which serve as a barrier between the wound and the surgeon's mouth. Participants in the operation should wear caps made of cloth on their heads; for people with long hair, caps should be considered mandatory. The most essential is another route of infection of a clean wound—through more or less prolonged contact with instruments, dressing materials, linen, sutures and ligatures, water, the hands of operators, etc. It is therefore necessary to thoroughly disinfect everything that comes into contact with the wound directly or indirectly (for example, brushes for washing hands).

The first preparatory stage in the process of disinfection, common to most items, is washing with room-temperature, sometimes hot (for better dissolution of fats) water with one kind of soap or another, using a hair or vegetable fiber brush. Hair brushes, even made from the stiffest bristle, become soft after boiling or sterilization in an autoclave and are therefore not always convenient. Sterilized brushes should be stored either dry, in special closed metal boxes from which they are obtained automatically one at a time, or in some solution (most often in 0.1% mercuric chloride), in a closed glass vessel. Instruments are simply and reliably sterilized by boiling in water for 15-20 minutes (from the moment of boiling); according to observations, even five minutes of boiling kills all microorganisms that do not have spores. Instruments are placed in already boiling water on nets with handles so that they can be easily removed without touching them with hands. To prevent the appearance of sediment or rust on instruments during boiling, it is necessary to add 1% sodium bicarbonate (without impurities) or 0.25-1% sodium hydroxide to the water. Some also add a small amount of lysol, which prevents the nickel plating of instruments from deteriorating. Cutting instruments become dull from boiling, which is why many avoid boiling them, limiting themselves to thorough washing and storing them before an operation in wine alcohol, pure or with an admixture of formalin or thymol. The recent appearance of instruments made from non-oxidizing Krupp steel allows cutting instruments to be boiled without damage.-- In addition to boiling, instruments can be sterilized in an autoclave; disinfected by the action of dry heat in special apparatus and by burning (flaming), passing the instruments several times through the flame of a gas or alcohol burner or by pouring a small amount of alcohol onto instruments placed in metal vessels and igniting this alcohol. During burning, it is necessary that the instruments be heated to a sufficiently high temperature (200° and above), as only then can one expect the destruction of all bacteria and spores; such repeated heating damages the tempering of the instruments, and, in addition, one cannot always be sure that the instruments to be disinfected have heated evenly everywhere to the desired temperature. Disinfection of instruments in sterilizers acting with dry heat requires a long time (up to two hours), if one takes a temperature that does not damage the instruments. A higher temperature damages the tempering of the instruments, cutting instruments rust and become dull. Sterilizing dressing material with dry heated air is also not advisable, as too high a temperature damages the material, making it brittle; at a lower temperature, dry heat penetrates very slowly and insufficiently into the interior of the sterilized bundles. It is necessary to remember that dry heat has less effect on microorganisms than moist heat. The use of dry heat is limited to glass objects and those that are damaged by steam or water (paper, cardboard, etc.). Some subject gauze to treatment with chemical substances (iodoform, mercuric chloride, carbolic, etc.) with the expectation of some effect of such gauze on infection in the wound and on the fact that gauze, by delaying decomposition processes, suppresses bad odor. It is necessary to point out the instability of impregnated gauze, as iodoform, carbolic acid and mercuric chloride are volatile. In addition, it is necessary to remember that bacteria and their spores can remain viable in iodoform and on dry mercuric chloride. For the treatment of dressing material and linen, steam sterilization is now used everywhere. In extreme cases, dressing material and linen can be sterilized by boiling, like instruments, but the material will, of course, be wet, which is not always convenient. For steam sterilization, apparatuses using either flowing steam under ordinary pressure (temperature 100°) or flowing steam under high pressure are usually used. Flowing steam penetrates faster and more completely into the thickness of the material laid out for sterilization than stationary steam. Apparatuses for flowing steam under ordinary pressure are inexpensive, simple in design and operation (Shimmelbusch, Mendel, Turner apparatuses). Sterilization of dressing material and linen in them is quite reliable, but for complete sterilization a long time is required (1-1¹/₂-2 hours), depending on the density of the material, and the sterile material turns out to be rather damp. Apparatuses for flowing steam under pressure (autoclaves) are more complex in design, more expensive, require more attention in operation and care, but give better results in a shorter time (see Autoclave). The thorough sterilization of material for sutures and ligatures, which remain in tissues for a long time and even permanently, is extremely important (see Sterilization). For wires and silk, ordinary boiling is sufficient. Silk, threads, after preliminary washing (for degreasing) with soap alcohol or soap, alcohol, ether, are wound not tightly, in 1-2 layers, on glass spools or plates and sterilized in an autoclave. Sterilized silk or thread is stored in pure alcohol or with an admixture of formalin (1:1,000), thymol, mercuric chloride (it must be remembered that an alcoholic solution of mercuric chloride is not very bactericidal). Silk and threads can be sterilized after preliminary degreasing by repeated boiling (sometimes in mercuric chloride 1:1,000), but their strength suffers from this. Ligatures and submerged sutures made of non-absorbable material are foreign bodies to tissues and can serve as a site for the localization of late infection. Absorbable material for sutures and ligatures (catgut, deer and kangaroo tendons) requires exclusively chemical treatment, as it cannot withstand boiling or steam treatment, and sterilization with dry heat is not sufficiently reliable and easily damages the material (see Catgut). Tendon threads can be sterilized by the method of Graefe [2 days ether, 30 days juniper oil, 2 days ether, 3 days alcohol, 2 days in mercuric chloride with table salt (aa 1.0:200.0 water), store in alcohol]. Skin sutures after two days already contain bacteria either because the threads become infected by hands that have lost their sterility by the end of the operation, or due to infection of the thread from the depth of the skin during suturing. It is therefore more advantageous, wherever possible, to suture the skin with Michel clips. The sterile water and sterile physiological solution necessary for the operating room and dressing room (for rinsing hands, moistening surgical towels, etc.) are obtained by prolonged (up to 1 hour) or repeated (fractional) boiling. Large quantities of sterile water are obtained with the help of special apparatuses of various systems (e.g., Sitkovsky), which are usually quite complex. Various filters have been proposed for sterilizing water; the most reliable were considered to be the Chamberland and Berkefeld filters. They hold back bacteria and spores well, but for reliable operation they need to be cleaned and sterilized every 1-2 days. Filters are powerless against the so-called filterable virus. It turns out that the so-called 'invisible' forms of mutations of some microorganisms, including streptococci, should also be included in the group of filterable viruses. Thus, the filtration method is completely unreliable; water must be sterilized only by boiling. The skin of the operative field and, especially, the skin of the surgeon's hands are the main 'suppliers' of wound infection. Folds, cracks and hair follicles of the skin, sweat and sebaceous glands and their excretory ducts serve as an excellent refuge for bacteria. Surgeons should take care of the condition of their skin's hands, avoid various minor injuries, contamination of the skin with pus and other infected secretions (fecal masses, vaginal discharge, etc.). Special attention must be paid to the condition of the nails, subungual spaces and nail beds. The disinfection of the skin of the hands (and the operative field) has always been a difficult task, as reliable chemical or physical disinfection methods cannot be applied to living tissue. The initially recommended abundant rinsing of the hands with a solution of carbolic acid, mercuric chloride and other antiseptic substances proved to be completely insufficient, as they can only have the most superficial effect. Penetration deeper is hindered by the keratinized epidermis and the products of the sebaceous glands enveloping the skin, usually mixed with dirt and sloughing epidermis, etc. For dissolving fat, softening the epidermis, the use of various kinds of soap (potassium green soap acts most energetically), especially in combination with warm water, wine alcohol, gasoline, ether, etc., proved most favorable. The removal of the superficial softened layers of the epidermis is best achieved with sterilized brushes, with which washing should be done very thoroughly, evenly, covering all areas of the hand to be cleaned, the spaces between the fingers, the nail beds, etc. The brushes should not be used too strongly, so as not to unnecessarily traumatize the epidermis, but also not too weakly, as otherwise the superficial softened layer of the epidermis will not be sufficiently removed. It is recommended to wash hands in a stream of running water, not in any cups, basins, etc.

Combined mechanical-chemical methods aimed at removing and killing microorganisms of the skin were dominant for a long time and are still largely used today. Individual moments in the preparation of hands by various surgeons were combined differently in duration, supplemented with new techniques that sometimes extended hand processing to 30-40 minutes, but always originated from the principle of removing and destroying bacteria of the skin. Among the most commonly used methods of this type, the methods of Fürbringer and Ahlfeld should be mentioned. The original method of Fürbringer (1888), requiring 1) cleaning of the nails, 2) washing with warm water and soap and brush for 1 minute, 3) rinsing for 1 minute in 80% alcohol, 4) immersion in mercuric chloride (0.1-0.2% solution) was later modified by the author himself (extending the washing, alcohol and mercuric chloride processing times to 3-4 minutes) and by other surgeons who further extended the washing time, replacing mercuric chloride with other antiseptics, etc. Ahlfeld excluded mercuric chloride, using only washing with hot water and soap and brush, followed by treatment of the hands with 96% alcohol. The initially established times for washing and alcohol (3 and 3 minutes) in Ahlfeld's method were extended (repeated washing up to 10 minutes, 80-90% alcohol up to 5-8 minutes). Roux additionally proposed treating the fingertips with tincture of iodine. The clinical results of these methods and many others were satisfactory, though not always, as bacteriological checks showed that there is no method that could kill and remove all bacteria from the skin and thus make it sterile. The idea arose of not allowing bacteria to pass from the skin of the hands into the wound. On one hand, for this purpose various substances for treating the skin of the hands were proposed: paraffin, chirozoter, gaudanin, etc. (covering the skin as if with a film), alcohol, tincture of iodine, alcohol-acetone, iodine-benzene, alcohol-tannin, which harden the skin, fix bacteria in skin folds, crevices, etc., and prevent the transfer of bacteria from the skin into the wound. On the other hand, to eliminate direct contact of the skin of the hands with the wound, gloves were proposed-rubber, thread, and even leather. Means covering the skin with a film were abandoned as they proved little suitable. Hardening of the skin and the use of gloves are gaining more and more supporters. However, with the slightest damage to the thin glove (which is very easy and often happens), the so-called 'glove juice' accumulating during longer operations due to increased sweating of the hands, which usually contains many microorganisms, can get into the wound and infect it. This is the main inconvenience and danger of gloves. Moreover, the possibility of fully utilizing the sense of touch, so important for the surgeon, is lost. Some surgeons use rubber gloves only for purulent operations, when examining infected cavities, purulent wounds, wanting to protect the skin of their hands from contamination; others, having easily injured skin of the hands, protect it from excessive irritation by ordinary treatment methods with gloves; third, protect the wound from existing imperfections of the skin of the hands-scrapes, etc., with gloves; fourth, resort to gloves for operations in which infection is especially harmful, e.g., in bone plastic surgery, and finally, fifth, apply gloves at all operations as a principle. Thick rubber gloves or wearing thread gloves over thin rubber ones reduce the danger of damage to the rubber gloves, but make the hands and fingers clumsy and to a large extent deprive the surgeon of the sense of touch. Using only thread gloves is not very expedient, as they are a barrier to infection only in dry form, and when impregnated with blood they become excellent breeding grounds for infection, which is why frequent changing during the operation is necessary. Rubber gloves are sterilized by boiling or in an autoclave. Putting on gloves is facilitated by pouring a small amount of sterile glycerin, alcohol into them, or dusting their inside and the hands with sterilized talc. The rapid changing of gloves, eliminating the usual irritation of the skin of the hands by long washing in other methods, allows surgeons in large institutions to develop great operative activity (10-15 operations and more per day). The putting on of gloves at the beginning of work should be preceded by disinfection of the hands by one of the accepted methods. Among methods that fix and harden the skin, Brunn's method deserves attention, which uses only 96% alcohol (wiping for 5-10 minutes), with a brief preliminary washing of the skin to remove visible dirt. Grossieh's method is very reliable-smearing the skin with tincture of iodine without preliminary softening of the skin by prolonged washing. The method is extremely simple, quick and has found many followers, but is applicable only to the operative field, as no hands can withstand frequent repeated smearing with iodine. Tincture of iodine acts bactericidally, tans the skin and causes hyperemia in the area of application. Its use requires certain caution, as on more delicate skin it easily causes burns, often dermatitis, and cases of severe iodine poisoning with fatal outcome have been noted. The 5% solution of tannin in 80-95% alcohol proposed by Zabludovsky and Tatarinov is a powerful tanning agent that acts quickly (wiping the skin with a cloth moistened in the solution for 2-3 minutes) and reliably. Bacteriological checks and clinical observations have shown the high merits of the method, which is gradually coming into use both here and abroad. Preliminary washing of the skin can be both brief and prolonged, as tannin combines well with water (in softened skin) and exerts its tanning effect. After wiping the hands with alcohol-tannin, it is necessary to let them dry and only then take linen, instruments, etc., as otherwise yellow spots remain on the linen, and when moistened with blood-black spots; contact with poorly nickel-plated instruments gives black spots on the hands, easily removable by 1% oxalic acid or lemon. There are indications that the skin of the hands does not always tolerate treatment with alcohol-tannin well. The skin of the hands sometimes tolerates alcohol-tannin better if the hands are washed briefly with water at room temperature or cold; with warm water, subsequent treatment with alcohol-tannin leads to significant roughness of the skin. As with other methods, during long operations it is useful to repeat (after 30-40-50 minutes) the treatment of the hands, as by this time from movements, increased work of the fingers, the activity of the skin glands increases, and from contact with tissues, the superficial layers of the skin begin to soften somewhat and can be sources of infection. It is necessary to wash blood off the hands before repeated wiping, as otherwise alcohol-tannin fixes it very tightly to the skin. In 1924, Pokotilo proposed treating the hands with aqueous 5% solution of tannin, which should be kept in mind in case of alcohol shortage. Treatment with aqueous solution is inferior in speed to the alcoholic solution and acts on the skin more superficially, as if varnishing it. Even with the most reliable methods of neutralizing the skin of the hands, it is necessary to act in the wound with hands as little as possible, and, if possible, do everything with instruments. The skin of the operative field, as well as mucous membranes, are treated according to the same principles as the skin of the hands. Former complex methods with prolonged washing, compresses of mercuric chloride, formalin, etc., are now abandoned. It is recommended to shave the hair beforehand, which of course removes the most superficial layer of the stratum corneum. Shaving must be done carefully, without injuring the skin, as this alone can introduce infection. When using tanning methods (mainly Grossieh's), it is better not to use prolonged washing to avoid excessive softening and moistening of the skin, as well as excessive exfoliation of the epidermis, as this easily causes dermatitis, even without irritation from tincture of iodine. Alcohol-tannin and alcohol do not cause burns. The operative field is isolated from the rest of the skin surface, as well as from the patient's mouth, with sterile linen. Many protect the wound itself from the edges of the skin incision by suturing or pinning sterile gauze. The presence of infectious foci in the body can lead to autoinfection, through the blood and lymphatic vessels, into the area of operation as a place of least resistance. It is therefore better not to perform a clean operation without special need if the patient has any infectious foci, for example, a furuncle, pyoderma, angina, chronic purulent inflammation of the middle ear; carious teeth also require attention. It is more advantageous to wait out the acute process and to neutralize, as much as possible, the chronic one by local treatment and by increasing the protective forces of the body and developing immunity in it. This last circumstance has enormous importance in the matter of destroying infection that has entered the wound. Sera, vaccines, introduction of foreign protein into tissues (protein therapy), the patient's own blood (autogenous blood therapy), the use of irritating therapy with non-specific agents (turpentine, sodium nucleinate, yatren, etc.), Bezredka's antivirus therapy-all these measures aim to increase the protective forces of the body.