АSEPTICS AND ANTISEPTICS

Aseptics is a set of measure aimed at the prevention of infection getting to the wound, in an organism of the patient, creation of sterile conditions for surgical work by use of organizational actions, active disinfecting chemical substances, as well as technical means and physical factors.

Two basic principles are underlined in modern aseptics:

Everything that adjoins to the wound should be sterile.

All surgical patients should be divided into two groups: “pure”and “purulent”.

It is impossible to work without aseptics rules observance in surgery.

It is necessary to know its sources and ways of spread to prevent infection from getting to the wound

Exogenous infection gets to the wound from the environment by three basic ways: respiratory, contact and implant.

With the air-drop way of spreading the infection gets to the wound from the air.

The complex of measures is provided to prevent respiratory infection.

In order to prevent infection all patients should pass sanitaryand-hygienic treatment at admission: shower, changing clothes of the patient, special processing — under indications.

The organization of medical-diagnostic departments is arrenged according to a contingent of patients, sanitary norms.

Careful, repeated damp cleansing with antiseptic means should be carried out in the surgical department.

The rooms are to be ventillated according to the ventillating schedule, which cleans the air.

The usage of special clothes (surgical coates, special suits, headdresses, mask, slipper, stockings) is necessary in the department. It is prohibited to leave the department in special clothes.

The strict observance of aseptics rules is obligatory in the operational block, as it is the cleanest place in the surgical hospital. For prevention of dirtying the air and rooms in immediate proximity to the operational wound a zone-like principle is observed in the organization of the operating room: zones of absolute sterility, relative sterility, limited routine and general hospital mode (non sterile).

There are some kinds of cleansing in the operating room: current, after each operation, at the end of the working day, in the beginning of the working day and general (once a week).

Preventive maintenance of contact and implantation infections consists in reaching sterility (full clearing from microorganisms of everything that adjoins the wound): surgical tools, dressing material and surgical linen, hands of the surgeon, operating area (skin of the patient), as well as in maintenance of the strict sterility of all subjects introduced in an organism of the patient (material for suturing, drainages, catheter, artificial limbs, metal constructions, transplanted organs, etc.).

Sterilization is the basis of aseptics. It is the achieved by methods and means of sterilization are used which provide destruction of pathogenic and non-pathogenic microorganisms. Hence they should be effective in relation to bactericidal and sporiсidal activity, safe for the patient and medical personnel.

Physical and chemical methods of sterilization are used in aseptics.

Physical Methods of Sterilization

Burning and boiling are not used in surgical clinic for sterilization now, as these methods of sterilization do not create conditions for destruction of microbes, spores in particular.

Steam sterilization under pressure of 2 atmospheres (in theautoclave) allows to raise a boiling point of water and accordingly temperature of the steam up to 132.9°C . At this method of sterilization the tools, dressing, the linen and other materials are loaded into the autoclave in a special metal boxes of Schimmelbusch. At pressure of 1,1 atmospheres a mode of sterilization spend lasts for 1 h, at 1,5 atmospheres — 45 min, at 2 atmospheres — 30 min.

Sterilization by hot air (dry heat) is carried out in dry-heatcases sterilizers within 1 h at the temperature of 180°C .

Central sterilizing should be organized in hospitals.

Ray sterilization is carried out with the help of γ-ray, ultraviolet ray, ultrasound.

Chemical Methods of Sterilization

Gas sterilization is carried out in special hermetic wards withthe use of formalin or ethylene steams within 6–48 h. This method is used first of all for sterilization of optical tools.

Sterilization by solutions of chemical antiseptics is applied firstof all for processing cutting surgical tools. Chemical antiseptics are 6% solution of hydrogen peroxide, chlorhexidine alcoholic solution, pervomure, threefold solution, 96° ethanol. Tools wetted in the given solutions for 2–6 h are considered to be sterile.

Sterilization of Instruments

The best method of instruments sterilization is boiling in a 2% solution of sodium hydrocarbonate or in water for 45 min. Before sterilization the instruments are cleansed — washed with hot water for 30 s, then washed in a washing solution at the temperature of 50°C  for 15 min. After that they wash in a washing solution for 30 s, rinse in running water, boil in distilled water for 5 min, dry with hot air at the temperature of 85°C . The quality of the sterilization is determined with the help of amidopyrine, benzidine and phenolphtalein tests for the presence of residual components of the washing preparation in the blood. With the presence of pus disinfection of the tool is carried out — it is boiled for 30 min in a 2% solution of sodium hydrocarbonate. Besides boiling, the instruments are sterilized in dry exciccators or autoclave, and undergo chemical sterilization (threefold solution, spirit, etc.).

Sterilization of Gloves

Gloves are sprinkled with powder or talc, wrapped in a gauze napkin and kept in sterilizer boxes. Sterilization is on under pressure of 1.5 atm at the temperature of 120°C  for 45 min. Gloves are also boiled in water for 45 min or dipped into a detergent solution for 60 min. Gloves are sterilized with ethylene oxide in portable gas sterilizers. After using gloves wash under running water with soap, disinfect in a 1% solution of chloramines for 30 min, rinse under running water, dry.

Sterilization of Suture Material

Sterilization of suture material takes place in different ways: thermal, chemical, gamma irradiation. The suture material applied in surgery differs by chemical structure, physical properties and origin. It is mostly silk, cotton and synthetic materials. Now the silk isn’t almost used, as it irritates very much.

Generally, silk sutures are received sterile. But if they are not processed, the following measures are used:

Silk is washed in warm water with soap, dried, reeled on a coiland dipped into ether for 12–24 h, then dipped into a 70% solution of ethanol for the same time period, then boiled for 10 min and stored in hermetically sealed cups according to the Cocher’s method (in 95% ethanol). Before using this silk is boiled again for 2 min in a solution of corrosive sublimate.

Silk is washed with soap twice, rinsed with warm water, driedand wound on the reels. They degrease, dip into ether for 12–24 h. Then they boil in distilled water for 45 min and sink into the hermetically sealed cup with 96% spirit for 6–12 h. After that, the silk is suitable for application. In the cup, the spirit is replaced every 7 days. Kapron and lavsan sutures are sterilized in the steam autoclave (like operational linen) or boiled (like tools) for 45 min.

Catgut is produced with a preserving solution (96% spirit — 89.0 ml, glycerin — 6.0 ml, gasoline aviation — 1 ml, distilled water — 4.0 ml), sterilized by gamma irradiation. Polymers hydroxyacetic acid (dexon) or polypropylene (proflax), and also vicryl are artificial sutures, which are absorbed.

Preparation of the Surgeon’s Hands and the Operating Field

Preparation of the surgeon’s hands plays a special role in the preventive measures of wound infections. The surgeon should avoid of pollution of hands, diligently watch the condition of the skin, for occurrences of microtraumas (cracks); the skin is processed with special creams, oil solutions (glycerin, liquid ammonia, etc.).

There are many different methods of surgeon’s hands processing. Various methods of surgeon’s hands processing can be divided into three groups:

methods with mechanical cleaning of the skin and its subsequent stiffenning with different antiseptics;

methods of only stifenning;

methods of processing with the application of surface-activesubstances — detergents.

The Furbringer’s and Ahlfeld’s methods belong to the first group. According to the Furbringer’s method the hands are washed with warm water and soap with the help of brushes for 10 min, after drying hands are processed with 70% ethanol (3 min) and 0.5% solution of corrosive sublimate (3 min). Ahlfeld modified this method — excluded the processing with the solution of corrosive sublimate and replaced 70% ethanol by 96% one.

These methods today are almost not applied because of significant trauma to the epidermis by the brushes and the occurrence of dermatitis.

Methods which are based only on the stiffenning of the skin are applied, basically, under field conditions and in emergency situations. The methods of Brun (processing of hands with 96% spirit), Heisner (processing of hands with a mixture of iodine and gasoline in a ratio of 1:1), Pokotilo (processing of hands with 5% water solution of tannin), Zabludovsky (processing of hands with a 5% spirits solution of tannin), Bakkala (processing of hands with a 1% solution of brilliant green) belong to this group. An essential disadvantage of these methods is their negative influence on the skin (burns, dermatitis, and allergy).

The third group of methods with the application of detergents is the most wide-spread. A high sterility is seen because detergents deep penetrate into skin. Having excluded mechanical cleaning and long skin stiffenning, damage to the epidermis and the occurrence of dermatitis is prevented. The Spasokukotsky—Kochergin’s method of hand processing with a 0.5% solution of liquid ammonia in two basins by 3 min each, after drying up — with 96° spirit, fingertips — with the iodine solution belongs to this group.

Recently, such detergents are widely used in processing hands as: 0.5% spirit solution of chlorhexidine bigluconate, 3% water solution of novosept, 1% solution of degmine or degmicide, 0.02% solution of dioxide, solution of pervomur (hydrogen peroxide with antacid). Dioxide, the preparation of mercury, is very toxic, accumulates in the kidneys, can cause dermatitis of the hand skin. Sterilium, hospisept are applied for processing hands of the surgeon now.

OP-7, rocal are also used in hands processing. However, all these methods do not guarantee 100% sterility, therefore surgeons use gloves (rubber, latex, etc.) after processing hands.

The operational field is processed by the modified Grosich— Filonchikov’s method: twice processing of the skin with 70% spirit and rubbed with 2–5% solution of iodine. Solutions of Iodonatum, iodoperonium, 1% solution of degmicidium, 1% solution of rocal, 2.4% solution of pervomurium are also used to process the operational field.

Ways of Control over Sterility

Methods of the control over sterility are divided into direct and indirect.

The direct method of sterility consists in bacteriological exam of sterilized tools, hands of the surgeon, the operational field, operational linen, dressing. Sampling is carried out by way of smear taking with a sterile wadded tampon, inoculation of medium is performed in order to determine bacterial pollution.

The indirect methods allow to get quickly data on sterility and is applied at each sterilization. At autoclaving an ampoule with a powder substance which temperature of fusion ranges within 110–120°C is packed in the box. If during sterilization the substance has fused, the material is sterile and vice versa. Benzoic acid, resorcin, antipirin are used for this purpose. Similar methods are applied for sterilization in dry heater: ascorbic acid, succinic acid, tiourea.

Antiseptics is a system of measures directed on destruction of microorganisms in a wound, the pathological focus, in organs and tissues, and an organism of the patient as a whole, using active chemical substances and biological factors, and mechanical and physical methods of influence as well.

There are mechanical, physical, chemical, biological and mixed antiseptics.

Mechanical antiseptics is elimination of microorganisms by mechanical methods: removal of tissue sites sated with bacteria, infectioned clots of blood, purulent exudation. The methods of mechanical antiseptics consist of:

A toilet of a wound which is made at any bandaging. Thebandage applied before is removed, the skin is processed around the wound. Purulent exudation, the infected clots, free necrotizing tissue are deleted from the wound. The wound processing with a pulsing jet of antiseptics is applied with the same purpose.

Primary surgical processing of the wound, which makes aninfected wound sterile by way of incision the edges, walls and floor of the wound together with alien bodies and necrotic zones.

Secondary surgical processing of the wound which is carriedout with the presence of a purulent wound, consists of the removal of necrotizing tissues, revision of the wound itself, carrying out additional incisions for providing free outflow of pus.

Other operations and manipulations: lancing of abscesses, phlegmons, a puncture of abscess, etc.

Physical antiseptics is elimination of microorganisms with the help of physical methods. The basic methods of physical antiseptics are as follows:

Usage of hygroscopic dressing for exudate evacuation: gauzetampons, balls, napkins, cotton wool, cotton-gauze tampons.

Usage of hypertonic NaCl 10% solution for improvement ofoutflow from the wound, which osmotic pressure is higher than in the blood plasma.

Drainage, as an important element of physical antiseptics, isapplied for treatment of all kinds of wounds and based on a capillary principle and communicating vessels. Passive, active and flowwashing drainage are distinguished.

The sorptional way of wounds treatment is applied with sorbents usage — substances which adsorb toxins and microorganisms. They are carbon-containing substances as a powder or fibres.

In treatment of wounds with the purpose of struggle againstmicrobes the method of drying is applied: special wards with the controlled abacterial medium, various devices for local use.

Use of technical means:

— ultrasonic devices for ultrasonic cavitation of wounds;

— laser devices for processing wound surfaces with focused and unfocused ray, irradiations of blood;

— use of ultra-violet ray for processing wounds, blood;

— use of X-ray radiation for suppression of an infection in tissues.

The chemical antiseptics is elimination of microorganisms in the wound, pathological focus or an organism of the patient and in the environment around with the help of various chemical substances.

The basic groups of chemical antiseptics.

Group of haloids:

Iodine — 1–5% alcohol tincture;

— iodinol — 1% solution;

— iodonate, iodopirol, povidon-iodine

— organic compounds of iodine;

— water and alcohol solution of iodine and potassium iodid;

— chloramin — 3% water solution.

Salts of heavy metals:

— corrosive sublimate (sulema) — in concentration 1:1,000;

— mercury oxycyanid — desinfectant means;

— preparations of silver — 0.1–2% and 5–20% solutions of nitrate of silver;

— protargol, collargol — antiseptic means of external application.

Spirits — ethanol 70%, 96%.

Aldehydes — formalin — 37% solution of formaldehyde — astrong disinfectant, lisol, a 2% solution — a disinfectant.

Phenols — carbolic acid, a threefold solution (20 g of formalin,10 g of carbolic acid, 30 g of natrium bicarbonate and water up to 1 l).

Dyes — brilliant blue 1–2% a solution, brilliant green 1–2%solution.

Acids —boric acid — 2–4% a solution, salicylic acid.

Alkalis — liquid ammonia — for external application.

Oxidizer — hydrogen peroxide — 3–6% solution, potassiumpermanganate — 0.02–0.1% and 2–5% solutions.

Detergents (superficially active substances) — chlorhexidinbigluconate — 0.5% alcoholic solution and 0.1–0.2% water solution, cerigel, degmin, degmicid.

Derivatives of nitrofuran — furacillin 1:5,000, furadonin, furagin, furasolidon.

Derivatives of 8-oxychinolon — nitroxolin (5-NOX), enteroseptol, intestepan.

Derivatives of chinoxalin — dioxydin — 0.1–1% water solution.

Derivatives of nitroimidasol — metronidazole (metragil, flagil, trychopol).

Vegetable antiseptics — phytoncides, chlorophylipt, ectyricide, balis.

Sulfonamides — streptocide, ethasol, sulfadimesin, sulfasin,sulfadimetoxyn, sulfalen, biseptol (Bactrim).

Biological Antiseptics

The basic preparations and methods:

Proteolytic enzymes — trypsin, chemotrypsin, chemopsin, terralitin.

Means of passive immunization — antitetanus serum, antitetanus gamma-globulin, antigangren serum, antistaphylococcal, antistreptococcal, anticoli bacteriophages, antistaphylococcal and anticoli hyperimmune plasma.

Methods of stimulation of nonspecific immunity — ultra-violetirradiation, vitamin treatment, a full-value nutrition, ultra-violet and laser irradiation of blood, haemotransfusion and its preparations (a suspension of lymphocytes).

The substances stimulating nonspecific immunity — Thymalin,T-activin, prodigiosan, levomisol, reaferon, roferon, roncoleukin, β-leukin.

The preparations stimulating specific immunity — staphylococcal and tetanic anatoxin.

The basic means of biological antiseptics are antibiotics.

Antibiotics (AB) — products of the microorganism’ vital activity, inhibiting growth and development of certain groups of other microorganisms and used for treatment and prophylaxis of a surgical infection.

According to the mechanism of action AB are divided into:

Inhibitors of the cellular wall synthesis (β-lactam АB — penicillins, cephalosporins, carbopenems, monobactams; glycopeptids — vancomycin and teicoplanin.

Inhibitors of protein synthesis (aminoglycosides, tetracyclines,macrolids, lincosamines, streptogramines, chramphenicol, fusidic acid, oxasolidones).

Inhibitors of the nucleinic acids synthesis (the inhibitors synthesis predecessors — sulfonamides; the DNA replication inhibitors — chinolones; the RNA-polymerase inhibitors — rifampicin.

Other АB (cytoplasmic membranes inhibitors — polymyxines; the preparations changing DNA — nitroimidasols).

Basic Groups of Antibiotics

Рenicillins: penicillin, oxacillin, methycillin, ampicillin, amoxycillin, bicillin, ampiox, augmentin, unasin.

Streptomycins.

Tetracycline: methacyclin, doxacyclin.

Macrolids: erythromycin, oleandomycin, roxythromycin, azythromycin, clarythromycin.

Aminoglycosides: kanamycin, gentamycin, thobramycin, sizmomycin, amycacin, netromycin.

Chloramphenicols.

Rifampicins.

Antifungal antibiotics: levorin, nystatin.

Polimyxin B.

Lincosamins: lincomycin, clindamycin.

Cephalosporins: 1st generation — ceporin, cephalexin, cephazolin, cephamesin, kefzol, 2nd generation — cephamandol, cephmetazol, cephoxitin, cephaclor, cephuroxim, cephotetam, 3rd generation — cephthriaxon, cephotoxim, cephixim, cephtibuten, cephpiramid, cephtazidim, 4th generation — cephpirom (caten).

Carbopenems: imipenem, meropenem, tienam.

Glycopeptids — vancomycin and teicoplanin.

The search for new АB preparations last years are concentrated on preparations active against Gr+ microorganisms.

The first representative of synthetic antibiotics of a new class — oxasolidons is Zivox (linesolid).

For rational choice of АB we should know the most often agents of nosocomial and outhospital infections and their resistency to these preparations in the given hospital. It is necessary to make a list of drugs preferable for administration in the given surgical hospital which is revised 1–2 times a year taking into account epidemic data, appearing of new АB, changes of approaches for prophylaxis and treatment of pyo-septic complications.

The new approach to application of АB is their rotation — cyclic change of antibacterial means used as preparations of choice. Rotation promotes reduction of quantity, but does not eliminate resistant microorganisms strains.