Ways of infection entering the wound. Ways of penetration of infectious agents into a wound Ways of exogenous infection of a wound

Prevention of infectious complications in surgery. Asepsis, general questions. Sterilization. Treatment of surgeon's hands

1. Asepsis

Asepsis is a set of measures aimed at preventing contamination of the surgical wound by microorganisms. The principles of asepsis are implemented using various methods: chemical, physical, biological. The principles of asepsis must be observed carefully and strictly, starting from the first contact of the patient with the doctor in the emergency department, with the emergency doctor. First contact doctors, when faced with wounds and injuries, must provide first aid and transport the patient to the hospital as quickly as possible. To prevent infection from entering the wound, a sterile gauze bandage is immediately applied to it. In a surgical hospital, the principles of asepsis are ensured by the correct organization of staff work, the correct layout of departments, and thorough theoretical training on this issue. The main task of asepsis in a surgical hospital is to prevent microbial agents from entering the wound. All instruments, tissues, materials, and surgeon’s hands that come into contact with the wound must be sterile. In addition to preventing this route of infection entering the wound, it is necessary to prevent airborne transmission of infection.

One of the main points is the organization of hospital work. Each surgical hospital has different departments according to specialization. Such departments include thoracic, urological, cardiac surgery, etc. There is always a purulent surgery department. This department should be isolated from other departments; medical personnel and patients themselves should not have contact with patients from other departments. If such a department is not provided in the hospital, the department should have separate operating rooms, manipulation rooms, and dressing rooms for patients with purulent-inflammatory diseases. Doctors, nurses, materials and instruments, as well as rooms for such patients should be separated from other patients. In addition, it is known that the content of microorganisms in the air of the operating room increases significantly during the day, therefore, when working in the operating room, it is extremely important to dress in sterile clothes, use sterile gauze masks, caps, completely limiting any possibility of microorganisms entering the wound. It is especially important to follow these rules for students observing the operation directly near the surgical field.

2. Sterilization

This is a method aimed at eliminating living microorganisms and their spores from the surface of materials, instruments and other objects that come into contact with the wound surface before, after and during surgery.

Dressings, underwear, suture material, rubber gloves (some simple outpatient procedures, such as taking blood for analysis, can be carried out in disposable sterile gloves), and instruments should be sterilized. The following sterilization methods are distinguished.

1. Boiling (the duration depends on the type of contamination).
2. Treatment with flowing steam or steam supplied under pressure in a special apparatus - an autoclave (for sterilization of contaminated dressings, linen, gowns, shoe covers). The temperature in it is controlled by various methods. One of these methods is to place test tubes containing substances whose melting point is equal to or slightly lower than the required temperature in the sterilization apparatus. The melting of these substances indicates that the temperature required for sterilization has been reached.
3. Bactericidal effect of ultraviolet radiation (for disinfecting the air in operating rooms, dressing rooms and manipulation rooms).

Germicidal lamps are turned on at the end of the working day after cleaning the room for 3 hours, and if there is a large flow of patients during the day, it is advisable to carry out treatment with lamps during the day.

Treating the surgeon's hands using the Spasokukotsky-Kochergin method

Hand disinfection is one of the most important methods of asepsis, which completely prevents microorganisms from accessing the surgical field.

Before treating your hands using this method, you must wash your hands with soap and a brush. The surgeon's hands are thoroughly soaped using a brush in a certain direction. They begin to process the hands from the proximal phalanges of the fingers, first their palmar surface, and then their dorsal surface. Carefully treat each finger and interdigital spaces, following the specified sequence.

Then wash the wrist: first from the palm, then from the back. The forearm is treated in the same sequence. The left hand is washed first, then the right hand according to the same principle. This allows you to cleanse the skin of your hands from contaminants received during the day during professional and household activities. Subsequently, the skin of the hands is treated using a special technique. The first stage includes treating hands in a 0.5% solution of ammonia.

The sequence of treatment of the surgeon's hands must be carefully followed. A solution of ammonia is placed in two basins, in each of which the hands are treated sequentially according to the described method for 3 minutes: first in one basin, and then for the same time in the other. After this, hands are blotted with a sterile napkin and then wiped dry.

The second stage is treating hands in the same sequence with a 96% alcohol solution for 4-5 minutes. After this, the surgeon puts on sterile gloves, after which he can only touch the surgical field.

Particular attention is paid to the treatment of the hands of a surgeon working in the department of purulent surgery. Control over sterility must be especially careful, for which it is necessary to clean hands not only before surgery, but also after examining a purulent wound, manipulating it, and dressing it. To do this, hands are treated according to the indicated method with gauze swabs moistened with 70% ethyl alcohol for 3 minutes.

Every person can prevent the penetration and development of various infections; the main thing is to know the main dangers that lie in wait at every step and the ways of their spread. Sources of infection are places where microorganisms live and live.

There are two types of sources of infection - exogenous and endogenous. In the first case, we are talking about sources that are outside the human body, in the second – factors that are in the patient’s body.

In turn, exogenous sources of infection spread include:

Patients with purulent-septic diseases;
Animals;
Bacilli carriers.

Do not forget that for a weakened body, a potential danger is posed not only by pronounced pathogenic microorganisms, but also by opportunistic pathogens, which are an integral part of various human tissues and organs, but in certain circumstances become a source of disease. Similar microflora is also present on foreign objects that surround a person.

Sometimes a person may not be sick himself, but may be a carrier of viruses, that is, a carrier of the bacilli. In this case, the infection is likely to spread to both weakened people and healthy people, although to varying degrees.

In rare cases, animals act as sources of exogenous infection.

Pathogenic microflora enters the human body in the following ways:

Air;
Drip;
Contact;
Implantation;
Fecal-oral;
Vertical.

1. With the airborne method of spreading infection, microorganisms attack a person from the surrounding air, in which they are suspended or as part of dust particles. A person, by inhaling, can become infected with any disease that can be transmitted this way.

2. The droplet method of spreading infection means the penetration of pathogens into the wound, which are contained in small droplets of secretions from the upper respiratory tract. But microorganisms enter this environment from an infected person when coughing, talking and sneezing.

3. When they talk about the contact route of infection, we are talking about the penetration of microbes through objects into wounds and damaged areas of the skin through direct contact. Thus, you can become infected through surgical and cosmetic instruments, personal and public items, clothing, and so on.

4. With implantation infection, pathogens enter the human body in the case of various operations that involve leaving foreign objects in the body. These can be suture materials, synthetic vascular prostheses, artificial heart valves, pacemakers, etc.

5. Fecal-oral infection is the penetration of infection into the human body through the gastrointestinal tract. Pathogenic microflora can enter the stomach through unwashed hands, dirty and contaminated food, water and soil.

6. The vertical method of spread of infection refers to the transmission of viruses from mother to fetus. In this case, they most often talk about HIV infections and viral hepatitis.

Endogenous infection provokes a disease from within or from the integument of the human body. Its main foci include:

inflammation of the covering layer - epithelium: carbuncles, boils, eczema, pyoderma;
focal infections of the gastrointestinal tract: pancreatitis, caries, cholangitis, cholecystitis;
respiratory tract infections: tracheitis, bronchitis, pneumonia, sinusitis, lung abscess, bronchiectasis, frontal sinusitis;
inflammation of the urogenital tract: salpingoophoritis, prostatitis, cystitis, urethritis, pyelitis;
foci of unknown infections.

Endogenous infection occurs by such methods as contact, hematogenous and lymphogenous. In the first case, bacteria can enter the wound from skin surfaces close to the surgical incisions, from the lumens of opened internal organs during operations, or from a source of inflammation located outside the surgical intervention area. Pathways of infection spread, such as hematogenous and lymphogenous, mean the penetration of viruses into the wound through lymphatic and blood vessels from the source of inflammation.

Hospital infection

The concept of hospital infection appeared in the 70-80s of the 20th century, as cases of infections caused by highly pathogenic strains of microorganisms that circulate inside medical institutions, while practically not occurring outside them, became more frequent. These strains were formed by selecting the most adapted antibiotic-resistant microorganisms that spread from sick patients to hospital staff and vice versa. Such microorganisms include: Escherichia coli, Staphylococcus aureus, Proteus, Pseudomonas aeruginosa, Peptococcus, Bacteroides, and fungi. According to WHO definition, HIV and viral hepatitis infections in hospitals are also classified as this type of infection spread.

The reservoirs of nosocomial infections are:

leather;
hair;
bed of the sick;
staff uniforms;
oral cavity;
intestines (feces).

The main route of transmission of infections within hospitals is contact, although previously it was considered airborne.

Unfortunately, it is impossible to completely eliminate the likelihood of infection through hospital transmission, but today a number of measures have been developed to help significantly reduce the risk of infection.

It has been observed that the longer a patient or worker stays in a hospital facility, the higher the risk of contracting infections. This is especially true for patients with purulent-septic diseases. Hospital infections often develop in patients who are forced to stay in a hospital bed for a long time and have limited movements.

In many developed countries today, constant bacteriological monitoring of pathogens of hospital infections is carried out. If certain microorganisms are detected, appropriate preventive measures are taken to prevent the spread of infection.

Practical lesson No. 1

Prevention of surgical nosocomial infections

Infection – the process of interaction between micro and macro organisms, leading to a response from the macro organism.

Surgical infection– a purulent-inflammatory process in the body that requires surgical treatment.

Reinfection– re-infection against the background of elimination of the primary infection.

Superinfection– re-infection against the background of an unfinished infectious process.

Pathogens of surgical infection

Aerobes– (staphylococci, streptococci, Pseudomonas aeruginosa, pneumococci, gonococci, meningococci).

Anaerobes– (tetanus bacillus, gas gangrene).

Microbial association– (bacteria, fungi, viruses).

Reservoirs of surgical infection in the hospital

In the human body - ( pharynx, upper respiratory tract, intestines, urinary tract, vomit, hair, nails, etc.).

In the external environment– (in the liquid environment of IV infusions, medical equipment, instruments, patient care items, linen, bedding, dressings, suture material, etc.).

Methods of transmission of infection (paths of infection into the wound)

Exogenous (from outside, outside) - an infection caused by a pathogen entering the body from the environment.

Endogenous (from within) – which is located in the patient’s body

In turn, exogenous sources of infection spread include:

Patients with purulent-septic diseases;
Animals;
Bacilli carriers.

In rare cases, animals act as sources of exogenous infection.

Pathogenic microflora enters the human body in the following ways:

· Air;

· Drip;

· Contact;

· Implantation;

· Fecal-oral;

· Vertical.

3. When they talk about the contact route of infection, we are talking about the penetration of microbes through objects into wounds and damaged areas of the skin through direct contact. Such images can be infected through surgical and cosmetic instruments, personal and public items, clothing, and so on. (HIV infection, hepatitis, abscess, mycoses, scabies, etc.).

6. The vertical method of spread of infection refers to the transmission of viruses from mother to fetus. In this case, they most often talk about HIV infections and viral hepatitis.

Endogenous infection provokes a disease from within or from the integument of the human body.

Its main foci include:

· inflammation of the covering layer - epithelium: carbuncles, boils, eczema, pyoderma;

· focal infections of the gastrointestinal tract: pancreatitis, caries, cholangitis, cholecystitis;

· respiratory tract infections: tracheitis, bronchitis, pneumonia, sinusitis, lung abscess, bronchiectasis, frontal sinusitis;

· inflammation of the urogenital tract: salpingoophoritis, prostatitis, cystitis, urethritis, pyelitis;

· foci of unknown infections.

Endogenous infection occurs in the following ways:

contact,

2. hematogenous

3. lymphogenous.

In the first case, bacteria can enter the wound from skin surfaces close to the surgical incisions, from the lumens of opened internal organs during operations, or from a source of inflammation located outside the surgical intervention area.

Pathways of infection spread, such as hematogenous and lymphogenous, mean the penetration of viruses into the wound through lymphatic and blood vessels from the source of inflammation.

4. Asepsis– a set of measures to prevent microbes from entering the wound.

Antiseptics – a system of measures aimed at reducing or destroying the number of microbes in a wound or body.

Measures to ensure asepsis

The importance of organizational measures should be especially emphasized: they become decisive. In modern asepsis, its two main principles have retained their importance:

Everything that comes into contact with the wound must be sterile

Organizational events of a general nature:

a) separation of flows of “clean” and “purulent” patients;

b) sanitary and hygienic treatment of patients;

c) compliance with sanitary and hygienic standards by medical personnel;

d) use of special clothing;

e) wet repeated cleaning of premises using antiseptic agents;

f) compliance with the ventilation schedule;

g) compliance with access control and monitoring compliance with sanitary and hygienic standards by visitors;

h) regular examination of personnel for carriage of staphylococci in the nasopharynx, medical examinations on a schedule and removal from work in the presence of pustular and colds.

Types of cleaning of dressing rooms and operating rooms

Preliminary – carried out at the beginning of the working day (wiping all horizontal surfaces from dust that has settled overnight, preparing disinfectant solutions, covering sterile tables).

Current – (performed during surgery or dressings).

Final – carried out at the end of the working day (used material is removed, all horizontal surfaces and walls are washed to arm’s length, bactericidal lamps are turned on).

General – carried out once every 7 days (all horizontal and vertical surfaces are processed)

Disinfection is the destruction of pathogenic and opportunistic microorganisms on all surfaces in premises, including the floor, walls, door handles, switches, window sills, as well as on hard furniture, surfaces of medical equipment, in the indoor air, on dishes, linen, medical products and patient care items, sanitary equipment, biological fluids.

All instruments and consumables used in the operation of any health care facility must be disinfected.

The purpose of disinfection is to prevent or eliminate the accumulation, reproduction and spread of pathogens. And first of all, nosocomial infections.

Disinfection can be preventive and focal.

Preventive disinfection is carried out to protect people from possible infection. In medical institutions, it is carried out in the form of routine daily wet cleaning and general cleaning of epidemiologically significant rooms (operating rooms, dressing rooms) once a week. Focal disinfection is carried out in the event of the occurrence or suspicion of an infectious disease.

The disinfection agent and its concentration are selected based on the specific infectious disease. Depending on the type of medical device, high (HLD), intermediate (DPU) and low level (DNU) disinfection is carried out.

Medical products or instruments can be divided into several types.

“Non-critical” contact with intact skin.

“Semi-critical” contact with mucous membranes or damaged skin.

“Critical” ones penetrate sterile body tissues or vessels, come into contact with blood or injection solutions, for example, surgical instruments.

Ways of infection entering the wound

Conditions for the development of infection in the body.

1. Decrease in the body’s defenses (during cooling, blood loss, severe infectious diseases, fasting, hypovitaminosis).

2. High virulence of the microorganism.

3. Large dose of infection.

A special place is occupied by “dormant infection”, which manifests itself clinically with a decrease in protective forces.

“Entry gate” is the path by which a microorganism enters the human body, not necessarily through a wound (food, water, contact, wound).

It enters the wound in two main ways:

1. Exogenous route - from the external environment:

a) air

b) contact

c) drip

d) implantation

Contact path has the greatest practical significance, because In most cases, wound contamination occurs through contact. A typical example of a contact infection is a wound received on the street or in a field. In these cases, the object that caused the wound (a car wheel, a shovel, a stone, etc.) is covered with dust or soil and contains a significant number of microorganisms, including such dangerous ones as the tetanus bacillus or the gas gangrene bacterium. Microbes that penetrate the wound enter the deepest parts of it and cause the wounds to fester. Microbes can get into surgical wounds from the surgeon's hands, instruments and dressings if they were not sterile. Prevention of contact infection is the main task of operating nurses and surgeons.

By implantation the infection is introduced deep into the tissues through injections or together with foreign bodies (shards, splinters, scraps of clothing). In peacetime, implantation infection is most often associated with suturing and implantation of prostheses. Prevention of implantation infection is carried out by extremely careful sterilization of suture threads, nylon mesh and other objects intended to be left in the tissues of the body. Impregnation of implanted threads or prostheses with antiseptic substances is also used. An implantation infection can manifest itself after a long period of time after surgery or injury, occurring as a “dormant” infection. In these cases, suppuration around sutures, splinters or prostheses develops after the weakening of the body's defenses, due to some disease or injury. Implantation infection is especially dangerous during tissue and organ transplant operations, when the body’s defenses are specifically suppressed by special drugs, immunosuppressants, which inhibit the body’s reaction to foreign tissue, including the introduction of microbes. In these cases, some types of bacteria that usually do not cause suppuration become virulent.

Air route– infection of the wound by microbes from the operating room air is prevented by strict adherence to the operating room regime.

drip path occurs when small droplets of saliva get into the wound and fly through the air when talking.

2. Endogenous pathway:

a) hematogenous

b) lymphogenous

c) contact

Sources of endogenous infection are often carious teeth, inflammatory processes in the oropharynx and nasopharynx, pustular skin formations, etc. In this case, the infection is brought into the wound from an internal source through the blood or lymph flow. Through contact, the infection spreads to a neighboring organ.

Based on the clinical course and pathological changes in tissues, surgical infection is divided into nonspecific and specific.

Nonspecific surgical infections include:

1) purulent, caused by various pyogenic microbes - staphylococci, gonococci, streptococci, dysentery bacillus, pneumococci, etc.;

2) anaerobic, caused by microbes that reproduce without access to oxygen - Cl. Perfringens, Cl. oedematiens, septic vibrio, Cl. histoliticus, etc. These microbes are facultative anaerobes that can reproduce in both aerobic and anaerobic conditions. In addition, there are obligate anaerobes that reproduce only without access to oxygen. In the presence of oxygen they die. They are called non-clostridial. These include anaerobic staphylococci, streptococci, actinomycetes, etc. These non-sporogenous microbes cause pleurisy, abscesses of the lung, liver, brain, peritonitis, sepsis, etc.;

3) putrefactive, caused by both anaerobic (Cl. sporogenes, Cl. tertium, etc.) and aerobic (Escherichia coli, B. proteus vulgaris, streptococcus faecalis, etc.) putrefactive microorganisms.

A specific surgical infection causes erysipelas, tetanus, diphtheria and scarlet fever, anthrax, bubonic plague, tuberculosis, syphilis, leprosy and other diseases.

Depending on the nature of the pathogen and the body’s response to the development of the disease process, surgical infection is divided into acute and chronic.

Acute surgical infection is often characterized by a sudden onset and a relatively short-term course.

Chronic nonspecific infection develops from an acute infection when it becomes chronic (chronic osteomyelitis, pleurisy and other diseases). A chronic specific infection can also begin initially (joint tuberculosis, actinomycosis, syphilis and other specific diseases).

In both acute and chronic surgical infections, local symptoms and often local and general manifestations are observed.

Surgical infection penetrates the wound through exogenous and endogenous routes.

In the first case, the infection enters the wound from the outside - by air, droplet, contact and implantation. With the airborne route of penetration, airborne microbes enter the wound; with drip - microbes contained in drops of saliva, mucus, secreted from the mouth or nose when talking, coughing, sneezing. Contact route - when the infection enters the wound through contact with another person. If the infection enters the wound from objects inserted into it (drains, turundas, napkins, etc.) - the implantation path.

The endogenous route of penetration involves infection entering the wound directly from the patient himself. In this case, the infection can enter the wound from the skin or mucous membrane of the patient or from a dormant inflammatory focus (tuberculosis) through the lymphatic or blood vessels.