Anaerobic gas gangrene is an infectious disease that occurs against the background of the reproduction and growth of bacteria of the genus Clostridium in human soft tissues, most often on the limbs. The pathogen enters the body when the skin is broken.
Definition
The lesion is considered a severe surgical pathology, which is formed due to anaerobic infection in the wound, which leads to significant tissue necrosis. The disease is dangerous with extensive toxic effects on the body, which even leads to death if medical assistance is not provided in time. Due to the vital activity of microorganisms in the wound, a large amount of gas appears, which collects in the form of bubbles inside the soft tissues.
Pathogens
Gas gangrene can occur when certain micro-organisms enter the wound, which infect the limbs and lead to tissue death.
Cl. perfringens are large and immobile polymorphic rods that produce oval spores. They are located subterminally and form inthe body is a kind of capsule. Microbes have mild proteolytic properties and produce a large set of saccharolytic enzymes. As a result, sugar is fermented with the further formation of gas and acid. Pathogenic infection is divided into six serovars (A, B, C, D, E, F), which have a variety of necrotic characteristics. Clostridia "A" are the primary causative agents of gas gangrene and form the disease in 70-80% of cases. The spores can withstand 100°C lesions for 1 to 6 hours.
Cl. novyi are large and thick Gram-positive motile rods that form oval spores and are located internally without capsules and subterminally. They have weak proteolytic characteristics. Saccharolytic properties are expressed less actively. There are four serovars (A, B, C, D) that can secrete toxins of various antigenic characteristics that have hemolytic and necrotic properties. Spores stably react to various environmental factors and survive boiling for several hours, they can stay in the soil for 7-8 years in an active form.
Cl. Septicum are polymorphic, motile, and Gram-positive rods that form oval spores, do not form capsules, and are located subterminally. This causative agent of gas gangrene has mild saccharolytic and proteolytic properties. Has six serological types (A, B, C, D, E, F), secretes necrotic, lethal and hemolytic toxins.
Cl. Histolyticum are small, mobile, and Gram-positive rods that form spores without forming capsules. They have strong proteolytic properties. They are engaged in the production of exotoxin, which leads to necrotic and fatal outcome. These characteristics are formed due to the release of enzymes such as hyaluronidases, collagenoses and lecithinases.
Reasons
Gas gangrene is caused by rods of the Clostridium family, which often live in the intestines of herbivores and from there get into the ground, on clothes and street dust. In some cases, the pathogen can be found on the skin and in the feces of he althy people. Microorganisms reproduce only in an oxygen-free environment, but if air gets on them, they remain for a long time in the form of spores, and under favorable circumstances become active again and become dangerous.
Most often, the pathology develops as a result of multiplied, extensive wounds and traumatic breaks of the limbs, less often - as a result of lesions of the large intestine after the ingestion of foreign bodies. In some situations, signs of gas gangrene may appear due to small cuts contaminated with soil particles and torn clothing.
How it develops
Clostridia is widely distributed in the environment, as well as in the soil, where it exists in the form of spores and enters the human body through abrasions and scratches if they are not treated in time. The main factors in the development of anaerobic gas gangrene infection are the following indicators:
- Often the situation arisesin violation of oxygenation and in poor communication between the cavity and the external environment. Also, the lesion is formed when a hemostatic tourniquet is worn for a long time on the extremities in case of injury to the main vessel and in patients who have chronic arterial insufficiency.
- A favorable background is the presence of a significant mass of bruised and crushed tissues, as well as factors that lower the body's resistance.
- The causative agent of gas gangrene is activated when positive anaerobic conditions are formed. Microorganisms begin to multiply vigorously and form toxins, which have a damaging effect on tissues, and also contribute to the rapid spread of necrosis.
- Due to the saccharolytic function, glycogen is destroyed, and the proletic action leads to the melting and destruction of proteins.
- Clostridia are characterized by the formation of edema and gas.
- Due to the action of the toxin, arterial and vein thrombosis is formed, paralysis and destruction of vascular permeability occurs.
- Enzymatic elements of blood and plasma enter the necrosis zone, which causes rapid absorption of bacterial toxins, and decay products lead to severe intoxication.
- The incubation period ranges from a couple of hours to 2-3 weeks. On average, this time takes 1-7 days, and the shorter the period, the more unfavorable and difficult the course and prognosis.
Clostridia secrete exotoxins consisting of several fractions, which have local and systemic effects, to whichrefer to:
- lecithinase C - has a hemolytic and necrotic effect;
- collagenase - blocks protein structures;
- hemolysin - has a cardiotoxic and necrotizing effect;
- fibrinozolin;
- hyaluronidase - is a factor in the penetration of bacteria;
- hemagglutinin - inhibits the formation of phagocytosis;
- neuraminidase - neutralizes immune receptors on red blood cells.
Symptoms
Crepitus is considered a specific sign - on palpation, you can feel sounds similar to the crunch of snow. Most often, the onset of the disease is rapid with a significant development of severe intoxication. The classic symptoms of gas gangrene are:
- pronounced edema, passing without hyperemia;
- bubbles containing hemorrhagic compounds and green spots on the skin;
- significant arching pains;
- mass necrosis of muscle and connective tissues;
- decrease in temperature;
- formation of cloudy exudate of non-purulent manifestation, accompanied by an unpleasant odor;
- gas accumulation.
Anaerobic infection is typically characterized by a rapid increase in local symptoms of gas gangrene, as well as widespread processes throughout the limb. After a few days, as a rule, aerobic microflora begins to join, accompanied by a purulent infection.
Stages
- Early. During this period, patients complain of pain. The wound looks dryappeared dirty gray coating. Necrosis resolves with little or no discharge of brownish exudation. There is a slight swelling near the wound, the skin is pale with a slight yellowness.
- Distribution stage. With it, the process of gas formation and edema progresses. The pain acquires bursting properties. The causative agent of gas gangrene begins to kill the tissues, they get a lifeless and dry appearance, the muscles look fragile, dull and bled. The icteric coloration of the epidermis extends far from the wound.
- At this stage, the limb becomes cold, no peripheral pulsation is detected in it, its sensitivity is disturbed, and the pain stops. The integument becomes pale, and the lesion site increases significantly in size. Gases and edema spread to the body, blisters with hemorrhagic or brown exudate are observed. The wound is lifeless, and the muscles in it look like boiled meat. Bloody-purulent discharge is possible from the depth of the lesion.
- Sepsis. Pus collects in the problem area, severe intoxication and metastatic foci are observed.
Classification
There are three main forms:
- clostridial myositis - characterized by local muscle damage;
- clostridial cellulitis - subcutaneous fat and connective tissues are predominantly destroyed;
- mixed form.
Diagnosis
First of all, it is necessary to conduct a clinical examination and identify an anamnesis of the disease:
- in the woundpractically no pus;
- there is a black color and crepitus of the affected area;
- shifting gas bubbles form under pressure;
- muscles look like boiled meat;
- despite such a severe pathology, there is practically no temperature increase.
When X-rays are taken, characteristic porous muscles are present. Diagnosis of gas gangrene also involves laboratory tests. The material is elements of necrotic tissue, scraps of clothing, edematous fluid, blood and particles of the earth. The bacteriological method consists of inoculation on Wilson-Blair blood agar, Kitt-Tarozzi medium and identification of distributed cultures.
Treatment
For therapy, the patient must be isolated in a separate room with the maintenance of a sanitary and hygienic regime. Indoors, it is necessary to exclude the possibility of contact spread of the causative agent of gas gangrene. Adequate and timely disinfection of medical equipment, dressings and toiletries is required.
The set of events includes the following items:
- timely and permanent debridement of the wound;
- prevention of the spread and reproduction of bacteria is carried out with the help of oxygenation, antibacterial agents and specific serums are used;
- changes in the functions of organs and all systems are corrected using anticoagulant and infusion therapy, immunostimulation andimmunocorrection;
- transmission pathways for gas gangrene are blocked by neutralizing the circulating toxin through the administration of specific toxoids and the use of extracorporeal detoxification techniques.
Surgery can be indicated in three cases.
- If there was a wide separation of the affected tissues, namely, "lamp" incisions with the opening of the fascial sheaths to the bone and aponeuroses. All activities are performed to adequately aerate the wound and eliminate edematous fluid, as it contains a large amount of toxins.
- If there is an excised muscle lesion.
- When amputation of limbs is performed above the level of visually viable tissues without using the primary suturing procedure.
In order to improve the oxygenation process, which is so necessary for the treatment of the disease, procedures are prescribed in the pressure chamber, where oxygen is supplied under strong and targeted pressure, so that it penetrates better into the tissues. Intravenous administration of antigangrenous serum is required. It is pre-diluted in half with warm saline. Antibacterial therapy is carried out with clostridial infection only with significant doses of penicillin (20-30 million units per day intravenously).
The duration of treatment depends on the medical picture of the patient's recovery. If there is a rapidly developing necrosis with a sharp deterioration in the condition, then timely amputation is required. The operation is performed only to save life,as the infection spreads rapidly, and a person may die.
It is already known how gas gangrene is transmitted and how it spreads rapidly, which is why its prompt treatment is so important. Many doctors recommend using a complex technique. A more effective method is the use of a combination of aminoglycosides and penicillins, aminoglycosides and cephalosporins. Drugs that selectively act on anaerobes are widely used, namely Chloramphenicol, Metronidazole, Clindamycin, Rifampicin, Carbenicillin.
The use of serotherapy consists in the introduction of anti-gangrenous sera. One ampoule contains toxoids against the main types of pathogens, which are actively neutralized, thereby returning initiative activity to the tissues. If there are cases of extensive damage or severe contamination of the wound, then the mandatory introduction of polyvalent serum at an average maintenance dose of 30,000 ME is required.
Prevention of gas gangrene
With various lesions, the main action to prevent the disease is the timely decontamination of the wound, as well as the application of a bandage to prevent secondary contamination of the surface.
It is also recommended to introduce tetanus and anti-gangrenous serum in the first few hours if there is a puncture, deep, incised or contaminated wound. When a tourniquet is applied, it is necessary to indicate the time of the procedure nearby, and also, if there is a need for a longwhen transporting the patient to the hospital, loosen the bandage every two hours to resume blood flow to the distal part of the limb. The note needs to be updated after each procedure. Next, you need to carry out the timely conduct of the full volume of surgical treatment of soft tissues and bones.
