Anaerobic gas gangrene is an infectious disease that occurs against the background of the reproduction and growth of bacteria of the clostridium genus in human soft tissues, most often on the extremities. The causative agent enters the body in violation of the skin.
Definition
The lesion is considered a serious surgical pathology, which is formed due to anaerobic infection in the wound, which leads to significant tissue necrosis. The disease is dangerous due to extensive toxic effects on the body, which even leads to death if medical attention is not provided on time. Due to the vital activity of microorganisms, a large amount of gas appears in the wound, which collects in the form of bubbles inside the soft tissues.
Pathogens
Gas gangrene can occur due to the entry of certain microorganisms into the wound, which affect the limbs and lead to the death of tissues.
Cl. perfringens are large and immobile polymorphic rods, due to which oval spores form. They are located subterminally and form a kind of capsule in the body. Microbes have weak proteolytic properties and produce a large set of saccharolytic enzymes. The result is the fermentation of sugar with the further formation of gas and acid. Pathogenic infection is divided into six serovars (A, B, C, D, E, F), having a variety of necrotic characteristics. Clostridia "A" are the primary causative agents of gas gangrene and form the disease in 70–80% of cases. Disputes can withstand the temperature of the lesion at 100 ° C for 1 to 6 hours.
Cl. novyi are large and thick gram-positive movable sticks that form oval spores, and are located inside without capsules and subterminally. They have weak proteolytic characteristics. Saccharolytic properties are expressed less actively. There are four serovars (A, B, C, D), which can release toxins of different antigenic characteristics, which have hemolytic and necrotic properties. Disputes steadily respond to various environmental factors and survive boiling for several hours, in the soil can be 7-8 years in active form.
Cl. Septicum are polymorphic, motile and gram-positive rods that form oval spores, do not form capsules and are located subterminally. This pathogen of gas gangrene has mild saccharolytic and proteolytic properties. It has six serological types (A, B, C, D, E, F), secrete necrotic, lethal and hemolytic toxins.
Cl. Histolyticum are small, motile and gram-positive rods that form spores without capsule formation. They have strong proteolytic properties. Engaged in the production of exotoxin, which leads to necrotic and fatal outcome. These characteristics are formed due to the isolation of enzymes such as hyaluronidases, collagenoses and lecithinases.
Causes
Gas gangrene is caused by sticks of the Clostridia family, which often live in the intestines of herbivores and from there fall into the ground, on clothing and street dust. In some cases, the pathogen can be on the skin and feces of healthy people. Microorganisms reproduce only in an oxygen-free environment, but if air enters them, they remain for a long time in the form of spores, and under favorable circumstances they become active again and become dangerous.
Most often, the pathology develops as a result of multiplied, extensive wounds and traumatic breaks of the extremities, less often - as a result of damage to the colon after ingestion of foreign bodies. In some situations, signs of gas gangrene may appear due to small cuts contaminated with soil particles and scraps of clothing.
How does it develop
Clostridium is widely distributed in the external environment, as well as in the soil, where it exists in the form of spores and penetrates the human body through abrasions and scratches, if not treated on time. The main factors for the development of anaerobic infection of gas gangrene are the following indicators:
- Often the situation arises in violation of oxygenation and with poor communication of the cavity and the environment. Also, the lesion is formed with prolonged wearing of a hemostatic tourniquet on the limbs when the main vessel is wounded and in patients who have chronic arterial insufficiency.
- A favorable background is the presence of a significant mass of bruised and softened tissues, as well as factors that reduce the body's resistance.
- The causative agent of gas gangrene is activated by the formation of positive anaerobic conditions. 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 collapses, and the proletic effect leads to the melting and destruction of proteins.
- Clostridia are characterized by the formation of edema and gases.
- Due to the action of the toxin, thrombosis of arteries and veins is formed, paralysis and destruction of vascular permeability occur.
- The enzymatic elements of blood and plasma enter the necrosis zone, which causes the rapid absorption of bacterial toxins, and the decay products lead to severe intoxication.
- The incubation period is from a couple of hours to 2-3 weeks. On average, this time takes 1-7 days, and the shorter the time, the worse and harder the course and prognosis.
Clostridia secrete exotoxins consisting of several fractions that have local and systemic effects, which include:
- lecithinase C - has a hemolytic and necrotic effect;
- collagenase - blocks protein structures;
- hemolysin - has a cardiotoxic and necrotizing effect;
- fibrinosoline;
- hyaluronidase - is a factor in the penetration of bacteria;
- hemagglutinin - inhibits the formation of phagocytosis;
- neuraminidase - neutralizes immune receptors on red blood cells.
Symptoms
Crepitation is considered a specific sign - on palpation, you can feel sounds similar to a crunch of snow. Most often, the onset of the disease passes rapidly with a significant development of severe intoxication. The classic symptoms of gas gangrene are:
- severe edema, passing without hyperemia;
- bubbles in which hemorrhagic compounds are located, and green spots on the skin are also observed;
- significant bursting pain;
- massive necrosis of muscle and connective tissue;
- lowering the temperature;
- the formation of a turbid exudate of non-purulent manifestation, accompanied by an unpleasant odor;
- flatulence.
Anaerobic infection is typically characterized by a rapid increase in local symptoms of gas gangrene, as well as common 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 dry with a dirty gray coating. Necrosis passes almost without detachable or a slight amount of brownish exudation. There is a slight edema near the wound, the skin has a pale tint with mild yellowness.
- Stage of distribution. With it, the process of gas formation and edema progresses. Pain acquires bursting properties. The causative agent of gas gangrene begins to kill tissues, they get a lifeless and dry look, the muscles look fragile, dull and bloodless. The icteric color of the epidermis extends far from the wound.
- At this stage, the limb becomes cold, peripheral pulsation is not detected in it, its sensitivity is disturbed, and the pain ceases. The integument becomes pale, and the lesion site significantly increases in size. Gases and swelling spread to the body, there are bubbles with hemorrhagic or brown exudate. The wound is inanimate, and the muscles in it look like boiled meat. Bloody purulent discharge is possible from the depth of the lesion.
- Sepsis. Pus is collected 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 fatty tissue and connective tissues are mainly destroyed;
- mixed form.
Diagnostics
First of all, it is necessary to conduct a clinical examination and identify a medical history of the disease:
- pus is practically absent in the wound;
- there is a black color and crepitus of the affected area;
- displaced gas bubbles form under pressure;
- the muscles look like boiled meat;
- Despite such a severe course of pathology, there is practically no increase in temperature.
When conducting x-rays there is a characteristic porous musculature. Diagnosis of gas gangrene also involves laboratory tests. The material is elements of necrotic tissue, scraps of clothing, edematous fluid, blood, and earth particles. The bacteriological method consists of sowing on Wilson-Blair blood agar, on Kitta-Tarozzi medium and identifying distributed cultures.
Treatment
For therapy, the patient must be isolated in a separate room with maintaining a sanitary-hygienic regimen. Indoors, the probability of contact spread of the pathogen of gas gangrene should be excluded. An adequate and timely disinfection of medical equipment, dressings and toiletries is required.
The set of measures includes the following items:
- timely and ongoing surgical debridement of the wound;
- prevention of the spread and reproduction of bacteria is carried out using 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 and immunocorrection;
- the transmission paths of gas gangrene are blocked by neutralizing the circulating toxin through the introduction of specific toxoids and the use of extracorporeal detoxification methods.
Surgery can be indicated in three cases.
- If there was a wide separation of the affected tissues, namely, “strip” incisions with opening of the fascial sheaths to the bone and aponeurosis. All measures are performed to adequately aerate the wound and eliminate edematous fluid, since it contains a large amount of toxins.
- If there is excised muscle damage.
- When amputation of limbs is performed above the level of visually resident viable tissues without using the primary suture 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. An anti-gangrenous serum is required to be administered intravenously. It is previously diluted in half with warmed 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, then timely amputation is required. The operation is carried out only to save life, as the infection spreads quickly, and a person can die.
It is already known how gas gangrene is transmitted and how it spreads rapidly, which is why its surgical treatment is so important. Many doctors recommend using a comprehensive technique. A more effective method is the use of a combination of aminoglycosides and penicillins, aminoglycosides and cephalosporins. Widely used are drugs that selectively act on anaerobes, namely Chloramphenicol, Metronidazole, Clindamycin, Rifampicin, and Carbenicillin.
The use of serotherapy is the introduction of antigangrenous serums. One ampoule contains toxoids against the main types of pathogens, which are actively neutralized, thereby returning tissue to the initiative. If there are cases of extensive injuries or severe contamination of the wound, then the mandatory introduction of polyvalent serum in an average maintenance dose of 30,000 ME is required.
Prevention of gas gangrene
In case of various lesions, the main action to prevent the disease is timely disinfection of the wound, as well as dressing to prevent secondary contamination of the surface.
It is also recommended in the first few hours to introduce tetanus and anti-gangrenous serum if there is a stab, deep, cut or contaminated wound. When a tourniquet is applied, it is necessary to indicate the time of the procedure next to it, and if there is a need for long-term transportation of the patient to the hospital, every two hours, relax the bandage to resume blood flow to the distal part of the limb. The note needs to be updated after each procedure. Next, it is necessary to conduct the timely conduct of the full volume of surgical treatment of soft tissues and bones.