Gas gangrene

ICD-10 code

A48.0 Gas gangrene.

What causes gas gangrene?

Gas gangrene is caused by 4 types of spore-forming anaerobic clostridia: Clostridium perfringens, Clostridium oedematiens, Clostridium septicum, Clostridium histolyticum, sometimes Clostridium novyi.

How does gas gangrene develop?

Clostridium is widely distributed in the external environment, mainly in the soil, where they exist in the form of spores, penetrate the human body through damage to the skin - abrasions, scratches.

• An important factor contributing to the development of anaerobic infection is the disturbance of oxygenation.
• Usually, the situation occurs with deep canals, poor communication of the cavity with the external environment, injury of the main vessel and prolonged application of the hemostatic tourniquet to the limb, as well as in patients with chronic arterial insufficiency.
• A favorable background is the presence of a large mass of crushed and bruised tissues and factors that reduce the overall resistance of the body.
• Under anaerobic conditions, microorganisms begin to multiply rapidly, form toxins that have a damaging effect on surrounding tissues and promote the rapid spread of necrosis.
• Clostridia isolates complex, consisting of several fractions, the colloidal structure of exotoxins, which have a pronounced systemic and local action, the most active fractions include:
  • lecithinase C (pronounced necrotizing and hemolytic action),
  • hemolysin (pronounced necrotizing effect, specific cardiotoxic effect),
  • Collagenase (lysing protein structures),
  • hyaluronidase (penetration factor),
  • fibrinolysin,
  • neuraminidase (destruction of immune receptors on erythrocytes),
  • hemagglutinin (inhibits phagocytosis) and others.
• The saccharolytic function leads to the destruction of glycogen, and the proteolytic function leads to the destruction of proteins and melting.
• Clostridia are characterized by gas formation and edema, with a rapid spread along the vascular-neural bundles and with a significant advance in the formation of edema of the skin and subcutaneous tissue.
• Under the influence of a toxin, thrombosis of veins and arteries, paralysis and violation of the permeability of the vessels of the microcirculatory bed develops.
• Plasma and shaped elements of blood enter the zone of necrosis.
• Local circulatory disturbance promotes the growth of necrosis, and the rapid absorption of bacterial toxins and decay products leads to severe intoxication and a decrease in systemic blood pressure.
• The duration of the incubation period of anaerobic clostridial infection ranges from a few hours to 2-3 weeks, an average of 1-7 days, while the shorter it is, the heavier the course and the unfavorable prognosis.

How is gas gangrene manifested?

For acute clostridial infection characterized by pronounced necrotic process, massive edema and gas formation.

• Specific is considered a symptom of crepitus (palpation under the fingers feels like a crunch of snow).
• In most cases, the onset of the disease is violent, with the rapid development of severe intoxication.
• For classical clostridial infection is characterized by:
  • pronounced edema without hyperemia,
  • intense burial pain,
  • bubbles with hemorrhagic contents and greenish spots on the skin,
  • decrease in local temperature,
  • massive necrosis of connective tissue and muscle structures, imbibition by products of decay, for this reason muscles have the form of boiled meat, prolapse into the wound,
  • a cloudy exudate of an inflammatory nature, often hemorrhagic, with an unpleasant odor,
  • symptoms of gas accumulation: crepitus, the appearance of vesicles when pressing on the edge of the wound, with x-ray examination soft tissue of the pinnate and layered species.
• Anaerobic infection is characterized by rapid progression of local symptoms and the spread of the process.
• A few days later, an aerobic microflora with signs of a purulent infection usually joins anaerobic.

Gas gangrene has four stages

In the early stage (delimited gangrene gas), patients complain of pain. The wound is dry with a dirty gray coating, necrosis with little or no discharge, or with a small amount of brownish exudate. Edema is observed only around the wound, the skin in this area is strained, shiny, pale with a slight icteric tinge ("white edema", "white face").

The stage of spread, with the progression of the process, edema and gas formation increase, and their spread along the limb. The nature of pain changes, it becomes bursting. Fabrics in the wound acquire a lifeless appearance, dry, the muscles bulge out of the wound, dull, fragile, bloodless. Jaundice-pale skin color spreads widely from the wound, bronze or marble spots are observed in the affected area.

In the third stage, the limb becomes cold, peripheral pulsation is not detected, the pain stops, and its sensitivity is impaired. Finiteness pale, sharply enlarged; edema and gases spread to the trunk, blisters with a brown or hemorrhagic exudate are recorded. The wound is lifeless, the muscles in it are kind of "boiled meat", from the depth of the wound it is possible bloody-purulent discharge.

In the fourth stage (sepsis) in the wound, a purulent discharge, observe pronounced intoxication, distant purulent metastatic foci.

Early symptoms of anaerobic infection: the patient's expressed anxiety, excitement, taciturnity, followed by extreme inhibition, adynamics, impaired orientation in time and space, body temperature increased, tachycardia and hypotension. With the progression of the process, the development of hepatic renal failure, leading to parenchymal jaundice, is increasing, due to toxic hemolysis, oliguria and anuria.

Classification

Gas gangrene has three forms:

• Clostridial myositis (predominant local muscle damage);
• Clostridial cellulitis (primary lesion of subcutaneous adipose tissue and connective tissue, perivascular and perineural cases);
• mixed form.

[1], [2], [3], [4]

How is gas gangrene recognized?

Gas gangrene is diagnosed on the basis of an assessment of the nature of the pain syndrome, the rate of swelling and necrosis, the presence of crepitus, the nature of exudate and skin color.

• Observe a decrease in the temperature of the affected limb, in contrast to inflammation caused by non-clostridial infection.
• Radiographic and ultrasound studies in soft tissues determine the accumulation of gas, characterized by the spread of gas through loose fiber spaces with fragmentation of muscle segments.
• Laboratory studies: reduction of hemoglobin and hematocrit, leukocytosis reaches a level of 15-20x109 / l with a shift of the leukocyte formula to the left, an increase in ESR.
• Bacterioscopy of the wound separated from the Gram stain shows a "rough", unevenly thickened Gram-positive sticks, which confirms the diagnosis of clostridial infection.

Differential diagnostics

Carried out with anaerobic streptococcal myonecrosis, urinary infiltrates, crepitating cellulite, necrosis in diabetic angiopathy.

[5], [6], [7], [8], [9], [10], [11], [12]

How is gas gangrene treated?

The patient is isolated in a separate ward, the sanitary and hygienic regime in the ward must exclude the possibility of contact spread of pathogens of the infection.

It is necessary to make timely and adequate disinfection of medical instruments, equipment, facilities, toiletries and dressings.

Pathogenetic treatment complex includes the following main components:

• adequate surgical sanitation of the wound;
• prevention of reproduction and spread of bacteria by oxygenation of the focus of infection, use of antibacterial agents and specific sera;
• correction of changes in the functions of organs and systems with the use of infusion and anticoagulant therapy, immunocorrection and immunostimulation;
• neutralization of the action of circulating toxin by the administration of specific toxins and the use of extracorporeal detoxification methods.

Gas gangrene requires the use of surgical interventions of three types:

• wide dissection of affected tissues - "lamp-like" incisions with the opening of aponeuroses, fascial vaginas to the bone, for the purpose of adequate aeration of the wound and removal of edematous fluid containing a large number of toxins;
• excision of affected tissues, especially muscles;
• amputation (exarticulation) of the limb, above the level of visually determined viable tissues, without the imposition of primary sutures.

Antibacterial therapy with clostridial infection before the sensitivity of pathogens is determined by high doses of penicillin (20-30 million units per day intravenously).

More effective use of a combination of penicillins and aminoglycosides, cephalosporins and aminoglycosides.

Widely used drugs that selectively act on anaerobes: clindamycin (dalacin), chloramphenicol, metronidazole, carbenicillin, rifampicin, solutions of furazidine, dioxidine and others.

Seroterapy is the introduction of anti-gangrenous sera.

One ampoule of the standard polyvalent serum contains anatoxins against three types of pathogens (CI. Perfringens, oedematiens, septicum) of 10,000 IU. Clostridium histolyticum is rare.

In cases of extensive damage or severe contamination of the wound, a polyvalent antigangrenous serum is administered prophylactically at an average preventative dose of 30,000 IU.

Oxygenobarotherapy (treatment in a pressure chamber in conditions of increased oxygen pressure) is of great importance in the treatment, it allows to reduce the number of pathogens and prevents the formation of stable forms of microbes.

What is the prognosis of gas gangrene?

Gas gangrene has an unfavorable prognosis, patients recover with early diagnosis, timely and adequate treatment.