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ELECTRIC INJURY. PATHOGENESIS, CLINIC
An electrical injury is a lesion that occurs under the influence of an electric current and is the sum of the direct consequences of the passage of electric current through the tissues of the body and a burn with a voltaic arc flame.
Sources of electrical current that affects a person can be domestic and industrial electrical installations, atmospheric electricity. The damage occurs both in direct contact with the current-carrying parts and at a distance, due to the ionization of air - the formation of an electrical (volt) arc, which at ultrahigh voltages can reach 35 cm.
Electrical injury may occur from the so-called "step voltage", formed on the land around the current source. It is considered dangerous to enter the zone of a fallen high-voltage wire at a distance of 10 meters. The severity of an electric shock depends on:
1. Current strength (0.1 A is considered dangerous; 0.5 A is fatal)
2. Duration of action
3. Paths of passage through the body ("current loops") - the most dangerous are current loops, resembling through the heart, neck, head.
Electric current has a specific (biological, electrochemical, thermal, dynamic) and nonspecific effects on the body. The specific biological effect of the current lies in the stimulating effect on the muscles and nerve elements, leading to long-term disturbances in the work of the potassium-sodium pump cells, and, as a result, to pronounced neuromuscular disorders (up to ventricular fibrillation and instantaneous death).
The electrochemical action leads to the accumulation in the area of application of the anode of acidic products, and in the area of the cathode - alkaline. As a result, tissue necrosis occurs: under the anode - coagulation, and under the cathode - kollikvatsionny. Sometimes, due to the electrochemical advancement of metal ions from the conductor to the fabric, there is a "metallization" of the skin (color, according to the color of the metal ions).
The thermal effect of current is manifested by burns.
On the skin, as a rule
there are deep burns in the form of "current marks", in the bone tissue during its melting - "pearl beads".
The dynamic (mechanical) action of high-current currents is manifested in the separation of tissues or even the separation of body parts. The combined effect of thermal and mechanical energy can cause an explosive effect.
The nonspecific effect of electric current is caused by various types of energy produced outside the body. Voltaic arc, has a temperature of up to 4000 degrees Celsius, so hot conductors can cause thermal burns; the intense glow of the arc arc and ultraviolet radiation - burn the cornea and retina; sound wave during an explosion - damage to the auditory analyzer.
An electric shock clinic consists of common and local symptoms. In the early period (its duration is not clearly defined), violations of the function of the central nervous system, cardiovascular and respiratory systems come to the fore. Lesions of other internal organs are rare. In some cases, at the moment of electric shock or in the next few minutes after it, sudden death may occur due to functional disorders of the vasomotor and respiratory centers, ventricular fibrillation, or spasm of the coronary vessels. It should be remembered that similar reflex disorders can develop within a few hours after an electric shock. Therefore, each person affected by an electric current, regardless of his condition, should be considered potentially severe and hospitalized immediately.
Often with electric shock there is a loss of consciousness of various durations. A sharp oppression of the centers of the central nervous system can create the impression of the death of the victim ("imaginary death", "electric lethargy"). With persistent resuscitation, it is often possible to save such victims of death. In other, more rare cases, psychomotor and motor arousal is observed against a background of impaired consciousness.
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ELECTRIC INJURY. PATHOGENESIS, CLINIC
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