From Big Medical Encyclopedia

ELECTRIC TRAUMA — the injury caused by impact on an organism of electric current.

The electric trauma makes up to 2 — 2,5% of all injuries. Percent of a lethality at E. is much higher, than at other types of injuries.

The electric trauma can occur at direct contact of a body with a source of electric current or at arc contact when the person is in close proximity to a source of current, but does not concern it. This type of defeat by electric current should be distinguished from the damage caused voltaic exaggerated (a burn, light damage of eyes). High installed power per employee of the modern industrial enterprises and life increases danger of emergence E., especially at non-compliance with safety regulationss (e.g., the bared wires of the electrical household appliance, contact of the electric line with the case of the device, etc.). Danger E. raises also during the work with sources of current, electrical machines or devices in the conditions of high humidity, in the absence of effective grounding, at pollution of electric circuits, etc.

Extent of impact of electric current on an organism is defined by different factors, including physical parameters of current, a physiological condition of an organism, features of the environment, etc. It is established that at a voltage up to 450 — 500 volts (v) alternating current is more dangerous, and at more high tension — constant. Initial irritant action of electric current appears at current with a force of 1 milliampere (ma). At current with a force of 15 ma there is a convulsive reduction of muscles that as if «arrests» the victim to a source of electrical energy. However the «arresting» effect is possible also at smaller values of current. E is deadly. at current more than 100 ma.

Danger E. raises during the overheating of an organism therefore in hot workshops whenever possible use current of the lowered tension. AA. is less dangerous at the raised oxygen content in the environment and is more dangerous at a hypoxia.

Electric current works as locally, damaging fabrics in places of passing (i.e. along the electric chain arising in an organism), and is reflex.

Electric current, extending on tissues of a body of the person from the place of an entrance to the place of an exit, forms a so-called loop of current. The lower loop (from a leg to a leg), more dangerous — an upper loop (by hand to a hand) and the most dangerous — a full loop (both hands and both legs) is less dangerous. In the latter case electric current surely passes through heart that is followed, as a rule, by heavy disturbances of cordial activity.

Subjective feelings at E. are very various: little push, thermalgia, convulsive reduction of muscles, etc. After cancellation of electric current quite often there are a weakness, heavy feeling in all body, a fright, oppression of consciousness or excitement is observed.

Focal lesion of fabrics at E. the hl is shown in the form of so-called signs (tags) of current. obr. in places of an entrance and exit of current where electrical energy passes in thermal (heat of Joule). They are observed approximately at 60% of victims. The tension of electric current is higher, the it is heavier burns. Current tension of St. 1000 in can cause burns throughout all extremity, on the flexion surfaces of joints, etc. that is explained by emergence of the arc category between two adjoining body surfaces at convulsive reduction of muscles. Deep burns arise at action of current from 380 in above.

On the classification accepted in the USSR all burns, including and electric, divide on depth of defeat into four degrees (see Burns). So-called signs of current, or electrotag belong to electroburns of 1 degree — sites of coagulation of epidermis. Electroburns of the II degree are characterized by amotio of epidermis with bulging. At electroburns of the III degree there is a coagulation of all thickness of a derma. At electroburns of the IV degree not only a derma, but I sinews, muscles, vessels, nerves, bones are surprised.

Outward of an electroburn is defined by its localization and depth (tsvetn. the tab., Art. 336, fig. 1 — 5). If it proceeds as a wet necrosis, then and at electroburns of the III—IV degree the burn surface can look as at electroburns of the II degree, and only after removal of epidermis defeat of deeper layers of skin and the subject cellulose is found. At an electroburn with a carbonization owing to wrinkling of fabrics impression is formed as if. Electroburns of the head are almost always followed by change outside, and sometimes and an internal plate of bones of a calvaria. The deep electroburn of the head with penetration into a head cavity can be followed not only inflammatory changes in covers Mose by hectare, but also local defeat of substance of a brain.

At direct or arc contact with current of big force and high tension there can come the partial or full carbonization of an extremity. Owing to tetanic reduction of muscles rough contractures of all joints appear. Local complications depend hl. obr. from depth of an electric burn. There can be early complications caused by action of electric current at the time of its passing through an organism when sharp reduction of muscles is resulted sometimes by avulsion and compression fractures, dislocation-fractures and dislocations. Necks of a shovel, a separation of a big hillock of a humeral bone and dislocation of a shoulder are more often noted a compression fracture of vertebras. Refer rough cicatricial deformations with development to late local complications tontraktur (see). After healing of electroburns in cicatricial fabric quite often there are neurinoma (see). In some cases on site an electroburn are formed it is long not healing ulcers.

For E. delay of rejection of a scab, formation of granulyatsionny fabric and epithelization is characteristic. Changes of peripheral nerves as the ascending neuritis meet paresis, disturbances of sensitivity and a trophicity. They come to light usually after nek-ry time after E. Odnako at burns in a zone of the main nerves sluggish paralyzes develop directly after an injury.

In the general reaction of an organism to an electric trauma allocate four degrees: I \convulsive reduction of muscles without loss of consciousness; II \convulsive reduction of muscles with a loss of consciousness; III \convulsive reduction of muscles with a loss of consciousness and disturbance of cordial activity or breath; IV \clinical death. At the general reaction of I and II degrees there can be symptoms of increase in intracranial pressure, neurologic and mental disorders. At the general reaction of the III degree, besides, dullness of cardiac sounds, weakening of pulse, tachycardia, sometimes arrhythmia are possible. On an ECG decrease in amplitude and inversion of a tooth of T is noted. After high-voltage defeat heavier and permanent changes in cardiovascular system (premature ventricular contraction, increase in the ABP, systolic noise, diffusion or focal necrotic changes of a myocardium) are observed.

In patol. process at an electric trauma is quite often involved a nervous system. Defeat of c. in N of page it is caused as direct prokhozh by a deniye of current through its structural elements, and disturbances of blood circulation and breath. Also strong psychoinjuring influence of electric current matters.

Are characteristic respiratory depression up to its dead stop of the coma caused by influence of technical electricity and a collapse. The last is having connected both with fibrillation of ventricles of heart, and with paralysis of a vasomotor center, and also reduction of volume of the circulating blood. At victims tonic and clonic spasms can repeat, shock, a renal failure develops. After escaping of coma long slackness, an adynamia, retrograde amnesia are noted. Pressure of cerebrospinal liquid is quite often increased, subarachnoidal hemorrhages are possible. In rare instances at E. there are focal damages of a head and spinal cord: polusharny gemisindroma, the phenomena of parkinsonism, an acute cerebellar ataxy, spinal amyotrophy, isolated or in a combination to spastic paresis that creates looking alike an amyotrophic side sclerosis (see). Development of a syndrome of full disturbance of conductivity of a spinal cord is possible (see. Vertebral and spinal injury).

Focal nevrol. disturbances develop sharply and are most expressed immediately after defeat. This feature should be considered at differential diagnosis of an electric trauma with a mechanical injury, edges quite often accompanies the first. In development of focal cerebral and spinal defeats at E. along with influence of electric current accessory factors can have pathogenetic value: a condition of vascular system and feature of a metabolism in nervous tissue to an electric trauma. Defeats craniocereberal (cranial, T.) nerves at E. are usually connected with subarachnoidal hemorrhages. Injuries of nerves of extremities (elbow, median, fibular) are often caused by local thermal influence of current.

In the remote period after an electric trauma the psychoorganic syndrome sometimes develops (see) owing to the progressing atrophy of substance of a brain and hydrocephaly. Persistent headaches, astenisation, disturbances of memory, emotional and vegetative lability are characteristic. Also peripheral vegetative syndromes are frequent (local cyanosis, a hyperhidrosis or an anhidrosis, local canities or a hair loss, etc.). After E. long asthenic states are possible, at to-rykh psychogenias are often noted (see). Differentiation of the specified syndromes, sometimes externally similar, demands detailed a wedge. inspections.

Diagnosis of an electric trauma can be complicated if the victim is unconscious. In these cases existence of signs of current or deep electroburns, and also attestations of eyewitnesses and inspection of the scene matter (the victim is near a source of current, the bared wires, etc.).

Acute management to the victim consists in bystry cancellation of electric current. For this purpose it is necessary to switch off a knife switch (safety locks), to pull out a wire from hands of the victim by means of a dry wooden stick or other objects which are not carrying current. If it is impossible, then it is necessary to drag the victim of a source of current, previously having ensured the safety (not to touch open parts of a body of the victim, to hold it only for clothes, previously having put on rubber or dry woolen gloves, having wound hands with dry clothes or having risen on the isolating subject, e.g. on an auto tire, a board, dry rags). In the absence of the specified objects it is recommended to chop or cut wires (everyone) with the tool with the dry wooden handle. At assistance to the victim of influence of electric current tension of St. 1000 in it is necessary to put on previously rubber footwear (boats, boots), gloves. If the victim is in the sublime place (a roof, the bridge, a ladder, etc.), it is necessary to prevent its falling and drawing an additional mechanical injury.

Right after elimination of influence of current directly on site incidents and in the presence at the victim of signs of clinical death to it carry out an artificial respiration (see), the closed cardiac massage (see) and a defibrillation (see). It is possible to stop holding these resuscitation actions only on condition of recovery at affected independent breath or emergence of signs biol. death (see Resuscitation), Irrespective of a condition of the victim it is necessary to hospitalize him immediately for observation and treatment.

In to lay down. establishment hold antishock events and an oxygenotherapy according to indications. At sharp excitement purpose of sedative drugs is shown. In the first hours fight against a hypoxia (an oxygen tent, hardware inhalation of oxygen) is necessary. For reduction of a headache with the increased intracranial pressure dehydration, sometimes a spinal puncture is shown. At the first puncture produce up to 5 — 7 ml of cerebrospinal liquid, at repeated — to 10 — 12 ml. At functional frustration of a nervous system it is necessary to extend a dream of the patient by means of hypnagogues.

Treatment of local manifestations E. begin with imposing on places of burns of aseptic bandages. Everything struck enter antitetanic serum. At severe damage of an extremity with the expressed signs of a vascular and muscular spasm futlyarny or vagosympathetic novocainic blockade are shown, to-rye it is possible to repeat in 3 days. Locally apply antiseptic agents.

Rejection of nekrotizirovanny fabrics at E. there can be long, and its acceleration — one of problems of treatment. For this purpose at burns, small on the area, bathtubs with potassium permanganate, UF-radiation, oily-balsamic bandages are shown. Thereby preparation of a burn surface for operative measures is at the same time reached. After borders of a zone of a necrosis finally were defined (in 5 — 7 days after E.), at a satisfactory general condition of the victim the necretomy (see) with plastics of defect of skin is shown. At a total necrosis of an extremity or its parts (fingers, a brush), at damage of the main vessels amputation is shown. In the late period (in 2 — 3 weeks after an injury) indications to amputation depend on prevalence and a type of a necrosis (wet or dry), the general condition of the patient and threat of secondary bleeding. At deep electroburns, especially in case of defeat of a brush, quite often there is a need for multi-stage treatment. In the beginning it is necessary to recover an integument. The main way of closing of wounds after electric burns is the method of not free skin plastics (see) in various options. The plastics can be used by local fabrics at the electroburns limited on the area. After removal of nekrotizirovanny fabrics at preservation of sinews and sheaves it is necessary to operate patients as soon as possible (in the next 2 — 4 weeks after an injury), before involvement in inflammatory process of intact fabrics.

Fig. of Mikropreparata electrotags on skin: and — in a corneous layer of epidermis numerous emptiness are visible (are specified by shooters); coloring hematoxylin-eosine; x 35; — cells of basal and partially acanthceous layer of epidermis have the extended form (are specified by shooters); coloring hematoxylin-eosine; X 280.

The immobilization of the struck segment of an extremity in functionally advantageous position is reached by means of a plaster bandage or the distraktsionno-compression device (see). Use of the last provides reliable fixing of the struck segment and allows to make full topical treatment of burn surfaces.

Recovery treatment is defined by features E. also includes, according to indications, massage, LFK, physiotherapeutic procedures, etc.

The forecast depends on expressiveness of the general and local disturbances. In some cases after E. endocrine frustration are observed, men have an impotence. Persistent mental disorders are possible. It is important that external manifestations E., the general and local, not always give sufficient data for the authentic forecast.

Defeat by atmospheric electricity (lightning) perhaps as at stay out of the room, and indoors. More often the persons which are during a thunder-storm near the working electric equipment are surprised (the TV which is turned on in network, the radio receiver, etc.). At the victim of lightning discharge occur same patol. changes, as well as at defeat by technical electricity. However in case of death either the sudden apnoea, or a sudden stop is the reason of the termination of the main vital signs (an asystolia, but not fibrillation!) hearts as a result of direct action of current on the respiratory or vasomotor centers of a myelencephalon. On skin also the signs of a lightning representing treelike light pink or red strips on skin often are found (color. the tab., Art. 336, fig. 6) disappearing during the pressing by fingers (remain during 1 — 2 days after death). They are result of a trichangiectasia in a zone of contact of a lightning with a body.

First aid and treatment same, as at defeat by technical electricity (see above). During the carrying out dignity. - the gleam, works should be explained to the population full groundlessness of the occurring prejudice that victims of lightning discharge need to be dug in to the earth.

In cases of a lethal injury on clothes of the victim the gaps which burned places can be found, fusion of metal objects (coins, keys, etc.) with a carbonization of the respective sites of skin is possible. In some cases damages of clothes and a body can be absent. The data obtained at inspection of the scene can have essential value (damages by a lightning of trees, structures, various objects, soils).

Electric trauma in the medicolegal relation. Death from E. is violent (see. Violent death) therefore in each case, suspicious on a lethal injury, the court is appointed electric current. - medical examination for the purpose of establishment of a cause of death and its circumstances. At nonlethal defeats by electric current court. - medical examination can be appointed for definition of severity of injuries, and also extent of permanent disability.

At lethal injuries elekrichesky current poizvoditsya surely survey of a corpse on site of incident. At the same time pay attention to a pose of a corpse, its arrangement in relation to possible sources of electric current, to damages of clothes and footwear, damage on a body of the victim, on a possibility of his falling from height after E. In case of accidents on production technical expertize is carried out, the cut shall be informed of the act court. - the medical expert.

At a research of a corpse signs of current, or an electrotag have the greatest diagnostic value — the peculiar damages of skin arising in places of contact with a source of current, most often on hands. Also output signs of current, usually on skin of bottom surfaces of feet are sometimes formed. Typical electrotags on hands and legs represent the dense, grayish-yellowish, smooth, towering sites with retraction in the center. The form them quite often reflects a uniform of the conductor of electric current. At defeat the carbonization of fabrics occurs a voltaic arch. At ignition of clothes there can be burns a flame, usually more superficial, than at action of a voltaic arch. Sometimes clearly metallization of skin in the field of electrotags is expressed as deposits of greenish-brown or yellowish-brown color (tsvetn. tab., Art. 336, fig. 4).

Quite often electrotags have no idiosyncrasies and represent the grazes, superficial wounds reminding chipped and cut or chipped, occasionally wounds with the charred edges that gives them looking alike fire (tsvetn. tab., Art. 336, fig. 5). In 10 — 12% of cases of an electrotag are not formed at all.

In recognition of death from E. an important role is played a lab. researches. Gistol, both typical electrotags, and grazes, other injuries of skin, and also internals are subject to a research. At gistol. a research in the field of an electrotag in a corneous layer of epidermis find numerous emptiness (fig., a), cells of basal and partially acanthceous layers of epidermis have the extended form (fig.). The spectral research is conducted for the purpose of identification in places of contact with a source of current of deposits of metal. Sometimes it is necessary to differentiate defeat by current with bruises.

At survey of the persons who transferred E., its effects often come to light: cicatricial changes of skin in places of its damages, mental disturbances, various functional frustration ts.n.s. and internals. In such cases court. - medical examination is carried out with participation of the corresponding specialists.

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H. V. Petrov, V. I. Berezneva,

R. L. Ginzburg; G. A. Akimov,

A. M. Lvovsky (not BP.), A. V. Kapustin (court.), I. V. Buromeny (author tsvetn. fig.).