Technical electric shock. Issues resolved by forensic medical examination
The action of electric current in production and at home can cause severe and even fatal injuries from contact with faulty household appliances (table lamps, kettles, irons, etc.) connected to a network with a voltage of 127 or 200 V. In industry, three-phase current with a voltage of 380 V is used. and frequency 50 Hz. At this voltage, severe electrical injury often occurs. A distinction is made between direct and alternating current. The voltages of direct and alternating current, equivalent in their effect on the body, are respectively equal to 120 and 42 V. Direct current is less dangerous than alternating current, only up to a voltage of 500 V. At a voltage of 500 V, the danger of both types of current is equalized, and at voltages more than 500 Direct current is more dangerous. In practice, direct current injuries are rare. The severity of injury from electric current depends mainly on its physical parameters, but often the circumstances under which the current operates, as well as the state of the body, are of great importance. The greatest danger of injury exists when exposed to alternating current with a frequency of 40-60 Hz.
With an increase in the frequency of electrical oscillations, the danger of injury decreases, and with high frequency currents (more than 10,000 and up to 1000,000 Hz) and even with high voltage (1500 V) and high power (2-3 A), no damaging effects on the body are observed. This is the basis for the widespread use of high-frequency currents in medical practice - for physiotherapeutic procedures.
Depending on the magnitude of the current voltage, primary damage to the respiratory or circulatory organs occurs. The international standard for safe voltage, the so-called reduced voltage, is a potential difference of 24 V. Fatalities are possible even at a voltage of 40 V. High voltage currents - over 3000 V - are less dangerous and rarely lead to death. This is explained by the fact that at high voltages between the body and the electrode, an electric arc flash effect occurs and most of the electrical energy is converted into heat, causing local damage in the form of burns. The most common fatalities are when exposed to current voltages from 100 to 1500 V.
The magnitude of the current is important in the development of electrical damage; exposure to a current of 100 mA is fatal in the vast majority of cases.
The effect of the biological action of the current depends on the time during which the body is exposed to a current of a certain intensity, which is an important factor for the occurrence of ventricular fibrillation of the heart. Prolonged contact with electrical conductors at a current strength of 0.25-80 mA (minimum “non-releasing” current) can lead to death, causing spasms of the respiratory muscles and, as a consequence, acute asphyxia.
The spread of electric current throughout the body is possible if there are conditions for the entry and exit of the current. This happens when a person simultaneously comes into contact with two electrodes - bipolar connection or contact with one of the electrodes, and any part of his body is grounded - single-pole connection. Switching on can be partial, when a person isolated from the ground touches opposite poles with one hand. Under these conditions, current passes through the switched-on arm segment, which usually does not pose a danger. At high voltage, an electric current can strike a person without directly touching the conductor - at a distance, through an arc contact that occurs when dangerously close to it. As a result of air ionization, human contact is created with live installations or wires. The danger of damage at a distance increases significantly in damp weather due to the increased electrical conductivity of the air. At extremely high voltages, the electric arc can reach a length of 35 cm.
Electrical injury can occur from the so-called step voltage. The defeat in this case occurs when a person’s feet touch two points on the ground that have different electrical potentials. Stepping voltage occurs when a high-voltage wire falls to the ground, when grounding faulty electrical equipment, when lightning strikes the ground, etc. When exposed to step voltage, the current passes from one leg to the other along the lower “loop”. This path of current through the human body is less dangerous. In the same case, when a person falls due to convulsive contraction of the muscles of the lower limb, the lower loop turns into a full, more dangerous one. It is considered dangerous to enter within 10 steps of a fallen high-voltage wire. At the same time, the wider the step, the greater the potential difference and the more stress a person comes under.
Fatal injuries can occur from a low voltage current, and, conversely, a person can survive when exposed to a very high voltage current. The degree of injury from technical electricity is influenced by the path of current in the body. In the literature they are conventionally called current loops. The most dangerous path is when the electric current passes through the brain or heart, which can be observed when the left arm and leg, right arm and left leg, left and right arm, chest or back and arm, head and leg or arm are connected to the electrical circuit etc. Electric current passes predominantly through tissues that have the highest electrical conductivity and the lowest resistance.
Tissue resistance to electric current increases in the following sequence - blood, mucous membranes, liver, kidneys, muscles, brain matter, lungs, tendons, cartilage, nervous, bone tissue, skin. Dry skin has the greatest resistance. Wet skin and excessive sweating contribute to electric shock.
The state of the body at the moment of exposure to current is of great importance. Persons suffering from diseases of the cardiovascular system, kidneys, endocrine glands and anemia, the elderly, children, pregnant women, as well as subjects under the influence of alcohol, are especially susceptible to the effects of electric current. Deep asphyxia and overheating reduce the body's resistance to electric current.
Electrical energy has an effect not only at the point of contact, but also on the entire body, which can manifest itself in various symptoms depending on the damage to a particular organ system. The mechanism of the general effect of electricity is considered as shock, leading to respiratory and circulatory disorders.
Shock, which develops as a result of the action of electric current, belongs to the group of painful ones. With a longer current flow, shock occurs due to sharp painful irritation of receptors, nerve trunks, painful muscle spasms and vascular spasm (ischemic pain).
When an electric current of significant intensity spreads through the body, death occurs, as a rule, instantly as a result of the primary cessation of breathing or cardiac activity. Sometimes the so-called delayed death is observed, when the victim experiences convulsions for some time after the electric shock, he screams and tries to free himself from the current conductor. Often the victim is freed from the guide, but soon dies. The death of the victim can occur even after a significant period of time after exposure to the current. During the closure of the electric current, maximum exhalation occurs, because the power of the expiratory muscles is greater than that of the inspiratory muscles. This significantly aggravates the course of electrical injury, since the oxygen reserve in the body is significantly reduced.
Changes in the place of contact with the conductor along the flow of current are associated with the transition of part of the electricity into other types of energy, which determines its warm, mechanical and physico-chemical effect.
The action of electric current during a short circuit leads to the formation of an electric tag, and when an electric arc flashes, significant burns may occur, as well as charring of soft tissues and bones.
Electrical markers: a - at the entrance; 6 - at the current output
With local action of current, in addition to electrical marks and burns, swelling, necrosis, metal impregnation and damage may occur. The thermal effect of electric current is also manifested by the death of underlying tissues, up to charring. Sometimes it is possible to see peculiar formations in bone tissue - “pearl beads”, resulting from the melting of bone substance with the release of calcium phosphate. The mechanical action is associated with convulsive muscle contractions, which can even lead to their rupture. The electric arc that sometimes occurs between the body and the conductor leads to ignition of clothing and, consequently, the formation of extensive burns on the body. The remains of burnt clothing must be especially carefully examined to determine the point of contact with the current-carrying conductor. It is necessary to examine the shoes, since with a single-pole connection there may be traces of current on them. As a rule, electric tags are pale yellow, gray-white or gray-yellow in color. They are dense to the touch, have a sunken bottom and ridge-like raised edges, usually without inflammatory exudative phenomena in the surrounding tissues. Electrical marks can take the form of scratches, small wounds, calluses, hemorrhages in the skin, or small-point tattoos. Sometimes electrotags resemble gunshot entry holes. The epidermis in the area of the electromark may be detached and raised. One of the signs of an electric tag is metallization, which is formed both during close contact with the skin of an energized object, and in the event of an electric arc. Traces of metal in the area of electrical marks can be detected using color prints. Microscopic changes in the skin after electric shock are very characteristic. Numerous voids are visible in the horny and lucid layers of the epidermis, giving the epidermis a cellular appearance. The shape of voids of various sizes can be round, oval and angular. They are often found in groups, but can also occur alone. The horny and lucid layers of the epidermis are completely separated from the granular layer. In the granular and spinous layers of the epidermis, voids in the form of cracks can also be found, separating the superficial layers of cells from the deep ones. Sometimes the altered epidermis can completely peel off from its own skin, rising above it like a bubble, the upper part of which is often torn. More often, the exfoliated epidermis is separated from the skin itself only by a narrow gap. The boundaries of the epidermal cells are not defined; the nuclei of the basal and partially spinous and granular layers are elongated, located perpendicular or oblique to the surface of the skin. Sometimes the nuclei deviate in two directions, arranged as if in the form of panicles; in some places, vortices of the nuclei are observed. When the epidermis is separated from the skin itself, the cells remaining in the recesses between the papillae are also elongated. Using special methods of staining preparations, the presence of metals can be determined by microscopic examination. When exposed to electric current, in 10-20% of cases no morphological changes in the skin can be detected. When exposed to electricity, phenomena of congestive plethora, swelling of the wall and bed of the gallbladder, and hemorrhages are observed. Congestion, edema, and sometimes pinpoint hemorrhages are detected in the pia mater and the substance of the brain. In difficult cases, to study current sources, conductors and obtain other data, it is necessary to conduct a technical examination, without which it is sometimes impossible to judge the cause of death. In case of electric shock, the statement of the actual occurrence of death is of particular importance, since there are cases of imaginary death, in which, first of all, it is necessary to carry out medical care measures aimed at restoring vital functions (artificial ventilation, cardiac massage and other resuscitation measures).
Action of atmospheric electricity
The action of atmospheric electricity is a gigantic electrical discharge in the atmosphere. The current voltage reaches a million volts, the current strength is hundreds of thousands of amperes. The damaging factors of lightning are electric current, light and sound energy and shock wave. The duration of lightning exposure can be very short, limited to fractions of a second, but the extremely large amount of energy at the moment of its action causes various bodily injuries and even death. The action of lightning is, in principle, no different from the action of high voltage electric current.When the skin is struck by lightning, damage occurs, mainly in the form of burns, hair loss, as well as tree-like, branched red or pink shapes - the so-called lightning shapes. The appearance of “lightning figures” is explained by a sharp expansion of the superficial vessels of the skin and small hemorrhages along their course. In survivors, such changes can be observed for several days, and on the corpse they turn pale and disappear quite quickly. The effects of lightning are characterized by symmetry of the lesion - paresis of both limbs, paraplegia with deep prolonged loss of consciousness, respiratory arrest, depression of cardiac activity.
Occasionally, skin lesions occur in the form of small holes with burnt edges (they can be mistaken for a gunshot entry hole), and sometimes severe damage up to extensive skin burns, bone fractures, separation of limbs and ruptures of internal organs. There are often cases of complete absence of visible traces of lightning on the human body.
The pathomorphological picture of the internal organs when death occurs from the action of atmospheric electricity is similar to the picture observed in case of injury from technical electricity.
When struck by lightning, clothing may rip in different directions or have small holes. The edges of the defects may be burned or remain completely unchanged. Typical features include holes in the soles of shoes, as well as charring of the skin around metal nails on the soles. Metal objects often melt completely or are melted, resulting in impregnation of the skin with metal, which is of expert diagnostic value.
In the absence of signs of lightning damage, it is very difficult to resolve the issue of the cause of death. The participation of an expert in examining the place where the corpse was found is of great importance, since traces of lightning are often visible at the scene of the incident, for example in the form of splitting trees, fire, etc. Lightning damage can be direct or occur through any objects, for example through a radio or telephone . There are known cases of lightning strikes when talking on the phone during a thunderstorm, or when working with radios. Being struck by lightning does not always result in death. It may cause health problems or leave no consequences.
The effect of electric current on the body is based on the sum of electrochemical, thermal and mechanical effects, accompanied by a sharp disorder of cardiac activity (ventricular fibrillation) and respiration, as well as the occurrence of shock reactions. In forensic medical practice, there are two types of electrical damage: technical and atmospheric. Technical electric shock. Severe and fatal electric shocks are possible from contact with faulty household appliances (table lamps, kettles, irons, etc.) connected to a 127 or 220 W network. Depending on the magnitude of the current voltage, primary damage to the respiratory or circulatory organs occurs. The severity of injury from electric current depends mainly on its physical parameters (strength, type, voltage, frequency), the time of contact with the current-carrying surface, the density and area of contact, the circumstances of the injury, as well as the individual characteristics of the body. The degree of damage from technical electricity depends on the path of current passage in the body, that is, the electric current passes predominantly through tissues that have the greatest electrical conductivity and the least resistance to their damage.
Tissue resistance to electric current increases in the following sequence: blood, mucous membrane, liver, kidneys, muscles, brain, lungs, tendons, cartilage, nervous, bone tissue, skin. The local action of technical electricity at the point of contact of the body with the conductor leads to the formation of an electrical mark, and when an electric arc flashes, burns and charring of soft tissues and bones are possible. When externally examining a corpse at the site of its discovery or in the morgue, the expert must carefully examine the shoes for moisture and the presence of metal parts with traces of melting on the plantar surface. When examining the body of a corpse, the presence of electrical marks is established.
A typical electrotag is small in size, pale yellow or gray-yellow in color, dense to the touch, predominantly oval in shape, with a sunken bottom and raised ridge-like edges, without inflammatory exudative phenomena in the circumference. One of the signs of an electric tag is metallization, which is formed both during close contact with the skin of a current-carrying object, and in the event of an electric arc. Traces of metal in the area of electrical marks can be detected by the method of color prints, for example, metallization from copper conductors gives a bluish, greenish color, iron - yellow, yellow-brown, black, lead - grey-yellow, grey, gray-black. An internal examination reveals signs of acute death. Atmospheric electricity damage. Lightning is a giant electrical discharge in the atmosphere.
The current voltage reaches a million volts, the current strength is H hundreds of thousands of amperes, the lifetime is H 0.0001 s. On the skin when struck by lightning, damage occurs in the form of burns, singed hair, as well as “lightning figures” - tree-like branching figures of red or pink color, which is explained by the expansion of the superficial vessels of the skin and small hemorrhages along their course. Occasionally, skin lesions occur in the form of small holes with burnt edges (they can be mistaken for a gunshot entrance hole), and sometimes severe damage, including extensive skin burns, bone fractures, separation of limbs and ruptures of internal organs. There are often cases of complete absence of visible traces of lightning on the human body, which greatly complicates the work of an expert in establishing the cause of death. The main issues addressed during the forensic medical examination of electrical injuries:
- 1. Properties of electrical energy: X atmospheric electricity; X mains electricity; X electric discharge; X electric arc; X combination of individual species.
- 2. Features of current-carrying contacting parts: X material; X shape; X size; X relief.
- 3. Mechanism of damage formation: X place of application of electrical energy; X current path in the victim’s body; X features of the biological effects of electrical energy on the victim’s body; X duration of exposure; X possibility of electrical injury under given conditions.
EFFECT OF HIGH AND LOW BAROMETRIC PRESSURE
Significant changes in internal organs from the action of high and low barometric pressure are associated with special types of human activity: diving and caisson work, high-altitude ascents, flights in airplanes, spacecraft, underwater sports. the effect of high barometric pressure. This type of effect on the body occurs during deep underwater diving and underwater sports.
It has been established that hydrostatic pressure at a depth of 10 m doubles, at 20 m it triples compared to atmospheric pressure, etc. Increased hydrostatic pressure reduces the sensitivity of skin receptors to traumatic influences, so damage caused under water is detected only upon ascent. As a result of the large difference between external and internal pressure, anatomical cavities and organs containing air (lungs, gastrointestinal tract, middle ear, etc.) are subject to greater damage (compression). The main damage caused by high barometric pressure includes: rupture of the alveoli, bronchi, lung tissue, and damage to the eardrum. During an internal examination, the expert detects enlarged lungs, multiple hemorrhages, liquid and coagulated blood in the cavities of the heart and large vessels and in the lumen of the respiratory tract, and signs of bleeding. When examining the corpses of people who died from barotrauma, the organocomplex is removed from the chest with the arteries and veins ligated, after which it is necessary to inflate the lungs under water and determine the location of ruptures in the lung tissue by the escaping air bubbles. With a rapid rise from the depths to the surface, gases dissolved in the blood and body fluids begin to be released in the form of free gas bubbles - gas emboli. Blockage of blood vessels by gas bubbles leads to the appearance of various symptoms, which is called decompression sickness. When examining the corpses of people who died from decompression sickness, the following is observed: the presence of blood clots with small gas bubbles in the right half of the heart and veins, and the formation of subcutaneous emphysema. The effect of low barometric pressure on the human body occurs when working in high mountain regions, flying on airplanes and spacecraft. The main mechanism for the development of this process is a decrease in the partial pressure of oxygen (hypoxia), decompression disorders and “boiling” of body fluids.
The first symptoms include: dizziness, rapid breathing, palpitations, fatigue, muscle weakness, bleeding from the nose and ears. When examining the corpses of people who died from acute hypoxia, only general signs of asphyxial or rapid death are found. When examining corpses found in the mountains, one should take into account the possibility of sudden death in persons suffering from cardiovascular diseases, as well as the likelihood of being struck by lightning, falling from a height, or sunstroke or heatstroke. In these cases, a zone of significant increase in pressure alternates with a zone of sharp rarefaction of air, which causes a variety of damage, mainly of a mechanical nature.
temperature pressure electricity body
The action of atmospheric electricity is a gigantic electrical discharge in the atmosphere. The current voltage reaches a million volts, the current strength is hundreds of thousands of amperes. The damaging factors of lightning are electric current, light and sound energy and shock wave. The duration of lightning exposure can be very short, limited to fractions of a second, but the extremely large amount of energy at the moment of its action causes various bodily injuries and even death. The action of lightning is, in principle, no different from the action of high voltage electric current.
When the skin is struck by lightning, damage occurs, mainly in the form of burns, hair loss, as well as tree-like, branched red or pink shapes - the so-called lightning shapes. The appearance of “lightning figures” is explained by a sharp expansion of the superficial vessels of the skin and small hemorrhages along their course. In survivors, such changes can be observed for several days, and on the corpse they turn pale and disappear quite quickly. The effects of lightning are characterized by symmetry of the lesion - paresis of both limbs, paraplegia with deep prolonged loss of consciousness, respiratory arrest, depression of cardiac activity.
Occasionally, skin lesions occur in the form of small holes with burnt edges (they can be mistaken for a gunshot entry hole), and sometimes severe damage up to extensive skin burns, bone fractures, separation of limbs and ruptures of internal organs. There are often cases of complete absence of visible traces of lightning on the human body.
The pathomorphological picture of the internal organs when death occurs from the action of atmospheric electricity is similar to the picture observed in case of injury from technical electricity.
When struck by lightning, clothing may rip in different directions or have small holes. The edges of the defects may be burned or remain completely unchanged. Typical features include holes in the soles of shoes, as well as charring of the skin around metal nails on the soles. Metal objects often melt completely or are melted, resulting in impregnation of the skin with metal, which is of expert diagnostic value.
In the absence of signs of lightning damage, it is very difficult to resolve the issue of the cause of death. The participation of an expert in examining the place where the corpse was found is of great importance, since traces of lightning are often visible at the scene of the incident, for example in the form of splitting trees, fire, etc. Lightning damage can be direct or occur through any objects, for example through a radio or telephone . There are known cases of lightning strikes when talking on the phone during a thunderstorm, or when working with radios. Being struck by lightning does not always result in death. It may cause health problems or leave no consequences.
Control questions
1. Describe the pathogenesis of death due to injury from technical electricity.
2. Describe the concept of “stepping electricity”.
3. What is the mechanism of electrotag formation?
4. How to determine what material the contact current-carrying wire was made of?
5. What damage occurs when struck by lightning?
Electrical injuries are divided:
Injuries associated with disturbances in the normal operation of electrical installations, in which an electrical circuit occurs through the human body
Injury due to side effects of electric current that does not pass through the body (blinding by the arc, falling, fractures).
Injuries are mixed from the first two conditions.
Unlike all other types of influences, electricity acts not only through contact, but also indirectly through objects that a person holds in his hands. In addition, electricity can strike a person at a distance - through arc contact and step voltage.
Sources of electric current can be industrial and domestic installations, and sometimes atmospheric electricity (lightning).
In industry, a three-phase power current voltage of 380 W with a purity of 50 Hz is used. This tension causes severe injuries.
However, high frequency currents from 10 thousand to 1 million Hz or more, even at a voltage of 1500 W and a current strength of 2-3 A, are safe and are used in medical practice, although it is known that when injured by high voltage currents (1000 V), death often occurs from common burns, and not from cardiac dysfunction.
Damp clothes, shoes, and moisturized skin reduce resistance and increase current conductivity in the body. Shoes with metal nails on the soles are dangerous in this regard.
Often, with an electrical injury, melted nails are found on the soles and heels of shoes, melted coins and keys in a pocket.
An electric current of 0.1A is dangerous to humans, and above it is fatal.
The paths along which electric current passes are of great importance; these are current loops. Taking into account the knowledge of the physical properties of current, the following factors of the effect of current on the body can be identified:
2) Resistance
3) Duration
4) Contact area and density
5) Current path
The current in the tissue moves in different directions depending on the electrical conductivity of the tissue, so current loops are formed.
The following current paths are considered the most dangerous:
hand-hand,
left hand - lower limbs,
head - lower limbs.
Effect of current on the body (10 minutes)
1. Biological effect.
Electric current is an irritant to all tissues and organs, therefore, when electric current passes, tonic (general) spasms of skeletal muscles are observed, which can lead to respiratory arrest, fractures, dislocations and separation of limbs. Muscle contraction is accompanied by increased pressure, involuntary urination and the release of feces. The action of current directly on the heart muscle causes fibrillation.
2. Electrochemical action
This is electrolysis, when polarization of cell membranes occurs, resulting in protein coagulation and necrosis (tissue death).
Thermal impact
It manifests itself as burns (electric marks) and tissue death, including charring.
Mechanical action
When exposed to high current. It manifests itself in tissue separation and even separation of body parts, because currents have colossal thermal and mechanical energy, which, when combined, has an explosive effect.
When an electric current passes, death can occur immediately or 2-3 minutes after the injury, which is most often associated with paralysis of the cardiovascular and respiratory centers.
If the heart enters the electron flow zone (upper loop, arm-arm), then fibrillation of the ventricles of the heart occurs, the heart stops contractile function and blood circulation stops
Any victim of electrical injury should be considered severe, regardless of the condition, because death can occur several hours after injury.
It must be remembered that resuscitation measures for victims due to electrical trauma should begin and be carried out before the appearance of early cadaveric phenomena (cadaveric spots).
Local effects of current manifested by electromagnetic marks(thermal effect of current).
An electric mark is a small round or oval speck with a diameter of 6-8 mm, grayish-white or white, dense, with a roller-like elevation at the edges and a recessed center.
These marks are painless and without signs of inflammation, the hair does not show signs of singeing.
If the temperature of the electrical conductor was high enough, then the nature of the electrical marks changes and they look like large thermal burns, even charring.
The microscopic picture of electric marks is very characteristic. In the stratum corneum. And often in the granular and spinous layers of the skin there are multiple voids of various shapes and sizes. The stratum corneum or the entire thickness of the epidermis may be detached from the underlying layers of skin. The cells of the basal and lower sections of the spinous layers extend perpendicularly or at an angle to the surface of the skin and form brush-like, panicle-like or racemose figures. Cellular pits, clear, intensely stained. The vessels of the dermis are dilated. Filled with hemolyzed blood.
When a metal current source comes into contact with the skin, it leaves metal particles on the skin or even deep in the skin - metallization of the skin.
The presence of metal can be proven by chemical or spectral examination.
A distinction is made between technical and atmospheric electricity. Electrical discharges produced by special organs of some species of marine animals have not been studied and are very rare. Electrical injury almost always occurs through direct contact with an electrical conductor. Rarely, a person can be shocked by high voltage electric current without touching the conductor, through an arc contact at a close distance from the conductor. Electric shock can occur from step voltage, which occurs due to the difference in potential between two feet touching the ground near a high voltage conductor lying on the ground.
Technical electricity can have a damaging effect through technical electrical installations and household electrical appliances, as well as through other sources of electric current when a person comes into contact with a current conductor.
Electrical injury in everyday life is usually observed due to a violation of the insulation of wires, from faulty electrical appliances, or from a lack of basic knowledge about current or from a frivolous attitude towards it.
A forensic medical examination is carried out jointly with a technical expert (engineer) to resolve the issue of the circumstances of the injury and examine the scene of the incident. This is due to the fact that forensic doctors are always interested in physical, technical, biological, meteorological and personal factors that contribute to the pathological effect of electricity and electrical injury.
Physical and technical factors - these include voltage and current, time of exposure to electric current, paths through the body, area of contact with current-carrying wires, principles of the technical design of an electricity source.
Biological factors - These include the health status of the victim, his age (children and the elderly are more susceptible), individual resistance of the skin, tissues, and internal organs (at the entry point).
Meteorological factors - these include high humidity (rainy weather) and high ambient temperature (promotes sweating).
Personal factors - persons with increased excitability, hysterical individuals and all those who have suffered from mental disorders for a long time are more susceptible to electrical trauma.
In case of electrical injury, a person simultaneously receives the following damage:
a) burns - they form at the site of even short-term contact with a high-voltage current conductor in the form of various deep damages up to charring of the skin, tissues, bones;
b) mechanical injuries - quite common when a person is thrown from an electric current conductor onto objects surrounding him, with possible ruptures of clothing and shoes, dislocations and fractures of limbs, severe damage to internal organs and even death;
c) electrolysis of body fluids - it occurs under the influence of electric current and leads to a sharp disruption of the chemical composition and physical properties of tissues.
The most characteristic signs of the thermal effect of electric current are electrical marks that are located at the points of entry and exit of the current. In appearance, an electric mark differs from a regular burn in that there is no swelling or redness around it. An electric tag is quite often round or oval in shape, sometimes in the form of a strip, a trace from a current conductor touched by the victim. The electrotag looks dry and dense, has a brownish-yellow or gray-brown color. In the middle of the mark there is a depression, which is surrounded by a roller. In places where the stratum corneum of the skin is well defined (hand, foot), the electric mark has the appearance of a second-degree burn in the form of a bubble, but without content, with a detached, raised epidermis. Sometimes an electrical mark may look like a dark red abrasion, the nature of which can only be determined by microscopic examination
Clinical picture of electric shock. Upon contact with the conductor, there is a sharp contraction of the skeletal muscles and, depending on specific conditions, sometimes the inability to tear away from the conductor. The person struck by the current often screams. Spasms of the larynx are observed. Asphyxia develops as a result of contraction of the respiratory muscles. There is cyanosis of the skin, involuntary release of urine, feces, ejaculation of semen, muscle pain, tinnitus, flickering and sparks in the eyes, fear, emotional histamine shock. Consciousness may be retained or lost. Depending on the nature of the lesion, death may occur or the person may remain alive after separation from the guide. The living experience a number of painful disorders (mental disorders, neuroses, epilepsy, hearing and vision disorders, etc.).
Forensic doctors classify options for death due to electric current as:
Instant death - from paralysis of the respiratory center and secondary asphyxia;
Death is quick - from loss of consciousness, acute respiratory failure and circulatory disorders;
Delayed death - with preserved consciousness from severe fear and stupor (the victim may scream and try to free himself from the electrical conductor), subsequent fainting with loss of consciousness, depression and paralysis of the respiratory center and cardiac arrest;
Death interrupted - the victim is freed from the guide and comes to his senses, but then soon dies;
Late death - from complications caused by electric current, or exacerbation of diseases caused by electrical trauma.