Educational program on electrical injuries: from burns and cataracts to fractures and fibrillation

Electrical injury is an injury resulting from a person being struck by electric current or lightning. A potential threat to humans is represented by a current strength of more than 0.15 Amperes, as well as direct and alternating voltages of more than 36 Volts. The consequences of electrical injuries can take a variety of forms - from minor burns to cessation of blood circulation, breathing and loss of consciousness, which, accordingly, often causes death. In almost all cases, exposure to current greater than normal is accompanied by damage to the skin, mucous membranes and bones at the points of entry and exit of the electrical discharge. The central and peripheral nervous systems are also affected.

Features of electrical injury

The degree of danger of electric shock depends not only on its parameters, but on the physical condition of the person, as well as on the environment. An electric shock greater than 100 mA is considered fatal. At low voltage (up to 500 volts), alternating current is more dangerous.

Other factors that increase the likelihood of electrical injury:

• overheating of the body;
• low oxygen levels in the environment.

Electric current upon impact causes reflex disorders and also damages soft tissue at the entry and exit points. Spreading throughout the human body, it is capable of forming loops of 3 types:;

1. The lower one is less dangerous for humans, since it only affects the lower limbs.
2. Upper - medium danger, the current affects the upper body, passing from one hand to the other.
3. Full - the most dangerous type of loop, which completely covers the human body (both legs and both arms).

Important! In case of high voltage shock, the greatest danger is the step voltage or voltaic arc. In these cases, electrical injury is possible without direct contact with the source of electricity.

“Step voltage” is the electrification of the ground as a result of lightning entering it or the presence of a high-voltage conductor in the ground. The average voltage is 0.8 m, which is equal to one step.

A “Voltaic arc” is formed when current moves through the air at a distance of up to 1 m from the source of electric current. A person caught in such an arc receives limited local but deep burns to the body. The occurrence of this phenomenon is facilitated by a high level of air humidity in the environment.

Causes of Electrical Damage

Many causes of electrical injuries are very banal - absent-mindedness of the victim himself. Damage occurs as a result of incorrect current supply and power surges. The reason may be poor insulation or direct contact with electrical installations without first disconnecting.

The causes of electric shock can be systematized as follows:

• technical - faulty equipment;
• organizational - safety precautions are not followed;
• psychophysiological - severe fatigue, inattention.

Most injuries occur at work. As a result of examining each case, it was noted that people are more often injured at the end and beginning of a work shift. Electric shocks often occur during workers' morning shifts. At the end of work, attentiveness decreases and severe fatigue develops. But the frequency of morning injuries is explained by the peculiarity of the work order: most work with electrical installations occurs at the beginning of the shift.

Types of electrical injuries;

Depending on where a person received an electric shock, there are household, industrial and natural shocks. According to the nature of the damage, all electrical injuries can be divided into 2 types:

1. Local are burn injuries to the skin. Such injuries are typical when a short period of current is applied to a certain part of the body.
2. General - accompanied by disruption of the internal organs, mainly the heart and respiratory organs. Reflex disorders, respiratory arrest, and convulsions occur. With such an injury, current passes through the entire body. General electrical injury is typical during a lightning strike.

There are also immediate and chronic electrical injuries. In the first case, a person receives a high electric shock in a few minutes. This is a life-threatening condition and requires immediate medical attention. In the chronic form, a person is near a high voltage source for a long time. Negative consequences for the body arise gradually. People suffering from chronic electrical trauma complain of headaches, sleep disturbances, apathy, limb tremors, and high blood pressure.

Causes and conditions of injury

They often become:

1. Contact with live parts under electrical voltage.
2. Contact with electrically live parts due to faulty insulation or protective devices.
3. Violation of safety rules when using electrical equipment and electrical installations.
4. Entering the step voltage zone.
5. Step voltage or step voltage is the voltage formed between two points of the current circuit, located one step apart from each other, on which a person simultaneously stands. The step voltage depends on the resistivity of the soil and the strength of the current flowing through it; it has a maximum value near the point of the fault. At a distance of over 8 meters it poses virtually no danger. To avoid injury in the step electrical voltage zone, it is necessary to take small steps, without lifting your legs from each other.

Signs of electrical injury and possible complications

Local manifestations:

• the presence of electrical marks on the skin in the form of burns at the points of entry and exit of current;
• high voltage over 380 V can lead to extensive deep burns throughout the entire limb, wrinkling of soft tissues;
• electrical burn of the head is characterized by damage to the outer and inner bones of the skull;
• partial or complete charring of the limb is possible;
• Due to sudden muscle contraction, muscle contracture occurs.

Physical manifestations at the time of electrical injury depend on the strength of the current and the duration of exposure. Typical general signs of electric shock:

• confusion;
• heart rhythm disturbances;
• convulsions;
• drowsiness;
• memory loss at the time of injury;
• visual impairment.

There are 4 degrees of severity of the body’s condition after exposure to electric current:

1. Grade I is the easiest. It is characterized by reflex muscle contraction, small electrical burns, without loss of consciousness.
2. II degree - convulsions with loss of consciousness. Neurological disorders are possible.
3. In grade III, loss of consciousness is combined with respiratory and cardiac dysfunction (arrhythmia, tachycardia);
4. Grade IV is characterized by a high risk of mortality. Clinical death is often observed.

The effect of electric current on the human body

The mechanism of the negative impact of electric current on the human body is complex and diverse. As the current passes through the body, it has the following types of effects:

1. Thermal effects, manifested by heating of the skin and tissue of internal organs, up to burns, leading to damage to blood vessels, nerve fibers and the brain and necrosis of tissue in parts of the body. When exposed to thermal effects, sharp functional disorders of human life support systems are observed, for example, sudden bleeding;
2. Electrolytic effects, causing electrolysis of lymphatic fluid and decomposition of blood, disrupting the physico-chemical composition of all body tissues;
3. Biological impact, expressed in disruption of the normal course of bioelectric processes inherent in living matter. The action of biocurrents that control the internal movements of the tissues of the human body is disrupted, which leads to involuntary unnatural convulsive contractions of the heart muscles and lungs. Living cells and tissues, with which the vitality of the organism is associated, become dangerously excited by the influence of current and may die;
4. The mechanical action of an electric current, which causes separation and rupture of tissue due to the explosive formation of steam from blood and lymphatic fluid. The mechanical action provokes strong muscle contractions, up to the rupture of muscle fibers;
5. Light effect, characterized by electroophthalmia after exposure to a powerful stream of ultraviolet radiation from an electric arc flash. External signs of electric shock include inflammation of the outer membrane of the eye.

In Fig. Below is an eye with signs of electroophthalmia.

Manifestations of electroophthalmia

First aid and treatment methods for electrical burns

For a favorable prognosis, it is important to competently provide emergency care to a victim who has received an electrical injury.

1. Immediate release of a person from the effects of current. This must be done carefully, since there is a high probability that the rescuer will get caught in an electric current loop or be exposed to step voltage. Initially, you need to ensure your own safety.
2. After eliminating the impact of the current, you need to check the victim’s breathing and heart rate. If necessary, perform artificial respiration.
3. Cover local injuries with a clean bandage.

If a person is conscious, then medical assistance is also required. Keep the victim calm and call a doctor.

Treatment methods in hospital

Depending on the severity of the patient’s condition, anti-shock measures and oxygen therapy are carried out in the hospital. Oxygen therapy is especially effective in the first hours after an electrical injury, when the level of hypoxia in the body is high. When excited, sedatives are indicated.

The main goal in the treatment of electrical burns is to accelerate the rejection of necrotic tissue. If large areas of the body are affected or with deep burns, a tetanus vaccination is required. Treatment regimen:

1. Applying an antiseptic bandage.
2. Novocaine blockade for severe muscle spasms.
3. For minor burns, baths with potassium permanganate are performed. UV irradiation is also recommended.

A week later, when identifying areas of tissue necrosis, surgical treatment is performed - necrectomy. It is aimed at removing non-viable tissue, which speeds up the healing of burns and prevents complications. If necessary, plastic surgery of the skin defect is performed. If the main vessels are damaged during an electrical burn and total necrosis of the limb is observed, amputation is recommended.

Deep skin damage is eliminated step by step. Sometimes several staged operations are performed. This depends on the general condition of the victim. Recovery includes exercise therapy, physiotherapy and massage.

The prognosis with timely assistance is favorable. To protect yourself from electrical injuries, you must not forget about the rules for using electrical appliances. In case of any, even minor, electric shock, it is recommended to contact a medical facility. It is not always possible to make an accurate diagnosis based on external manifestations.

Degrees of electrical burns

There are several degrees of severity of electrical damage to a person:

• First. The mildest, accompanied by slight redness and swelling of the skin. After properly provided first aid, treatment can be continued at home.
• Second. Involves deeper tissue damage with the formation of blisters. The victim feels severe pain. Treatment usually takes place at home, but under the supervision of a doctor.
• Third. It is characterized by skin necrosis and the formation of blisters with bloody contents. If, after opening the blisters, the red wound surface is exposed, this indicates a favorable prognosis with adequate therapy. If the skin becomes dark and does not hurt, we can assume complete tissue death with no prospect of recovery.
• Fourth. Necrosis occurs of both the skin itself and subcutaneous fatty tissue, muscles, and bone tissue. In this case, only emergency medical intervention will save a person’s life.

Anti-static electricity

Each of us has probably encountered static electricity. Static electricity charges often form on clothing, especially synthetic materials. When you take off clothes (shirt, jacket, sweater) made of synthetic material in dry weather, you hear a crackling sound, and in the dark, sparks are noticeable. Electrolysis occurs when two dielectric materials, or a dielectric and a conductive material, rub against each other if the latter is insulated. When two dielectric materials are separated, electrical charges are separated, and materials with a higher dielectric constant are charged positively, and those with a lower dielectric constant are charged negatively.

The more the dielectric properties of materials differ, the more intense the separation and accumulation of charges occurs. The greater the force and speed of friction and the greater the difference in electrical properties, the more intense the formation of electrical charges.

For example, electrostatic charges are formed on the body of a car moving in dry weather if the tire rubber has good insulating properties. As a result, an electrical voltage arises between the body and the ground, which can reach 10 kV (kilovolts) and lead to a spark when a person exits the car - a discharge through the person to the ground.

In addition to friction, the cause of the formation of static charges is electrical induction, as a result of which bodies isolated from the ground in an external electric field acquire an electric charge. Induction electrolysis of electrically conductive objects is especially great.

For example, on metal objects (car, etc.) isolated from the ground, in dry weather, under the influence of the electric field of high-voltage power lines or thunderclouds, significant electrical charges can form.

On monitor and TV screens, positive charges accumulate under the action of an electron beam created by a cathode ray tube.

Factors influencing the severity of electrical injuries

Circumstances that influence the severity of electric shock include:

• The magnitude of electric current and voltage;
• The time it takes for an electric current to pass through the human body;
• Type of current (direct or alternating);
• A path or loop of electrical current;
• Condition of the human body;
• Environmental conditions.