electrical injury– this is the impact on a person of an electric current and voltage that exceeds the maximum parameters in its value and duration. These include direct and alternating voltages of more than 36 volts and currents of more than 0.15 amperes. So, for example, the electrostatic charge accumulated by an artificial fur coat can reach 6000 volts, but we will only shudder when we feel it, because the magnitude of the current is very weak – thousandths of an ampere. In addition to these parameters, the current path through the body is also taken into account: for example, if the current passed through both legs, a person may not even lose consciousness, and if through the left arm and right leg, then even at lower current values, death from cardiac arrest is possible . It is also dangerous for the current to pass through the head and limbs, when a bare wire falls from above (breakage of the contact or lighting network on the street).
The widespread use of electricity has led to an increase in accidents caused by electric current. Sometimes the cause of them is the defeat of atmospheric electricity – lightning. For life, alternating currents with a voltage of 120 V and above are considered dangerous, although cases of fatal outcomes of a current of much lower voltage (65 V) are described.
Symptoms and course.
With the direct action of the current on the body, general disorders develop (shock, disruption of the central nervous system, cardiovascular and respiratory systems, etc.). Under the influence of heat (Joule heat), as well as the chemical effect of electric current, characteristic changes appear on the skin – the so-called. “current signs” at the place of its entry and exit. The consequences of electrical injury are blinding, burns by a voltaic arc, damage to the hearing organs, etc.
If you suspect an electric shock, you will need to stop its impact in any way – turn off the voltage, discard the bare wire with a dry non-metallic object, or drag the sick person away from the current-carrying object (for clothes!).
The causes of death in electrical trauma are paralysis: primary heart, respiratory, simultaneous heart and breathing, paralysis of the brain (electric shock). A state of imaginary death may develop with a sharp violation and weakening of the functions of vital organs and an almost complete absence of signs of life in the victim. After the return of consciousness, patients complain of headache, weakness. There is a high excitability, photophobia, a sense of fear. Neurological examination reveals the disappearance of normal or the appearance of pathological reflexes. The pulse is traditionally slow, tense, sometimes rapid, the boundaries of the heart are expanded (radiologically and percussion), muffled tones, arrhythmia. Significant deviation from the norm of the electrocardiogram and electroencephalogram. In severe lesions, pulmonary edema, acute liver failure, and enteritis develop.
Studies of peripheral blood indicate leukocytosis, shifts of the formula to the left, the appearance of pathological forms. Often these disorders do not develop immediately, but after some time, some remain for a more or less long period. Local changes in electrical injury are very similar to those in thermal burns.
“Signs of current” – are round gray spots, sometimes dense, dry patches of skin raised above the surface, often in the form of a traditional scab. Current signs are not painful and are almost devoid of an inflammatory reaction around. In more severe cases, the affected parts of the body are charred and sometimes look like dissected areas (dissecting electrical injury). Bones in such cases melt.
Local disorders clinically proceed favorably, without suppuration and general phenomena, with good granulations and later with soft scars, but healing is slow.
Since the vessels are severely affected by electrical injury, severe, secondary bleeding can be observed.
Chronic electrical injury.
Prolonged action of electric current (work with powerful generators, etc.) can cause a number of changes, which are expressed in fatigue, headaches, sleep disorders, forgetfulness. Hypotension, tremor, dilated pupils are noted.
First aid for electrical injury.
Should be immediately – at the scene, without wasting time to transfer the victim. A complex of therapeutic measures is carried out persistently for 2-3 hours. Only clearly expressed signs of death (the appearance of cadaveric spots, rigor mortis, electrocardiogram readings) indicate the hopelessness of the situation.
The victim must be immediately released from the effects of current. The opinion that exists in everyday life that burying in the ground contributes to revival has no scientific justification and is very harmful, as it leads to asphyxiation and cooling of the body. In the absence of cardiac activity, artificial respiration is performed. At the same time, anti-shock measures are taken (intravenous administration of cardiac agents, lobelin, warming of the extremities, intravenous and intra-arterial blood transfusion, oxygen therapy).
A sterile dressing is applied to burns and other injuries.
After an electrical injury, a sharp deterioration in the condition is likely, so careful care and bed rest are necessary. Treatment of general disorders is reduced to generally accepted measures (the use of therapeutic agents, the observation of a neurologist, etc.).
Electrical injury burns are treated conservatively, which is explained by the uncertainty of their boundaries and, over a large extent, by vascular changes. An active tactic is possible in cases where a significant excision of tissues during third-degree burns does not lead to a decrease in the functions of the organ. In severe lesions, the prognosis is doubtful, even if the victim feels relatively good at first. Cases are described when the victims, having come out of a serious condition, died after a while.
If a person is lying on the ground, then one should not approach him with wide steps (there may be a high step voltage between the legs), only shuffling and taking small steps.
If, as a result of an electric shock, a person has lost consciousness or his heart has stopped, they begin resuscitation – artificial respiration, heart massage, do everything to bring him to consciousness. The victim will need to be taken to the hospital by ambulance, since such patients may experience unexpected cardiac arrest even a day later as a result of an electrical injury. Electric shock burns tend to suppurate, so it is best to treat them in a purulent surgical department.
The shocked person, after coming to his senses, will need to be given painkillers, sedatives or sleeping pills, make an ECG control, check for the presence of other injuries, probably received during an unconscious state.
Prevention of electrical injury is entirely composed of safety measures and explanatory work carried out by both medical and technical personnel.
When struck by atmospheric electricity, the action is very powerful (the voltage is measured in millions of volts), but a short-term discharge. It is believed that lightning causes more severe consequences (separations of individual parts of the body, charring), as well as the symmetry of movement disorders. A characteristic “figure” of lightning is a branching (tree-like) winding curve. The treatment is the same as for victims of electric shock.