Injury by electricity is damage caused by artificial, flowing through the body of electricity. Symptoms range from skin burns about damage to internal organs and connective tissue, even heart arrhythmia and respiratory arrest. Diagnosis is based on history, clinical criteria and specific laboratory tests. Treatment is supportive intensive care in serious injury.
Although accidental electrical injuries in the house (eg. As touching a socket or an electric shock from a household appliance) rarely bring serious injury or sequelae with it, the inadvertent exposure leads to electrical high voltage in the US to approximately 400 deaths per year. There are> 30,000 non-fatal electric shock accidents / year in the US and electrical burns account for about 5% of admissions in the emergency rooms for burns in the USA.
Injury by electricity is damage caused by artificial, flowing through the body of electricity. Symptoms range from skin burns about damage to internal organs and connective tissue, even heart arrhythmia and respiratory arrest. Diagnosis is based on history, clinical criteria and specific laboratory tests. Treatment is supportive intensive care in serious injury. Although accidental electrical injuries in the house (eg. As touching a socket or an electric shock from a household appliance) rarely bring serious injury or sequelae with it, the inadvertent exposure leads to electrical high voltage in the US to approximately 400 deaths per year. There are> 30,000 non-fatal electric shock accidents / year in the US and electrical burns account for about 5% of admissions in the emergency rooms for burns in the USA. is pathophysiology Traditional teaching that the severity of the injury depends on the Kouwenhoven factors: Current (DC [DC] or alternating [AC]) voltage and current (measurements of current) duration of exposure (prolonged exposure increases the severity of injury) resistance of body conduction of electricity (which the specific tissue damage determined) the electric field strength, a newer concept, the severity of the injury appears, however, to predict accurately. Kouwenhoven factors The alternating frequently changed the direction; it is the current that is provided in the electrical sockets of households in the US and in Europe. Constant DC current flows in the same direction; it is provided by batteries current. Defibrillators and cardioverter usually provide direct current. As the alternating current (AC) affects the body depends largely on the frequency. Low frequency AC (50-60 Hz) is in the budgets of the USA (60 Hz) and Europe used (50 Hz). Because low-frequency AC current causes a strong muscle contraction (tetany) which can fix the hand to the power source, thereby increasing the time of exposure, it may be more dangerous than high frequency alternating current, and is 3 to 5 times more dangerous than DC with the same voltage and current. Exposure to direct current causes more of a single convulsive muscle contraction, often wegstößt the affected person from the power source. With alternating current and in direct current, a higher voltage (V) and current means greater consequent injury by electricity (with the same duration of the exposure). The household electricity in the US has 110 V (standard on electrical sockets) to 220 V (used for large electrical appliances, such. As refrigerators, clothes dryer). High voltage power (> 500 V) gives rather deep burns, and low voltage power (110-220 V) gives a Muskeltetanie and fixing on the power source. The highest current that leads to a contraction of Armflexoren but still releasing the hand permits from the power source, is called “free-state current.” The free forward current varies depending on the weight and muscle mass. For a man of average 70 kg of the free-state current is 75 mA at DC and about 15 mA at AC. If low-voltage alternating current of 60 Hz flows only for a fraction of a second through the chest, it may be enough to cause at a current of 60-100 mA ventricular fibrillation; in DC about 300-500 mA would ensure necessary. When the current is a direct route to the heart (eg., Via a cardiac catheter or pacemaker electrodes), can already cause ventricular fibrillation <1 mA (AC or DC). Tissue damage due to electrical exposure is mainly caused by the conversion of electrical energy into heat, leading to thermal damage. The amount of heat energy dissipated is equal Stromstärke2 resistance × × time; therefore, tends for each type of current and exposure time, the fabric with the highest resistance to suffer the greatest damage. The body resistivity (measured in ohm / cm2) is mainly made from the skin, because the entire internal tissues (except bone) has low resistance. Skin thickness and dryness increase resistance; dry, well-keratinized, intact skin has an average resistivity of 20,000-30,000 ohms / cm2. In a thick callused palm or sole of the resistance may be 23 million ohms / cm 2; In contrast, moist, thin skin has a resistance of about 500 ohms / cm2. The resistance at destroyed skin (eg. As by cutting, abrasion, needle penetration), or in wet, mucous membranes (eg., In mouth, rectum, vagina) is as low as 200-300 ohms / cm2. When the skin resistance is high, more electrical energy can be dissipated to the skin, but less leads to large skin burns, internal damage. When the skin resistance is low, the burns on the skin are less extended or non-existent, and more electrical energy is dissipated to the internal structures. Therefore, the absence of external burns does not say anything about the lack of electrical injuries and the severity of external burns does not say anything about the severity of electrical injury ahead. Tips and risks The absence of external burns does not say anything about the lack of electrical injuries and the severity of external burns does not say anything about the severity of electrical injury ahead. The damage to internal tissue depends on its resistance, and also on the strength of the stream from (current per unit area, the energy is concentrated, if the same current through a smaller area flows). For example, when an electric current in an arm flows (mainly by tissues, for low resistance. B. muscles, vessels, nerves), the current density on the joints increases, as a significant proportion of the cross-sectional area of ??the joints of fabric is higher resistance (. eg bone, tendons), whereby the surface of the fabric is reduced lower resistance; therefore the damage to tissues with lower resistance is at its worst at the joints. The path of the current through the body determines what structures are injured. Since AC constantly changes direction, the terms commonly used "entry" and "exit" are unsuitable; the terms "source" and "Earth" are more precise. The hand is the most common source point, followed by the head. The foot is the most common "grounding point". The current flowing between an arm and the other arm or between an arm and a foot, probably passing through the heart and may cause cardiac arrhythmia. This current tends dangerous than current flowing from one foot to the other. Current flowing in the head, the central nervous system schädigen.Elektrische field strength In addition to the factors Kouwenhoven, electric field strength determines the degree of tissue injury. For example, yield 20,000 V (20 kV), distributed from head to foot on a 2 m wide man, an electric field strength of about 10 kV / m. Similarly give 110 V, acts on only 1 cm (e.g., across the lip of an infant.) A similar field strength of 11 kV / m; this is the reason why such a "low-voltage" injury can cause the same severity of tissue injury as some high-voltage injuries that affect a larger area. Conversely, if one thinks of electrical voltage instead of electric field strength, scale small or trivial danger of electric shock as a high voltage injury. So has the impact that can be obtained when shuffling in winter across a carpet of thousands of volts, but causes only a trivial injury. The electric field effect can cause cell membrane damage (electroporation), even if there is not enough energy to generate a thermal damage to verursachen.Pathologie The application of low electric field strength immediate discomfort (you get a "shock"), but rarely follows a serious or permanent injury. The application of high electric field strength adds thermal or electrochemical damage to internal tissue. Damage may include hemolysis protein coagulation coagulation necrosis of muscle and other tissues thrombosis dehydration muscle and Sehnenausriss injuries caused by high electric field strengths may cause massive edema, the fact that blood in the veins and thrombosed swell the muscles can result in a compartment syndrome. Strong edema may continue to cause hypovolemia and hypotension. The destruction of the muscles can lead to rhabdomyolysis and myoglobinuria for and electrolytic disturbances. Myoglobinuria, hypovolemia and hypotension increase the risk of acute kidney injury. The consequences of organic disorders do not always correspond to the amount of tissue destroyed (z. B. ventricular fibrillation can occur even at relatively low tissue damage). Symptoms and complaints burns can be delimited sharply on the skin, even if the current penetrates irregularly into deeper tissue. Strong involuntary muscle contractions, seizures, ventricular fibrillation or respiratory arrest due to damage to the central nervous system or muscle paralysis may occur. Brain, spinal or peripheral nerve damage can affect various neurological deficits. A cardiac arrest can not burn as bathtub accidents occur (if a wet [grounded] person with a 110-V circuit comes into contact - for example, from a hair dryer or radio.). Small children who chew on electrical cords or extension -lutschen, can burn the mouth and lips. Such burns can cause cosmetically significant distortions and hinder the growth of the teeth of the mandible and maxilla. A bleeding lip artery that occurs when the scab solves 5-10 days after the injury occurs in up to 10% of these infants. Electric shock could strong muscle contractions or falls cause (eg., From a ladder or the roof), the dislocation (an electric shock is one of the few causes of a posterior dislocation of the shoulder), vertebral fractures or other fractures, injuries to internal organs and other blunt can result in injury. Subtle or vaguely defined neurological, psychological and physical consequences may develop 1 to 5 years after the injury, and lead to significant morbidity. Diagnostic examination from head to toe Sometimes ECG, cardiac enzyme measurement and urinalysis Once the patient is free of electricity, it is examined for a cardiac arrest and respiratory arrest. If required resuscitation is performed. After resuscitation the patient from head are examined for traumatic injuries to toe, especially if the patient has fallen or been pushed away. Asymptomatic patients who are pregnant do not have no known heart disease and were exposed only briefly to the household electricity, usually have no significant acute internal or external damage and require no further investigation or observation. For other patients, an ECG, a complete blood count, measurement of cardiac enzymes and urinalysis should be considered (to assay for myoglobin). In patients with impaired consciousness, a CT scan or MRI may be necessary. Treatment elimination of current resuscitation analgesia Sometimes cardiac monitoring for 6-12 h wound care Preclinical supplies Most important is first the breaking contact between the affected patients and the power source (eg., By operating a circuit breaker or an ordinary switch by disconnecting the device can not always be easily distinguished from the electrical socket.) high and low voltage power lines, v. a. outdoors. Caution: If it could be high-voltage current in the electrical lines, no attempts should be made to the affected patient to solve before the current ist.Reanimationsmaßnahmen parked Patients will be revived during the investigation. Then a shock that may result from trauma or massive burns is treated. Standard formulas for fluid therapy for burns that are based on the area of ??the burned skin can underestimate the fluid requirements for electrical burns; therefore, such formulas are not applied. Instead, fluids are titrated to obtain a sufficient amount of urine (approximately 100 mL / h in adults and 1.5 ml / kg / h in children). In a myoglobinuria maintaining adequate urine output can be especially important during an alkalinization of urine can help to reduce the risk of kidney failure. Spacious surgical debridement of muscle tissue can also help to reduce a myoglobinurisches kidney failure. Severe pain with electrical combustion are appropriately dosing with iv Opioids behandelt.Andere measures asymptomatic patients who are not pregnant, have no known heart disease and were exposed only briefly to the household electricity, usually have no significant acute internal or external damage that can capture the image necessary and can be dismissed at ease. Cardiac Monitoring 6-12 h is indicated in patients with the following conditions: arrhythmias chest pain of suspected cardiac damage pregnancy (possibly) Known heart disease (possibly) An appropriate tetanus prophylaxis undtopische treatment of burn wounds are required. Pain are treated with NSAIDs or other analgesics. All patients with significant electrical burns should be handed over to a specialized center for burns. Young children with burns on the lips should be referred to a pediatric dentist or a pediatric facial and oral surgeon who is familiar with this type of injury. Prevention Electrical devices that touch the body or which may be touched by the body should be insulated properly grounded and inserted into circuits that have a safety breaker. Switches that interrupt the circuit in the absence of grounding, when only 5 mA current escape to the earth, to get effective and easy. with child safety protection reduce the risk of electrical outlets in homes with infants and young children. Important Points In addition to burn injuries, air conditioning can freeze the patient's hand with the power source, during DC "throw" the patient, causing injury. Although the severity of the skin burn can not predict the degree of internal damage, internal damage is more severe if the skin has a lower resistance. Examine the patient completely, including traumatic injury. Pull ECG, blood count, cardiac enzymes, urine analysis and monitoring into consideration, unless the patients are asymptomatic, not pregnant, have no known heart disease, and had only brief exposure to household electricity. Please transfer patients with significant electrical burns in a special ward for burns and start when substantial internal damage is suspected, a volume therapy.