Electrical Injuries in Emergency Medicine

Background

Electrical injuries (see the images below), though relatively uncommon, are inevitably encountered by most emergency physicians.^[1] Adult electrical injuries usually occur in occupational settings,^[2] whereas children are primarily injured in the household setting. The spectrum of electrical injury is broad, ranging from minimal injury to severe multiorgan involvement to death.

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Grounded sites of low-voltage injury on feet.

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Electrical burns to hand.

Classifications of electrical injuries generally focus on the power source (lightning or manufactured electricity), voltage (high or low), and type of current (alternating [AC] or direct [DC]), each of which is associated with certain injury patterns.

This article reviews the pathophysiology, diagnosis, and treatment of electrical injuries caused by manufactured electricity. (For further information on lightning injuries, see Lightning Injuries.)

Medicolegal concerns

Litigation concerning occupational injuries is to be expected, but lawsuits against practitioners in such cases are rare. Detailed documentation of the presence of electrical burns, including diagrams, can be extremely helpful. It is worthwhile, if possible, to obtain photographic records of injuries, with proper consent.

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Pathophysiology

Electricity is generated by the flow of electrons across a potential gradient from high to low concentration through a conductive material. The voltage represents the magnitude of this potential difference and is usually determined by the electrical source. The type and extent of an electrical injury is determined by voltage, current strength, resistance to flow, the duration of contact with the source, the pathway of flow, and the type of current (ie, DC or AC).

Voltage

Electrical injuries are typically divided into high-voltage and low-voltage injuries, with 500 V or 1000 V used as the dividing point. High morbidity and mortality have been described in 600 V DC injury associated with railroad "third rail" contact.^[3] In the United States and Canada, typical household electricity provides 110 V for general use and 240 V for high-powered appliances, whereas industrial electrical and high-tension power lines can carry more than 100,000 V.^[4] Voltage is directly proportional to current and indirectly proportional to resistance, as expressed by Ohm's law:

• V = I × R

where I = current, V = voltage, and R = resistance.

Current

Current (I) is the volume of electrons flowing across the potential gradient, as expressed in amperes (A). It is a measure of the amount of energy that flows through a body. Energy is perceptible to the touch at a current as low as 1 mA. A narrow range exists between perceptible current and the "let go" current—that is, the maximum current at which a person can grasp and then release the current before muscle tetany makes it impossible to let go.

For children, on average, the "let go" current is in the range of 3-5 mA; this is well below the 15-30 A of common household circuit breakers. For adults, the "let go" current is in the range of 6-9 mA and is slightly higher for men than for women.

Different electrical currents have varying physiologic effects (see Table 1 below). For instance, skeletal muscle tetany occurs at 16-20 mA, and ventricular fibrillation (VF) can occur at currents of 50-120 mA.^[5]

Table 1. Physiologic Effects of Different Electrical Currents

View Table

See Table

Resistance

Resistance (R) is the impedance to flow of electrons across a gradient, as expressed in ohms (Ω). It varies according to the electrolyte and water content of the body tissue through which electricity is being conducted. Blood vessels, muscles, and nerves have high electrolyte and water content (and thus low resistance) and are good conductors of electricity—better than bone, fat, and skin.^[1] Heavily callused areas of skin are excellent resistors, whereas a moderate amount of water or sweat on the skin surface can decrease its resistance significantly.

Types of circuit

Electrical current can flow in one of two types of circuits: (1) DC, in which electrons flow is unidirectional, and (2) AC, in which the flow of electrons changes direction at a regular frequency. AC is the most common type of electricity in homes and offices and is standardized to a frequency of 50 or (in the United States) 60 cycles/sec (Hz).

High-voltage DC often causes a large single muscle contraction that throws the victim away from the source, resulting in only brief contact with the source flow. In contrast, high-voltage AC is considered to be approximately three times more dangerous than DC of the same voltage because the cyclic flow of electrons causes muscle tetany that prolongs exposure to the source flow. Muscle tetany occurs when fibers are stimulated at 40-110 Hz; the standard 60 Hz of US household current is within that range. When the source contact point is the hand, tetanic muscle contraction induces the extremity flexors to contract, causing the victim to grasp the current source and thereby resulting in prolonged contact with the source.

Types of electrical burns

Depending on the voltage, current, pathway, duration of contact, and type of circuit, electrical burns can cause a variety of injuries through several different mechanisms.

Direct contact

Current passing directly through the body will heat the tissue, causing electrothermal burns both to the surface of the skin and to deeper tissues, depending on their resistance. It will typically cause damage both at the source contact point and at the ground contact point. (See the image below.)

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Contact electrical burns, 120-V alternating current nominal. Right knee was energized side; left was ground. These are contact burns and are difficult....

Electrical arcs

Current sparks are formed between objects with differing electric potentials that are not in direct contact with each other, most often a highly charged source and a ground. The temperature of an electrical arc can reach 2500-5000ºC, resulting in deep thermal burns where it contacts the skin. These are high-voltage injuries that may cause both thermal and flame burns in addition to injury from DC along the arc pathway.

Flame

Ignition of clothing causes direct burns from flames. Both electrothermal and arcing currents can ignite clothing.

Flash

When heat from a nearby electrical arc causes thermal burns but current does not actually enter the body, the result is a flash burn. Flash burns may cover a large amount of the body surface area (BSA) but usually are only partial-thickness injuries.

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Etiology

High-voltage alternating current

High-voltage AC injuries most commonly occur from a conductive object touching an overhead high-voltage power line. In the United States, most electric power is distributed and transmitted via bare aluminum or copper conductors, which are insulated by air. If the air is breached by a conductor, (eg, an aluminum pole, antenna, sailboat mast, or crane), any person touching the conductor can be injured. Occupational injuries may include direct contact with electrical switching equipment and energized components.

Low-voltage alternating current

Patients with low-voltage AC injuries generally fall into one of the following two broad categories:

• Children who bite into electrical cords and sustain lip, face, and tongue injuries
• Adults who become grounded while touching an appliance or other object that is energized

Injuries in the second category are becoming less common with the increasing use of ground fault circuit interrupters (GFCIs) in circuits where people might easily become grounded. GFCIs stop current flow in the event of a leakage current (ground fault) if the ground fault is greater than 5 mA (0.6 W at 120 V).

Direct current

DC injuries are commonly encountered when the third energized rail of an electrical train system is contacted while the person is grounded. This sets up a circuit of electric current through the victim, causing severe electrothermal burns and myonecrosis.^[3]

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Epidemiology

US statistics

It has been estimated that electrical injuries are estimated to cause as many as 1000 deaths per year in the United States, with a mortality of 3-5%.^{[4, 5]}  According to data on workplace injuries and fatalities from the US Bureau of Labor Statistics (BLS) and the Occupational Safety and Health Administration (OSHA), electrical fatalities account for 5.6% of all workplace fatalities, and the overall average electrical fatality rate for all occupations is 0.10 per 100,000 workers, with electrical power line installers and repairers at highest risk (6.56 fatalities per 100,000 workers).^[2]

Electrical injuries have been reported to be responsible for 3-5% of all burn unit admissions and to cause 2-3% of emergency department (ED) burn visits in the pediatric population.

Although there is some evidence that the incidence of low-voltage injuries among children has been declining (possibly because of more widespread use of GFCIs), the incidence of high-voltage injuries, usually involving power lines or rail sources, has not changed significantly.^[6]  With the near-ubiquity of potental electrical hazards in occupational settings, electrical injuries have come to represent the fourth leading cause of work-related traumatic death (5-6% of all workers' deaths).^{[2, 7]}

Age-, sex-, and race-related demographics

A bimodal age distribution of electrical injuries exists, with peaks in very young children (< 6 y) and in young and working-aged adults. Patterns of electrical injury vary by age (eg, low-voltage household exposures being more common among toddlers and high-voltage exposures being more common among risk-taking adolescents and via occupational exposure).^{[8, 9]}

Rates of childhood electrical injury are higher among boys than girls^{[10, 6]} ; rates of adult injury are significantly higher in men than in women, likely because of occupational predisposition. In most series, more than 80% of electrical injuries have been found to occur in men.^{[11, 12, 13, 8]}

No racial susceptibility to electrical burns exists. Occupational trends indicate that tradespeople in high-risk occupations are disproportionately White; therefore, this group may be more likely than other racial groups in the United States to experience occupation-related electrical injuries.

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Prognosis

For those without prolonged unconsciousness or cardiac arrest, the prognosis for recovery is excellent. Burns and traumatic injuries continue to cause most of the morbidity and mortality from electrical injuries.

Morbidity and mortality are largely affected by the particular type of electrical contact involved in each exposure. Overall mortality is estimated to be 3-5%.^[11] Flash burns have a better prognosis than arc or conductive burns do.^[1]

Mortality is generally low in persons who experience low-voltage injuries without immediate cardiac or respiratory arrest, but there may be significant morbidity from oral trauma in children who bite electrical cords^[14] or adults who suffer burns to the hand.

Persons who experience low-voltage injuries with cardiac or respiratory arrest may recover completely with immediate cardiopulmonary resuscitation (CPR) on scene; however, prolonged CPR and transport time may result in permanent brain damage.

High-voltage injuries often produce severe burns and blunt trauma. Patients are at high risk for myoglobinuria and renal failure. Often, burns ultimately prove to be much worse than they initially appeared in the ED.

One study (N = 118; age range, 4-82 y) of the outcomes of electrical injuries in the ED found that at 2-year follow-up, 43.9% of the patients had aesthetic sequelae and 25.3% had psychological disorders; 7% of adults had been unable to return to their previous occupations.^[15]

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History

Electrical injuries can present with a variety of problems, including cardiac or respiratory arrest, coma, blunt trauma, and severe burns of several types. It is important to establish the type of exposure (high or low voltage), the duration of contact, and the presence and nature of any concurrent trauma.

Low-voltage alternating current injury

No loss of consciousness or arrest

Low-voltage alternating current (AC) injuries without loss of consciousness or arrest involve exposure to voltages lower than 1000 V and usually occur in the home or office setting. Typically, children with electrical injuries present after biting or chewing on an electrical cord and have sustained oral burns. Adults working on home appliances or electrical circuits can also experience these electrical injuries. Low-voltage AC may result in significant injury if there is prolonged tetanic muscle contraction.

Loss of consciousness and/or arrest

In cases involving respiratory arrest or ventricular fibrillation (VF) that is not witnessed, an electrical exposure may be difficult to diagnose. All unwitnessed arrests should include this possibility in the differential diagnosis. Emergency medical services (EMS) personnel, family, and coworkers should be queried about this possibility. It is helpful to inquire into whether a scream was heard before the patient’s collapse; this may be due to involuntary contraction of chest-wall muscles from electrical current.

High-voltage alternating current injury

No loss of consciousness or arrest

Usually, high-voltage AC injuries do not cause loss of consciousness but instead cause devastating thermal burns. In occupational exposures, details of voltage can be obtained from the local power company.

Loss of consciousness and/or arrest

This is an unusual presentation of high-voltage AC injuries, which, as noted, do not often cause loss of consciousness. It may be necessary to obtain the history from bystanders or EMS personnel.

Direct current injury

Direct current (DC) injuries typically cause a single muscle contraction that throws the victim away from the source. They are rarely associated with loss of consciousness unless there is severe head trauma, and victims are often able provide their own history.

Conducted electrical devices

Conducted electrical weapons (CEWs; also referred to as conducted energy devices [CEDs] or electronic control devices [ECDs]), such as tasers, are devices used by law enforcement that deliver a high-voltage current that is neither true AC or true DC but is most like a series of low-amplitude DC shocks. CEWs can deliver 50,000 V in a 5-second pulse, with an average current of 2.1 mA.^[16]  Although these devices have been temporally associated with deaths in the law enforcement setting, they have been shown to be safe in healthy volunteers without evidence of delayed arrhythmia or cardiac damage as measured by troponin I.^{[17, 16]}

One study of CEW use in 1201 law enforcement incidents reported mostly superficial puncture wounds from the device probes, with significant injuries resulting only from trauma subsequent to shock, not from the device itself.^[18] Of the two deaths that occurred in custody, neither was related to CEW exposure.

Overall, significant injuries from CEW exposure are rare, and they usually occur as a result of trauma or in conjunction with intoxication.^{[19, 20]}  A study by Kroll et al noted that out of more than 3 million instances of CEW application by law enforcement in the United States, only 12 published case reports suggested a link to cardiac arrest.^[21] However, the issue of whether CEW use can cause cardiac arrest is not without controversy, in that some studies have suggested a direct cardiac risk.^[22]

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Physical Examination

Electrical injuries can cause multiorgan dysfunction and a variety of burns and traumatic injuries. A thorough physical examination is required to assess the full extent of injuries. Because the likelihood of future litigation is high with occupational injuries, it is advisable to document physical examination findings with photographs if possible, to obtain the proper releases, and to file the images in the patient's medical record.

Overall, low-voltage exposure tends to cause less overall morbidity than high-voltage exposure. It is important, however, to confirm, by obtaining an accurate history, that a seemingly low-voltage burn was not in fact from a high-voltage source (eg, a microwave, computer, or TV monitor—any device that "steps up" voltage via a transformer). Low-voltage burns can still cause cardiac arrhythmias, seizures, and long-term complications if contact is near the chest or head.

Cardiovascular

Patients may present in asystole or VF, in addition to other arrhythmias. Sudden death due to VF is more common with low-voltage AC, whereas asystole is more often associated with high-voltage AC or DC. VF can be caused at voltages as low as 50-120 mA, which is lower than the typical household current. One series showed cardiac arrhythmias following 41% of low-voltage injuries.^[23]

Electricity can also cause conduction abnormalities and direct trauma to cardiac muscle fibers. Survivors of electrical shock can experience subsequent arrhythmias, usually sinus tachycardia and premature ventricular contractions (PVCs). One study identified three cases of delayed ventricular arrhythmias up to 12 hours after the incident.^[24] Other studies found no risk of delayed arrhythmias in patients with initially normal electrocardiograms (ECGs), both after low-voltage household exposure and after CEW exposure.^{[25, 18, 19, 26, 27]} One case report described coronary artery dissection after electrical injury.^[28] Long-term cardiac complications from electrical injury are rare.

Respiratory

Chest-wall muscle paralysis from tetanic contraction may cause respiratory arrest if the pathway of the current is over the thorax. Injury to the respiratory control center of the brain can also cause respiratory arrest. The lungs are a poor conductor of electricity and generally are not as susceptible to direct injury from current as tissues with lower resistance are. Case reports have described pneumothorax after electrical injury.^[29]

Skin

Various burns and thermal injuries from electricity affect the skin and soft tissues. These are often the most severe sequelae of electrical burns (after cardiac arrhythmias) and may initially appear minor despite involving significant deep-tissue injury that subsequently necessitates fasciotomy or amputation. Burns are often most severe at the source and ground contact points; the source is usually in the hands or the head, whereas the ground is often in the feet. The strength and duration of contact with the source largely influence the severity and extent of tissue damage. All burns should be carefully documented and, if possible, photographed.

High-voltage electrothermal burns

Typically, high-voltage electrothermal burns (see the image below) show a contact point (where the person touched the circuit) and a ground point. These burns may produce significant damage to underlying tissue while largely sparing the surface of the skin. They may appear as painless, depressed areas with central necrosis and minimal bleeding. The presence of surface burns does not accurately predict the extent of possible internal injuries, because skin with high resistance will transmit energy to deeper tissues with lower resistance.

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High-voltage electrical burns to chest.

Arc burns

When an arc of current passes from an object of high resistance to one of low resistance, it creates a high-temperature pathway that causes skin lesions at the site of contact with the source and at the ground point (which is not always the feet). These areas typically have a dry parchment center and a rim of congestion around them. The locations of the surface wounds afford clues to the internal pathway taken by the arc. Because arcs can also cause electrothermal, flash, and flame burns, multiple burns of varying appearance may be observed. Arcs do not occur in low-voltage injuries. (See the image below.)

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Arcing electrical burns through shoe around rubber sole. High-voltage (7600 V) alternating current nominal. Note cratering.

Flash burns

Flash burns are caused by heat from a nearby electrical arc that can reach upward of 5000^o C. These burns can pass over the surface of the body or through it, depending on the path of the arc causing the flash. They may splash over the surface of the body, resulting in diffuse but relatively superficial partial-thickness burns. There is no internal electrical component. (See the image below.)

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Superficial electrical burns to knees (flash/ferning).

Flame burns

Flame burns are caused by ignition of clothing or nearby objects. They cause thermal burns resembling other flame burns.

Low-voltage burns

Low-voltage burns (see the images below) behave like ordinary thermal burns and range from local erythema to full-thickness burns. Low-voltage current requires several seconds of contact to cause skin burns, sometimes reaching levels high enough to cause VF before causing any significant skin damage.^[5] Direct contact burns may occur only if the circuit through the person was prolonged for more than a few seconds.

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Energized site of low-voltage electrical burn in 50-year-old electrician.

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Grounded sites of low-voltage injury in 33-year-old male suicide patient.

Contact burns

Contact burns (see the image below) usually exhibit a pattern from the contacted item (branding) and may appear similar to flash burns.

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Contact electrical burn. This was ground of 120-V alternating current nominal circuit. Note vesicle with surrounding erythema. Note that thermal and c....

Pediatric oral burns

These are most commonly encountered in children younger than 6 years who bite or suck on a household electrical cord. A local arc of current crosses from one side of the mouth to the other. The orbicularis oris muscle may be involved, and cosmetic deformity of the lips may occur if the burn crosses the commissure. Significant edema may be noted, and eschar typically forms within 2-3 days. Life-threatening bleeding can occur at 2-3 weeks post injury if the labial artery is exposed when the eschar falls off.

Initial assessments at presentation may underestimate the ultimate extent of the injury. These patients require aggressive airway management.^[14] They should be referred  to a burn specialist, a plastic surgeon, and an oral surgeon for early follow-up.

Neurologic

Most acute central nervous system (CNS) or spinal deficits resulting from electrical injuries are due to secondary blunt trauma or burns. Often, the patient has transient confusion, amnesia, and impaired recall of events, if not frank loss of consciousness. The direct effects of electrical current are most severe if the respiratory control center of the brainstem is affected, resulting in respiratory arrest. The current may also cause seizure or direct spinal cord injury (SCI) if there is hand-to-hand flow. SCI can also result from direct current effects or blunt trauma. Unless a patient is completely lucid with full recollection of the events, initial immobilization of the cervical spine is indicated.

Electrical currents can cause acute muscle tetany at relatively low levels and frequencies, such as those found in most households. Muscle tetany causes victims to grasp the source, prolonging contact time, and can also paralyze respiratory muscles, resulting in asphyxiation.

Long-term neurologic complications include seizures, peripheral nerve damage, delayed spinal cord syndromes, subacute infarcts,^[30] and psychiatric problems ranging from depression to aggressive behavior.

Musculoskeletal

Acute musculoskeletal injuries include fractures from blunt trauma and compartment syndrome from burns. The chest and extremities should be examined for circumferential burns. The extremity should be palpated and distal neurologic, vascular, and motor examination performed to determine whether there are grounds for suspecting a compartment syndrome. If this is the case, compartment pressure can be measured and early fasciotomy may help prevent subsequent amputation.^[13] Early surgical consultation, if available, should be obtained if compartment syndrome is a concern. Massive muscle damage can cause severe rhabdomyolysis and subsequent renal failure.

ENT/head

The head is a common entry point for high-voltage injuries. Patients may have perforated tympanic membranes, facial burns, and cervical spine injury. Approximately 6% of victims develop cataracts, usually months after the initial injury; the closer the contact point is to the head, the greater the frequency.^{[12, 31]}

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Complications

Low-voltage current

If no significant burns are present and if consciousness returns before arrival at or admission to the emergency department (ED), full recovery is expected. Rare instances of persistent arrhythmia have been reported.

Persistence of unconsciousness carries a worse prognosis, and full recovery is not expected after 24 hours of unconsciousness.

With proper treatment, the disfigurement caused by low-voltage mouth injuries can be minimized. Scarring is almost always present.

High-voltage current

For patients with massive burns, survival is now the rule rather than the exception. However, rates of amputation and significant morbidity from traumatic injuries and burns remain high.

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Laboratory Studies

In all patients with more than a trivial electrical injury or exposure, the following tests should be considered:

• Complete blood count (CBC) - Hemoglobin level, hematocrit, and white blood cell (WBC) count are determined.
• Electrolytes - Sodium, potassium, chloride, carbon dioxide, blood urea nitrogen (BUN), and glucose concentrations are measured
• Creatinine - There is a high risk of rhabdomyolysis/myoglobinuria in electrical injuries; mortality in one study was 59% for patients with acute renal failure^[32]
• Urinalysis - Values for specific gravity, pH, hematuria, and urine myoglobin are obtained if the urinalysis is positive for hemoglobin
• Myoglobin - If urine is positive for myoglobin, a serum level should be obtained
• Arterial blood gas (ABG) evaluation - This is indicated for patients needing ventilatory support or those with severe rhabdomyolysis who require urine alkalinization
• Creatine kinase (CK) -  This level may be extremely elevated in patients with massive muscle damage from high-voltage injuries; it should be kept in mind that normal CK values published by the laboratory may be low for typical construction and electrical workers whose vocation involves heavy exercise

Some evidence suggests that initial CK levels may help predict which patients could benefit from early fasciotomy to prevent subsequent amputation.^[13]  CK-MB subfractions are also often elevated in electrical injuries, but the significance of such elevation in the setting of electrical injuries is not known.^[4] CK-MB fractions and troponin^[33] should be checked if the current pathway involved the chest, if any signs of ischemia or arrhythmia were apparent on electrocardiography (ECG), or if the patient specifically complained of chest pain.

One retrospective review created a decision rule for clinical identification of patients likely to have rhabdomyolysis.^[34] Multivariate modeling revealed that high-voltage exposure, prehospital cardiac arrest, full-thickness burns, and compartment syndrome were associated with myoglobinuria. With "positive" defined as the presence of two or more of these findings, the rule showed a sensitivity of 96% and a negative predictive value of 99%.

Initial CK and myoglobin levels have been found to correlate with burn size, ventilator days, length of hospital stay, need for surgical intervention, sepsis, and mortality.^[35]

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Imaging Studies

The choice of imaging studies is dictated by the presence of blunt trauma, altered mental status, or cardiac or respiratory arrest, as well as the type of electrical exposure. The following modalities should be considered:

• Chest radiography - This is warranted for any patient who has cardiac or respiratory arrest, shortness of breath, chest pain, or hypoxia; has undergone cardiopulmonary resuscitation (CPR) at the scene; or has experienced a fall or sustained blunt trauma
• Head computed tomography (CT) - This warranted for any patient with altered mental status, significant traumatic mechanism, seizure, loss of consciousness, or focal neurologic deficits
• Cervical spine imaging - Patients with loss of consciousness or significant trauma should undergo cervical spine immobilization and appropriate diagnostic imaging; clinical clearance may be appropriate for some patients who have normal mental status without significant injuries; patients who have focal neurologic deficits or evidence of spinal cord injury (SCI) should undergo full spinal imaging
• CT or ultrasonography (US) - Depending on the amount of trauma sustained and the pathway taken by the electrical current, patients may require further imaging to evaluate for internal injuries; the choice of imaging modality varies, depending on availability and the nature of the suspected injuries

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Other Tests

Electrocardiography and cardiac monitoring

All adult patients should undergo initial ECG and cardiac monitoring in the emergency department (ED). The duration of monitoring depends on the circumstances of the exposure; any patients with chest pain, arrhythmia, an abnormal initial ECG, cardiac arrest, loss of consciousness, transthoracic conduction, or a history of cardiac disease should undergo monitoring.

No definitive guideline is available on duration of monitoring for adults, but patients are unlikely to develop significant arrhythmias after 24-48 hours if they have no other significant injuries. In several large reviews, no significant risk of delayed arrhythmia was identified among patients who had low-voltage exposure and no arrhythmia on initial presentation. One such review of 196 exposures concluded that admission for cardiac monitoring is not indicated for such patients.^[36]

Several studies have shown that patients with low-voltage (household) exposures who have no cardiac complaints and a normal initial ECG can be safely discharged.^[37] It is unclear how this finding applies to patients with preexisting heart disease. In the pediatric population, healthy children who have been exposed to household current (120-140 V, no water contact) can be safely discharged if they are asymptomatic, have not experienced VF or cardiac arrest in the field, and have not sustained other injuries warranting admission.^{[27, 38]}

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Procedures

Intravenous (IV) access should be obtained in all adult patients with electrical injuries. Central access should be considered in any patient with significant trauma, large burns, cardiac or respiratory arrest, or loss of consciousness.

In high-voltage injuries or prolonged low-voltage injuries, fasciotomy of a burned extremity may be required. Early consultation with a surgeon—preferably one with experience in burn management—should be obtained early in the treatment of any patient with a high-voltage burn; appropriate early fasciotomies may prevent subsequent amputations. If fasciotomy is indicated on an emergency basis, it must not be delayed.

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Histologic Findings

A histologic picture of an electrical burn is shown in the image below.

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Histologic picture of electrical burn showing elongated pyknotic keratinocyte nuclei with vertical streaming and homogenization of dermal collagen (40....

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Prehospital Care

First, rescuers should practice awareness of scene safety and be sure there is no imminent threat to bystanders or responders in attempting to remove the victim from the electrical source. For high-voltage incidents, the source voltage should be turned off before rescue workers enter the scene.

After ensuring scene safety, rescuers should approach victims of electrical injuries as both trauma and cardiac patients. Patients may need basic cardiac life support (BCLS) or advanced cardiac life support (ACLS) and should undergo spinal immobilization as indicated by the mechanism of injury.

Given that injuries may be limited to a ventricular arrhythmia or respiratory muscle paralysis, aggressive and prolonged cardiopulmonary resuscitation (CPE) should be initiated in the field for all electrical injury victims, who are likely to be younger with fewer comorbid conditions and to have better chances of survival after prolonged CPR.

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Emergency Department Care

Patients should be stabilized and airway and circulatory support provided as indicated by ACLS/ATLS (advanced trauma life support) protocols. For any patient with severe hypoxia, facial or oral burns, loss of consciousness, inability to protect airway, or respiratory distress, airway protection should be obtained and oxygen provided. Cervical spine immobilization, with or without spinal immobilization, is provided on the basis of the mechanism of injury or the findings from the neurologic examination. The primary survey should assess for traumatic injuries such as pneumothorax, peritonitis, or pelvic fractures.

After primary assessment, adequate intravenous (IV) access for fluid resuscitation, whether peripheral or central, must be obtained. Fluid resuscitation is initiated and titrated to a urine output of 0.5-1 mL/kg/hr in any patient with significant burns or myoglobinuria. Furosemide or mannitol may be considered for further diuresis of myoglobin; urine alkalinization increases the rate of myoglobin clearance and can be achieved with sodium bicarbonate titrated to a serum pH of 7.5.^{[39, 40]}   Cardiac monitoring should be initiated for all patients with anything more than trivial low-voltage exposures.

Burn care should include tetanus immunization as indicated, wound care, measurement of compartment pressures as indicated, and possibly early fasciotomy if warranted. Extremities with severe burns should be splinted in a functional position after careful documentation of a full neurovascular examination.

Electrical injury to a pregnant woman can lead to fetal compromise and death^[41] ; however, the risks such injury poses to the fetus have not been precisely defined. Pregnant women who are involved in electrical injuries should be carefully examined for traumatic injuries and obstetrical consultation. Women in the second half of pregnancy should be admitted for fetal monitoring in any cases of severe electrical injuries, high-voltage exposures, or minor electrical injuries with significant trauma.

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Further Inpatient Care and Transfer

Further inpatient care

Inpatient care is required for patients with anything other than minor low-voltage injuries. Burn and trauma care, preferably at a specialized center, should be instituted early. Any patients with cardiac arrest, loss of consciousness, an abnormal electrocardiogram (ECG), hypoxia, chest pain, dysrhythmias, or significant burns or traumatic injuries must be admitted.

Transfer

All patients with a history of exposure to high-voltage electricity and all patients with significant burns should be transferred to a specialized burn center for further inpatient treatment and rehabilitation.

Pediatric patients with significant oral burns should be transferred to a pediatric burn center. Patients with minor oral burns who have close follow-up can be discharged.

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Prevention

Prevention of high-voltage electrical injuries requires ongoing public education about potential hazards, as well as education specifically focusing on individuals in construction trades, those using cranes and lifts, and those exposed to the extreme danger of overhead power lines. One study found particularly high rates of electrical injuries in cable splicers, electricians, line workers, and substation operators.^[42] Prevention strategies and occupational safety changes should be targeted to these high-risk occupations.

Prevention of household exposures requires public education about child protection, outlet covers, and appliance safety. Appliances that produce a shock should not be used until professionally repaired. The use of ground fault circuit interruptors (GFCIs) should be encouraged for all electrical outlets but especially for those in bathrooms, kitchens, and exterior locations.

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Consultations

Patients with high-voltage electrical injuries require the ongoing care of a burn specialist, which should be instituted as early as possible; aggressive early intervention via fasciotomy can prevent subsequent limb amputation.

Additional consultations with a trauma/critical care specialist, an orthopedist, a plastic surgeon, and a general surgeon may be considered, depending on the type and severity of traumatic injuries present.

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Long-Term Monitoring

Patients exposed to low-voltage electrical sources who are otherwise completely asymptomatic with a normal physical examination can often be discharged from the emergency department (ED).^[43]

Patients with minor burns or mild symptoms can be observed for several hours and discharged from the ED if their symptoms resolve and they do not have elevated creatine kinase (CK) levels or myoglobinuria. Patients should be made aware of the possible long-term neurologic or ocular effects of electrical injuries, and follow-up care should be available as needed. Significant hand burns should be referred to a hand specialist for close follow-up.

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Furosemide (Furoscix, Lasix)

• Dosing, Interactions, etc.

Clinical Context: 

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Mannitol (Osmitrol)

• Dosing, Interactions, etc.

Clinical Context: 

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