Electrical Injury

Essentials of Diagnosis

• The extent of injury is determined by

  • Amount and type of current

  • Duration and area of exposure

  • Pathway of the current through the body

• Clinical findings of death are unreliable; therefore, resuscitation must be attempted before assuming the electrical injury victim is dead

• Skin findings may be misleading, and not indicative of the degree of deeper tissue injury

General Considerations

• With alternating currents (AC) of 25–300 Hz

  • Low voltages (< 220 Hz) tend to produce ventricular fibrillation

  • High voltages (> 1000 Hz) cause respiratory failure

  • Intermediate voltages (220–1000 Hz) cause both

• More than 100 mA of domestic house current (AC) of 110 V at 60 Hz can cause ventricular fibrillation

• Direct current (DC) contact is more likely to cause asystole

• Lightning injuries differ from high-voltage electric shock injuries

  • Lightning usually involves higher voltage

  • It usually has a briefer duration of contact

  • It may cause asystole, nervous system injury, and multisystem pathologic involvement

• Electrical burns are of three distinct types

  • Flash (arcing) burns

  • Flame (clothing) burns

  • Direct heating effect of tissues by the electric current

Symptoms and Signs

• May vary from tingling, superficial skin burns, and myalgias to paralysis, massive tissue damage, or death

• Skin damage does not correlate with the degree of injury

  • Not all electrical injuries cause skin damage

  • Only very minor skin damage may be present with massive internal injuries

• Lesions caused by direct heating of tissues are usually sharply demarcated, round or oval, painless yellow-brown areas (joule burn) with inflammatory reaction

• Loss of consciousness

Laboratory Tests

• Obtain the following immediately

  • Complete blood count

  • Electrolytes

  • Kidney function tests

  • Liver biochemical tests

  • Creatine phosphokinase or urine myoglobin

  • Urinalysis

  • Cardiac enzymes

Diagnostic Procedures

• Obtain an ECG immediately

• Pain management with acetaminophen, nonsteroidal anti-inflammatory drugs, opioids

Therapeutic Procedures

Emergency measures

• Separate patient from the electric current before initiation of CPR or other treatments; the rescuer must be protected

• Turn off the power, sever the wire with a dry wooden-handled ax, make a proper ground to divert the electric current, or separate the victim using nonconductive materials such as dry clothing

• Resuscitation must be initiated on all victims of electrical injury since clinical findings are deceptive

Hospital measures

• Evaluate for

  • Hidden injury (eg, ophthalmic, otologic, muscular, compartment syndromes)

  • Organ injury (myocardium, liver, kidney, pancreas)

  • Blunt trauma

  • Dehydration

  • Skin burns

  • Hypertension

  • Posttraumatic stress disorder

  • Acid-base disturbances

  • Neurologic damage

• Fluid resuscitation is important to maintain adequate urinary output (0.5 mL/kg/h if no myoglobinuria is present, 1.0 mL/kg/h if myoglobinuria is present)

• Early debridement of devitalized tissues and tetanus prophylaxis may reduce the risks of infection

• In pregnant patients exposed to high voltage injury, the fetus may sustain intrauterine growth retardation, fetal distress, and fetal demise; fetal monitoring is recommended

Complications

• Cardiac or respiratory arrest

• Dysrhythmias

• Autonomic dysfunction (resulting in pupils that are fixed, dilated, or asymmetric)

• Paralysis

• Headache

• Altered mental status

• Seizures

• Vascular injury

• Tissue edema and necrosis

• Compartment syndrome

• Fractures from falls or muscle contractions

• Pneumothorax

• Rhabdomyolysis

• Acute kidney injury

• Hypovolemia from third spacing

• Ruptured ear drums

• Infections

• Acute or delayed cataract formation

• Sepsis

• Gangrene requiring limb amputation

Prognosis

• Prognosis depends on the degree and location of electrical injury, initial tissue damage, associated injuries, comorbidities, and complications

• Psychiatric support may be necessary following electrical injury

When to Refer

• Fasciotomy may be needed for compartment syndrome

• Tissue debridement of devitalized tissues may be needed

• Microvascular reconstruction may be required

When to Admit

• Indications for hospitalization

  • High voltage exposure

  • Dysrhythmia or ECG changes

  • Large burn

  • Neurologic, pulmonary, or cardiac symptoms

  • Suspicion of significant deep tissue or organ damage

  • Transthoracic current pathway

  • History of cardiac disease or other significant comorbidities or injuries

  • Need for surgery