Electrical Injuries

Electrical Injuries

Electrical injuries are infrequent but eventually are encountered by most practitioners of emergency medicine. These injuries encompass various diagnostic and treatment modalities. Generally, they may be classified as lightning, low voltage, and high voltage.

Lightning: Overall, the survival from lightning strike is greater than 50%. If cardiac and/or respiratory arrest has occurred, prolonged cardiopulmonary resuscitation (CPR) may cause recovery. Unfortunately, prolonged arrest comes with an increasing probability of permanent brain injury, persistent vegetative states, and brain death.

Low-voltage electrical injury without cardiac and/or respiratory arrest: This situation is encountered frequently in children who bite extension cords. The burns of the mouth are often severe and require extensive plastic revision. However, systemic problems are infrequent.
Low-voltage electrical injury with cardiac and/or respiratory arrest: These patients often are not transported to the ED, since they are pronounced dead at the scene. If they are transported and if CPR has been prompt and effective, complete and total recovery, usually with no apparent injury, may occur. Unfortunately, as with lightning, protracted periods without brain perfusion result in permanent brain damage.

High-voltage injury: Generally, patients who have been in high-voltage circuits do not arrest but have extensive injuries from burns and are at risk of acute and chronic problems from myoglobinuria. Electrical burns from high-voltage circuits generally are much worse than they appear in the ED.


Lab Studies:
In all patients in whom history or physical examination indicates more than a trivial electrical injury and/or exposure, obtain the following tests, which provide important baseline values for future treatment:
CBC (hemoglobin, hematocrit, white count, red cell indices)
Electrolytes (sodium, potassium, chloride, carbon dioxide, urea, glucose)
Creatinine
Urinalysis (specific gravity, pH, color, tests for glucose and hemoglobin)
In addition to the more common tests, an assessment of muscle damage should be performed by ordering the following:
Creatine phosphokinase (CPK), total and fractionated, if elevated
Urine myoglobin, if urine gives positive hemoglobin test
Serum myoglobin if the urine is positive for myoglobin
The above tests effectively measure the extent of muscle damage. High levels of CPK, identified as muscle with often some elevation in the myocardial component, are observed in significant exposures to low-voltage and high-voltage circuits. Lightning rarely causes an elevation. Extensive muscle damage leads to myoglobinemia and myoglobinuria.
In patients with arrest or loss of consciousness, strongly consider arterial blood gas analysis and a complete drug screen test.
Imaging Studies:
If clinically indicated because of chest trauma, shortness of breath, or history of CPR at the scene, obtain a chest x-ray.
Blunt trauma directly from involuntary contraction of muscles or indirectly from falling secondary to involuntary contraction of muscles requires imaging studies directed toward discovering possible fractures or even internal injuries.
Approach these in the same fashion as blunt trauma by other causes and order appropriate testing as indicated.

Other Tests:
Electrocardiogram
An ECG is indicated in any person in whom electrical injury is suspected. If arrhythmias are encountered or if the patient experienced a high-voltage injury, monitoring is indicated.
If no arrhythmias are encountered, further ECG studies are not necessary.
Electroencephalogram
An EEG may be indicated in a person who is unconscious or in arrest.
The necessity of performing an EEG in the ED depends on a number of institutional factors. It is not critical to early care decision making.

Procedures:
Obtain intravenous access in all persons who have electrical injury. Consider a central line in those with more than trivial burns and in those who were unconscious or arrested in order to monitor fluid status.
Fasciotomies of burned extremities may be required in high-voltage injuries. Obtain consultation with surgeons with experience in electrical burn injury early in the treatment of a patient with a high-voltage burn, since appropriate early fasciotomy may save a limb.
Prehospital Care:
First, remove the patient from the circuit.
Patients who are in arrest then require basic and advanced cardiac life support regimens. In electrically induced arrest, no underlying disease causes the arrest. Therefore, protracted efforts of resuscitation are met with success more often than usual.
Patients who are unconscious but not in arrest require careful ventilatory observation and assistance, if indicated.
Patients with burns above the neck require supplemental oxygen because of the high probability of airway and lung damage.
Secondary blunt trauma often is encountered due to falls caused by involuntary muscular contraction. It is dealt with identically to any other blunt trauma.

Emergency Department Care:
Stabilize patients with electrical burns and consider immediate transfer to the nearest burn center. If such facilities are not available, physicians with experience in burns, preferably in electrical burns, should assume care of the patient.
Hydrate all patients with burns and no apparent CNS abnormality. Using the ordinary rule of thumb for treating the typical burn patient may result in significant dehydration. In patients without CNS abnormalities, administration of physiologic fluids such as Ringer lactate at a rate of 10 mL/kg/h is reasonable during the initial resuscitation.
In patients with CNS abnormality, temper hydration with the possibility of worsening cerebral edema. No easy way of titrating this clinically difficult area is available.
Add mannitol or furosemide to the regimen of patients with elevated CPKs and/or myoglobinemia. These drugs provide diuresis for the toxic myoglobin, which can help to prevent acute tubular necrosis and renal failure secondary to myoglobinuria.
Treat a patient who has been struck by lighting based on CNS symptoms. If consciousness is present on admission or returns in the ED, inpatient therapy may not be required. If CNS abnormalities persist, hospitalization is indicated.
The successfully resuscitated patient exposed to low voltage without significant burns also may be treated primarily on the basis of CNS symptoms and CPK results. If consciousness returns, the CPK is no more than 2 times normal with negative hemoglobin in the urine, and the pulse is regular, hospitalization may be brief.
Irregularities of pulse, ECG changes, myoglobinuria, or CNS abnormalities require hospitalization.
Consultations: Patients with electrical burns require treatment by burn specialists. Prompt transfer to the care of such an individual is indicated. In high-voltage electrical burns, early fasciotomy may be indicated to improve circulation. Thus, seek guidance as rapidly as possible concerning when to initiate this procedure in the ED. Consultations include the following
Trauma and/or critical care
General surgery
Plastic and/or burn surgery