Due to multiple causes in electrical injury cases, the history can be
either very obvious or extremely subtle.
- Low Voltage Without Loss of Consciousness and/or Arrest:
Typically these patients are infants and young children who bite into
appliances cords. The circuit is generally restricted to the mouth. The adult will almost
always be able to relate that the child was found with the cord in his or her mouth. Older
children and adults may be injured this way while working on electrical appliances or home
electrical circuits, when the circuit does not involve the heart or brain.
- Low Voltage With Loss of Consciousness and/or Arrest:
The presentation may be so subtle, that the correct diagnosis may be
missed. Always be alert to the possibility that a sudden arrest might be the result of an
electric circuit. Rescue workers, co-workers, family and friends should be queried about
- High Voltage Without Loss of Consciousness and/or Arrest:
This is the characteristic situation with an electrical injury from
high voltage. Unless there is a very high resistance pathway in the circuit, voltages of
more than 780 usually do not cause cardiac/respiratory arrest. Thus, the history obtained
from the patient should tell you how the injury occurred. Details of the voltages can be
obtained from the power company.
- High Voltage with Arrest and/or Loss of Consciousness:
This is the more unusual presentation from high voltage circuit
injuries presenting to the ED. If the circuit traverses the head, there will be loss of
consciousness and amnesia for the events immediately prior to the injury. Thus, history
taking should be directed to rescue personnel, co-workers, family or friends who have
knowledge of the circumstances. Details of the voltages can be obtained from the power
- Direct Current:
current electrical injuries are generally seen in electrical train circuits. These often
involve risk taking behavior by young males. Arrest and coma are rarely, if ever, seen.
The history can be obtained from the patient.
The physical examinations should include a careful
documentation of injuries. There is a bit of difference depending upon the voltage.
- High Voltage (and, Occasionally, Low Voltage With Flash
Burns): These cases are characterized by burns. Some attention to the characteristics and
nature of the burns will assist in treatment.
- Contact Burns:
electrical burns generally have a pattern from the contacted item and are more limited in
size than flash burns, although their appearance otherwise is nearly identical to a flash
burn. One means of distinguishing is that in skin with hair, a contact burn of apparent
full thickness will have unburned hair, whereas a flash burn will always have the hair
singed and generally gone.
- Documenting the Types of Burns:
Arc and contact burns are associated with internal electrical injury;
flash burns are not. Entrance and exit burns in alternating electrical injuries are not
possible, as alternating current has no such wounds. However, there are arcing and contact
burns. These are markers to where the circuit traversed the body.
- Low Voltage:
low voltage injuries, there may be flash burns from various sources that will behave
exactly as ordinary thermal burns and should be documented as such. However, there are
electrical burns that should be documented.
- Direct Contact Burns:
will be seen only if the circuit through the person was prolonged for more than a few
seconds. In low voltage there is insufficient heat to produce skin burns quickly. Thus,
the areas where there was electrical contact will often not be distinguishable on physical
examination or will only show focal erythema.
is wide variability of findings in a lightning strike victim. Burns are generally not
significant, but should be documented. They will generally be of the flash type. Singeing
of the hair, without burning is characteristic. There are a few things to look for which
are out of the routine:
Electrical injuries are caused when a person becomes part of
an electrical circuit or is affected by the thermal effects of a nearby electrical arc.
The most common classifications of these injuries are lightning, and high and low voltage
alternating current (AC) and direct current (DC).
injuries occur when the patient is part of or is near the lightning bolt. Generally, the
patient will have been the tallest object around or near a tall object, such as a tree.
There is always a thunderstorm in the vicinity but oddly, the overhead sky can be clear.
- High Voltage AC:
voltage injuries most commonly occur when a conductive object touches an overhead high
voltage power line. In America, most electric power is distributed and transmitted by bare
aluminum or copper conductors, which are insulated by air. If the multiple feet of air are
breached by a conductor, such as an aluminum pole, antennae, sailboat mast or crane and a
person is on the ground at the time the conductor becomes energized, that person will be
injured. Rarely, patients will get into electrical switching equipment and directly touch
- Low Voltage AC:
there are 2 types: the child who bites into the cord producing severe lip, face and tongue
injuries and the child or adult who becomes grounded while touching an appliance or other
object that is energized.
The latter type is declining in frequency in North America
due to the use of ground fault circuit interrupters (GFCIs) in any circuits which supply
kitchens, bathrooms or the outside, as these are places where persons may become easily
grounded. GFCIs stop current flow if there is a leakage current (ground fault) or more
than 0.005 amps (0.6 watts at 120 volts).