Electrical burns
The spectrum of electrical injury is broad, ranging from minimal injury to severe multi-systemic injuries with multiple organ involvement, to death. Therefore, some parts of the primary and secondary survey require particular attention.
The type of electrical burn will determine the signs and symptoms, as well as any associated injuries.
Primary survey for electrical burns
Carry out the primary survey with the modifications outlined here.
As high voltage injuries may affect multiple organs, the patient should always be examined according to the Advanced Burn Life Support (ABLS) protocol.
When A, B, C and D are stabilized, remove all clothing and accessories from the patient.
The immediate effects of electrical injury include cardiac dysrhythmias, respiratory arrest and seizures. Therefore, it is important to monitor all patients who have suffered a cardiac arrest, or patients where it is suspected that the electrical current has passed through the thorax.
Secondary survey for electrical burns
Carry out the secondary survey with the modifications outlined here.
Take a history to ascertain how and when the accident occurred and with what sort of electricity. The severity of the injury increases with voltage level (see the table).
Ask whether there has been any loss of consciousness, and if so for how long. Assess the patient for the presence of amnesia, other associated trauma, and any indications of cardiac arrest or cardiac dysrhythmias.
Alternating current (AC) has a five times more severe impact on the human body than direct current (DC).
Remove all clothing and accessories from the patient to allow for detailed examination and distinguish the types of burn.
Flash burns appear on the body areas not covered by clothes, as deep dermal partial thickness and full thickness burns. Radiative heat transfer, caused by the electric arc, may cause direct burns to the skin and may also ignite clothing, resulting in full thickness burns.
When an entry wound is obvious during the initial examination, examine other parts of the body for exit wounds. However if contact with the earth was over a large surface area, exit wounds may be absent. Entry and exit wounds are always full thickness.
In between the entry and exit sites, mainly in the limbs, extensive soft tissue necrosis may be present underneath apparently normal skin. This manifests itself in the form of a swollen and tense limb, resembling compartment syndrome or a crush lesion.
The patient will complain of deep pain and tenderness in the limb and upon palpation; the limb will be very painful and tense, and there may be signs of decreased circulation.
Soft tissue necrosis leads to the production of the breakdown products of myoglobin and hemoglobin, which can cause renal failure. Therefore, assess the peripheral circulation hourly when an entrance or exit wound on an extremity is observed.
Types of electrical burns
Low-Voltage burns
Low Voltage (<1000V) | Current type, Voltage | Skin | Deep tissue | Other injuries |
---|---|---|---|---|
Car battery | Direct current (DC), 12V | Entrance and exit wounds | Only affected near the contact surface | No other injury |
Domestic electrical supply | Alternating current (AC), 220-230V | Entrance and exit wounds | Only affected near the contact surface | Cardiac arrest Transient ECG changes |
High-Voltage burns
High Voltage (>1000V) | Current type, Voltage | Skin | Deep tissue | Other injuries |
---|---|---|---|---|
Overhead train line | AC and DC 750V – 50 KV | Entrance and exit wounds Flash burn Electric arc Flame burn (clothes) | Muscle, bone and soft tissue damage Rhabdomyolysis Compartment syndrome | Myocardial damage Delayed arrhythmias Cardiac arrest Transient ECG changes |
Overhead power line | DC, 10KV to 380KV | |||
Lightning | DC, Extremely high | Entrance and exit wounds Deep dermal and subdermal burn wounds | Near contact | Respiratory arrest followed by cardiac arrest Corneal damage |
Further diagnostics
Always perform an ECG. If any abnormalities are present, the patient should be admitted and the ECG repeated after 12 hours. If the ECG is normal, further observation is not necessary and the patient does not need to be admitted. In addition to the ECG, always take a full panel of laboratory tests, including bloodwork (for CBC, CMP, lactate, troponin and CK) and urinalysis.
Treatment
Patients who have a burn injury resulting from a high-voltage shock require admission to intensive care. In areas where deep muscle damage is suspected, a fasciotomy and inspection of all compartments must be performed, as all necrotic tissue must be removed.
Treatment of skin defects is the same as in wounds caused by thermal injury.