In the broad sense, electrical burn injury includes both current burns and arc burns. Since arc burns resemble flame burns entirely, in the narrower sense, electrical burn injury refers specifically to various injuries caused by electric current passing through the body, also known as electric shock injury. The severity of electric shock injury depends on factors such as the intensity and type of current (direct or alternating, and its frequency), voltage, resistance at the contact site, duration of contact, and the path the current takes through the body.
Clinical Manifestations
Systemic Injuries
Mild cases may present with nausea, palpitations, dizziness, and transient loss of consciousness, generally leaving no lasting symptoms after recovery. Severe cases may result in transient shock, ventricular fibrillation, or sudden cessation of breathing and cardiac activity, potentially leading to death. After resuscitation from electric shock, patients may temporarily experience dizziness, palpitations, tinnitus, blurred vision, or auditory and visual disturbances, most of which resolve spontaneously.
Local Manifestations
Local signs of electric shock injury often include "entry" and "exit" wounds. Typically, the "entry" site exhibits more severe damage, appearing as a fissured or crater-like lesion; the "exit" site often appears grayish-yellow, yellow, or charred, with a slightly sunken center. In severe cases, tissue carbonization and coagulation may occur, though an "exit" wound may sometimes be absent. The surface area of skin injury may appear small, but actual tissue damage can be deep and extensive, involving muscles, bones, or internal organs. Additionally, due to intense muscle contractions during electric contact, short-circuiting across flexural joints (such as the elbow, axilla, or popliteal fossa) may cause multiple "jumping" burn injuries at various locations.
Other Effects
Electrical shock injury can cause severe tissue damage and significant swelling of affected limbs, increasing the risk of circulatory disturbances and subsequent tissue and limb necrosis. Besides direct electrical injury, ischemic-hypoxic damage often leads to extensive muscle injury and red blood cell destruction, resulting in the release of large amounts of myoglobin and hemoglobin into the bloodstream, which may precipitate acute renal failure. In rare cases, when electric current passes through the eyes, cataracts may develop after injury.
Management
Emergency Care
The power source should be disconnected as quickly as possible, or non-conductive objects such as a dry wooden stick or bamboo pole should be used to separate the victim from the electrical source. If breathing and cardiac activity have ceased, immediate on-site cardiopulmonary resuscitation (chest compressions and mouth-to-mouth resuscitation) should be initiated.
Systemic Treatment
General systemic treatment is similar to that for thermal burns, with additional attention to identifying and managing combined injuries. Severe electrical injuries often cause extensive tissue damage and significant edema, with large amounts of myoglobin and hemoglobin entering the bloodstream. Therefore, fluid replacement volumes are typically greater than those required for thermal burns of similar extent. Appropriate diuresis (e.g., with furosemide or mannitol) and urine alkalization may be used to help prevent acute renal failure. Routine administration of tetanus antitoxin serum and early initiation of appropriate antibiotics, with particular attention to the prevention of anaerobic bacterial infections, are necessary.
Wound Management
For significant limb swelling following electrical injury, early fasciotomy may be required to relieve tension. This involves layered incisions through the skin, subcutaneous tissue, and deep fascia, with opening of the muscle fascia if necessary, to fully release tension and prevent secondary necrosis of deep tissues and limbs. Early and thorough debridement of necrotic tissue, including necrotic muscle and tendons, should be performed. Depending on the condition of the wound after debridement, autologous free skin grafts or flap grafts may be used to achieve wound closure.
For wounds where complete debridement of necrotic tissue cannot be achieved in one procedure, or where immediate skin grafting is not feasible, options include temporary closure with dermal scaffolds, allografts, modern functional dressings, or bone cement. Once the wound bed is adequately prepared, autologous skin grafting can be performed. Severe electrical burns often result in vascular or endothelial damage, increasing the risk of thrombosis and massive hemorrhage. A tourniquet should be kept at the bedside in preparation for potential emergency hemorrhage control.