bubble_chart Overview

Electrical injuries in clinical practice are classified into two types. The first is systemic injury, referred to as electric injury. Here, the skin injury is minor, but the current enters the body and spreads immediately, primarily affecting the heart and causing drastic hemodynamic changes. This leads to symptoms such as palpitations, vertigo, and impaired consciousness, potentially resulting in electric shock or even sudden cardiac and respiratory arrest. Emergency treatment involves quickly removing the patient from the electrical source and performing resuscitation. The second type is localized injury, where the current generates heat in the tissues that resist its conduction, leading to coagulation or carbonization of tissue proteins, thrombosis, and other effects—this is termed electric burn. Additionally, tissue cells along the current's path (such as vascular endothelium) may suffer damage due to electrolysis, resulting in degeneration and necrosis. Patients with electric burns do not experience systemic injury, but because the latter is mild and causes only transient symptoms, the localized injury becomes the primary concern after recovery.

bubble_chart Etiology

Electrical injuries generally occur due to careless use of electricity or mistakes in electrical equipment and circuits. Therefore, it is necessary to strengthen power management and promote electrical safety knowledge to prevent electrical injury accidents. Electrical injuries can also occasionally be caused by lightning strikes, which can be prevented by installing lightning protection devices and using personal lightning protection methods.

bubble_chart Clinical Manifestations

Electrical burns have an "entry point" (the site of electric shock) and usually also an "exit point." The entry point exhibits third-degree burns, with the skin appearing charred yellow or carbonized, sometimes forming cracks or cavities. The burn may extend deep into muscles, tendons, or bones. The exit point generally also shows third-degree burn changes, though the severity is slightly less; in some cases, the damage at the exit point is not obvious. The extent of deep tissue injury in electrical burns often far exceeds the skin entry point, but this is difficult to determine in the early stages. After 24 hours, the area around the entry point begins to swell and redden, with the affected area gradually expanding. Localized skin or limb extremities may become necrotic, and swelling may spread proximally or peripherally. The reason for the extensive deep injury is that after passing through the skin, the electric current sequentially damages subcutaneous tissues, muscles, tendons, and other structures while also injuring blood vessel walls, promoting thrombosis. Postoperatively, this can lead to ischemic necrosis in the affected tissues. One to two weeks after the injury, the extent of necrotic tissue can be determined, with deep necrosis still exceeding the superficial necrotic and swollen areas. During the necrosis process following electrical burns, infections are prone to occur, potentially leading to wet gangrene, sepsis, or even gas gangrene. After superficial necrotic tissue sloughs off, the injured blood vessels may become exposed, resulting in severe and recurrent bleeding.

bubble_chart Diagnosis

The diagnosis is relatively easy, but close monitoring of the progression of deep injuries and concurrent infections is essential. Attention should also be paid to hypovolemia, decreased urine output, abnormal urine components (such as protein, casts, red blood cells, etc.), ECG changes, and anemia.

bubble_chart Treatment Measures

The treatment of electrical burns is fundamentally similar to that of third-degree burns as described earlier. Based on their pathological and clinical characteristics, the key points of management are as follows:

1. Patients should rest in bed, including those with small entry wounds and limited skin burn areas, and close observation of their condition is necessary. The wound is generally treated with the exposure method, keeping the affected limb clean and dry, with skin disinfection performed 2–3 times daily.

2. The first surgical procedure can be performed 3–5 days after the injury. Initially, the clearly necrotic tissue or eschar is excised, and the deeper tissues are explored. If no significant infection is present, the nonviable tissue (which does not bleed or respond to electrical stimulation of muscles) is thoroughly excised, followed by dressing with medicated gauze. Another surgical exploration is performed 2–3 days later to remove any remaining necrotic tissue until the wound can be sutured or skin-grafted.

Severe limb swelling may occur after the injury, potentially obstructing local blood circulation. In such cases, the skin and fascia should be incised for decompression. Extensive muscle necrosis often necessitates high-level amputation. However, muscle necrosis typically occurs in bundles (not limited by the limb’s cross-section) and is related to vascular occlusion. Therefore, around one week post-injury, angiography can help identify blocked and patent vessels, allowing preservation of healthy muscle or lowering the amputation level.

3. Infected wounds require adequate drainage and wet dressings, with daily debridement of necrotic tissue and eschar until granulation tissue forms for healing or skin grafting. Extensive deep infections can easily lead to toxemia, sepsis, or acute renal failure. In addition to high-dose antibiotics, prompt multiple incisions for drainage are essential, and amputation may be unavoidable. Exposed wounds carry a risk of bleeding, and compression or hemostatic drugs provide only temporary relief. A tourniquet and surgical kit should be prepared at the bedside.

Severe electrical burns have a high disability rate. With advances in surgical techniques, treatments such as free vascularized flaps or greater omentum coverage, autologous vein grafting after excision of damaged vessels, or even limb segment resection followed by replantation have been adopted to improve outcomes.