In all patients with more than a trivial electrical injury and/or exposure, the following tests should be considered:
-
CBC count: Obtain values for hemoglobin, hematocrit, and white blood cell count.
-
Electrolytes: Assess sodium, potassium, chloride, carbon dioxide, blood urea nitrogen, and glucose.
-
Creatinine: There is a high risk of rhabdomyolysis/myoglobinuria in electrical injuries; mortality in one study was 59% for patients with acute renal failure. [31]
-
Urinalysis: Obtain values for specific gravity, pH, hematuria, and urine myoglobin if the urinalysis is positive for hemoglobin.
-
Serum myoglobin: If urine is positive for myoglobin, a serum level should be obtained.
-
Arterial blood gas: This is obtained for patients needing ventilatory support or those with severe rhabdomyolysis who require urine alkalinization therapy.
-
Creatine kinase (CK) levels: This level may be extremely elevated in patients with massive muscle damage from high-voltage injuries. Normal CK values published by the laboratory may be low for typical construction and electrical workers whose vocation involves heavy exercise. Some evidence suggests that initial CK levels may help predict which patients could benefit from early fasciotomy to prevent subsequent amputations. [10] CK-MB subfractions are also often elevated in electrical injuries, but their significance in the setting of electrical injuries is not known. [3] CK-MB fractions and troponin should be checked if the current pathway involved the chest/thorax, if the patient has any signs of ischemia or arrhythmia on ECG, or if the patient has specific complaints of chest pain. One retrospective review created a decision rule for clinical identification of patients likely to have rhabdomyolysis. [32] Multivariate modeling revealed that high-voltage exposure, prehospital cardiac arrest, full-thickness burns, and compartment syndrome were associated with myoglobinuria. Defining "positive" as two or more of these findings has a sensitivity of 96% and negative predictive value of 99%. Initial CK and myoglobin levels correlate with burn size, ventilator days, hospital length of stay, need for surgical intervention, sepsis, and mortality. [33]
-
Arcing electrical burns through the shoe around the rubber sole. High-voltage (7600 V) alternating current nominal. Note cratering.
-
Contact electrical burn. This was the ground of a 120-V alternating current nominal circuit. Note vesicle with surrounding erythema. Note thermal and contact electrical burns cannot be distinguished easily.
-
Contact electrical burns, 120-V alternating current nominal. The right knee was the energized side, and the left was ground. These are contact burns and are difficult to distinguish from thermal burns. Note entrance and exit are not viable concepts in alternating current.
-
Electrical burns to the hand.
-
Electrical burns to the foot.
-
High-voltage electrical burns to the chest.
-
Superficial electrical burns to the knees (flash/ferning).
-
Energized site of low-voltage electrical burn in a 50-year-old electrician.
-
Grounded sites of high-voltage injury on the chest of a 16-year-old boy who climbed up an electric pole.
-
Energized site of the high-voltage injury depicted in Media File 9 (16-year-old boy who climbed up an electric pole).
-
Entrance site of a low-voltage injury.
-
Grounded sites of a low-voltage injury in a 33-year-old male suicide patient.
-
Grounded site of a low-voltage injury in the same 33-year-old male patient depicted in Media File 12.
-
Grounded sites of low-voltage injury on the feet.
-
A histologic picture of an electrical burn showing elongated pyknotic keratinocyte nuclei with vertical streaming and homogenization of the dermal collagen (40X). Courtesy of Elizabeth Satter, MD.
