Electrical injury is a potentially life-threatening form of trauma. Depending on the cause (low vs. high-voltage current), the clinical presentation ranges from mild and clinically inapparent injury to ventricular fibrillation, respiratory arrest, and significant neuronal, cutaneous, and/or vascular injury. Both short-term and long-term sequelae can ensue, primarily neurologic and psychiatric in nature, illustrating the importance of an early diagnosis.
Electrical injury is responsible for about 20,000 emergency visits every year in North America, making it one of the most common causes of work-related injuries encountered in clinical practice . Several factors determine the extent of injury, but the most important classification divides electrical injury into those caused by low currents (< 1000 volts, principally seen due to contact with household items) and high-current (> 1000 volts, predominantly in the occupational setting, or lightning strikes)    . Paradoxically, injuries caused by low currents are responsible for a more severe clinical presentation, as the electricity travels at a much slower rate through the body compared to high-current injuries, during which the contact with the source is minimal  . As the current passes, it damages several tissues in the body, including the skin, the musculoskeletal system, the nervous system, and might interfere with the cardiac pacing activity    . Extensive skin burns at the site where the current entered (and exited) the body are the principal manifestation of electrical injury, followed by signs such as pain, paresthesia, weakness, or even muscle tetany, whereas fatigue is a frequent complaint  . Compartment syndrome (as a result of venous thrombosis) can also occur and is more frequent in high-voltage injuries . More severe damage to the CNS may cause seizures, quadriplegia, paralysis, coma, and loss of consciousness . Electrical injuries are life-threatening in the presence of cardiac arrhythmia (mainly ventricular fibrillation) or respiratory arrest, and studies estimate that the overall mortality rate is 20-30%  . One of the reasons why low currents are more dangerous for humans is its transmission through tissues with lower resistance - blood vessels and the central nervous system . Hence, if patients survive the attack, both short-term and long-term sequelae, primarily neurological (paresthesia, numbness, persistent pain), but also psychological (anxiety, depression, insomnia, flashbacks, nightmares), ophthalmological, and auditory, are more common in low-current vs. high-current injuries   .
A properly obtained patient history is a pivotal step for identifying the source of signs and symptoms and further clarification of the source (high vs. low current) can be helpful in assessing the risk of complications. A thorough physical examination is equally important, during which physicians must evaluate the musculoskeletal, nervous, and vascular systems through appropriate examination. A complete neurological examination is particularly important, as it may reveal pathological changes long after the initial event . A thorough laboratory and imaging workup is required to evaluate the status of the patient - laboratory studies (a complete blood count, serum electrolytes, urinalysis, creatine kinase levels, cardiac enzymes, etc.) and imaging procedures (plain radiography, ultrasonography, and echocardiography). Electrocardiogram (ECG) should be immediately performed to exclude cardiac arrhythmias, however some authors claim that conscious patients who suffer from minor symptoms after low-current injuries are not at risk for cardiac complications . Furthermore, electrophysiological studies (nerve conduction testing, electromyography, etc.) are recommended for nerve damage .