Emergency Medicine · Trauma and Environmental Emergencies
The facts most likely to be tested
Cardiac arrhythmias are the most common cause of immediate death following high-voltage electrical injury.
Continuous cardiac monitoring is mandatory for all patients with high-voltage exposure or documented loss of consciousness.
Rhabdomyolysis resulting in myoglobinuria is a frequent complication of deep tissue damage, requiring aggressive intravenous fluid resuscitation.
Lichtenberg figures are pathognomonic fern-like skin markings associated with lightning strikes.
Compartment syndrome is a high-risk complication of electrical burns due to extensive deep muscle necrosis and edema.
Cataracts are a classic delayed ocular complication that can manifest months after a high-voltage electrical injury.
Renal failure secondary to acute tubular necrosis from myoglobin pigment load is a critical systemic sequela of severe electrical trauma.
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A 34-year-old male electrician is brought to the emergency department after accidentally grasping a 7,000-volt power line. He was briefly unconscious at the scene but is now alert and oriented. Physical examination reveals a full-thickness burn on his right palm and a charred entry wound on his left foot. His urine is dark brown in color, and a dipstick is positive for blood but negative for red blood cells on microscopy.
What is the most appropriate next step in management to prevent renal failure?
Aggressive intravenous fluid resuscitation
The patient's presentation of dark urine positive for blood but negative for RBCs indicates myoglobinuria from rhabdomyolysis, which requires aggressive fluid resuscitation to prevent acute tubular necrosis.
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Etiology / Epidemiology
High-voltage (>1000V) injuries carry high mortality. Occupational exposure is the primary risk factor.
Clinical Manifestations
Lichtenberg figures are pathognomonic. Cardiac arrhythmias are the leading cause of immediate death.
Diagnosis
ECG is the gold standard for all patients. Monitor creatine kinase (CK) for rhabdomyolysis.
Treatment
Aggressive IV fluid resuscitation is mandatory. Do not delay fasciotomy for compartment syndrome.
Prognosis
Delayed cataracts and neurological deficits are common long-term sequelae.
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Epidemiology & Etiology
Electrical injuries occur via direct contact, arc flash, or lightning strikes. High-voltage (>1000V) injuries are associated with significant internal tissue destruction despite minimal surface burns. Occupational settings, particularly construction and utility work, represent the highest risk factors.
Pertinent Anatomy
Current follows the path of least resistance: nerves, blood vessels, and muscles. Bone has high resistance, generating intense heat at bone-soft tissue interfaces, leading to deep, hidden necrosis.
Pathophysiology
Electrical current causes direct cell membrane damage (electroporation) and thermal injury. The conversion of electrical energy to heat causes coagulation necrosis. Massive muscle damage releases myoglobin, leading to acute tubular necrosis.
Clinical Manifestations
Patients may present with Lichtenberg figures (fern-like skin markings). Cardiac arrest or ventricular fibrillation is the primary cause of death. Look for entry and exit wounds, which often underestimate the extent of internal damage.
Diagnosis
Perform an ECG on all patients to rule out arrhythmias. Obtain creatine kinase (CK) and urinalysis to screen for myoglobinuria. Gold standard for assessing deep tissue injury is surgical exploration if clinical suspicion is high.
Treatment
Initiate IV fluids to maintain urine output of 1-2 mL/kg/hr to prevent renal failure. Do not use diuretics until volume status is optimized. Perform fasciotomy for compartment syndrome; do not delay based on pulses.
Prognosis
Monitor for delayed cataracts occurring months post-injury. Long-term neurological deficits including peripheral neuropathy and cognitive impairment are frequent. Renal failure is a major complication of untreated rhabdomyolysis.
Differential Diagnosis
Lightning strike: Lichtenberg figures present
Thermal burn: superficial damage matches depth
Chemical burn: localized tissue liquefaction
Seizure disorder: history of tonic-clonic activity
Myocardial infarction: primary cardiac event without external trauma