High-voltage injuries (1,000 volts or more) send current through the body that heats and destroys deep tissue, so small skin burns can hide major muscle damage. They can cause cardiac arrest, arrhythmias, trauma from falls, compartment syndrome and kidney injury from muscle breakdown.
Key symptoms
- Entry and exit burns, often on the hands and feet
- Pain, numbness or weakness in a limb
- Palpitations or chest pain
- Loss of consciousness or confusion
- Dark urine in the following hours
What you find on exam
- Scene safety: the power must be off before touching the patient
- Pulse, rhythm and ABCs; CPR and AED if needed
- Burns at contact points and along the current path
- Limb compartments: tense, painful swelling
- Trauma survey for falls or being thrown, including the spine
Tests
- 12-lead ECG and continuous cardiac monitoring
- CK, electrolytes and kidney function
- Urinalysis for myoglobin
- Imaging for trauma; troponin if chest pain or ECG changes
Treatment basics
- Do not approach until the utility confirms the line is dead
- Treat cardiac arrest with standard CPR and defibrillation
- Spinal motion restriction after a fall or a throw
- Generous IV fluids aiming for urine output near 1 mL/kg/hour if myoglobin is present; burn formulas underestimate needs
- Transfer to a burn center; fasciotomy for compartment syndrome
Red flags
- Cardiac arrest or arrhythmia on the monitor
- Tense, painful limb swelling
- Dark or red-brown urine
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Related guides
Sources: NASEMSO National Model EMS Clinical Guidelines; NREMT psychomotor skill sheets (EMT and Paramedic); National EMS Education Standards (2021). Written by Making Synapses. Making Synapses is not affiliated with these organizations.