Electrical injuries
Electrical injuries produce a wide spectrum of problems that extend far beyond the visible skin lesion. Harm depends on current type, voltage, contact duration, contact area and the pathway through the body.
Electricity can directly damage myocardium, nerves and muscle, cause deep thermal injury with deceptively small surface burns, provoke violent muscle contractions causing fractures and dislocations, and precipitate systemic complications such as rhabdomyolysis, acute kidney injury and multi‑organ dysfunction.
Emergency clinicians must combine rapid resuscitation with awareness of delayed complications and a low threshold for monitoring and specialist referral.
Mechanism and determinants of injury
- Current type
- Alternating current (AC, common in domestic supply) is more arrhythmogenic, tends to produce tetanic muscle contraction and ventricular fibrillation/tachycardia (VF/VT).
- Direct current (DC) is less likely to produce VF but can cause asystole and powerful single shocks.
- Voltage
- High‑voltage (>1,000 V) is associated with greater deep tissue destruction.
- Low voltage (<1,000 V) can still be serious if the thorax is in the current pathway or contact is prolonged.
- Contact area and skin condition
- Small‑area (point) contact concentrates current density and increases deep tissue injury.
- Wet skin markedly reduces resistance and increases current flow.
- Pathway and duration
- Thoracic pathways increase cardiac risk.
- Longer contact increases energy transfer and tissue necrosis.