Pathology
- High voltage injuries are over 1000 volts
- Current follows the path of least resistance, heating bone and causing deep muscle necrosis beneath intact skin
- Tetanic muscle contraction causes fractures and dislocations, such as posterior shoulder dislocation
- Low voltage injuries are mostly household and cause local burns
- Tissue resistance rises from nerve and vessel through muscle and skin to bone
- Lightning causes a flashover with fewer deep injuries but high mortality from cardiac arrest
Clinical Features
- Entry and exit wounds may be small
- Compartment syndrome
- Myoglobinuria from rhabdomyolysis
- Cardiac arrhythmia
- Peripheral nerve injury and later neuropathy
- Cataracts and spinal cord injury can appear late
- Associated falls cause spinal and long bone fractures
Investigations
- ECG and cardiac monitoring
- CK, renal function and urine myoglobin
- X-ray for fractures and dislocations
- Serial compartment pressures where examination is unreliable
- CT of the spine after falls from height
- Full trauma survey following EMST principles
Management
- Aggressive IV fluids to maintain high urine output
- Early fasciotomy and serial debridement
- Amputation rates are high after high voltage injury
- Burns unit referral
- See Compartment Syndrome
- Target urine output of 1 to 1.5 mL/kg/hr while myoglobin persists
- Early debridement within 48 hours, repeated every 2 to 3 days
- Delayed coverage with flaps once wounds are clean
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.