How do you classify and manage an electrical burn to the forearm and arm?

Classification and Management of Electrical Burns to the Forearm and Arm

Classification by Voltage

Electrical burns are classified as either high-voltage (≥1000 volts) or low-voltage (<1000 volts), with high-voltage injuries causing significantly more extensive subcutaneous, muscle, and bone damage. 1

• High-voltage injuries (≥1000 volts) are associated with:

  • Greater likelihood of loss of consciousness (69.1% vs. 23.6% in low-voltage) 2
  • Higher risk of cardiac arrest (20% vs. 3.6%) 2
  • Increased amputation rates (23.6% vs. 5.5%) 2
  • Predominantly male victims (98.2%) 2
  • Extensive deep tissue destruction affecting subcutaneous fat, muscles, and bones 1

• Low-voltage injuries (<1000 volts) typically result in lesser tissue damage but still require careful evaluation 1

Severity Classification for Triage

All electrical burns—regardless of voltage—are classified as severe burns requiring immediate referral to a specialized burn center. 3

For adults, electrical burns meet severe burn criteria when they involve:

• Burns from high-voltage electricity (as a standalone criterion) 3
• Burns from low-voltage electricity combined with TBSA >10% or deep burns 3-5% 3

For children, any electrical or chemical burn automatically qualifies as severe 3

Initial Assessment and Documentation

Use the Lund-Browder chart to document total body surface area (TBSA) affected, as it is the most accurate method and prevents both overtriage and undertriage that increase morbidity and mortality. 4

• The open hand (palm and fingers) represents approximately 1% TBSA as a practical alternative 4
• Smartphone applications (e.g., E-Burn) can facilitate assessment 4
• Critical caveat: Visible skin damage does NOT correlate with the extent of internal injury in electrical burns 1. The typical high-voltage injury involves extensive subcutaneous and muscle damage beneath seemingly limited cutaneous burns 1

Immediate Management Priorities

Cardiac Monitoring

Continuous cardiac monitoring is mandatory due to the risk of life-threatening arrhythmias including ventricular fibrillation, ventricular asystole, and ventricular tachycardia. 4

• Cardiopulmonary arrest is the primary cause of immediate death from electrocution 4
• Both low and high-voltage currents can precipitate cardiac arrhythmias 4

Fluid Resuscitation

Initiate aggressive fluid resuscitation with crystalloid isotonic fluids (0.9% saline) targeting urine output of 100 ml/hour. 5, 6

• Conventional burn resuscitation formulas based on body surface area are inadequate for electrical burns due to hidden musculoskeletal damage 1
• Avoid hypotonic solutions like lactated Ringer's, which increase tissue edema in electrical injuries 5
• Use fluid challenge technique with boluses of 250-1000 ml, reevaluating after each bolus 4
• Target 20% reduction in lactate levels within the first hour 4

Myoglobin Management

Monitor for heme pigments in urine and treat aggressively to prevent acute renal failure. 1, 6

• Large volumes of muscle destruction release myoglobin and hemoglobin products 1
• Treatment includes aggressive volume resuscitation, possible urine alkalinization, or IV mannitol to minimize pigment precipitation in renal tubules 1
• Maintain urine output at 100 ml/hour (higher than standard burn resuscitation) 6

Surgical Considerations

Perform escharotomy within 48 hours if compartment syndrome develops, ideally at a burns center by an experienced provider. 4

• Approximately 24% of electrical burn patients require amputation 7
• Damaged muscle swelling within investing fascia commonly causes compartment syndromes requiring urgent attention 1
• Serial and multiple debridement of wounds should be performed, preserving nerves, tendons, joints, and bones even if denatured, as these can partially regenerate if covered with vascularized skin 8
• Carpal tunnel release is associated with prolonged hospital stay (OR=4.25) 7

Specialist Referral

Immediately refer to a burn specialist to determine admission to a burns center, as direct admission reduces time to excision, duration of mechanical ventilation, and improves survival. 4

• Use telemedicine when no burns specialists are readily available, as it reliably improves TBSA measurement and prevents inappropriate transfers 4
• Burns involving the hands (as in forearm/arm injuries) require surgical intervention to prevent permanent disability and should be treated in a specialized burn center 4

Associated Injuries

Approximately 15% of electrical burn victims sustain traumatic injuries from falls or being thrown against objects. 1

• Tetanic muscle contractions cause imbalance favoring flexor groups, leading to:
  • Inability to release from electrical contact 1
  • Risk of bone fractures from prolonged muscular contracture 1
• Perform full neurologic examination on admission, documenting initial presentation 1

Neurologic Complications

Neurologic complications are highly variable and may present early or up to 2 years after injury. 1

• 16.7% of patients develop neurological deficits on or after admission 2
• Of those with deficits: 48.2% recover, 33.3% persist, 7.4% die, and 11.1% are lost to follow-up 2
• The prognosis for electricity-related neurologic injuries is generally better than other traumatic causes, suggesting a conservative approach with serial neurologic examinations after initial CT scan 1
• No significant differences in long-term neurological deficits between high and low voltage injuries 2

Common Pitfalls

• Never underestimate injury severity based on visible skin damage alone—electrical burns have extensive deep tissue damage not apparent on surface examination 5
• Do not delay reconstruction—functional outcome is inversely proportional to time elapsed before starting reconstructive procedures 8
• Monitor for infection—wound infection is associated with prolonged hospital stay (OR=2.60) and is the most common site of infection 7
• Assess for elevated CPK levels—associated with prolonged hospital stay (OR=1.40) 7