Electrical Injuries Summary

Severity Factors

  • AC vs. DC current
  • Voltage (high vs. low)
  • Current magnitude
  • Resistance
  • Current pathway
  • Contact area & duration

Cardiac Effects

  • VF (most common with AC)
  • Asystole (more common with DC)
  • Myocardial ischemia
  • Coronary artery spasm

Respiratory Effects

  • Central respiratory depression
  • Respiratory muscle paralysis
  • Prolonged muscular paralysis

Lightning Specific

  • 300 kV over milliseconds
  • External flashover phenomenon
  • Head/neck/shoulder contact points
  • Massive catecholamine release

Emergency Management

  • Ensure scene safety first
  • Early intubation if facial burns
  • VF: Immediate defibrillation
  • IV fluids for tissue damage
  • Watch for compartment syndrome

Key Complications

  • Deep tissue injury along neurovascular bundles
  • Compartment syndrome
  • Rhabdomyolysis
  • Neurological sequelae
  • Multi-system organ failure

Admission Criteria

  • Cardiorespiratory symptoms
  • Loss of consciousness
  • Cardiac arrest
  • ECG abnormalities
  • Significant burns/tissue damage

Lightning Strikes and Electrical Injuries

Potentially devastating multi-system injuries requiring comprehensive emergency management

Overview

Electrical injury is a relatively infrequent but potentially devastating multi-system injury with high morbidity and mortality. Most electrical injuries in adults occur in the workplace and are associated generally with a high voltage, whereas children are at risk primarily at home, where the voltage is lower (220V in Europe).

Epidemiology: Adults - workplace high voltage; Children - home low voltage (220V Europe)

Factors Influencing Injury Severity

Current Characteristics

  • AC vs. DC: AC causes tetanic muscle contraction
  • Voltage: High voltage (>1000V) vs. low voltage
  • Current magnitude: Higher current = greater injury

Patient Factors

  • Resistance: Tissue resistance affects current flow
  • Current pathway: Transthoracic most dangerous
  • Contact area: Smaller area = greater current density
  • Duration of contact: Longer contact = worse injury

Tissue Resistance (Highest to Lowest)

  • Bone → Fat → Tendon → Skin → Muscle → Blood → Nerve
  • Current follows path of least resistance (neurovascular bundles)

Pathophysiology

Mechanisms of Injury

Direct Electrical Effects

  • Tetanic muscle contraction (AC current)
  • Myocardial effects: VF, asystole, ischemia
  • Respiratory arrest: Central depression or muscle paralysis

Tissue Damage

  • Thermal injury: Joule heating effect
  • Electroporation: Cell membrane disruption
  • Deep tissue destruction along current pathway

Current Pathways and Mortality Risk

Pathway Description Mortality Risk
Transthoracic Hand-to-hand Highest
Vertical Hand-to-foot High
Straddle Foot-to-foot Lower

Cardiac Vulnerability: Current traversing myocardium during vulnerable period (analogous to R-on-T phenomenon) can precipitate VF.

Lightning Strikes

Lightning strikes deliver as much as 300 kV over a few milliseconds and cause about 1000 deaths worldwide each year.

Unique Characteristics

  • External flashover: Most current passes over body surface
  • Massive energy: 300 kV over milliseconds
  • Contact points: Head, neck, shoulders (vs. hands in industrial)
  • Indirect injury: Ground current or "splashing"

Mechanisms of Injury

  • Direct strike
  • Contact injury (touching struck object)
  • Side flash/splash
  • Ground current
  • Blast effect (explosive force)

Cardiovascular Effects

  • Massive catecholamine release and autonomic stimulation
  • Hypertension and tachycardia
  • ECG changes: QT prolongation, T wave inversion
  • Myocardial necrosis with CK release
  • Cardiac/respiratory arrest as cause of death

Neurological Effects

Emergency Management

Scene Safety First: Ensure power source is switched off. High voltage electricity can arc and conduct through ground for several meters.

Initial Resuscitation

Primary Survey
  1. Scene safety: Ensure electrical source is disconnected
  2. Airway: Early intubation if facial/neck burns present
  3. Breathing: Ventilatory support for muscular paralysis
  4. Circulation: Manage arrhythmias per ACLS guidelines
  5. Disability: Neurological assessment
  6. Exposure: Remove smoldering clothing

Specific Management

Cardiac Management

  • VF: Most common after high voltage AC - immediate defibrillation
  • Asystole: More common after DC - standard ACLS
  • ECG monitoring: All patients require cardiac monitoring

Fluid and Tissue Management

  • IV fluids: For significant tissue destruction
  • Urine output: Maintain good output for myoglobin clearance
  • Compartment syndrome: Monitor for and perform fasciotomy if needed
  • Surgical consultation: Early for severe thermal injuries

Secondary Survey

Conduct thorough secondary survey to exclude injuries from:

  • Tetanic muscular contraction
  • Being thrown by shock force
  • Blast effect (lightning)
  • Fall from height

Complications and Monitoring

Immediate Complications

Cardiac

  • VF/Asystole
  • Myocardial necrosis
  • Coronary artery spasm
  • ECG abnormalities

Neurological

  • Respiratory center depression
  • Muscle paralysis
  • Seizures
  • Peripheral neuropathy

Musculoskeletal

  • Compartment syndrome
  • Rhabdomyolysis
  • Fractures/dislocations
  • Deep tissue necrosis

Admission Criteria

Admit all patients with:

  • History of cardiorespiratory problems
  • Loss of consciousness
  • Cardiac arrest
  • ECG abnormalities
  • Significant soft tissue damage or burns

Long-term Prognosis

Morbidity and long-term prognosis determined by:

  • Severity of burns (thermal or electrical)
  • Extent of myocardial necrosis
  • Central nervous system injury
  • Secondary multiple system organ failure