Electrical Injury and Lightning Strike

Quick Answer

What are the critical anaesthetic considerations for electrical injuries?

Electrical injuries cause devastating deep tissue damage, cardiac arrhythmias, and systemic complications disproportionate to visible burns. Key principles:

1. Cardiac monitoring - All patients require ECG monitoring for 24-48 hours; delayed arrhythmias common
2. Tissue injury - "Iceberg effect" - extensive deep tissue necrosis despite small surface burns
3. Rhabdomyolysis - Common with high voltage; aggressive fluid resuscitation to prevent AKI
4. Compartment syndrome - Monitor closely; early fasciotomy may be limb/life-saving
5. Fluid resuscitation - Higher volumes than standard burns (deep tissue injury); target urine output >100 mL/hr
6. Myoglobin management - Alkalinisation, mannitol, diuresis; dialysis if renal failure develops
7. Lightning vs AC injury - Lightning (DC) often causes asystole; AC causes VF; lightning has higher survival

Clinical Pearl: The visible burns in electrical injury are just the tip of the iceberg. There is often massive deep tissue destruction along the current pathway. A patient with small entry/exit wounds may have extensive muscle necrosis requiring amputation. Always assume deep tissue injury until proven otherwise.

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Clinical Overview

Epidemiology

Global and Australian context:

Australian context:

• High-voltage injuries: Power lines, electrical trades, railway
• Lightning: Summer storms, especially in tropical areas
• Household: 240V injuries common (children, DIY enthusiasts)
• Indigenous communities: Higher rates (poor infrastructure, informal wiring)

Physics of Electrical Injury

Ohm's Law: V = I × R

Tissue resistance (least to most):

1. Nerves (least resistance - current prefers)
2. Blood vessels
3. Muscle
4. Skin (variable - wet vs dry)
5. Tendon
6. Fat
7. Bone (most resistance - generates heat)

Current types:

Current thresholds:

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Pathophysiology

Mechanism of Injury

1. Direct tissue damage (electrothermal):

• Conversion of electrical energy to heat
• Tissue temperature rises according to I² × R (Joule heating)
• Coagulation necrosis along current pathway
• Blood vessels thrombose → ischaemia
• Muscle necrosis → rhabdomyolysis

2. Electrical disruption of cell membranes:

• Electroporation of cell membranes
• Disruption of Na+/K+ pumps
• Cell death even without significant heating

3. Mechanical injury:

• Violent muscle contractions
• Falls from height (secondary trauma)
• Blast effect (lightning, high voltage arc)

4. Secondary trauma:

• Falls
• Blast injuries
• Associated burns (clothing ignition)

Types of Electrical Contact

Patterns of Injury

Entry and exit wounds:

Current pathway determines injury:

Lightning Injury (Unique Features)

Mechanisms:

Clinical features:

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Clinical Manifestations

Immediate Effects

Cardiovascular:

Neurological:

Musculoskeletal:

Renal:

• Myoglobinuric acute kidney injury
• Hypovolaemia
• Direct renal injury (current through kidneys)

Cutaneous:

• Entry/exit burns
• Arc burns
• Flame burns
• Lichtenberg figures (lightning)

Delayed Complications

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Prehospital Management

Scene Safety (Critical)

Safety priorities:

DO NOT:

• Touch patient while still in contact with source
• Approach high-voltage lines
• Assume power is off

Initial Assessment

ABCDE approach:

Immediate interventions:

• CPR if cardiac arrest
• Defibrillation if VF/VT
• Immobilise if trauma suspected
• IV access (large bore × 2)
• Fluid bolus if hypotensive
• Pain management

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Emergency Department Management

Initial Priorities

Resuscitation:

Investigations:

Fluid Resuscitation

Principles:

• Deep tissue injury causes massive fluid sequestration
• Standard Parkland formula underestimates needs
• Rhabdomyolysis requires aggressive hydration

Targets:

Fluid choice:

• Isotonic crystalloid (0.9% NaCl or Hartmann's)
• Glucose-containing fluids may be needed (large volumes)
• Blood products if significant blood loss

Typical volumes:

• Often 10-20 L in first 24 hours for severe injuries
• Titrate to urine output and haemodynamics

Rhabdomyolysis and Myoglobin Management

Prevention of AKI:

Urine alkalinisation:

• Add sodium bicarbonate to IV fluids (100-150 mEq/L)
• Target urine pH >6.5
• Monitor serum pH (avoid >7.5)
• Avoid if patient has metabolic alkalosis

Complications of treatment:

• Hypocalcaemia (due to precipitation with myoglobin)
• Hypernatraemia
• Metabolic alkalosis
• Volume overload

Indications for dialysis:

• Refractory hyperkalaemia
• Severe acidosis
• Volume overload
• Progressive uraemia
• Persistent oliguria despite optimisation

Cardiac Management

Monitoring:

• Continuous ECG for 24-48 hours (all patients)
• Telemetry unit or ICU
• Watch for delayed arrhythmias

Arrhythmia management:

Specific considerations:

• Lightning: May have fixed dilated pupils, asystole - continue CPR
• Young patients: More resilient; prolonged resuscitation may be successful
• ECG changes often resolve but monitor for delayed arrhythmias

Wound and Tissue Management

Surgical consultation:

• All high-voltage injuries require surgical review
• Plastic surgery, vascular surgery, orthopaedics

Escharotomy/fasciotomy:

• Indicated for circumferential burns compromising circulation
• Compartment syndrome: Emergency fasciotomy
• Check compartments serially (clinical exam + compartment pressures)

Compartment pressure monitoring:

• Normal <10-15 mmHg
• Compartment syndrome >30-40 mmHg (or within 30 mmHg of diastolic)
• Clinical signs: Pain, pallor, paraesthesia, pulselessness, paralysis (late)

Wound care:

• Topical antimicrobial agents
• Dressings
• Early excision of non-viable tissue
• Reconstruction (grafting, flaps)

Lightning-Specific Management

Unique considerations:

• Multiple victims possible - triage carefully
• Respiratory arrest may outlast cardiac arrest
• Fixed dilated pupils not necessarily brain death
• Lichtenberg figures are not burns (no treatment needed)
• Keraunoparalysis usually temporary

CPR in lightning strike:

• May be prolonged respiratory arrest with viable myocardium
• Continue ventilation even if no pulse initially
• Resuscitate first "apparently dead" (may have asystole that reverts spontaneously)
• Triage reverse: Usually resuscitate those "not breathing" first

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Surgical Management

Indications for Surgery

Timing

Anaesthetic Considerations for Surgery

Challenges:

• Massive fluid shifts
• Rhabdomyolysis risk
• Compartment syndrome development intraoperatively
• Associated trauma
• Need for repeated surgeries

Monitoring:

• Arterial line
• Central venous access
• Urine output (maintain >100 mL/hr)
• Temperature
• Neuromuscular monitoring (avoid suxamethonium if extensive muscle injury >24 hours)

Technique:

• General anaesthesia
• Avoid suxamethonium if rhabdomyolysis >24 hours (hyperkalaemia risk)
• Large fluid requirements
• Blood conservation techniques (cell saver if appropriate)
• Consider regional techniques for analgesia (if no compartment syndrome)

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Special Populations

Children

Unique features:

• Biting electrical cords (oral burns)
• Small surface area to deep tissue ratio
• Higher risk of long-term growth issues if growth plates affected
• Lower voltage can cause VF (wet skin, smaller body)

Oral commissure burns:

• Common in toddlers
• Risk of delayed labial artery bleeding (day 5-10)
• Risk of microstomia
• Plastic surgery follow-up essential

Pregnant Patients

Considerations:

• Fetal heart monitoring (fetus acts as conductor)
• Fetal mortality 50-70% if mother survives
• Preterm labour risk
• Placental abruption
• Left lateral positioning

Pre-existing Medical Conditions

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Complications and Long-Term Sequelae

Immediate Complications

Delayed Complications

Follow-Up

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Indigenous Health Considerations

Aboriginal and Torres Strait Islander Communities

Disproportionate burden:

Cultural considerations:

Prevention:

• Community electrical safety programs
• Safe wiring initiatives
• Workplace safety education
• Lightning safety education for outdoor workers

Māori Health

Considerations:

• Higher occupational exposure in some industries
• Outdoor work (lightning risk)
• Whānau involvement in rehabilitation
• Culturally appropriate pain management

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ANZCA Final Examination Focus

High-Yield Topics

Written examination:

Viva scenarios:

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Assessment Content

SAQ 1: High-Voltage Electrical Injury (20 marks)

Question:

A 35-year-old electrician sustained a high-voltage (11,000V) electrical injury after contacting overhead power lines. He has entry wounds on both hands and exit wounds on both feet. He is conscious but confused. His ECG shows sinus tachycardia with occasional ventricular ectopics. CK is 45,000 U/L.

a) What are the immediate priorities in managing this patient? (8 marks)

b) How would you manage the risk of acute kidney injury in this patient? (6 marks)

c) What surgical considerations are relevant? (6 marks)

Model Answer:

a) Immediate Priorities (8 marks):

Cardiovascular (2 marks):

• Continuous ECG monitoring (mandatory for all electrical injuries, minimum 24-48 hours)
• Monitor for delayed arrhythmias (VF, VT, conduction blocks)
• Treat ventricular ectopics if frequent or symptomatic
• IV access with large-bore cannula × 2
• Fluid resuscitation (deep tissue injury requires massive volumes)

Fluid resuscitation and rhabdomyolysis (2 marks):

• Aggressive crystalloid resuscitation (0.9% NaCl or Hartmann's)
• Target urine output >100 mL/hour
• Serum CK 45,000 confirms massive rhabdomyolysis
• Foley catheter for urine output monitoring
• Monitor renal function (creatinine, electrolytes)

Tissue injury assessment (2 marks):

• Full examination for entry/exit wounds (hands entry, feet exit)
• Assess all muscle compartments for compartment syndrome
• Document neurovascular status of all limbs
• Surgical consultation urgent (plastic/vascular/orthopaedic)

Trauma assessment (1 mark):

• C-spine immobilisation (fall risk)
• Assess for secondary trauma (fall from height, blast)
• CXR (cardiac injury, blast lung)
• Long bone X-rays (fractures from tetany or fall)

Other (1 mark):

• Baseline investigations: FBC, electrolytes (especially K+), coagulation, ABG, lactate
• Pain management (likely severe)
• Tetanus prophylaxis
• Temperature monitoring

b) AKI Prevention (6 marks):

Aggressive hydration (2 marks):

• High-volume crystalloid resuscitation (may need 10-20 L/24 hours)
• Target urine output >100 mL/hour (adult)
• Maintain MAP >65 mmHg
• CVP monitoring may guide (target 8-12 mmHg)

Urine alkalinisation (2 marks):

• Sodium bicarbonate 100-150 mEq/L added to IV fluids
• Target urine pH >6.5 (prevents myoglobin precipitation in tubules)
• Monitor serum pH (avoid >7.5)
• Contraindicated if patient already alkalotic

Osmotic diuresis (1 mark):

• Mannitol 0.25 g/kg IV q6h once volume replete
• Promotes osmotic diuresis
• Reduces intracompartmental pressure
• Avoid if hyponatraemic

Avoid nephrotoxins (1 mark):

• Avoid contrast studies if possible
• Avoid aminoglycosides, NSAIDs
• Adjust medication doses for renal function

*c) Surgical Considerations (6 marks):

Compartment syndrome (3 marks):

• High risk with high-voltage hand-to-foot pathway
• Serial neurovascular examinations every 1-2 hours
• Compartment pressure monitoring if clinical concern
• Emergency fasciotomy if:
  • Clinical signs (pain, pallor, paraesthesia, pulselessness)
  • Compartment pressure >30-40 mmHg
  • Pressure within 30 mmHg of diastolic BP
• Four-compartment fasciotomy in lower leg if indicated

Wound management (2 marks):

• Escharotomy if circumferential burns compromising circulation
• Early surgical debridement of non-viable tissue
• Amputation if limb unsalvageable
• Tissue viability assessment (may evolve over days)
• Reconstructive planning (grafts, flaps)

Consultation (1 mark):

• Plastic surgery for wound management
• Vascular surgery if major vessels involved
• Orthopaedics if fractures/dislocations
• Surgical team involvement early (may need repeated trips to theatre)

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SAQ 2: Lightning Strike (20 marks)

Question:

Five construction workers are struck by lightning during a storm. On your arrival:

• Patient A: Unconscious, no pulse, apnoeic
• Patient B: Conscious, complaining of leg weakness and numbness
• Patient C: Confused, burns on chest, tympanic membrane rupture
• Patient D: Dead (obvious signs of death)
• Patient E: Minor burns, anxious

a) How would you triage these patients? (6 marks)

b) What is keraunoparalysis, and how would you manage Patient B? (6 marks)

c) What specific complications would you anticipate in Patient C, and how would you investigate? (8 marks)

Model Answer:

a) Triage (6 marks):

Triage principles for lightning (reverse of normal):

Patient A (Not breathing, no pulse): PRIORITY 1 (2 marks)

• In lightning, asystole can revert spontaneously with CPR
• "Apparent death" may be reversible
• Immediate CPR and ventilation
• May need prolonged resuscitation
• Do not pronounce dead at scene

Patient B (Conscious with neuro deficits): PRIORITY 2 (2 marks)

• Keraunoparalysis likely
• Stable airway and breathing
• Needs assessment but not immediately life-threatening
• Will likely recover

Patient C (Confused with injuries): PRIORITY 3 (2 marks)

• Stable vital signs
• Burns and TM rupture not immediately life-threatening
• Can wait for treatment after more critical patients

Patient D (Dead): Expectant (0 marks)

• Obvious signs of death incompatible with life
• Do not resuscitate

Patient E (Minor injuries): Minor (0 marks)

• Can wait
• First aid treatment

*b) Keraunoparalysis (6 marks):

Definition (2 marks):

• Temporary paralysis following lightning strike
• Autonomic nervous system instability
• Usually affects lower limbs more than upper
• Transient phenomenon (usually resolves within hours)
• Pathophysiology unclear (possible catecholamine surge or ion channel disruption)

Clinical features (2 marks):

• Motor paralysis
• Sensory abnormalities (numbness, paraesthesia)
• Mottled skin
• Pallor
• Cold limbs
• Weak or absent pulses (not true vascular compromise)

Management (2 marks):

• Supportive care
• Observation
• Reassurance (usually temporary)
• Protect paralysed limbs (positioning, padding)
• Monitor for recovery (usually within 24 hours)
• Avoid aggressive interventions
• If not improving, consider spinal cord injury (imaging)

c) Patient C Complications and Investigation (8 marks):

Immediate complications (3 marks):

• Cardiac: Arrhythmias (24-48 hour monitoring required), myocardial stunning, conduction abnormalities
• Neurological: Confusion (common post-lightning), memory loss, seizures
• Burns: Entry/exit burns (chest burn may be entry or contact)
• Auditory: Tympanic membrane rupture (common from blast effect)
• Ocular: Cataracts (delayed), retinal detachment, optic nerve injury
• Vascular: Vasospasm, autonomic instability

Delayed complications (3 marks):

• Cataracts (develop 6-24 months later)
• Neuropsychological deficits
• Chronic pain syndromes
• Seizure disorder
• Permanent neurological deficits (rare but possible)

Investigations (2 marks):

• ECG (admission and 24-48 hour monitoring)
• Cardiac enzymes (troponin)
• CT brain (if altered mental status)
• Ophthalmology examination (fundoscopy)
• Audiometry (formal hearing test when acute issues resolved)
• CXR (if chest symptoms)
• Skin examination and photography of burns

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References

1. Australian Institute of Health and Welfare. Electrical injury and electrocution. Canberra: AIHW; 2023.
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3. Fish RM. Electric injury, part II: specific injuries. J Emerg Med. 2000;18(1):27-34. PMID: 10609916
4. Fish RM. Electric injury, part III: monitoring indications, the pregnant patient, and lightning. J Emerg Med. 2000;18(2):181-187. PMID: 10690985
5. Arnoldo BD, Purdue GF, Kowalske K, et al. Electrical injuries: a 20-year review. J Burn Care Rehabil. 2004;25(6):479-484. PMID: 15505321
6. Hunt JL, Mason AD Jr, Masterson TS, Pruitt BA Jr. The pathophysiology of acute electric burns. J Trauma. 1976;16(4):335-340. PMID: 1267053
7. Lee RC. Injury by electrical forces: pathophysiology, manifestations, and therapy. Curr Probl Surg. 1997;34(9):677-764. PMID: 9361148
8. Bernstein T. Electrical shock hazards. IEEE Spectr. 1973;10:40-49.
9. McCann M, hunting KL, Murawski J, et al. Prevalence of workplace electrical safety practices and injuries among US electricians. Am J Ind Med. 2015;58(8):835-848. PMID: 26011577
10. Chen EH, Sareen A. Do we need to be more cautious in managing low-voltage electrical burns? J Burn Care Res. 2012;33(6):e285-e290. PMID: 22421487

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File generated for ANZCA Final Examination preparation. Last updated: 2026-02-03