Emergency Medicine Hub / Toxicology & Environmental • 3 min read • 4 sections

Electrical & Lightning Injuries: Physics & Resuscitation

Comprehensive emergency evaluation and protocolized resuscitation for electrical shock and lightning strike emergencies: the biophysics of electrical tissue damage (Ohm's law, Joule's law, and tissue resistance hierarchy); low-voltage alternating current (AC) 'no-let-go' flexor tetany and Ventricular Fibrillation; high-voltage direct current (DC) blast forces, Asystole, and deep 'iceberg' muscle necrosis; acute compartment syndrome and myoglobinuric rhabdomyolysis; pediatric oral commissure labial artery burns; and Lightning Strikes (flashover effect, pathognomonic Lichtenberg fern figures, transient keraunoparalysis, ruptured tympanic membranes, and the mandatory 'Reverse Triage' algorithm).

Resuscitation Quick Actions • First 2 Minutes

High-Acuity

Lightning Reverse Triage

Triage dead/pulseless/apneic victims FIRST; spontaneous ROSC occurs while medullary apnea persists -> Immediate prolonged rescue breathing and CPR saves lives

High-Voltage Fluid Target

Resuscitate with balanced crystalloids targeting a high urine output of 100 to 200 mL/hour (1.5-2.0 mL/kg/h in kids) until myoglobinuria clears

AC vs DC Dysrhythmias

Alternating Current (AC: 60 Hz household) = Ventricular Fibrillation; Direct Current (DC: lightning, industrial high-voltage) = Asystole

Lichtenberg Figures

Pathognomonic cutaneous fern-like, arborizing erythematous skin arborization caused by electron showering along dermal pathways; not true burns, fade in 24-48h

Keraunoparalysis

Transient, flaccid, pulseless paralysis of lower extremities with cold mottling caused by intense sympathetic vasospasm; typically resolves within hours

Pediatric Labial Artery Warning

Chewing on electrical cord: 7 to 14 days later, when necrotic eschar sloughs, severe arterial bleeding occurs from the LABIAL ARTERY -> Instruct parents on digital pinching

Bottom-Line Clinical Pearl

In lightning strike mass casualty incidents, standard disaster triage is completely inverted: execute **REVERSE TRIAGE**, resuscitating victims in respiratory and cardiac arrest FIRST. Lightning acts as a massive cosmic countershock producing instantaneous asystole and medullary respiratory center paralysis; the cardiac intrinsic pacemaker often spontaneously restarts, but the patient suffocates into secondary hypoxic cardiac arrest unless immediate rescue breathing and CPR are provided. In high-voltage electrical burns (> 1,000 V), cutaneous surface wounds represent merely the 'tip of the iceberg': massive thermal coagulative necrosis occurs in deep muscle and bone, mandating aggressive fluid resuscitation (target urine output 100-200 mL/hr) and emergent operative fasciotomies.

1. Biophysics of Electrical Trauma: Ohm's & Joule's Laws

Electrical tissue damage is governed by physical laws: Ohm's Law ($I = V/R$) dictates that current ($I$) is directly proportional to voltage ($V$) and inversely proportional to tissue resistance ($R$). Joule's Law ($Q = I^2 imes R imes t$) demonstrates that heat generated ($Q$) is proportional to the square of current multiplied by resistance and duration of contact ($t$). Body tissues have a strict hierarchy of electrical resistance:

Tissue Resistance Hierarchy	Specific Anatomical Tissue	Conduction Behavior & Vulnerability
Least Resistance (Best Conductors)	Nerves, Blood Vessels, Blood, Mucous Membranes	Current flows preferentially along low-resistance vascular conduits and peripheral nerves, producing immediate intravascular thrombosis, endothelial destruction, and extensive neural transmission block.
Intermediate Resistance	Muscle, Skin, Tendon	Muscle conducts current well, but because of its large mass, generates tremendous heat ($I^2 imes R$), producing deep coagulative necrosis and rhabdomyolysis.
Greatest Resistance (Worst Conductors)	Bone, Fat, Dry Calloused Skin	Bone has the highest electrical resistance in the human body; current traveling through bone generates massive temperatures, radiating intense heat outwards and cooking adjacent deep muscle groups from the inside out.

2. Alternating Current (AC) vs. Direct Current (DC) Mechanisms

Parameter	Alternating Current (AC: Standard Household)	Direct Current (DC: Industrial & Lightning)
Voltage Definition	Low voltage: < 1,000 V (standard 120V/240V). High voltage: > 1,000 V (power lines).	Industrial power, train third-rails, automotive batteries, and Lightning (> 100 million to 1 billion Volts).
Musculoskeletal Impact	Continuous Tetanic Muscle Spasms: Standard 60-Hz AC current matches the frequency of human muscle tetany (40-110 Hz). Produces the 'No-Let-Go' phenomenon: involuntary, irreversible flexor muscle contraction in the hand clamps the victim tightly to the live electrical conductor.	Single Violent Muscle Contraction: A massive, instantaneous muscular spasm throws the victim violently across the room, causing secondary blunt polytrauma, long-bone fractures, and posterior shoulder dislocations.
Cardiac Dysrhythmia Predilection	VENTRICULAR FIBRILLATION (VF): 60-Hz AC current triggers repetitive ventricular depolarizations during the vulnerable phase of cardiac repolarization (the relative refractory period on the T-wave), easily precipitating VF.	ASYSTOLE: Massive instantaneous direct current depolarizes the entire myocardium simultaneously, producing complete cardiac standstill (asystole).

3. The 'Iceberg Effect' & High-Voltage Electrical Resuscitation

In high-voltage electrical injuries (> 1,000 Volts), cutaneous entry and exit wounds represent less than 5% of total tissue destruction. Massive thermal coagulation occurs deep within muscular compartments along the neurovascular bundles, producing extensive subfascial muscle necrosis (The Iceberg Effect):

Complication/Intervention	Clinical Hallmark & Pathology	Emergency Action Protocol
Severe Rhabdomyolysis & Myoglobinuria	Lysis of skeletal myocytes releases massive amounts of intracellular myoglobin, potassium, and creatine kinase (CK often > 50,000-100,000 IU/L). Myoglobin precipitates in renal tubules under acidic conditions, causing acute tubular necrosis.	Aggressive Intravenous Crystalloid Resuscitation: - Infuse balanced crystalloids (Lactated Ringer's or Plasmalyte) to maintain Urine Output >= 100 to 200 mL/hour in adults (1.5-2.0 mL/kg/h in children) until urine is visually clear of pigment. - Alkalinize urine with Sodium Bicarbonate (target urine pH > 6.5) to prevent myoglobin precipitation.
Acute Extremity Compartment Syndrome	Deep muscular edema within rigid osseofascial envelopes. Pain on passive stretch is the earliest sign.	High index of suspicion; measure compartmental pressures (Stryker needle: Delta-P <= 30 mmHg). Stat Orthopedic/Burn surgery consultation for emergent operative decompressive fasciotomies.
Pediatric Oral Commissure Burns	Toddler bites or chews an electrical extension cord; arc burn across the corner of the mouth.	Immediate mucosal burn heals over 7-10 days into a thick dry eschar. DELAYED LIFE-THREATENING HEMORRHAGE: Between Day 7 and 14, the eschar sloughs, causing massive, pulsatile arterial bleeding from the Labial Artery! Instruct parents to pinch the lip firmly between thumb and forefinger and call 911 immediately.

4. Lightning Injuries: The Flashover Effect & Reverse Triage

Lightning delivers a high-voltage electrostatic discharge of up to 300 million Volts and 30,000 to 100,000 Amperes over a fraction of a millisecond (1/10,000th of a second). Because the exposure duration is so brief, current predominantly flows over the external surface of the body (a phenomenon known as the 'Flashover Effect'), which paradoxically prevents the massive internal deep-muscle cooking seen in industrial high-voltage burns:

Lightning Hallmark	Clinical Manifestation & Pathology	Diagnostic/Management Rule
REVERSE TRIAGE (Disaster Management Rule)	In mass casualty lightning incidents, PULSELESS, APNEIC VICTIMS ARE PRIORITIZED FIRST OVER BREATHING SURVIVORS!	Physiological Rationale: Lightning causes simultaneous instantaneous cardiac arrest (asystole) and paralysis of the medullary respiratory center. The myocardium has intrinsic automaticity and often spontaneously resumes sinus rhythm; however, medullary respiratory paralysis persists much longer. If bystander CPR and rescue breathing are initiated immediately, victims have an extraordinarily high survival rate (> 70-80%)!
Lichtenberg Figures (Feathering/Fern Patterns)	Erythematous, branching, fern-like, arborizing cutaneous patterns resembling tree branches or lightning bolts.	Pathognomonic for lightning strike! Caused by electrons showering through subcutaneous vascular trees and microvascular capillary rupture. These are not true thermal burns and disappear spontaneously within 24 to 48 hours without scarring.
Keraunoparalysis	Transient, dense, flaccid paralysis of the lower extremities accompanied by sensory loss, cold extremities, and absent peripheral pulses.	Caused by extreme, transient sympathetic vasospasm and neurostunning. Typically resolves spontaneously within 4 to 24 hours. (Do not confuse with permanent spinal cord injury!).
Bilateral Tympanic Membrane Rupture	Acoustic and blast shockwave generated by superheated expanding air (thunderclap).	Tympanic membrane rupture occurs in > 50% to 80% of direct lightning strike victims. Examine both ears with otoscope in all victims.

The Standard Triage Black Tag Error & The Superficial Burn Fluid Under-Resuscitation Trap

Applying standard mass casualty triage to lightning strikes is a lethal error: in typical disaster algorithms, unresponsive, pulseless, apneic patients are tagged with Black Tags (Expectant/Dead) and bypassed. In lightning strike disasters, this is DEADLY WRONG: execute REVERSE TRIAGE immediately. Apneic and pulseless victims are resuscitated FIRST; their hearts frequently recover automaticity, but their medullary breathing center is temporarily paralyzed. A few minutes of aggressive bag-valve-mask ventilation and chest compressions results in miraculous, neurologically intact survival. Concurrently, in high-voltage industrial electrical burns, NEVER calculate fluid resuscitation using standard thermal burn formulas (Parkland formula) based on visible skin surface area! Visible skin entry and exit wounds represent less than 5% of actual injury: the true damage is massive subfascial myonecrosis. If you calculate fluids based on the tiny skin wounds, the patient will receive inadequate fluids, precipitating massive myoglobinuric renal failure, uncal compartment syndrome, and death. Always titrate IV crystalloids to a strict objective target urine output of 100 to 200 mL/hour until myoglobinuria clears.

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