Author: Erica Cohen, MD

Editor: Brian Gilberti, MD

 

Definition:

  • Naturally occurring electric arc between a cloud and the ground
  • Most common during thunderstorms
  • Direct strikes can be > 10 million volts [1]
  • Usually last between 1/10-1/1000 of a second [1]

 

Epidemiology:

  • ~300-500 injuries/year, ~50-100 deaths/year [2,3]
  • Most commonly occurs in young males and those who perform outdoor work or pursue outdoor recreational activities.
    • Most common during the spring and summer months (i.e., fishing, golfing, camping).
  • Lightning strikes may injure a group of people simultaneously.
  • Lightning strikes occur most frequently in areas with higher incidence of thunderstorms such as unexposed areas at higher elevations (i.e. mountain terrain will have more lightning strikes than surrounding lower elevations)

 

Pathophysiology:

  • Flashover: lightning travels across the body’s surface
    • Wet skin allows current to travel along the outside of the body
    • Less likely to result in internal injuries
    • Higher survival incidence
  • Mechanisms of Injury:
    • Electric current travels through the body (not common)
    • The conversion of electrical energy to thermal energy results in burn injury
    • Mechanical trauma (i.e. being thrown from a transmitted shock wave or direct strike from a bolt)
    • Rapid expansion and contraction of air (ex., TM perforations)

 

  • Keraunoparalysis (Stunning): flashover effect on the peripheral nervous and vascular systems [4,5]
    • Benign and reversible (transient) paralysis from peripheral vascular spasm
    • Signs: sensory abnormalities, pallor, coolness, diminished or absent pulses
      • Usually in the lower extremities > upper extremities
    • Avoid performing a fasciotomy on these patients as these findings are likely to resolve spontaneously within hours to days, though rarely they can be permanent
      • More permanent symptoms: muscular weakness, pain, photophobia, neurotic behavior

 

  • Types of lightning strikes [3]:
    • Direct (5%), contact (15%), side flash (30%), ground strike (50%)
      • Direct strike: struck directly by lightning discharge
      • Contact strike: lightning strikes an object held by a person and travels through the person to the ground
      • Side flash: current jumps to the victim from a nearby object via air (no physical contact)
      • Ground current (Step Voltage): current travels through the ground from the strike point
        • Stride Potential: The foot closer to the strike point will receive higher electrical potential compared to the foot farther away

 

Causes of Death:

  • Most deaths that occur within 1 hour of injury are from cardiac arrest due to fatal arrhythmia or respiratory arrest
    • Depolarization of the myocardium can result in asystole 
    • Depolarization and paralysis of the medullary respiratory center leads to respiratory arrest
      • Spontaneous cardiac activity usually resumes before respiratory activity, resulting in secondary hypoxic cardiac arrest
    • Ventricular dysrhythmias such as ventricular fibrillation are less common.

 

Evaluation:

Pre-Hospital: Reverse triage system – in mass casualty events, treat those with respiratory arrest and cardiac arrest first

  • After a lightning strike, prehospital providers should be advised to leave the scene as soon as possible and continue resuscitation and stabilizing efforts en route to the hospital, as the environmental conditions that led to a lightning strike in that location may persist (ie, lightning can strike twice!).

 

ED: Follow ATLS guidelines

  • Full trauma exam, including primary and secondary exam
    • Cutaneous burns demonstrate the current pathway
  • Labs: CBC, CMP (electrolytes, creatinine and BUN for kidney function), glucose
    • CK (though rhabdomyolysis is rare), troponin, EKG
    • UA to evaluate for myoglobinuria

 

Unique workup considerations:

  • Spinal fractures can occur from muscle contractions, therefore maintain spinal immobilization during initial resuscitation
  • Parkland Formula for extensive burns (& transfer to burn center if appropriate)
  • Aggressive IV fluid replacement is not always needed [6]
  • Consider hemorrhagic blood loss as the etiology of hypotension
  • Monitor for compartment syndrome and rhabdomyolysis (rare)
    • If concerned for compartment syndrome, fasciotomy should be performed within 6 hours of injury
  • Myotonic contractions can lead to shoulder dislocations

 

Organ Injury:

Cutaneous Injury:

  • Look for singed clothing, holes as below
  • Patients should be completely exposed to evaluate for cutaneous injuries
  • Treatment: tetanus prophylaxis, irrigation, debridement, wound dressings

 

  • Lichtenberg Figures
    • Pathognomonic, red superficial feathering or ferning pattern
    • Not true thermal burns, disappear within 24 hours
  • Flash Burns
    • Mild erythema
    • May involve cornea
  • Punctate Burns
    • Circular burns (cigarette shaped)
    • < 1cm, full thickness
  • Contact Burns
    • Metal close to the skin is heated resulting burn pattern unique to shape
  • Superficial Erythema and Blistering Burns
  • Linear Burns:
    • < 5 cm, skinfolds (axilla, groin)

 

Cardiac Injury:

  • Sympathetic activation may result in hypertension and tachycardia
    • Should resolve spontaneously
  • Effects: global depression of myocardial contractility, coronary artery spasm, pericardial effusion, and arrhythmias
  • EKG: ST elevation, QT prolongation, non-specific T wave inversions [5,7]
  • True MIs are rare… but initial EKG can mimic STEMI (ECG changes usually resolve, trend troponins)
  • Cardiac arrest secondary to a lightning strike has a better prognosis compared to other etiologies (ex., Occlusive MI); therefore, consider prolonged code

 

Neurologic Injury:

  • Peripheral nerve damage can present with abnormal sensory and/or motor findings
  • Other findings include:
    • AMS and depressed consciousness
    • Lower extremity paralysis
    • Seizures
  • Autonomic damage, such as fixed, dilated, and asymmetric or non-reactive pupils are an unreliable indicator of death and do not correlate with the degree of brain injury [6]
  • Most lethal injuries include heat-induced coagulation of the cerebral cortex, epidural or subdural hematomas, and intracranial hemorrhage
  • Pursue CT in cases of coma, persistent altered mental status, focal neurologic deficit, or persistent headache

 

Metabolic

  • Cerebral Salt Wasting
    • Symptoms: hyponatremia + extracellular volume depletion (i.e. hypotension, decreased skin turgor, increased hematocrit) [8]
    • Treatment: Sodium correction

 

Ophthalmic Injury:

  • Lightning-induced cataracts, usually bilateral, can form weeks to years after lightning injury
  • Other occular findings: hyphema, vitreous hemorrhage, corneal abrasion, uveitis, retinal detachment or hemorrhage, and optic nerve damage [5,6]
  • Perform an ocular exam on all patients and consider ophthalmology consultation for persistent pain or vision changes (dilated exam, etc)

 

Auditory Injury:

  • Blast effect results in tympanic membrane (TM) rupture (seen in 50-80% of patients) [9,10,11]
  • Other findings: sensorineural hearing loss, tinnitus, ataxia, vertigo, and injury to the facial nerve [12]

 

Special Populations: [3]

  • Pregnant patients: Fetus is especially prone to injury
    • ~50% of lightning strikes result in fetal demise in utero
    • May also cause placental abruption
    • Pregnant patients should undergo  fetal monitoring for at least 4 hours
  • Electronic Control Devices (ECDs): taser, stun gun, during arrest
    • Most are treat and release injuries
    • Rare to have electrical injuries
    • Barbs or hooks can cause superficial punctures, minor lacerations, cutaneous burns
    • Consider injury from falls and other trauma

 

Hospital Course:

  • Cardiac symptoms lasting more than 6 hours, including persistent ECG changes, dysrhythmia, cardiac arrest, elevated troponin, new cardiac dysfunction (e.g., new cardiomyopathy), or suspicion of direct lightning strike warrant inpatient admission for at least 24 hours for telemetry monitoring and cardiology consultation.
  • Consider ICU admission with signs of instability (i.e. hypotension), significant trauma, large burns, or deep tissue injury.
  • Once stabilized, patients with significant burns or deep tissue injury should be transferred to a burn center.
  • Patients with a reassuring physical exam with no additional risk factors can be watched on telemetry in the ED for 4-6 hours and discharged if no dysrhythmia is apparent [5]

 

Ways to Avoid Lightning Strikes:

  • “When thunder roars, go indoors” — ideally inside a large building
  • Stay in a metal-roofed vehicle with doors and windows closed (Faraday cage)
  • Remove metal objects to avoid contact burns
  • Avoid open, exposed areas, summits, and ridgelines, as well as doors and windows
  • Avoid tall structures
  • If in a group space, stay >20 feet (6 m) apart
  • If outdoors, use the ‘lightning position’ as a last resort: crouch with feet together to make one contact point
    • Alternatively, if sitting – lift feet off the ground; insulate from the ground if possible (e.g. sit on a pack)
  • Stay indoors until 30 minutes after the last thunderclap is heard (to ensure a 10-mile buffer)
  • Exit any water and stay away from the water edge
  • Be aware that lightning can strike despite clear skies (typically after a storm – ‘bolt from the blue’) 

References: 

  1. Browne BJ, Gaasch WR. Electrical injuries and lightning. Emerg Med Clin North Am. 1992;10(2):211-229.
  2. Zafren K, Durrer B, Herry JP, Brugger H; ICAR and UIAA MEDCOM. Lightning injuries: prevention and on-site treatment in mountains and remote areas. Official guidelines of the International Commission for Mountain Emergency Medicine and the Medical Commission of the International Mountaineering and Climbing Federation (ICAR and UIAA MEDCOM). Resuscitation. 2005;65(3):369-372. doi:10.1016/j.resuscitation.2004.12.014
  3. Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9. McGraw-Hill Education; 2016.
  4. ten Duis HJ, Klasen HJ, Reenalda PE. Keraunoparalysis, a ‘specific’ lightning injury. Burns Incl Therm Inj. 1985;12(1):54-57. doi:10.1016/0305-4179(85)90183-4
  5. Davis C, Engeln A, Johnson E, et al. Wilderness medical society practice guidelines for the prevention and treatment of lightning injuries. Wilderness Environ Med. 2012;23(3):260-269. doi:10.1016/j.wem.2012.05.016
  6. Jain S, Bandi V. Electrical and lightning injuries. Crit Care Clin. 1999;15(2):319-331. doi:10.1016/s0749-0704(05)70057-9
  7. Lichtenberg R, Dries D, Ward K, Marshall W, Scanlon P. Cardiovascular effects of lightning strikes. J Am Coll Cardiol. 1993;21(2):531-536. doi:10.1016/0735-1097(93)90699-2
  8. Emet M, Caner I, Cakir M, Aslan S, Cakir Z. Lightning injury may cause abrupt cerebral salt wasting syndrome. Am J Emerg Med. 2010;28(5):640.e1-640.e6403. doi:10.1016/j.ajem.2009.07.010
  9. Patten BM. Lightning and electrical injuries. Neurol Clin. 1992;10(4):1047-1058.
  10. 10.Gluncić I, Roje Z, Gluncić V, Poljak K. Ear injuries caused by lightning: report of 18 cases. J Laryngol Otol. 2001;115(1):4-8. doi:10.1258/0022215011906858
  11. 11.Wetli CV. Keraunopathology. An analysis of 45 fatalities. Am J Forensic Med Pathol. 1996;17(2):89-98. doi:10.1097/00000433-199606000-00001
  12. 12.Liew L, Morrison GA. Bilateral hearing loss following electrocution. J Laryngol Otol. 2006;120(1):65-66. doi:10.1017/S0022215105000514
  13. 13.O’Keefe KP. Electrical injuries and lightning strikes: Evaluation and management. UpToDate. November 3, 2023. Accessed July 4, 2024. https://www.uptodate.com/contents/electrical-injuries-and-lightning-strikes-evaluation-and-management/print.
  14. 14.Nickson, C. Lightning injury. Life In The Fast Lane. November 3, 2020. Accessed July 4, 2024. https://litfl.com/lightning-injury/