Lightning injuries

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Background

  • Second most common storm-related injury
  • Approximately 30 million ground strikes per year

Injury Mechanisms[1]

  • Direct effect of electrical current on body
  • Electrical to thermal conversion of energy causing superficial and deep burns
  • Direct strike = patient is hit directly by lightning current
    • Often fatal and may cause penetrating injuries[2]
  • Splash Injury = current "splashes" to the patient from another object which is struck first
  • Conduction = patient is in contact with an object (e.g. metal fence, tree) that is struck by lightning
  • Ground current = Also known as step voltage. Occurs when the current spreads out from the initial strike point and then travels through the patient's body
    • Most common mechanism of injury
  • Blunt Trauma = Secondary injury pattern that results when the lightning causes a wave of force to propagate through the air to the patient or as a secondary object strikes the patient.

Prehospital Care

  • Reverse triage = in lightning-related MCI cases, care should be delivered to patients in cardiac arrest first
    • Patients struck by lightning who are alive on EMS arrival will likely survive[1]
  • All patients should be transported, preferably to a burn center
  • Consider spinal precautions in all patients

Clinical Features

Superficial second degree burn from lightning injury.
Lichtenberg figure.
Patterned charring along the contact points of a metallic locket due to lightning strike.
Lightning-induced cataract.
Perforated TM

Injuries often involve multiple organ systems[3]

Cardiopulmonary

  • Both cardiac and respiratory arrest may be present without evidence of external injury
  • Ventricular dysrhythmias, asystole, and QT prolongation most common
  • Although cardiac automaticity may spontaneously return, apnea may persist
    • Duration of apnea rather than cardiac arrest is the critical prognostic factor
  • Myocardial infarction after lightning injury is unusual

Neuro

  • Symptoms are usually immediate and transient or delayed and permanent
  • Seizure, LOC, confusion, amnesia, extremity paralysis
  • Pupillary dilation or anisocoria may occur that is unrelated to brain injury
    • Neuroprognostication should not be based on dilated pupils alone in setting of lightning strike[4]
  • Keraunoparalysis - neuromuscular "stunning" that usually resolves spontaneously within hours
    • Thought of as a neurologic phenomenon but actually result of arterial vasospasm from catecholamine release

Vascular

  • Vasomotor spasm may cause loss of distal pulses, coolness of extremities, loss of sensation
  • Keraunoparalysis - see above

Ocular

  • Cataracts may occur weeks to years after injury (must document careful eye exam in all patients)
  • Other injuries include vitreous hemorrhage, corneal abrasion, retinal detachment

Auditory

Derm

  • Lichtenberg figures (ferning pattern) - pathognomonic for lightning strike
    • Occur due to electron showering over the skin leading to extravasation of RBC's, not a true burn; disappear within 24hr
  • Flash burns
    • Similar to those found in arc welders; appear as mild erythema, may involve cornea
  • Punctate burns
    • Look similar to cigarette burns; are full-thickness
  • Contact burns
    • Occur when metal close to the skin is heated from the lightning current

Ortho

Special Populations

  • 50% of pregnancies have fetal demise, though literature is sparse[5]
    • Third trimester appears to carry the greatest risk of adverse outcomes
    • Most surviving fetuses have no long term morbidity when carried to term
    • Any lightning strikes in pregnancy requires fetal monitoring, comprehensive testing in-hospital performed by Ob/Gyn

Differential Diagnosis

Burns

Evaluation

Work-Up

  • Exposure: complete and thorough physical exam head to toe
  • ECG
  • CBC
  • Chem
  • Total CK
  • UA - to evaluate for myoglobinuria
  • CT brain (for patients with coma, altered mental status, confusion)
  • Other imaging and workup is directed toward visible or suspected injuries

Diagnosis

  • Clinical diagnosis

Management

  • Aggressive resuscitation
    • Lightning-induced Cardiac Arrest has better prognosis than CAD-induced Cardiac Arrest
    • Hypotension is not an expected finding (i.e. suggests traumatic blood loss)
    • Maintain cervical spine precautions
    • Targeted Temperature Management between 32 and 36 degrees Celsius shown to be neuroprotective in setting of hypoxic ischemic encephalopathy after cardiac arrest

Disposition

  • Admit patients with persistent muscle pain or neuro, cardiac rhythm, or vascular abnormalities
  • Dishcarged patients require follow up to assess for delayed effects of lightning injury

See Also

References

  1. 1.0 1.1 Gatewood M, Zane R. Lightning injuries. Emery Med Clin N Am. 2004; 22: 369-403
  2. Waes. O et al. "Thunderstruck": Penetrating Thoracic Injury From Lightning Strike. Annals of Emergency Medicine. 63(4). 2014. 457-458
  3. Cooper M. et al. Blumenthal R: Lightning Injuries. Auerbach PS ed: Wilderness Medicine, 6th ed. Philadelphia: Elsevier/Mosby; 2012
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3361158/
  5. Galster K et al. Lightning Strike in Pregnancy With Fetal Injury. Wilderness and Environmental Medicine. June 2016. Volume 27, Issue 2, Pages 287–290.