Meteorologists called for a forecast of thunderstorms and light rain in the semi-arid landscape of Albuquerque, N.M. An engine company of firefighters was stopped at a traffic light when a bolt of lightning struck close to their unit. Having a high index of suspicion there could be injuries in the dense metro area, the crew tried to pinpoint the location of the strike.
Moments later, 9-1-1 operators received a call for two people unconscious, and immediately dispatched the engine and additional resources to the location. First responders found two patients lying on the ground, slowly regaining consciousness: a male in his early 30s and a female in her late 20sâwho was in her second pregnancy, 38 weeks gestation, one full-term delivery (G2 P1). The couple was headed inside after watching fireworks when lightning struck a tree adjacent to the home.
Responders began to triage the patients and prepare for transport, given the likelihood of additional lightning strikes. Both patients were breathing, their pulses rapid but irregular at the radial. They were awake but disoriented. Physical exams revealed injuries consistent with a side flash, where lightning strikes a nearby object and splashes onto the victim, rather than a direct strike.1
Responders decided to emergently transport the female first, performing treatment and focused trauma and neurologic exams en route to University of New Mexico Hospital, a Level 1 trauma center. The 3-lead ECG showed sinus tachycardia with a short PR interval at a rate of 118. Her blood pressure was 115/84. Her respirations were 22/min. She was placed on oxygen, IV access with isotonic fluids at a TKO rate, and was transported in left lateral recumbent position.
Physical exam revealed several mild patchy erythematous lesions on her chest. She complained of pain in her lower back and bilateral calves. The suspected exit wound was a 5 mm circular lesion at the distal tip of her left thumb. The pregnancy was uncomplicated, and she denied significant medical history.
Suspected exit wound from a lightning strike on the distal tip of a thumb. Screenshot KOAT-TV/Hearst Television
The male patient was transported second, complaining of pain, deafness, and mild drainage in his left ear. He had a sensation of numbness and tingling in his arms and legs. His chest hair was singed and mild homogenous erythema was noted to his chest, right flank and calf. He reported no past medical history. His 3-lead ECG showed sinus tachycardia without arrhythmia at 102 bpm. He had a respiratory rate of 12 and a systolic blood pressure of 120. He was placed on oxygen, and isotonic IV access established at a TKO rate. He was transported emergently to the trauma center.
Upon ED arrival, fetal assessment revealed a Category I fetal heart rate tracing, with a baseline heart rate within normal range at 155. The mother began to develop a Lichtenberg figure, or “ferning” pattern, characteristic of lightning injury to the epidermis and deeper soft tissue, to her right flank and lateral thigh. The next morning at 1:30 a.m, abnormal fetal activity led physicians to perform an emergency cesarean section.
A 6-pound, 3-ounce baby girl was delivered and transferred to the neonatal ICU for further care. She was started on Cerebyx (fosphenytoin) for seizure prophylaxis due to periodic episodes of shaking. Follow-up care showed the male patient experienced a ruptured left tympanic membrane, and required a cane for balance due to occasional bouts of vertigo. The female patient continued to have muscle spasms in her lower back and bilateral calves. However, the parents were discharged several days later with only mild symptoms and a healthy infant. They were later reunited with rescuers who were honored with the “hero’s coin,” presented by the Albuquerque Fire Department.2
Injury Epidemiology
While there are few cases of lightning strikes leading to the demise of pregnant women, there’s a high mortality rate among fetuses. Among in utero lightning injuries, there’s a 45% mortality rate. In one study, only six out of 11 pregnant women successfully delivered, their babies surviving the precarious gestation and perinatal period. The liquidity of amniotic fluid may serve as the preferred route for the flow of electrical current, leading to the high mortality rate.3
Lightning deaths have significantly declined for more than 40 years, with the lowest total of 29 recorded in 2008 and again in 2010.4 Predominately males are those who are killed, making up 85% of fatalities.5 Injury prevention efforts are best placed toward identifying time and place in which someone is likely to be killed, and developing avoidance strategies.
Ian Gordon, left, and his girlfriend, Kendra Villanueva, both struck by lightning on July 4, 2013, reunite with rescuers from the Albuquerque Fire Department who saved Villanueva’s unborn baby. The scenario in this article was based upon their story. Screenshot KOAT-TV/Hearst Television
Lightning detection equipment that alerts users via alert is available, but none has been peer reviewed and the efficacy remains unknown. Computerized models estimate more than 25 million ground strikes occur in the Lower 48 states annually and up to 50,000 strikes per hour have been recorded during the summer months of the U.S. Surveillance technology can detect up to 90% of ground strikes.6
Florida and Texas lead the nation for both civilian and occupational fatalities based on sheer numbers.7 However, adjusted on a population basis, the rural Rocky Mountain states of Wyoming and New Mexico emerge as the deadliest in the country.8
The National Oceanic and Atmospheric Association (NOAA) offers a plethora of weather-related resources, including automated weather alerts. For updates or more information, visit the National Weather Service’s website at www.weather.gov. Long-term climate monitoring data and forecasts are available at the National Climactic Data Center website at www.ncdc.noaa.gov, or NOAA’s website at www.noaa.gov.
Pathophysiology
Lightning causes direct injury to the body’s heart, brain, cell membranes and vascular smooth muscle. Lightning also causes damage as electrical injury is converted to heat energy, and is further dispersed throughout the body. Lightning is direct-current energy and depolarizes the sensitive myocardium and medullary respiratory center (in the lower brain stem), and causes thoracic muscles to spasmâsuppressing the body’s natural negative pressure ventilation mechanism.9
Once the myocardium is depolarized, two frequently encountered cardiac arrest rhythms are v fib and asystole. The stunned myocardium may quickly recover due to automaticity of cardiac cells, allowing return of spontaneous circulation (ROSC), similar to the process involved in medical defibrillation. However, because the myocardial cells of the heart typically recover quicker than neurons in the respiratory center and the temporarily paralyzed muscles of respiration, respiratory arrest may persist. The patient then dies from asphyxia, or a hypoxia-induced, secondary cardiac arrest.9
Lightning may cause a multitude of sequela in the non-cardiac arrest victim. Immediately following the event, the patient may have symptoms of tinnitus, blindness, confusion, amnesia, cardiac arrhythmias and vascular instability. Reported long-term effects include seizures, anxiety, peripheral nerve damage, anterior spinal artery syndrome, and neurological and psychological disorders.10 Barotrauma-type injuries include tympanic membrane rupture, ocular injuries and loss of consciousness.8
Physics
Lightning remains one of nature’s most perplexing forces. Legends abound since time immemorial, expressing ancient fears of the unknown and the variable nature of lightning. Today’s scientific understanding is a complex blend of atmospheric chemistry and physics.
Electrical charges build as static electricity when high-altitude water droplets and ice particles intermingle with turbulent updrafts and downdrafts. As thunderclouds roll over the landscape, earth and clouds reverse polarity, allowing negatively charged electrons to flow down to the positively charged earth in a lengthy branching process.
Lightning develops in a cascade, beginning with weak “leaders” that create a pathway of superheated ions from thunderclouds to 30â50 meters (98â168 feet) off the ground. A bolt of lightning is formed when a leader “sees” an ionic conduit to the ground. A return stroke is the highly luminous portion of the lightning lifecycle, and occurs as ions are discharged upward from ground to cloud.11
Lichtenberg figure, or “ferning” pattern, is characteristic of lightning injury to the epidermis and deeper soft tissue. Photo courtesy Catherine Burger
Subsequently, thunder is a shockwave of superheated air that follows the ionic path of lightning. The force of air expanding and contracting at supersonic speeds is recognized to cause tissue damage consistent with blast injuries.1 The “flash-to-bang method” allows rescuers to estimate the duration-to-distance ratio after seeing a flash of lightning to the point of audibly hearing the thunder. A total of five seconds elapse per one mile until the thunderclap is heard. However, thunder is usually dissipated over distances greater than 10 miles.
Lightning injuries can manifest in five ways: a direct strike, side flash, contact injury (direct contact with electrified objects), ground current (ground conducts nearby lightning strikes), blast injury (tympanic membrane rupture, or blunt trauma), and upward streamers (a positive ionic channel responsible for an upward strike).8
Response & Treatment
Whether treating a single victim or a group of people, prehospital providers are faced with a dynamic situation. Responders who arrive on scene first must employ situation awareness to judge safety of the rescue since there may be downed power lines, resultant fires and structural damage. Additionally, the storm may be actively producing lightning in the area and can travel distances of 10 miles or greater ahead of a thunderstorm.3
Important details unavailable from victims or bystanders can be gathered from approaching the scene. Consider assessing storm details, blast effects on nearby objects, burned or charred vegetation, magnetized metal objects or melted synthetic clothing.8
Triaging lightning strike victims in mass casualty incidents (MCIs) should follow a “reverse triage” method, whereby cardiac arrest victims are treated firstârather than “black tagged”Ââgiving the optimum chances of survival. Due to the pathology involved, airway and ventilation are paramount, allowing the stunned respiratory center to regain function. Following current resuscitation guidelines, cardiac arrest victims need immediate CPR, ventilation, and defibrillation of shockable arrhythmias as soon as an AED or defibrillator is available. In addition, because of the high incidence of ear injuries, patients may not be able hear instructions during the initial global sorting.
Treatment is specific to lightning injuries, rather than electrical injuries in general. There may be a variety of full- and partial-thickness burns noted but rarely does lightning cause myoglobinuria, or rhabdomyolysis, as seen in cases of high-voltage electrical injuries. Large-volume IV fluid boluses are usually unnecessary due to few cases of renal failure attributed to lightning alone, and over hydration can cause cerebral edema.9
During patient assessment, consider the possibility of injuries consistent with blast trauma, including broken bones, burns, and injuries to the eyes and ears. Maintain spinal precautions when distracting injuries are present, the patient is unconscious, or there’s a positive finding on spinal assessment. Hypothermia should be considered in patients exposed to extreme weather associated with thunderstorms including drenching rain, hail, low temperatures and wind chill.
Cardiovascular effects include extensive catecholamine release or autonomic stimulation. The victim may develop hypertension, ectopy, tachycardia, nonspecific ECG changes, QT interval prolongation, or transient T-wave inversion.12 Continual ECG monitoring and a 12-lead ECG should be performed en route to the hospital and not delay transport.
Hospital assessment may include a complete blood count, electrolytes, blood urea nitrogen and creatinine (assessing kidney function), creatinine kinase-MB (CK-MB) and troponin to assess cardiac and skeletal muscle tissue damage. Cervical spine imaging may be indicated secondary to trauma. CT scan of the brain is indicated in patients who are confused, showing mental status changes or unconscious.
Ideally, transport should be to a Level 1 trauma center because specialty care may be necessary. EMS warning to avoid overwhelming any facility is crucial, especially in cases of MCIs. Fetal heart rate assessment is indicated in pregnant patients, and the possibility of an emergent caesarian section during the hospital care should be anticipated. Lightning is a survivable trauma and early intervention by prehospital providers can change the outcome.
Take-Home Points
- Most strikes occur during summer, predominately affect males, and have been steadily declining over the past 40 years.
- The “flash-to-bang method” allows rescuers to estimate distances of lightning. When thunder is heard after lightning is seen, five seconds = one mile.
- Personnel on scene may encounter downed power lines, electrical fires and structural damage.
- Lightning can travel distances of 10 miles or greater ahead of a thunderstorm.
- Consider blast trauma, including broken bones, burns, and injuries to the eyes and ears.
- Hypothermia should be considered in patients exposed to extreme weather including drenching rain, hail, low temperatures and wind chill.
- Rarely does lightning cause the same injuries seen in high-voltage electrical trauma, such as rhabdomyolysis. Large-volume IV fluid boluses are usually unnecessary and may cause cerebral edema.
- A 12-lead ECG may show nonspecific ECG changes, ectopy, QT interval prolongation, or transient T-wave inversion. Don’t delay transport for ECG interpretation.
- Lightning strike-induced MCIs should use reverse triage, where patients in cardiac and respiratory arrest are treated first.Â
References
1. Ritenour AE, Morton MJ, McManus JG, et al. Lightning injury: A review. Burns. 2008;34(5):585â594.
2. Thoren L. (July 11, 2013.) Woman delivers baby after being struck by lightning. KOAT-TV. Retrieved March 20, 2014, from www.koat.com/news/new-mexico/albuquerque/woman-delivers-baby-after-being-struck-by-lightning/20930376.
3. Fish RM. Lightning injuries. In: JE Tintinalli, GD Kelen, JS Stapczynski (Eds.), Emergency medicine: A comprehensive study guide. McGraw-Hill: New York, pp. 1235â1238, 2004.
4. National Weather Service. Medical aspects of lightning. Retrieved Aug. 22, 2013, from www.lightningsafety.noaa.gov/medical.htm.
5. Centers for Disease Control. QuickStats: Number of deaths from lightning among males and femalesâNational Vital Statistics System, United States, 1968â2010. MMWR. 2013;62(28):578.
6. Copper MA, Andrews CJ, Holle RJ, et al. Lightning injuries. In: PS Auerbach (Ed.), Wilderness medicine, 6th edition. Mosby: St. Louis, pp. 60â105.e5, 2012.
7. Adekoya N, Nolte KB. Struck-by-lightning deaths in the United States. J Environ Health. 2005;67(9):45â58.
8. O’Keffe Gatewood M, Zane RD. Lightning injuries. Emerg Med Clin North Am. 2004;22(2):369â403.
9. Vanden Hoek TL, Morrison LJ, Shuster M, et al. Part 12: Cardiac arrest in special situations: 2010 American Heart Association Guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2010;2(122):S848.
10. Copper MA. Emergent care of lightning and electrical injuries. Semin Neurol. 1995;15(3)268â278.
11. 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):260â269.
12. Sharp D. Lightning strikes. Lancet. 2002;360(9330):354.
