Written by: Sean Watts, MD (NUEM ‘22) Edited by: Michael Conrardy, MD (NUEM ‘21) Expert Commentary by: Gabrielle Ahlzadeh, MD
Lightning injury has significantly declined in incidence and as a cause of environmental mortality since the 1950’s. However, when it occurs, it can cause significant end-organ damage. It remains the second most common cause of storm related deaths in the United States and accounts for approximately 40-100 deaths per year as well as approximately 300 injuries [2,6]. While rare, it is important to outline the must not miss complications, presentation, and management of lightning injury in the emergency department.
Unlike other forms of electrical injury, lightning is considered direct current and can carry energy ranging from 30,000 to 110,000 amps [1]. The majority of subjects struck by lightning survive, however, 10% of injuries are fatal [2]. Injuries are classified in four ways—direct strike, contact injury, side splash, or ground current [1]. In direct strike, the bolt of lightning makes direct contact with the subject and accounts for approximately 5% of injuries [1]. Contact injuries occur when a subject makes contact with another object that is struck by lightning—i.e. a person is touching a metal pole that is struck [1]. Side splash injuries occur when the current jumps from an object to the subject, and ground current occurs when lightning strikes an object and current travels through the ground to the subject [1].
Lightning strikes can cause primarily neurologic injury, but the most common fatal complications are cardiac and respiratory arrest [2]. This is due to the relative nature of conductivity of the various organs in the body, with lightning following the path of least resistance. The order of conductivity is: nerve > blood > muscle > skin > fat > bone [1]. When lightning strikes, the surge of electricity induces cardiac standstill and apnea due to effects on the medullary respiratory center. Most patients will present with asystole and then degrade into a variety of arrhythmias, most commonly ventricular fibrillation. Interestingly, case-reports have documented successful resuscitations of lightning strike victims after being apneic and pulseless for as long as 15 to 30 minutes. This has lead to the notion that at the scene of a lightning strike, the apparent dead should be treated first.
Approximately 90% of lightning strike victims suffer from superficial skin burns, but less than 5% are deep burns [2]. Common presentations of lightning injury include the Lichtenberg figure that is considered pathognomonic for lightening strike [1]. Neurologic manifestations include keraunoparalysis, which is described as a transient tetraplegia affecting the lower limbs more than the upper limbs, and is often accompanied by sensory loss, pallor, vasoconstriction, and hypertension [2]. The pathophysiology is related to overstimulation of the autonomic nervous system that leads to vascular spasm [1]. Generally, this paralysis resolves within several hours; however, in some patients it can take as long as 24 hours or lead to permanent neurologic injury [2]. Most patients with lightning injury will have a perforated tympanic membrane or develop cataracts immediately following the incident.
Lichtenberg Figure
If lightning injury does occur, initial management in the emergency department is always focused around initial assessment of airway, breathing, and circulation. An important note is that lightning strike can cause fixed, dilated pupils in the absence of irreversible brain injury and should be taken into consideration when contemplating the termination of resuscitative efforts. In multiple casualty incidents Reverse Triage should be employed—meaning that patients without vital signs or spontaneous respirations should be attended to first [1]. This is because return of spontaneous circulation precedes the resolution of respiratory arrest, and has been demonstrated to be effective, as indicated by a case report in Sequoia and Kings Canyon National Park [4]. An ECG and troponin should be obtained, however, cardiac markers have not been shown to help indicate the extent of injury [1]. Additional diagnostic considerations include obtaining a CK and observing for signs of compartment syndrome, as patients with lightning injury often suffer from rhabdomyolysis. Telemetry using a holter-monitor is the standard of care to observe for subacute ECG changes following injury [1]. In terms of neurologic injury—specifically keraunoparalysis--resolution of symptoms without treatment is common; however, the use of heparin and intravenous hydration has been shown to have efficacy in some cases [2]. If other mechanisms of injury are suspected—e.g. head trauma from a fall—appropriate imaging modalities should be performed on the patient. Most patients with lightning injury should be observed in the emergency department for a minimum of six hours with telemetry.
Lightning injury is primarily a prevention-based approach. Prevention measures include avoiding tall objects such as ski lifts, cell phone towers, or isolated structures (such as a lone tree in an open field) [1]. If isolated in an austere environment, migration into a cave, dense forest, or a deep ravine is recommended [2]. Another recommended technique is that of “lightning position”. This is performed by sitting or crouching with the knees and feet close together to create a single point of contact with the ground [1]. Other prevention measures include utilizing the 30-30 rule: when lightning is observed, count the time until thunder is heard and if the time is under 30 seconds, seek shelter. The subject should then wait another 30 minutes before leaving shelter [3]. If in a group, individuals should spread themselves out to avoid side splash injury [4]. Signs of acute strike should also be monitored, which includes: a blue haze around objects, static electricity over hair or skin, an ozone smell, and a nearby “crackling” sound [1].
Lightning Position
Lightning injury, while rare due to increased public education and prevention measures, can present with life threatening injuries. Cardiac dysrhythmias and apnea are the most common life threatening presentations and should be managed according to ACLS guidelines. Take care when considering termination of resuscitative efforts, as patients may present with fixed dilated pupils and there have been remarkable case reports of patients surviving even when found down for a prolonged period of time. Most patients with lightning injury require a basic cardiac work up and can be discharged home after a period of observation on telemetry.
Expert Commentary
While lightning injury is an infrequent emergency department presentation, just like most cases in emergency medicine, it can range from insignificant to life threatening. From superficial skin burns to full cardiac arrest, it is important to understand the different types of injuries as well as sequelae. It is also important to remember that because electricity is conducted, lightning can cause deeper injuries that may not be immediately visible. This includes deep skin injuries as well as organ damage. For this reason, basic blood work including cardiac markers and a CPK level should be obtained as well as an ECG. Most injuries will present acutely though injuries such as compartment syndrome and rhabdomyolysis may take longer to develop. These should be suspected with any report of extremity pain or any superficial skin findings or swelling.
Recall that in addition to assessing for effects of lightning injury, also consider other traumatic injuries depending on where the victim was when they were struck. For example, victims may be on top of a building and fall as a result of a lightning strike. Thus, a thorough physical examination and re-examination are necessary. If there is doubt about trauma or unknown scene details, like most things in emergency medicine, assume the worst. Observing patients in the emergency department for a minimum of six hours with telemetry monitoring after any lightning injury will also give you time to reassess the patient and perform an adequate tertiary survey.
Perhaps one of the most important things to remember is that in the setting of mass casualty incidents, victims of lightning injury without vital signs or spontaneous respirations should be attended to first; this is in contrast to all other scenarios where these victims are typically triaged as black triage tags as they are unlikely to survive. Keep this in mind for any EMS personnel who may call in to terminate resuscitations from the field if patients were struck by lightning.
Gabrielle Ahlzadeh, MD
Clinical Assistant Professor of Emergency Medicine
University of Southern California
How To Cite This Post
[Peer-Reviewed, Web Publication] Watts, S. Conrardy, M. (2020, Aug 24). Lightning Injury [NUEM Blog. Expert Commentary by Ahlzadeh, G]. Retrieved from http://www.nuemblog.com/blog/epistaxis-management.
References
Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries: 2014 Update. Chris Davis, MD; Anna Engeln, MD; Eric L. Johnson, MD; Scott E. McIntosh, MD, MPH; Ken Zafren, MD; Arthur A. Islas, MD, MPH; Christopher McStay, MD; William R. Smith, MD; Tracy Cushing, MD, MPH. WILDERNESS & ENVIRONMENTAL MEDICINE, 25, S86–S95 (2014)
Acute transient hemiparesis induced by lightning strike. Rahmani SH1, Faridaalaee G2, Jahangard S3. Am J Emerg Med. 2015 Jul;33(7):984.e1-3. doi: 10.1016/j.ajem.2014.12.031. Epub 2014 Dec 19.
Lightning Safety Awareness of Visitors in Three California National Parks. Lori Weichenthal, MD; Jacoby Allen, DO; Kyle P. Davis; Danielle Campagne, MD; Brandy Snowden, MPH; Susan Hughes, MS. WILDERNESS & ENVIRONMENTAL MEDICINE, 22, 257–261 (2011)
A Lightning Multiple Casualty Incident in Sequoia and Kings Canyon National Parks. Susanne J. Spano, MD; Danielle Campagne, MD; Geoff Stroh, MD; Marc Shalit, MD WILDERNESS & ENVIRONMENTAL MEDICINE, 26, 43–53 (2015)
Curry, M. (2017, May 18). Rosen's Emergency Medicine: Concepts and Clinical Practice. Retrieved from https://www.us.elsevierhealth.com/rosens-emergency-medicine-concepts-and-clinical-practice-9780323354790.html.
Electrocution and life-threatening electrical injuries, Spies C, Trohman RG Ann Intern Med. 2006;145(7):531.