Lightning is a very dramatic natural phenomenon that tends to capture attention. Lightning strikes the earth approximately 8,000,000 times per day. Most of these strikes are benign and cause little damage to property or physical structures — and even less injury to humans. Because humans are rarely struck by lightning, this fascinating phenomenon is often disregarded as a potential immediate danger. However, it is the second leading cause of storm-related deaths in the United States and is consistently one of the top three leading causes of death due to a natural or environmental phenomenon. Although a standardized reporting system is lacking, it is estimated that 90 percent of lightning strike victims survive and experience some type of acute or permanent disability.
Lightning occurs from a transfer of an electrical charge. An electrical potential is created when warm low-pressure air rises through high pressure air. The inferior portion of the cloud becomes negatively charged while the ground remains positive. Static electricity generates lightning channels that are dissipated within the cloud or extend downward toward the ground. Objects on the ground send positively charged strokes upward. If both the downward and upward stroke makes contact, a lightning strike is observed. It is important to realize that not all upward strokes result in a visible lightning strike; however, these strokes contain enough energy to cause potential electrical injury to a person.
EMS Response to a Lightning Strike
A lightning strike is both a serious medical and traumatic event that can lead to significant injury, permanent disability and sudden death. The central, autonomic and peripheral nervous systems are extremely sensitive to electrical energy that can lead to acute and chronic neurologic disruptions and damage. Confusion, altered mental status, coma, headache, seizures, personality changes and a decrease in cognitive ability are some of the manifestations of central nervous system disruption. The sympathetic nervous system may respond with massive vasoconstriction producing hypertension and mottling of the extremities. The electrical energy may cause the autonomic nervous system to shut down the vital respiratory and cardiac centers in the medulla resulting in cardiopulmonary arrest.
Cardiopulmonary arrest is typically the cause of death of a lightning strike victim. Immense electrical energy enters the body and acts like a massive defibrillation. As with a standard defibrillation, the electrical energy depolarizes the myocardium and produces a period of asystole. However, due to the dysfunction of the autonomic nervous system and lack of a functioning medullary cardiac center to provide stimulation to the myocardium, the heart remains in asystole. Thus, the initial presenting rhythm immediately following the event is asystole.
Eventually, the inherent automaticity property of the cardiac conduction system produces electrical impulses and the heart begins to contract. However, the respiratory center in the medulla remains shut off. Due to lack of adequate ventilation, the heart begins to become severely hypoxic and acidotic resulting in a secondary cardiac arrest from ventricular fibrillation. Contrary to the normal thinking in initial rhythms in cardiac arrest, the lightning strike victim may be more viable in the initial asystolic cardiac rhythm. The ventricular fibrillation rhythm may reflect a severely acidic and hypoxic state associated with a secondary cardiac arrest that may be more difficult to resuscitate.
The sudden and immense electrical stimulation may produce a severe muscular contraction that can cause the victim to be thrown several yards. Likewise, the air around the strike is rapidly and massively heated, and then cooled, causing a sudden explosive and implosive displacement of air propelling the victim. This can potentially cause blunt trauma to the head, spine, chest, abdomen, pelvis, and extremities; soft-tissue trauma; internal organ damage; and barotrauma to air containing structures. Due to this mechanism, maintain a high index of suspicion of traumatic injury and consider spinal immobilization of lightning strike victims.
A common misconception about a lightning strike is that it produces massive and critical full thickness burns; however, the short duration time of the strike only allows for minimal internal and external burns to occur. The energy flashes over the body, typically producing only superficial burns. If the victim is carrying metal, such as a necklace or pocket change, the metal may retain the heat for a longer period of time and produce deeper partial thickness or full thickness burns to that isolated area of the body. There are no source (entry) and ground (exit) wounds associated with a lightning strike.
Superficial burns are normally present in lightning strike injuries. Severe burns are usually associated with a thermal source from the ignition of clothing or metal objects retaining heat. Linear burns may occur and appear as lines on the body. These result from sweat or rainwater running down the body at the time of the strike, being substantially heated, and then vaporizing. Punctuate burns may occur and appear as cigarette burns. A “feathering” or pathognomonic fern-like pattern is not actually a burn but a discoloration to the skin in a fern-like pattern due to an electron shower.
Other assessment findings include:
- Cardiac dysrhythmias (atrial fibrillation, PCVs, SVT, and persistent tachycardia)
- Apnea
- Cyanosis
- Reduced SpO2 reading
- Retrograde amnesia
- Hemiplegia
- Aphasia
- Vertigo
- Dizziness
- Temporary paralysis with mottling to an extremity
- Pain, numbness, burning or tingling sensation
- Fixed and dilated pupils
- Transient hypertension
- Sight disturbance
- Corneal burn
- Hearing loss
- Ruptured tympanic membrane
Approximately 90 percent of lightning strikes involve only one victim. The most common cause of death is from immediate cardiac arrest following the strike. If a patient is not apneic or pulseless following a lightning strike, it is highly unlikely that he or she will deteriorate to cardiac arrest or not survive the event. Thus, when performing triage at a lightning strike scene with more than one patient, it should be done in reverse order from what is typical, even if several patients are involved. The patient in respiratory or cardiac arrest is the priority and should be the first person to receive emergency care.
Ensure your own safety at the scene. Move the patient indoors or into the ambulance as quickly as possible to eliminate your risk of being struck. It is a myth that lightning strikes the same place only once. The Empire State building is struck thousands of times each year! Consider complete spinal immobilization since a lightning strike also has a blunt traumatic mechanism. If the clothing is on fire or smoldering, douse the area with water. Remove hot or smoldering jewelry or any other objects that may retain heat and continue to burn the patient. Assess, establish and maintain an airway. If the tidal volume or respiratory rate is inadequate, begin positive pressure ventilation. Provide supplemental oxygen. Place the patient on a continuous ECG monitor and treat any dysrhythmias according to your protocol. Initiate an intravenous line with normal saline and run it based on the patient’s hemodynamic status. Be cautious when assessing peripheral perfusion and pulses since the sympathetic dysfunction may have produced arterial spasm with mottled extremities and absent or weak peripheral pulses. Apply sterile dressings to any soft tissue injuries and immobilize any suspected fractures or dislocations. If the patient is in, or was to deteriorate into, ventricular fibrillation, defibrillate and administer medications according to your ventricular fibrillation protocols.
Lightning Strike Facts
The highest incidence of lightning strikes occurs between May and September and is associated with the increase in recreational, work-related or other outdoor activity. Approximately one-third of the injuries are work-related, one-third are associated with recreational or sports activity, and one third from other situations, such as while on the telephone. The most common days to be struck are Saturdays and Sundays, with the most common time being between noon and 6 pm.
Children younger than 16 and adults between 26 and 35 years of age experience the highest incidence of lightning strikes. Males have a five times greater likelihood of being struck than females.
Staying indoors provides the greatest protection during lightning due to the large amount of electrical wiring and plumbing that disperses the current throughout the structure. Due to this unique conduit of current, a lightning strike can occur indoors if the victim is in contact with sinks, showers, toilets, indoor pools and other plumbing, or near or using electrical appliances or devices that are hard-wired to the structure — such as a computer, phone or electronic game.
It has been estimated that approximately 250 people are struck each year while talking on their house telephone. In order for this to occur, it must be a landline phone that is hard-wired to both the receiver and jack. The lightning energy is transmitted through the phone line up to the receiver and to the person’s ear and head. If a portable phone is being used, a complete electrical circuit is not present; thus, no direct current can be transmitted to the person. However, it has been reported that a loud crack from static electricity has produced acoustic injury when a portable phone was in use.
Cars, buses, and other enclosed vehicles also provide good protection from lightning strikes. This is not a result of the rubber tires, but due to the ability of the metal structure to dissipate the electrical current along the outside of the vehicle, leaving the occupants inside relatively safe and unharmed — provided that they are not in contact with the metal frame, radio or any other electrical device.
It is important to recognize that lightning can occur 10 miles ahead of a thunderstorm. The sky may appear clear and blue with no rain in sight, but then a lightning bolt occurs. This type of lightning, which is a side cloud discharge that is carried by wind current, is often referred to as anvil lightning or a “bolt from the blue.” As an EMS provider, you must recognize that even though the sky is clear, the patient may have been struck by lightning if there was a thunderstorm in the area.
Lightning current is not considered to be either alternating current (AC) or direct current (DC), but is often referred to as a “cosmic direct current.” It is a massive electrical discharge that can create a current with 100 million to 2 billion volts with an amperage as high as 200,000. The contact temperature of lightning is 15,000 to 60,000 degrees Fahrenheit; however, its duration is only 1/100th to 1/1,000th of a second.
A lightning strike is a dramatic event that may produce a variety of acute medical and traumatic conditions. Thus, it is important to understand who is susceptible to being struck, possible assessment findings, and the emergency management of the patient.
References
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- Cooper, MA. Lightning Injuries. http://www.emedicine.com/emerg/topic299.htm. January 7, 2008.
- Cooper, MA, Andrews CJ, Holle RL. Lightning Injury. Wilderness Emergencies. CV Mosby, 2006.
- Cooper, MA. Lightning Injuries: Prognostic Signs for Death. Annals of Emergency Medicine. March 1980;9(3):134-138.
- Cooper, MA. Medical Aspects of Lightning. National Weather Service. http://www.lightningsafety.noaa.gov/medical.htm.
- Marx, JA, Hockberger RS, Walls RM. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 5th ed. St. Louis: Mosby, Inc., 2002.
- Mistovich J, Krost W, Limmer D. Lightning Strike Injuries: Pathophysiology, Assessment and Management. Emergency Medical Services. Volume 37, Number 2, March 2008.
- Part 10.9: Electric Shock and Lightning Strikes. Circulation. 2005;112:IV-154-IV155.
