Lightning Injuries 

Updated: Nov 20, 2017
Author: Mary Ann Cooper, MD; Chief Editor: Joe Alcock, MD, MS 

Overview

Background

For over a century, lightning injuries had been the second most common cause of storm-related death in the United States. They are now third, behind flash floods and tornados.[1, 2, 3] Although National Oceanic and Atmospheric Administration (NOAA) data showed as many as 3,000 deaths and nearly 10,000 casualties from lightning in the years from 1959-1994, the annual death rate has decreased to less than 0.1 case per million for the last 5 years, owing to public education by the media and the members of the Lightning Safety Week team.[2] While it is highly likely that all US deaths are recorded as a result of improved media coverage, the actual number of lightning casualties may be higher, because up to 50% may go unreported.[2] Nevertheless, in most years, lightning kills more people each year in the United States than hurricanes, volcanoes, and earthquakes combined.[4] (See Epidemiology and Etiology.)

Far more injuries and deaths occur in tropical and subtropical developing countries (see Epidemiology and Etiology), and newspaper reports frequently list multiple injuries and deaths in each event. Complicating the increased risk people in these countries have because of higher lightning density (lightning strikes/km2/year), lightning-unsafe housing, and greater everyday exposure are the folk beliefs that may prevent adequate prevention and mitigation. People in many countries believe in two kinds of lightning: "natural lightning" and "man-made lightning" that can be called down by witches or can be prevented with charms, herbs, or burying something under a structure as it is being built.[5, 6] In Zambia, it is believed that wearing the color red attracts lightning. Others believe that anyone injured by lightning has been cursed, shunning them and their family. Families may believe their only recourse is to move and start over in a village where their history is unknown.[7]

For most thunderstorms, 70-90% of lightning strikes are intracloud or from cloud to cloud. From 10-30% of lightning can be cloud to ground (CG), depending on the storm. Lightning strikes the earth more than 100 times each second and 8 million times per day. Worldwide, approximately 50,000 thunderstorms occur per day that may result in forest fires, injury to animals and people, and/or damage to electrical and communications lines and electronics, leading to millions of dollars in downtime for businesses. Everyone is a potential victim. 

In the United States, cloud-to-ground lightning strikes occur approximately 30 million times each year.[8] Lightning strikes in the United States are most common in Florida, the Atlantic coast, and along the southeastern coast of the Gulf of Mexico.[9] The National Weather Service (NWS) estimates that 100,000 thunderstorms occur in the United States each year. Lightning is evident in all thunderstorms. The danger of lightning may not be apparent to an individual because lightning can strike 10 miles or more away from the rain of a thunderstorm.[4] (See Epidemiology.)

Lightning starts with short (30-50 m) spurts of static energy in a cloud. The lightning retreats back to its origin, refills the original channel, and branches at the end of the original channel to make a second generation of 30- to 50-m channels. Lightning continues with the retreats and new generations until the charge is either expended (intracloud lightning) or randomly works its way downward as a CG flash.[10]

Any object near the intense electrical field of a thundercloud will have an opposite charge induced in it, be it a television tower, a tree, a person, or a blade of grass. Multiple upward leaders of current rise from these objects. Most do not contact the main lightning channel but may have sufficient energy to cause significant injury (Cooper upward streamer). Eventually, the downward leader may join one or more of the upward streamers to complete the lightning channel. At that point, a return stroke fills all of the branches and the lightning becomes visible. Lightning has more than one ground contact about 30-50% of the time.

Only three factors predispose to a lightning hit: height of an object, isolation, and "pointiness," which is not a factor with people. However, while lightning has a tendency to hit the tallest object, this 30- to 50-m radius from the last branch point means that tall objects, such as a mountaintop half a mile away, a television tower 300 yards away, a tree 75 yards away, or even the goal posts on a football field, are outside the range for protecting anyone (ie, the field's goalposts are unlikely to protect someone standing in the middle of a football field if lightning is coming down over the person's head). There are multiple instances and videos of strike points to cars passing tall telephone or electrical poles and other hits where lightning seems to “ignore” the height rule.[10] (See Etiology and Prevention.)

With all these data, it must be realized that while lightning science strives to describe and explain it, mostly in a statistical manner, these are not rules governing its behavior. Lightning is capricious and random, and any individual strike may defy common public assumptions.

Although most injuries occur outdoors, a few people are injured indoors every year from contact injuries with plumbing or landline telephone–mediated strikes.[11, 12] While use of cell phones, iPods, and other portable electronic devices may change the pathway of lightning around a person, it does not increase the risk of injury except by distracting the individual from paying attention to warning signs, such as storm clouds and thunder. In fact, the worldwide availability of cell phones is offering an ideal opportunity for texted or tweeted severe weather warnings and other public education.[6, 13]

The most important characteristic features of lightning injuries are multisystem, primarily neurologic, injuries and widely variable severity. This article discusses the physics of lightning and the pathophysiology and treatment of lightning injuries.[14] Because persons struck by lightning have a better chance of survival than persons who experience cardiopulmonary arrest from other causes, resuscitation for persons struck by lightning must be instituted immediately, followed by a comprehensive treatment program of the other systemic manifestations.[15] (See Prognosis, Presentation, and Treatment.)

In 2017, a proposal for an American Psychiatric Association Diagnostic and Statistical Manual (DSM) classification of postelectrical and postlightning injury syndrome was published.[16]

Types of injuries

Injuries range from tiny static electricity–like exposures to cardiac arrest.[10, 17, 18, 19, 20] No good statistics are available for the distribution of severity across the injured population.

Few individuals experience the full energy of a lightning strike because only about 3-5% of injuries are from a direct strike.[21] Most of the energy is mediated by other factors, including the ground, a tree, or other object that, once hit, transmits the energy to the person. In fact, fewer than half of affected persons have signs of burns or any other marks. When burns do occur in developed countries, they are usually superficial. In addition to electrical injury, many may suffer concussive blunt force trauma if they are close to the strike point.[22] Internal burns or deep burns, such as occur with high-voltage electrical injury, are rare.

In developing countries, severe burns are reported much more frequently. It is unclear if these are sampling bias, if reports are inflated by journalists who hear the story several times removed from the incident and expect the victims to be “charred beyond recognition,” if the mechanisms and physical damage are somehow different, or if the injuries appear to be more severe owing to delayed access to good medical care.[23] Ninety percent of sub-Saharan housing, usually mud brick with thatch or sheet metal roofs, is not lightning safe. Keraunoparalysis, a temporary paralysis after lightning injury that may last for minutes to hours, may keep even healthy individuals from escaping their home as the overhead thatch, ignited by lightning, burns and falls on them.[23]

Myoglobinuria is rarely caused by lightning, whereas cardiac and respiratory arrest, vascular spasm, neurologic damage, and autonomic instability are more common.[24] Blunt force injuries may occur from falling, being thrown by muscle contractions, or barotrauma from the explosive force of a nearby lightning strike.[10] Occasionally, a person may receive secondary shrapnel-like injuries by being hit by pavement or bits of an exploded tree.[25]

Lightning strikes are primarily a neurologic injury that affects all three components of the nervous system: central, autonomic, and peripheral.

Classification of lightning injuries

Because exposure to the effects of lightning can be so variable in mechanism and intensity, it is useful to characterize lightning injuries as mild, moderate, or severe.

Mild lightning injury is rarely associated with superficial burns, but persons struck often report loss of consciousness, amnesia, confusion, tingling, and numerous other nonspecific symptoms. Lightning burns are invariably superficial and have little or no deep-tissue damaging effects. Provided the patient is stable and there are no contraindications such as chest pain, hypotension, or continuing mental status changes, many of these patients can be released home with reliable caretakers. Since there is little known at this time that can be done to mitigate the outcome and sequelae, there is usually little benefit to hospitalization.

Moderate lightning injury may cause seizures, respiratory arrest, or cardiac standstill, which spontaneously resolves with resumption of normal cardiac activity. Much of the symptomatology mirrors that of mild lightning injury, except superficial burns are much more common, both initially and in a delayed fashion. These patients may have lifelong symptoms of brain injury, chronic pain, irritability, and sleep disorders. There is still little that hospitalization can offer these patients except careful monitoring for acute complications connected to the initial manifestations.

Patients with severe lightning injury usually present with cardiopulmonary arrest, often complicated by a prolonged period in which they did not receive CPR. The delay may be because the individuals are in an isolated location when injured or because of the myth that the person retains an electrical charge, making him or her dangerous to touch. Survival is rare in this group unless a bystander begins CPR immediately. There have been rare cases of recovery from this more severe group but usually only after prolonged ICU and rehabilitative care.

Additionally, as noted above, victims in developing countries may have more severe burns resulting from keraunoparalysis and burns by secondary fire.

Physics of lightning

Lightning is a natural atmospheric electrical discharge that occurs between regions of net positive and net negative electrical charges. It is dependent on a complex interaction of updrafts, moisture, atmospheric instability, temperature, and other factors. Readers with a special interest in this are referred to the NOAA article Understanding Lightning for a thorough but understandable discussion with animations.

Lightning

There are two basic types of lightning: cloud-to-cloud or intracloud (CC) and cloud-to-ground (CG). A lightning flash is initiated by an electrical breakdown between the positive and negative charge regions in a cloud. Sixty to 90% of lightning is intracloud. When the flash turns towards the ground, a barely visible downward leader descends in regular steps, typically 30-50 m long at intervals of 0.05 ms in a downward, branching fashion toward the ground. This initial flow of electricity, the leader stroke, reaches the ground in approximately 20 ms. The diameter of the stepped leader ranges from a few centimeters to a few meters, depending on what parameter is measured. Within the leader is a current-carrying core 1-2 cm in diameter.

As the branching process nears the ground, an upward discharge, termed the upward leader, completes the path of ionization approximately 30-50 m above the ground. At this moment of attachment, the cloud is short-circuited to the ground, and the major electrical discharge, a luminous return stroke of high current, occurs. Following the initial stroke, secondary leader and return strokes frequently occur.

See Lightning Safety for many other interesting facts about lightning.

Thunder

Air that is crossed by lightning is heated rapidly, and the cylindrical column expands at supersonic speeds. Within 1-2 meters, the shockwave decays to a sound wave called thunder. Thunder comes from the entire lightning channel length, producing a mixture of different tones that are further modified as it spreads outward. Thunder rarely is heard at distances greater than 10 miles because of such factors as terrain, atmospheric temperature, wind shear, large intervening structures, and urban noise.

The power of lightning is awesome, an estimated 10,000-200,000 amperes (A) of current and 20 million to 1 billion volts. A current of 100,000 A can shift blocks of stone weighing 5 tons, and rocks weighing 50 pounds may be thrown 20 yards or more.

Types of lightning

CG lightning, described earlier, is the most frequent type of lightning and accounts for human injuries. Another type, sheet lightning, travels within a cloud and gives the cloud the appearance of a white sheet. “Heat lightning” is a misnomer for lightning that does not appear to be connected with rain and is usually far enough away to make a wonderful show. It is equally as dangerous as any other form of lightning and can turn into deadly cloud-to-ground lightning just as easily.

Several rare forms of lightning are ribbon and bead lightning. These are forms of cloud-to-ground discharge with a flash consisting of several strokes. Ribbon lightning occurs when the channel is blown perpendicular to the line of sight by the wind, displacing subsequent strokes. Consequently, the flash appears as a ribbon of several strokes. In bead lightning, the main lightning flash breaks into luminous sections, or beads, as the light intensity of the channel decays.

The most rare and mysterious form of lightning is ball lightning.[26] A mix of fire and electricity concentrated in a fireball with a diameter of 10-30 cm, ball lightning usually appears suddenly, even in indoor conditions, during a thunderstorm. It moves quickly for several meters, can change direction, and ultimately disappears sometimes soundlessly and other times with a pop or larger explosive sound. It has a life span of several seconds, and its color is quite variable but most commonly described as white, yellow, or orange.

Etiology

Lightning can be considered the ultimate in cosmic cardioversion, producing atrial and ventricular arrhythmias, myocardial injury, and vasomotor responses.[27]

The mechanism of cardiac arrest is not known and may be from direct depolarization of the myocardium; damage or shock to the electrical systems of the heart, carotid body, atrioventricular (AV) node, or other parts; or damage to the autonomic nervous system or other mechanisms.

It has been theorized that lightning depolarizes the entire myocardium at once, causing a single systolic contraction followed by a variable period of asystole (primary cardiac arrest). Cardiac activity may return spontaneously, first at a markedly bradycardic rate and then slowly increasing in speed. Rhythm may deteriorate from apnea resulting from paralysis of the respiratory center in the medulla or from other mechanisms that are unknown at this time.

Lightning injuries versus common electrical injuries

Although lightning injuries can be classified as a special case of electrical injuries, the physics of lightning is far different from man-made electricity, leading to significant differences in the pathophysiology and injury patterns.[28]

Lightning cannot be classified as either direct current or alternating current. Lightning is not "scalable"—one cannot use his or her experience and knowledge of 110-volt lines or high-voltage injuries to predict what lightning will do. The physics of lightning is incredibly complex and substantially different from the physics of generated electricity. Unlike generated electricity, which is a voltage phenomenon, lightning is a current phenomenon. Once attachment occurs (completion of the lightning pathway to ground), any voltage in the lightning goes to zero.

Although the vast majority of news and witness reports credit “direct” strikes, this is often because of second-hand reporting, seeing only a portion of an unexpected and incredibly fast incident, lack of knowledge of other mechanisms, over-dramatization, and other factors.[21] Less than 5% of lightning deaths are caused by direct strike. The vast majority of lightning injuries are from indirect mechanisms.[21] The other 95% of deaths are caused as lightning first hits another object (eg, tree, tower, ground) and then side flashes to a nearby person or passes through the roots, ground, pipes, wires, or other object on its pathway to the person. Fewer than half of all survivors have any signs of burns or marks on their skin, probably because the lightning energy is mitigated by these primary targets and transit through other materials before it reaches the person.

Probably the most important difference between lightning and high-voltage electrical injuries is the duration of exposure to the current, which also affects the path it takes. While the energy from lightning may flow through the person for an incredibly brief period (4-6 ms), usually the vast majority of lightning energy flashes around the person's body surface, often vaporizing sweat or rainwater to cause secondary steam burns rather than primary lightning burns.[29]

Lightning has only brief contact with skin, and, in most instances, the contact is too brief to burn the skin substantially. Entry and exit are inappropriate terms to apply to lightning injuries.[10] In addition, because of this “flashover” effect by lightning, myoglobinuria, renal failure, and compartment syndrome occur much more rarely from lightning injury than from commercial electrical injury. When current does enter the body, almost every organ system is vulnerable. A wide variety of complications can result from damage to these organ systems, and specific sequelae dictate the choice of therapy.

Lightning also has a shockwave component that can cause injury.[22]

Although it is nearly impossible to document which mechanism of lightning injury was involved in a particular case, such knowledge or speculation of the mechanism of injury has no effect on patient care.

Types of human lightning strikes

Lightning may injure an individual in 6 ways.[10, 21, 30, 31]

  • Direct strike (approximately 3-5% of injuries)

  • Side splash from another object (approximately 30% of injuries)

  • Contact voltage from an object that is struck and conducts electricity to the site of touch, such as plumbing or wiring (approximately 1-2% of injuries)

  • Ground current effect as the energy spreads out across the surface of the earth when lightning hits a distance away from the person (approximately 40-50% of injuries)

  • Upward leader that does not connect with the downward leader to complete a lightning channel (approximately 15-20% of injuries)

  • Blunt trauma if a person is thrown and barotrauma from being close enough to experience the explosive force of lightning[22]

Direct strikes occur to victims who are outside. Although not always fatal, direct strikes are associated with high morbidity because they frequently involve the head. Lightning strikes near the head may enter the eyes, ears, and mouth to cause multiple problems. While most would conclude that a direct strike would be more likely to end in death than other mechanisms, there is no research or epidemiologic data to support this to date.

More commonly, the victim is struck by a flash discharge from another struck object. This type of splash injury occurs, for example, when someone seeks shelter beneath a tree, picnic shelter, or other object that is struck by lightning. A portion of the lightning may jump from the object struck to the victim. Splash injury also occurs from person to person when several people are standing close together.

Contact injury occurs when a person is touching an object that is either directly hit or splashed by lightning, such as indoor plumbing or wiring, hard-wired phones, a metal fence, bleachers, or other objects struck by the lightning.

Lightning also can result in harmful ground current that causes mass casualties in fields or other open areas. The severity of ground current injuries tends to decrease with distance from the point of the lightning strike.

Energy sufficient to cause death or injury also occurs in an upward streamer that can be induced in a person near a thunderstorm.[31]

Blunt trauma occurs when a person is thrown by a massive opisthotonic contraction caused by the lightning strike. There have been reports of both superficial and internal injury from blast effect.[32, 22, 33]

Risk factors

The primary risk factor for lightning injury is the failure to acknowledge that lightning poses a threat. Lightning safety and injury prevention is not convenient. It involves being aware of weather predictions, sometimes changing plans, and proactively planning evacuation to safer areas and the time to reach them. No place outside is safe when thunderstorms are in the area.[20, 34, 35, 36, 37, 38, 39] While safe areas are within a few yards in 98% of the time in developed countries, in developing countries, there may be no safe place within many miles for people to evacuate to.

Lack of knowledge of lightning danger and the mechanisms of injury also contribute to the risk. Many people try to finish one more inning or wait until rain begins before seeking shelter. This is often too late because lightning can travel as far as 10 miles in any direction from the thunderstorm clouds. The interstrike distance, depending on the local terrain and geography, may be as far as 5 ±5 miles, for a range of 0-10 miles (and sometimes more) from the last stroke.

Despite popular belief, nothing attracts lightning. The primary physical factors that make an object statistically more likely to be struck are isolation, height, and narrowness of the tip of the object facing the cloud. Only the first 2 factors apply to people.

While lightning can be seen hundreds of miles away on the Great Plains or not at all in heavily forested areas, thunder usually cannot be heard more than about 10 miles away. By the time one hears thunder, one is already in danger and should be seeking a safer structure or fully enclosed metal vehicle. The following 3 themes correctly summarize all of lightning safety and are the basis for Lightning Safety Week:

  1. When thunder roars, go indoors! (to a substantial building or fully enclosed metal vehicle)

  2. No place outside is safe when thunderstorms are in the area.

  3. Half an hour since thunder roars, now it’s safe to go outdoors.

The only reason that cell phones and iPods are dangerous in thunderstorms is that they distract the individual from paying attention to the weather and hearing thunder, the primary warning signal for lightning (see Telephone injuries below).

Although lightning injuries during recreational activities tend to predominate in industrialized countries, work-related lightning injuries also occur but have decreased markedly as many industries have adopted lightning safety guidelines for their workers. In the last few years, the vast majority of those killed have been within a few feet of safety.[2, 40] See Lightning Safety for statistics on the last decade of deaths in the United States by year, state, sex, age, and activity.

In the United States, certain geographic areas such as mountains, parts of Florida and the Gulf Coast, the Eastern Seaboard, and the major river valley areas of the Midwest are more prone to lightning because of weather patterns, moisture content of the air, and updrafts.

Around the world, the tropical and subtropical areas have far more lightning, less substantial housing, and, consequently, many more lightning injuries and deaths.[41, 42, 43] In developing countries with more labor-intense agrarian societies, the proportion of work-related injuries and deaths is probably higher.[44, 45]

Indoor exposures

Deaths inside buildings are rare in the United States and are usually to the infirm who are unable to escape secondary fires.[46] In general, being inside a substantial, habitable building such as a house, library, or school is one of the safer areas to seek shelter. The increased safety is credited, in part, to the fact that these structures tend to have plumbing and wiring in them, acting as a Faraday cage to transmit any electricity around the inhabitants.[34, 35, 38, 39]

Unfortunately, it is also true that lightning may hit or hit near a structure or recreational facility and be transmitted into the building through the plumbing, electrical wiring, emergency medical service (EMS) or fire dispatch radio, or other routes. This includes facilities with indoor pools, which should be evacuated using the same rules as outdoor pools. Individuals should avoid touching plumbing or objects that are electrically hard-wired to the structure's electrical system, including telephones, computers, and electronic games wired to televisions and computers.

Taking shelter in any structure that includes the word shelter (eg, bus shelter, sun shelter, park shelter, golf shelter, rain shelter) generally provides no protection. To date, national lightning-protection building codes (National Fire Protection Association: NFPA 780) address only physical protection of shelters but do not describe code to ensure the safety of people using them. Many believe that these structures may substantially increase the risk of lightning injury by increasing the functional height of the individuals standing under them, by increasing the risk of a side flash or ground current from a transmitted strike in structures with a lightning protection system, or by other mechanisms too long to go into in this discussion.

Being inside a fully enclosed metal vehicle is a very safe place because electricity will flow along the outside of any metal structure that it hits, not because of the miniscule effect of rubber composite tires. While being inside a vehicle when it is hit has been likened to "being inside a garbage can where someone threw two cherry bombs" and may be quite unpleasant, there has never been a substantiated electrical injury to a person inside a vehicle unless that person was touching a handheld radio hard-wired to the car’s lightning rod (antenna) or some similar connection to the outside.

Telephone injuries

As landline telephones have become less frequently used, indoor injuries from hard-wired telephones has substantially decreased. Hard-wired telephones become the conduit for the lightning charge to enter or to escape from a structure (and the person).[12] Although the telephone system may be grounded adequately for electrical surge protection, lightning energy surge is much too fast and strong for typical grounding and surge protection systems to be effective and reaches the person before the circuit breaker or other protection can be effective.

Injuries to persons using telephones or telephone headsets, such as those who take phone orders, used to be common but have decreased substantially now that wireless systems are more in use.

Older, portable phones, seldom used now in the United States, were a rare source of lightning injury to people standing within a yard or so of the base station or charger. Those injuries were caused by the lightning jumping from the charger to anything close by and had little to do with the phone the person was carrying.

No lightning danger is inherent to cellular phones. Although many reports of lightning injuries involve people who are using cellphones, these reports represent the ubiquity of cellphone usage and of their users' inattentiveness to weather conditions and have nothing to do with the phones themselves. Although it is theorized that cell phones or wearing earbuds or wires around the head may change the pathway of the lightning once a person is injured, they do not attract lightning. Conversely, since 90% of the world's population has access to cell phones, it may be possible to use them as a primary way of warning people in developing countries where forecasting and nowcasting are not available and weather reports are not easily accessed.[6]

In the past, acoustic injury was possible from the loud static noise in the earpiece of early portable phones, but to date, acoustic damage involving cellular phones has not been reported.[12]

Epidemiology

In the United States and northern hemisphere, thunderstorms and lightning are most common from June through September. Lightning strikes usually occur in the afternoon and evening, coinciding with times when people are active and outdoors. Hikers, campers, and other outdoor sports enthusiasts most often sustain lightning injuries. Lightning injuries are more common in rural or exposed environments than in the city, where high buildings have metal frames and lightning-protection devices. In the past 5 years, the majority of deaths have been to individuals who were within a few feet of safety and doing routine things, including mowing the lawn or going outside of a store to get better phone reception.[47] Because lightning deaths have been decreased so drastically by public education,[21, 47, 48, 49, 50, 51] only the outliers remain. In particular, boating and fishing have recently shown a disproportionate number of fatalities.[47]

In tropical and subtropical countries, lightning deaths may occur at any time of year but are more common during the rainy seasons. In developed countries, “safe” areas are usually all metal enclosed vehicles, homes, or other substantial buildings because of the wiring and plumbing in the walls, which tend to channel any lightning energy through the walls to ground. Unfortunately, risk of death or injury from lightning is much higher for most developing countries because of much higher lightning density; greater exposure from labor-intense work practices such as farming, tending animals, and growing rice; long unprotected distances to walk to school, work, or markets; and the lack of safe areas to seek shelter.[37, 42, 45, 52, 53, 54, 55, 56, 57, 58, 59, 60]

Many homes are simple huts or rondavels with thatched or metal sheet roofs, so that entire families are at risk at all times, even when they are sleeping. Unlike developed countries where injuries and deaths are usually isolated and individual, multicasualty incidents are common in developing countries, whether in open-air church meetings, sporting events, classrooms, or homes.[23]

Lightning may strike as far as 10 miles in any direction from a thunderstorm, before the rain starts, or while the sky above is still clear. At least 10% of lightning hits when blue sky is visible.[34, 35, 39, 61] The most dangerous times for lightning injury are when the person underestimates the likelihood of being hit (ie, before the storm or at the apparent end of the storm).

Occurrence in the United States

For the past 40 years, lightning has consistently been the second largest storm-related killer in the United States,[62] with 45-50 persons killed annually by lightning. From 2000-2006, the estimated annual rate of deaths attributed to lightning strikes was 0.2 per million people.[47, 52, 63] Since 2010, deaths from lightning have gone to third place behind tornado deaths, in large part because of a decade of public education by the media and the Lightning Safety Week team. In 2013, only 23 deaths from lightning were reported in the United States, for a rate of 0.06 deaths per million population.

Traditional sources of lightning injury data (the National Center for Health Statistics and Storm Data) systematically underestimate the number of fatalities by 28-42%.[10, 64] One reason is that much of the older data are taken from newspaper accounts using clipping services to catch them, so if people struck by lightning do not make the news, they are not entered into the statistics. Newspaper reports have been a major source of national statistics on lightning deaths for many years. In the last 10 years, search engines such as Google have supplemented or replaced clipping services for collection of lightning fatality data by the National Climate Data Center’s (NCDC’s) Storm Data and Lightning Safety Week (LSW) committee.[47]

As for using medical data to catalog injuries or deaths, most survivors of lightning strikes do not need to be admitted to a hospital and, as a result, do not show up in medical data banks. Moreover, many survivors do not seek immediate medical care and only come to the attention of medical personnel when they seek care for effects of the shock that have not resolved within a few days after their injury. Because injuries are so infrequently reported compared with fatalities, a rule of thumb developed from studies is that injuries occur about 10 times more often than do fatalities.[64]

In the United States, most injuries occur between May and September. The National Center for Health Statistics has documented that the majority of US deaths by lightning strike occur in the South and the Midwest, with Florida and Texas usually leading the list.[47, 63]

In 2005, Adekoya and Nolte used data from both the National Centers for Health Statistics multiple-cause-of-death tapes and the Census of Fatal Occupational Injuries, which is maintained by the US Bureau of Labor Statistics, to investigate the epidemiologic characteristics and annualized rates of lightning-related deaths for the United States.[63]

From 1993-2000, 374 struck-by-lightning deaths were recorded, for an average annualized rate of 0.23 deaths per million persons. Incidents in the South and the Midwest accounted for the majority of fatalities (286 deaths, 75%; with the greatest number of deaths in Florida [49 deaths] and Texas [32 deaths]). From 1995-2002, 1 of every 4 struck-by-lightning deaths was work-related (129 deaths; average annual rate of 0.12 deaths per million workers), with agriculture and construction industries accounting for the most fatalities at 44 and 39 deaths, respectively. Fatal occupational injuries were greatest in Florida (21 deaths) and Texas (11 deaths). As found in many other studies, incidence rates were higher for males and people aged 20-44 years.[63]

Almost all prior studies have looked at lightning injuries per state and not by geographic features or population centers. A novel and interesting study by Ashley and Gilson mapped deaths from 1959-2000 reported from multiple databases by location of occurrence to create a spatial map.[65]

The map revealed an urban theme with high fatality counts clustered along population centers and lower counts scattered across rural areas. The highest counts were noted along central and eastern Florida and a corridor paralleling Interstate Highway 95 from Washington DC, Baltimore, Philadelphia, and New York City. Overall, metropolitan areas in Florida showed the highest counts, the New York/Atlantic area the second, and the Chicago area the third highest clusters. In returning to a state analysis, when adjusted for area, 4 of the top 5 normalized fatality rankings by state were in the Mid Atlantic and Northeast, with Florida being the fifth state in the count.[65]

Another way to cluster injuries and direct prevention strategies is by looking at where the greatest number of thunderstorms occur: the South; Rocky Mountain area; Gulf and Atlantic Coasts; and the Ohio, Mississippi, and Hudson River valleys. Obviously, injury prevention efforts should be maximized in the areas of most historical risk, while at the same time being watchful of changing patterns. Specialized risk areas such as wilderness recreation and water have not been analyzed by population and other tight epidemiologic methods but seem to pose high risk based on viewing of the data and newspaper reports.

The most common days of injury in the United States are Saturdays and Sundays, probably reflecting the recreational activities on the weekends. The most common time of day to be injured by lightning is from noon to 6 pm, with 6 pm to midnight following, related to not only when thunderstorms occur but also to when people are most likely to be outdoors.[10, 47, 66]

International occurrence

Lightning is much more common near the equator. Increased risk is due to labor-intensive work practices; insubstantial housing; long unprotected distances that people must travel to work, school, or market; and lack of metal vehicles.

Several papers have been published with different methodologies for predicting lightning deaths worldwide.[66, 40, 67, 68, 69, 70] One paper estimated total annual fatalities to be about 24,000, and annual injuries are estimated to be about 240,000 for the tropical and subtropical areas of the world, where lightning is most common and the economies tend to be more subsistent, agrarian, and labor-intensive than they are in the more developed and temperate climates.[10, 52] In general, lightning injuries and deaths decrease in any country as the economic system, urbanization, and housing improve, not only because direct numbers of persons exposed to lightning decrease but also as housing that contains plumbing and wiring providing protection becomes more prevalent.[46]

Compiling and recording statistics in individual countries is a challenge because they often lack a good reporting system.[71] Fortunately, more and more researchers are investigating and reporting on injuries in their countries to reveal patters and educate governments to the need for injury prevention.[45, 42]

A new report has linked geographic information system (GIS) locations of known injuries to lightning-density maps in the United States.[60] If this technique can be validated in a developing country where injury statistics are well known, such as Colombia,[45] it may be a very useful tool to focus injury prevention efforts in parts of Africa, Asia, and South America, where risk is high but fatality data and location are largely unavailable or inaccurate.

Race-, sex-, and age-related demographics

No relationship to race is known to exist.

In a US study, data from 1959-1994 indicated that males were 4.6 times more likely to be killed and 5.3 times more likely to be injured by lightning than were females. This was not because of any physiologic differences but was considered to be a consequence of males' increased exposure to potential lightning-strike situations, such as outdoor activities or work, as well as to males’ higher level of risk-taking behaviors.[10, 47] Fatality statistics with a 70-85% male component is consistent across countries and continents regardless of economic or meteorologic conditions.

Of deaths and injuries, 85% occur to persons aged 10-59 years. Few adults older than 60 years are injured. This is probably related to the decreased chances of exposure of this age group during outdoor recreation or employment.[10, 47]

Prognosis

Many individuals struck by lightning have permanent disabilities that affect their families and their ability to return to their previous work. In patients who have endured a more severe injury, the potential for permanent and debilitating neurologic and cardiac injury is greater.

However, no good long-term, controlled studies are available to indicate if lightning-related injuries improve or progress to more serious disabilities or to give stratified prognoses for different subgroups of survivors. As with other injuries, the longer a person has a symptom or sign, the more likely each is to be permanent.

Uncontrolled long-term reports of sequelae have appeared sporadically.[12, 72]

Morbidity and mortality

In developed countries, lightning causes death in about 10% of its victims.[64] The ratio of deaths to injuries in developing countries is unknown. After a lightning injury, the probability of death is unrelated to sex, age, and the presence of trunk and arm burns. Factors that appear related to a fatal outcome are leg burns, head burns, and immediate cardiopulmonary arrest.[73] Some reports suggest as many as 74% of survivors of a lightning strike experience permanent injury and sequelae.[73] Other studies suggest the percentage with permanent injury is less; however, there continues to be controversy over the long-term effects in general.

Most lightning-associated deaths are caused by cardiac arrest.[74, 75, 76] Forensic physicians must consider lightning strike in the differential diagnosis of sudden unexpected death in persons found outside.[77, 78, 79] The most common minor injury reported is rupture of the tympanic membranes.[80] Superficial burns and eye injuries are frequently reported.[75, 73, 81, 82] The most common chronic sequelae reported are brain injury and chronic pain syndromes.

Lightning injuries differ from those resulting from high-voltage because lightning injuries usually do not cause significant tissue destruction along the path of grounding of the current. Blunt, concussive, and occasionally shrapnel-like physical injury may also accompany lightning injuries; therefore, medical personnel should also screen lightning victims for occult blunt trauma.[25, 75, 32, 33, 80]

Neuropsychological sequelae of lightning injury can cause significant morbidity.[83] Survivors of lightning injury report heightened anxiety states, hyperirritability, memory deficits, aphasia, sleep disturbance, attention deficit, deficits in working memory, and posttraumatic stress disorder.[84, 85] These symptoms also are found in patients with blunt head trauma, yet the sleep disturbance and memory difficulties are more severe than those caused by blunt brain injury.

Lightning injury is a neurologic injury, affecting all 3 parts of the nervous system, as follows[38, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93] :

  • Brain - Neurocognitive changes, sleep disturbance, personality change, seizures, learning disability, postconcussive-type headaches, nausea, attention deficit, distractibility, vestibular injury, pituitary and hypothalamic damage

  • Autonomic nervous system - Regulation of blood pressure and cardiac response (positive tilt test results, dizziness, hypertension), GI insult, impotence, sympathetically mediated pain syndromes

  • Peripheral nervous system - Chronic pain, sensory problems

Most patients with injuries caused by lightning regain consciousness. However, many patients injured by lightning experience transient motor paralysis (69% incidence of paralysis of the upper extremities and 30% incidence of paralysis of the lower extremities), usually sparing the ventilatory center. Paralysis from lightning injury is known as keraunoparalysis and is associated with sensory loss and cyanosis. Total resolution of paralysis usually occurs in minutes to days. If paralysis does not improve, other causes, such as direct spinal cord injury or musculoskeletal or blunt injury from a fall, should be suspected.

Patient Education

Patient resources include the following:

  • Lightning Strike and Electric Shock Survivors, International

  • Phone: (910) 346-4708; e-mail: info@lightning-strike.org

  • Lightning Safety

 

Presentation

History

Lightning injuries are obvious if they occur in a group setting with witnesses present. However, lightning injuries can be difficult to diagnose if the person presents without witnesses, is unable to relate the details of his or her injury, or is found dead in a field, mountain side, or street.[78]

Often, the person can relate what happened. However, it is common for the person to have anterograde amnesia or confusion.[24] While the person may be able to carry on a reasonably coherent social conversation, giving demographic and billing data, the examiner may also observe that he or she repeats the same questions multiple times or may not remember events in the emergency department (ED). More disturbing symptoms such as not recognizing a family member should draw suspicion for malingering or other litigious behavior.

Physical Examination

Each patient must receive a complete physical examination, including a neurologic assessment and a thorough examination of the skin for wounds and burns. Physical presentation may vary from mild disorientation with no immediate physical signs to cardiac arrest (the only direct cause of death) and anoxic brain injury. Conscious patients most often complain of muscle aches, dysesthesias, headaches, weakness, or other neurologic/musculoskeletal problems.[10, 24]

Indications of lightning injury noted on physical examination include the following:

  • Cold, pulseless extremities - A sign of vasomotor instability

  • Confusion, amnesia, paralysis, and loss of consciousness

  • Temporary hearing loss or tympanic membrane rupture - Caused by concussive shock wave

  • Hypotension - Usually from vasomotor instability and spasm but spinal cord injuries and other more common causes should be ruled out

  • Prolonged paresis or paralysis of the extremities - Indicates possible spinal cord injuries

  • Fixed and dilated pupils - Typically a result of transient autonomic disturbances, not serious head injuries; pupillary areflexia and dilatation therefore cannot be used as a reason to stop resuscitation

  • Lichtenberg figures - Rare but pathognomonic of lightning injury; also known as ferning pattern or keraunographic markings[94] or other singeing of hair or clothing

  • Clothing that is singed, shredded, or blown apart; shoes that appear to be exploded from the inside; magnetized watches, zippers, or other metal objects; streaming and cuprification of brass grommets or zippers.

Hypothermia

Because lightning injuries occur most commonly outdoors, often in wilderness or where the person may lie exposed for a period, hypothermia should be ruled out.

Cardiorespiratory symptoms

Cardiorespiratory arrest is the only known direct cause of death. Lightning may send the heart into momentary asystole, from which the heart often spontaneously recovers. Autonomic nervous system control of cardiac rhythm has been shown to be affected by lightning. In some cases, respiratory arrest may last longer than the initial cardiac arrest and a secondary cardiac arrest from hypoxia, from more serious brain injury prolonging the respiratory arrest, or from other unknown causes may occur.[10, 18, 19, 24]

QT prolongation is the most common electrocardiogram (ECG) abnormality, which generally resolves over several months and does not commonly require treatment. Other ECG abnormalities should receive standard treatments.[10, 18, 19, 20]

Neurologic symptoms

The immediate effect of the electrical current of a lightning strike on the CNS is an altered level of consciousness that varies from disorientation with retrograde amnesia to loss of consciousness. In the most severe cases, paralysis of the respiratory center may occur and cause sudden death or significant anoxic brain injury if the person is resuscitated. Rarely, the injury is so devastating that rapid onset of cerebral edema with brainstem herniation occurs. If the patient is unconscious, suspect and investigate anoxic brain injury or underlying brain injury. Contusion and intracranial hemorrhage have been reported.[83, 77, 86]

Cerebral edema should be managed in the standard way.

Patients who are awake are usually able to carry on reasonably appropriate social conversation. Later, they may develop disabling neurocognitive deficits similar to those of people with concussive or blunt brain injury, which may not be apparent until survivors attempt to return to their previous work and are unable to process new information, organize their activities, and multitask.[10, 95]

Acute pain, numbness, or other dysesthesias may be reported. Chronic pain syndromes may develop from lightning injuries and may be due to nerve injury, sympathetic nervous system injury, spinal cord injury, or other causes.[10]

Sympathetic nervous system injury may acutely cause vascular spasm; temporary paralysis and mottling of an extremity (keraunoparalysis); transient self-limited hypertension; and late problems with positive tilt test results, vertigo or dizziness, hypertension, and pain syndromes.[10, 87, 88]

Mechanical trauma from a fall after a lightning strike can also account for neurologic sequelae. Rarely, lightning may cause the victim to fall or be thrown with sufficient force to cause skull fracture and intracranial hemorrhage. Because a comatose or semicomatose state may follow the lightning strike, it is often difficult to distinguish coma resulting from electrical shock from intracranial hematoma until lateralizing signs develop.

Burns

Because lightning contact with the skin is brief, deep burns are typically rare.[17, 96] If burns occur, they should be treated like any other high-voltage injury, including investigating for myoglobinuria. Discrete entry and exit points are rarely seen with lightning injury.

The following types of burns are caused by lightning:

  • Feathering (Lichtenberg figures, keraunographic markings)

  • Linear

  • Punctate - Multiple, closely spaced, discrete, circular, usually full-thickness burn that results from current passing through dry skin; a few millimeters to a centimeter in diameter and resembles a cigarette burn

  • Thermal - Results when lightning ignites or melts clothing; can be a full-thickness burn

  • Contact - Occurs when metal, such as jewelry, zippers, or belt buckles, contacts the skin during a lightning strike; can be a full-thickness burn or can actually "tattoo" metal, such as a necklace, into the skin

  • Flash - Superficial burn that results in brown discoloration of the skin

An almost pathognomonic cutaneous feature known as feathering or lightning prints consists of linear, fernlike, superficial skin markings (also called keraunographic marks) that usually disappear after several days.[97] These cutaneous manifestations of lightning injury usually consist of erythematous streaks that do not blanch on diascopy. Erythema begins to fade in 4-6 hours with no residual skin changes. Keraunographic markings are probably related to the flashover phenomenon, from the transmission of electricity along the superficial vasculature. Recognition of this sign may save the life of an unaccompanied, comatose patient and should signal the need for immediate resuscitation if a victim is not breathing and has no pulse.

Linear burns are usually partial-thickness, 1-4 cm wide, that occur on sweat/rain-covered areas of the body, such as beneath the breasts or midchest, and in the midaxillary line. These burns present minutes to hours after the lightning strike and result from vaporization of sweat or rainwater into steam on the patient's body. These can be treated as any other superficial burn.

Although full-thickness burns rarely result from lightning in developed countries, lightning occasionally causes a more typical electrical burn from long continuous current flow, with clinical manifestations similar to those from a commercial, high-voltage electrical injury. Rarely, scarring following lightning burns may develop into squamous cell carcinoma (Marjolin ulcer).

Therapy for more severe burn injuries should include cleansing the burn wound with poloxamer 188, followed by treatment with a topical antimicrobial cream containing polymyxin (10,000 U/g), nystatin (4000 U/g), and nitrofurantoin (0.3%). Tetanus prophylaxis is required. Any devitalized skin should be excised and autogenous, split-thickness skin grafts considered.

In developing countries where marginal housing is the norm, keraunoparalysis may prevent victims from escaping subsequent fires, resulting in much more severe thermal injuries that can be managed with standard burn treatments.[98]

Blunt injury

Concomitant myoglobinuria should be considered if blunt injury is present. Fractures are uncommon and occur more rarely in lightning injuries than in high-voltage injuries.

Organ contusions, pulmonary hemorrhage, and cardiac contusions have been reported but are rare. If the patient has a history of a fall or being thrown a distance, investigate for fractures and blunt injuries. A patient may also have experienced explosive trauma and shrapnel effects if he or she was close to an object that has been exploded by lightning.[22]

Musculoskeletal system

Lightning may injure the musculoskeletal system either by mechanical trauma or by passage of the electrical current.[99] Fractures of the skull, ribs, extremities, and spine have been reported but are rare.

As current passes through tissue, electrical energy is converted to heat that can rarely damage muscle tissue. Muscle necrosis causing compartmental syndrome or rhabdomyolysis and renal failure are extremely rare, occurring much less frequently than in commercial electrical injuries.[100]

Eyes and adnexa

Lightning can injure the eye and its adnexa.[101] Nearly every type of eye injury has been reported with lightning injury, including cataracts, macular holes, retinal separation, and iritis.[81] Cataracts may be an early or late sequela of lightning injury, as are chronic pain syndromes, sleep disturbance, and severe headaches.

Disruption of the autonomic nervous system can cause dilated and/or nonreactive pupils. This reaction to lightning strike is usually short-term and should not be used as an indicator of brain death.

Cataracts are the most common intraocular lesions caused by lightning.[102] Two types of cataracts are seen: (1) an ordinary traumatic cataract that develops shortly after the injury from a concussion that results in minute tears of the lens capsule and (2) a type of cataract that is characteristic of an injury from either lightning or high-voltage current. In the latter, a high-voltage current produces anterior subcapsular changes, while lightning causes opacities in the anterior and posterior capsules. The cataract most commonly appears within the first few days or weeks but has been reported as late as 24 months postinjury and is often bilateral. Generally, opacification develops more rapidly after lightning injury than after commercial high-voltage electrical injury.

Retinal involvement after lightning injury is less frequently documented, although chorioretinal atrophy, macular holes, macular cyst, papilledema, hemorrhage, and detachment have been noted. Macular cyst can be diagnosed with optical coherence tomography. Consequently, consider the possibility of retinal damage when evaluating the visual potential of a patient who has developed a cataract following a lightning strike.

Lid lesions caused by lightning vary from a partial-thickness burn to ulcerated necrotic lesions. Conjunctival chemosis frequently occurs, and corneal lesions vary from transitory punctate keratitis to severe interstitial keratitis. Iridocyclitis may be mild and short-lived or more severe and chronic. Paresis of accommodation also may occur following a lightning strike.

Ears

In contrast to direct electrical current accidents, lightning commonly causes ear injuries, occurring in up to half the patients.[10, 11, 80] Direct electrical injury and blast effects can injure the ear. In lightning-damaged ears, substantial ear damage and hearing loss are common, as are tinnitus and other eighth nerve symptoms, including dizziness and unsteadiness.[24]

Temporal bone pathology shows tympanic membrane rupture, middle ear and mastoid effusion of blood, total rupture of the Reissner membrane, degeneration of the stria vascularis and organ of Corti, edema of the intracanalicular portion of the facial nerve, herniation of a portion of cerebellum into the internal auditory meatus, and a possible microfracture of the otic capsule. These lightning-damaged ears often are associated with other injuries (eg, burns of the skin, acromioclavicular joint separation).

Perforation of the tympanic membrane occurs in more than half of patients more severely injured by lightning but should always be sought in lesser injuries as well. This injury is caused by the blast effect, basilar skull fracture, or direct burn damage from lightning. Simple ruptures of the tympanic membranes from lightning usually heal well without surgical intervention.

Occasionally, unilateral hearing loss can occur without other trauma after lightning injury.[33] An audiogram often shows typical nerve-type hearing loss. The tympanic membrane is intact but markedly inflamed. Hearing disability is temporary, and recovery occurs in 9 months.

Almost all lightning survivors report chronic tinnitus as one of their most irritating sequelae.

Complications

Serious lightning injuries involve primarily cardiac arrest and neurologic injury in developed countries.[74, 75, 76] Otologic injury and cutaneous burns have also been noted as frequent sequelae of these events.[75, 32, 73, 81, 82] Cataract formation resulting from lightning injury typically occurs within days to weeks of injury. (See Prognosis, Presentation, Treatment, and Medication.)

Major complications are rare in mild and moderate lightning injuries, although musculoskeletal discomfort and subjective sensations of paresthesias, irritability, and other nonspecific neurologic sequelae may be present. In severe lightning injury, with cardiopulmonary resuscitation (CPR) required in the field, permanent neurologic deficit and hypoxic injury are common.

Complications of being struck by lightning include the following:

  • Chronic pain syndromes

  • Neuromuscular and musculoskeletal pain

  • Neurocognitive deficits, including short-term and working memory deficits, difficulty accessing, processing, and incorporating new information, attention deficit, personality change, distractibility, decreased executive function, and loss of ability to multitask

  • Isolation or depression

  • Sympathetic nervous system dysfunction, including positive tilt tests and hypertension

  • Dizziness, balance problems, tinnitus, nausea, and other eighth cranial nerve symptoms

  • Sleep disorders

  • Symptoms similar to postconcussion syndrome (eg, headaches, nausea, confusion)

  • Atypical seizure disorders

  • Pituitary or hypothalamic damage with secondary endocrine effects

Cardiopulmonary complications include the following:

  • Transient hypertension

  • Electrocardiographic changes

  • Myocardial injury

  • Congestive heart failure

  • Dysrhythmia

  • Transient asystole

  • Atrial fibrillation

  • Ventricular fibrillation

  • Frequent premature ventricular contractions

  • Respiratory complications

  • Apnea

  • Hypoxemia

Damage to the central nervous system (CNS) is the second most debilitating group of lightning injuries.[83] Neurologic complications include the following:

  • Immediate loss of consciousness

  • Keraunoparalysis lasting minutes to hours

  • Amnesia and confusion

  • Retrograde amnesia

  • Hemiplegia, aphasia

  • Coma

  • Seizures

  • Intraventricular hemorrhage

  • Hematomas

Vascular complications include the following:

  • Vasomotor instability

  • Arterial spasm

  • Vasoconstriction

  • Vasodilatation

Ophthalmic complications include the following:

  • Cataracts

  • Macular holes

  • Corneal lesions

  • Hyphema

  • Iritis

  • Vitreous hemorrhage

  • Retinal detachment

  • Optic nerve injury

Otologic complications include the following[32] :

  • Ruptured tympanic membrane

  • Temporary hearing loss

  • Disruption of the bones of hearing

  • Dizziness, instability, and tinnitus from eighth cranial nerve damage

Photophobia, difficulty with noise and crowds, lack of appetite, nausea, headache, and other concussionlike symptoms are common in the first weeks post injury.

More acute and severe gastrointestinal (GI) complications of lightning injuries are similar to those following any major trauma and tend to occur only in the most severely injured patients.[103, 104] Most common is gastric atony with gastric dilatation, for which placement of a sump nasogastric tube is mandatory to decompress the stomach and remove swallowed air. Another complication seen in victims of lightning injury is GI bleeding, albeit a very rare complication. GI perforation is another rare complication of lightning injury.[103, 105] Buffering the gastric secretions with antacids and administering cimetidine may prevent this. In 2 unusual fatal cases of lightning strike, autopsy findings showed hemorrhage and necrosis in the pancreas.

 

DDx

Diagnostic Considerations

Conditions to consider in the differential diagnosis of lightning injury include the following:

  • Intracranial hemorrhage

  • Seizure

  • Cardiorespiratory arrest

  • CNS injury or stroke

  • Autonomic nervous system injury

  • Peripheral nervous system injury

  • Blunt and explosive trauma

  • Musculoskeletal injury

  • Acoustic injury

  • Barotrauma

Differential Diagnoses

 

Workup

Approach Considerations

Routine blood work findings in mild or moderate lightning injury are usually within reference ranges and do not contribute to patient outcome. If, for some reason, the physician believes it is warranted, blood work may include complete blood cell (CBC) count, creatine kinase (CK) with isoenzymes, routine urinalysis, and urine or serum myoglobin levels, although all of these are normal in the vast majority of cases. Screening for myoglobin should be performed on the initial evaluation and admission to the hospital, but results are unlikely to be positive except in the most severe lightning strikes.[14] Extensive muscle damage producing myoglobinuria is quite rare with lightning strikes and can easily be screened with a dipstick of fresh urine.

Isoenzyme fraction creatine phosphokinase-BB (CPK-BB) may be elevated following lightning accidents that result in cerebral anoxia. The significance of this finding is uncertain, because no correlation has been found between an increase in CPK-BB and the extent of brain injury.

Patients admitted to the hospital may also benefit from blood electrolyte determinations, blood urea nitrogen (BUN) testing, creatinine level evaluation, and serial CK determinations.

Electrocardiography

Many changes may be observed on the ECG, but the most commonly reported change is QT prolongation, which generally resolves over several months and does not commonly require treatment. Unless ECG changes or cardiaclike chest pain is present, admission for cardiac monitoring is not needed.

Early ECG is frequently performed, but findings are often normal. Conduction abnormalities or evidence of subepicardial ischemia is common in more severe strikes.

Electromyography and electroencephalography

Electromyography and electroencephalography may be helpful later in the course of more severe injuries, but they are rarely helpful in the immediate postinjury period.

Neuropsychological battery

A neuropsychological battery may be indicated later if the person reports memory loss, an inability to process new information, and other cognitive difficulties and can contribute to cognitive therapy. However, these tests are expensive and usually not warranted unless the patient is in litigation or is applying for accommodations for education or work.

Imaging Studies

Imaging studies should be guided by clinical suspicion based on history and physical examination. Routine imaging is not warranted because most lightning survivors have reasonably minimal injury. However, for the unconscious patient, the threshold for imaging should be low owing to the possibility of head injury, intracranial bleeding, and spinal cord damage.

Radiography

In the case of blunt trauma or blast injury, plain radiographs should be considered for all contused or injured areas, including the cervical spine and chest.

CT scanning and MRI

If a patient had loss of consciousness or presents with confusion or clouded consciousness, a noncontrast computed tomography (CT) scan or magnetic resonance imaging (MRI) scan can evaluate brain injury. The vast majority of scans are normal.[106]

 

Treatment

Approach Considerations

Do not assume that lightning injuries are like high-voltage injuries or treat them as such in the absence of deep burns. Only the rare lightning patient requires aggressive fluid resuscitation, alkalinization of the urine, or transfer to a burn unit.

Anecdotal reports of survival with prolonged CPR started in the field have been received, but the overall prognosis remains extremely poor in these situations.[107] If resuscitation is successful, rare cases of reasonable recovery have been reported but only after extensive critical and rehabilitative care.

Resuscitation dosages and administration schedules for cardiac medications are the same as for persons with cardiac arrest from other causes. Initial treatment should begin with assessment and stabilization of the airway, breathing, and circulation. Persons who have been struck by lightning should be treated as trauma patients, with close attention to spinal immobilization. If lightning causes asystole, a sinus rhythm may be spontaneously reestablished in some cases. Respiratory support should be provided if the patient's efforts are inadequate to prevent deterioration to cardiac arrest or ventricular fibrillation. Automated external defibrillators (AEDs) have been reported to be used successfully in several cases.[108]

Emergency department care

Routine care should be performed for any complications such as seizures, chest pain, and other symptoms. Reasonable reassurance and referral for continuing problems/sequelae is indicated. The vast majority of lightning survivors do not need to be admitted.

Referral to a support group (eg, Lightning Strike and Electric Shock Survivors International) can be made. Much more information is available on the Internet about lightning injuries than in the past.

Surgical therapy

No surgical therapy is indicated initially in cases of lightning injuries. Rarely, persons with severe lightning injuries may require fasciotomies for extremity compartment syndromes or escharotomies for severe burns.

Patients requiring surgery for any reason after a lightning injury should have adequate intravenous (IV) access and cardiac monitoring throughout the procedure.

Consultations

Consultations are based on physical findings and may include referral to a neurologist, cardiologist, ophthalmologist, otolaryngologist, or, rarely, a burn surgeon. Later consultations may include referral to a neuropsychologist, pain specialist, or psychiatrist.

Transfer

Transfer the patient as appropriate for patient status and stability, as well as for the capabilities of the treating facility. The vast majority of lightning survivors do not need admission, much less transfer.

Follow-up

If the patient continues to experience pain, dysesthesias, or other neurologic symptoms, referral to a neurologist or a pain specialist is appropriate.

A neuropsychological battery may be helpful for patients who develop neurocognitive (eg, memory, processing, endurance, sleep disorders) problems.

Pregnancy

Effect of lightning injury in pregnancy varies. Of 11 pregnant women struck by lightning, approximately half of the pregnancies resulted in full-term live births without evidence of birth defects. One fourth of the pregnancies resulted in neonatal deaths and one fourth in stillbirths or deaths in utero.[76, 109]

Prehospital Care

Typically, all lightning strike victims who do not experience cardiac or respiratory arrest survive; therefore, normal triage priorities do not pertain to these individuals. Immediate attention should be directed to the resuscitation of those patients in respiratory or cardiac arrest.[14]

Patients with dysrhythmia who traditionally have a poor prognosis (eg, those with asystole) may occasionally recover. It is reasonable to end resuscitative efforts if there has been no response after 20, or at most 30 minutes, of aggressive and persistent resuscitation.

Remember that no place outside is safe when thunderstorms are in the area and rescuers may be at significant risk. National lightning safety guidelines indicate that significant risk continues for 30 minutes after the last lightning is seen or thunder is heard. If it is judged that there is no risk of continuing danger of lightning injury to emergency medical services (EMS) personnel, resuscitation can occur in the field. Otherwise, safe evacuation to the unit or a substantial building is indicated. Immobilization should be considered because of risk of blunt trauma from the lightning concussion or from being thrown by involuntary muscle contraction. (Obviously, a sober, alert, minimally injured patient can help to decide if this is necessary.) Resuscitation or supportive care, including advanced cardiac life support (ACLS) and AED use, can then proceed as indicated based on clinical status.

Fluid loading and alkalinization of the urine is not warranted in the vast majority of cases.

Immediate resuscitation

Immediate resuscitation of the person struck by lightning greatly influences prognosis. If a witness to the accident is present, he or she should initiate resuscitation at the scene. The rescuer first should check the person's responsiveness. If a spinal cord injury is suspected, stabilize the person's head during assessment of the level of consciousness. Keraunoparalysis or evidence of head injury or tenderness or hematomas of the neck or back should alert the rescuer to the possibility of an injury to the spinal cord. In such cases, stabilize the head until the person is secured to a long backboard by emergency medical technicians.

If a group of persons is struck by lightning, attention should be directed to those with no signs of life, because the others will probably recover although they may have burns or injuries that need treatment. Immediate cardiopulmonary resuscitation and prevention of anoxic death are essential, but the majority of these patients die despite these resuscitative efforts.

Altered level of consciousness

If the person has an altered level of consciousness or is unresponsive, the rescuer should assess ventilatory impairment. Kneeling at the person's side, the rescuer places his or her cheek close to the person's mouth. While listening and feeling for breathing, the rescuer should watch the movement of the bared chest. Movement of the chest wall should be synchronous and symmetrical with each ventilation. Satisfactory air exchange is evidence of adequate ventilation.

Inadequate ventilation

The most common cause of inadequate ventilation in the unconscious victim is blockage of the pharynx by the relaxed tongue. This airway obstruction is relieved by the modified jaw thrust maneuver that moves the jaw forward and lifts the tongue from the posterior pharyngeal wall with minimal movement of the spinal cord. Ideally, emergency medical technicians should continue monitoring throughout transport to the advanced life-support facility.

Electrocardiographic changes

Electrocardiographic changes observed following lightning accidents probably stem from vascular spasm or arrhythmia without coronary artery occlusion.[74] Occasionally, there is direct damage to the myocardium. Autopsy studies of victims of lightning injuries have demonstrated epicardial hemorrhages and a peculiar spiral malformation of the myocardial fibers.

Electrocardiographic evidence for direct myocardial damage includes ST segment elevation, T-wave inversion, and prolongation of the QT interval. Fortunately, these electrocardiographic changes usually resolve without serious cardiac complications, although occasionally more serious sequelae develop. Usually, no evidence of cardiac dysfunction is seen at several months after injury, and the patient's exercise tolerance returns to normal.

Vasomotor spasm

Keraunoparalysis with vasomotor spasm is the local response of the vasculature to electrical current from direct sympathetic stimulation. Vasoconstriction may be so prolonged and intense that it causes early and severe loss of pulses and mottled, cool extremities. This vasoconstriction is usually self-limited and resolves within hours.

Transient hypertension

Transient hypertension may occur and usually requires no short-term therapy. However, hypertension that persists 12-72 hours after the lightning strike responds to beta-blockers.

Pharmacologic Therapy

Nonsteroidal anti-inflammatory drugs (NSAIDs), as well as narcotics, are often used for the acute pain. Chronic pain management may include acetaminophen, tricyclic antidepressants or selective serotonin reuptake inhibitors (SSRIs), medications for adult attention deficit, neuroleptics, narcotics, sympathetic blockade, and other pain control measures, as indicated by the patient's symptoms.

Burn surgeons administer NSAIDs, vitamin C 1 g/day, and vitamin E 400 U/day to decrease scarring from electrical injuries. Vitamin C and vitamin E are hypothesized, but not proven, to be effective against other injuries as well, such as nerve damage. Whether they are effective for lightning survivors is not known.

Treatment of Lightning-Damaged Ears

Immediate treatment of lightning-damaged ears includes cleaning blood and debris from the external auditory canal and aural hygiene. Otic drops can be used unless the patient has cerebrospinal fluid otorrhea.

Prudence dictates delaying surgery on unresolved tympanic membrane perforations for at least 6 months for several reasons. Edema, burning, and charring of the ear canal may interfere with tympanoplasty. Spontaneous healing often occurs. A delay may also reveal partial ossicular necrosis and discontinuity, which can be corrected at the time of tympanoplasty.

Following tympanoplasty or spontaneous healing of the tympanic membrane, prolonged observation for a blast-induced cholesteatoma is advised. Implants of squamous epithelium from the drum may be blown into the promontory, where they proliferate and cause cholesteatoma.

Management of peripheral facial nerve palsy involves frequent stimulation to see if the nerve is injured and if surgical decompression or repair is necessary.

Even after repair of the ear, the patient may report continuing and irritating tinnitus from eighth nerve damage, as well as problems with balance and dizziness.

Inpatient Care

The vast majority of patients do not need inpatient admission and few need cardiac monitoring. Routine and supportive care is administered to patients as indicated by physical findings. Sometimes, however, chronic pain syndromes, neuromuscular injury, and neurocognitive deficits, which are significant and life changing, become apparent in patients who initially seemed to be only minimally injured.

Obviously, persons who have been severely injured by lightning require hospital admission, often to an intensive care unit. There is nothing special or specific regarding the care of such patients; care is routine, being carried out as indicated by the injuries. Rehabilitation may be prolonged and extensive for the more seriously injured patient.

If a patient has evidence of cardiac dysrhythmias or myocardial injury or has been revived from cardiorespiratory arrest, he or she should be admitted to the appropriate monitored setting. A patient who has suffered significant blunt trauma as a result of the lightning strike should be admitted to the appropriate trauma service and setting for further management.

Prevention

Predicting the possibility or severity of any given lightning strike is impossible. Altering the course of injury, once set in motion, is also difficult. Therefore, preventive measures and education for individuals at risk are the most effective methods of minimizing lightning-related mortality and morbidity.[14, 62]

Guidelines by the Lightning Safety Group (LSG) have been published in the Annals of Emergency Medicine.[62] In 2000, some of the LSG authors were invited by the National Oceanic and Atmospheric Administration (NOAA) to become founding members of National Lightning Safety Awareness Week (LSW). The LSW Web site is now the premier reference for lightning safety in the world. It includes links to media and teacher sections, science sections with animations, the LSESSI support group, children’s games and curricula, free downloadable educational and safety materials, statistics and individual injury reports for the last several years, and multiple links to other related lightning sites.

Over the last decade, committee members have given thousands of interviews to the media, educating broadcasters and the public in lightning injury prevention. Lightning safety guidelines now appear in almost every sports, scouting, coaching, and public venue in the United States.[34, 49, 110, 111] Several individuals from other countries have worked with committee members to modify Web site source materials with pictures, language, and safety rules appropriate to their settings.

The US National Collegiate Athletic Association (NCAA) has been an active partner in this, with guidelines for their coaches since 1997.[34] Multiple professional and college-level games, including those being televised, have been delayed or called for lightning risk in the last decade. High schools have adopted similar guidelines for lightning stoppage. There are now lightning safety toolkits for stadia, beaches, and other mass gatherings to help managers plan appropriate response to bad weather and thunderstorms that are also available on the NOAA Web site.[111]

Hurricanes and, often, floods can be predicted days ahead of time, and tornadoes can be predicted minutes to hours in advance, allowing time for people to prepare, evacuate, or seek appropriate shelter. Small thunderstorm cells arise and disappear and lightning occurs far too often and unpredictably for the government to issue warnings for every event. The National Weather Service (NWS) issues severe storm or thunderstorm warnings upon danger of (1) straight-line winds exceeding 60 miles per hour, (2) hail three fourths of an inch or larger in diameter, or (3) tornadolike gusts.

In the last decade, largely in response to LSW team efforts, many offices now report the possibility of "dangerous lightning" as well. However, lightning safety continues to be primarily an individual responsibility, requiring individual decisions for prevention. With improved nowcasting, nearly real-time warnings can be issued and there are subscription services for this type of information that are available to scouting, entertainment, sporting, and other outdoor enthusiasts.

One exception to the individual responsibility caveat is if an adult, such as a parent or coach, or an organization, such as a pool, school, park, or scouting organization, is responsible for children. In those cases, the adult or organization is accountable and responsible for being aware of lightning safety rules, exercising prudent judgment, having an evacuation plan, and exercising that plan when appropriate to protect the children from harm and injury. The NCAA handbook’s section on lightning injury prevention policy is particularly useful for parents, who can present a copy to their children's team managers to spur lightning safety planning. The NOAA LSW Web site has many resources for teaching lightning safety. Coaches, who used to be resistant to cancelling practices and games, are now among the most proactive when it comes to lightning safety.

Event planners should be proactive and may need to monitor the weather hours to days in advance of an event. A number of online, real-time services may be accessed or subscriptions purchased. Some will warn via cell phones or other electronic devices, which is particularly handy for camps and large, outdoor sports venues. Users of these services should ensure they are using real-time data, not reports that have been delayed 10-30 minutes by some services. Lightning safety plans should include safer areas for shelter, appropriate signage and written material in event programs, and clear warning signals with different "seek shelter" and "all clear" signals.

Lightning protection for stadia and other outdoor venues can be done surprisingly inexpensively, particularly if planned in the initial construction. More stadia and large venues are establishing lightning safety plans, warnings, signage, and other appropriate means of preventing lightning injuries. Look for this material in programs or brochures. If it is not present in lightning-prone areas, ask management about it so that those who run the venue are spurred to carry out appropriate planning.

Monitoring of a radius around a park district, municipality, or sporting event to warn people of approaching thunderstorms can potentially decrease the number of lightning injuries.

Individual preparation

No place outside is safe when thunderstorms are in the area. Do not resume outside activity for 30 minutes after thunder is last heard or lightning is last seen.

Be aware of weather forecasts before beginning outdoor activities. Make appropriate evacuation plans, identify safer locations beforehand, and include the time to reach them in preplanning of activities. Also be aware of local thunderstorm patterns. For instance, 1-5 pm is a common time for thunderstorms to occur on some mountain slopes but may be different on others; ascent and descent should be done before lightning risk is likely.

Although it is now "duty to warn" on US golf courses and lightning safety and injury prevention information is widespread in sports literature, park management and coach's materials, ultimately, individuals are responsible for their own safety and the safety of any children in their care.

Evacuation

When lightning is seen or thunder is heard, danger is present. A simple safety-teaching tool is, "When thunder roars, go indoors."[38] Lightning may travel as far as 10-12 miles anywhere around a thunderstorm; clouds need not be overhead and rain need not be present for a lightning strike to occur.

Safer areas

Common safety precautions during thunderstorms include remaining inside a metal-topped and enclosed vehicle or a steel-framed building or other substantial habitable building because these have plumbing and wiring that act as a Faraday cage, diverting lightning from the inhabitants. Rented school buses distributed around a large outdoor venue make excellent shelters during activities such as golf tournaments, concerts, and marathons.[62]

Stay away from trees, bleachers (whether wood, plastic, or metal), fences, towers, other structures that transmit current, and any small or open structure that has the word shelter in it; get out of water, pools, and other wet areas such as beaches; and stay off of high areas, such as ridges and mountains, when thunderstorms are likely.

The lightning crouch has been shown to be less effective than standing with the feet close together to minimize the “footprint” for ground current effect.[112] For most people, it is also difficult to get into or maintain the lightning crouch for more than a short time. Sheltering inside shallow caves or overhangs can actually increase the person's risk of injury. Lightning can travel through water; thus, swimming, boating, and bathing should be avoided during a thunderstorm.

Avoid the use of landline telephones, hard-wired electronic equipment, or any contact with conductive surfaces inside a structure (eg, plumbing, sinks, devices connected to electrical wiring) during a thunderstorm. Side flashes from landline telephones, plumbing fixtures, and appliances connected to the outside by metal conductors have injured people inside buildings.

Avoid metal door and window frames, as they can build up a substantial static charge. While this may not technically be a lightning injury, it is still precipitated by the lightning event. Approaching and touching a vehicle after a thunderstorm can sometimes result in the discharge of a static electrical charge that has built up on the vehicle. This is similar to static discharge from winter carpet conditions. Technically, it is not a lightning injury but anyone presenting with this history should still be evaluated and then reassured if nothing is found on examination.

Activities should not be resumed until 30 minutes after the last lightning is seen or thunder is heard.[10, 38] The phrase "Half an hour since thunder roars, now it’s safe to go outdoors!" can be used to teach when it is safe to resume activities. This strategy provides about a 90-95% confidence interval.

Home protection systems

Lightning rods do not divert or prevent lightning strikes but serve as the contact point for lightning protection systems that provide a path along which lightning can travel with less damage to the structure.

Each year, thousands of homes and other properties are damaged and destroyed by lightning. Home lightning damage accounts for more than a quarter of a billion dollars’ worth of damage in the United States alone.[46] State and local building codes include requirements for those structures that require protection. Damage to electronics and the cost and time of replacing data on hard drives has become the major cost to most home and business owners affected by lightning. Damage can only reliably be averted by unplugging electronics from wall units prior to the storm. Common surge protectors and power strips are almost always inadequate for protection from lightning surges, despite claims on the packaging material.

 

Medication

Medication Summary

In an individual who has been struck by lightning, the use of NSAIDs for the first few days may decrease inflammatory sequelae.

Ibuprofen, vitamin C (1 g/day), and vitamin E (400 U/day) have been used to prevent long-term injury and scarring with electrical injury. Whether these free-radical scavengers have any effect on lightning injuries is unknown.

No controlled studies have been performed to show whether there is any efficacy of steroids for lightning injuries

For chronic pain management, other drugs may be added, including acetaminophen, narcotics, tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), gabapentin, and other drugs as appropriate for relieving and managing the pain from many angles.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Class Summary

These are used as prophylaxis to prevent long-term neurologic damage and to treat chronic pain syndromes that may develop from sympathetic nervous system injuries caused by lightning.

Ibuprofen (Motrin, Advil, Ibu, Neoprofen)

Ibuprofen inhibits inflammatory reactions and pain, probably by decreasing the activity of the enzyme cyclo-oxygenase, which results in prostaglandin synthesis.

Naproxen (Anaprox, Aleve, Naprosyn, Naprelan)

Naproxen is used for the relief of mild to moderate pain. It inhibits inflammatory reactions and pain by decreasing the activity of the enzyme cyclo-oxygenase, which results in prostaglandin synthesis.

Sulindac (Clinoril)

Sulindac decreases cyclo-oxygenase activity and, in turn, inhibits prostaglandin synthesis. This results in decreased formation of inflammatory mediators.

Meloxicam (Mobic)

Meloxicam decreases cyclo-oxygenase activity, and this, in turn, inhibits prostaglandin synthesis. These effects decrease the formation of inflammatory mediators.

Ketoprofen

Ketoprofen is used for relief of mild to moderate pain and inflammation. Small dosages are indicated initially in small patients, elderly patients, and patients with renal or liver disease. Doses greater than 75 mg do not increase the therapeutic effects. Administer high doses with caution, and closely observe the patient's response.

Flurbiprofen

Flurbiprofen may inhibit cyclo-oxygenase, thereby, in turn, inhibiting prostaglandin biosynthesis. These effects may result in analgesic, antipyretic, and anti-inflammatory activities.