Lightning injuries

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					S1 Lightning Injuries

                                        Lightning Injuries

                         Hsien-Tsung Hsu, MD; Tzong-Luen Wang, MD, PhD

Lightning strikes the earth millions of times every day. Lightning causes serious injuries in 1000-
1500 individuals and over 1000 people death every year worldwide. Lightning causes damage to a
wide range of body systems including cardiopulmonary, neurological, vascular, cutaneous burns,
ophthalmic, and otological injuries. The most common cause of death in lightning strikes is cardiop-
ulmonary arrest. If multiple persons are struck by lightning, triage priorities must be reversed. Those
in cardiac and/or respiratory arrest must be treated first. Lightning-injured patients often require a
combination of cardiac and trauma care. Care for all persons hit by lightning is aimed at initial
immobilization of the spinal column, basic and advanced life support, and then supportive care.
Management of burns, cardiac arrhythmias, and blunt trauma injuries should proceed according to
standard advanced cardiac and trauma treatment principles. About 70 percent of survivors sustain
significant morbidity and permanent sequela. Preventive measures and lightning safety education
are the most effective methods to minimize the mortality and morbidity of lightning injury. Familiarity
with and implementation of lightning safety guidelines is everyone’s responsibility to decrease light-
ning injuries.(Ann Disaster Med. 2004;3 Suppl 1:S1-S7)

Key words: Lightning Injury; Environmental Medicine; Wilderness Medicine

Introduction                                                ing information on only the most severe and fa-
Millions lightning flashes occur every day                  tal cases. About 70 percent of survivors sus-
worldwide. Lightning causes approximately 300               tain significant morbidity and permanent sequela.
injuries each year in the United States with ap-                   Lightning most often occurs during thun-
proximately 100 reported deaths each year. 1                derstorms in association with large cumulonim-
Lightning causes serious injuries in 1000-1500              bus clouds. However, about 10 percent light-
individuals and over 1000 people are estimated              ning occurs without rain and when the sky is
to die from lightning every year worldwide.                 blue. 2 In addition, lightning can occur during
Mortality rates associated with lightning have              dust storms, sandstorms, snowstorms, nuclear
been estimated to range from 20 to 30 percent               explosions, and in the clouds over volcanic
but are thought to be overestimated, because                eruptions. Lightning injuries can occur in
medical databases are biased toward collect-                outdoors, transportation, water sports, and even

From Department of Emergency Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
Address for reprints: Dr. Tzong-Luen Wang, Department of Emergency Medicine, Shin Kong Wu Ho-Su Memorial Hospital,
No 95, Wen Chang Road, Taipei, Taiwan
Received: Sep 1 2004.          Revised: Sep 20 2004.     Accepted: Oct 1 2004.
TEL: 886-2-28389425           FAX: 886-2-28353547        E-mail:

Ann Disaster Med Vol 3 Suppl 1 2004
                                                                                Lightning Injuries S2

indoor telephone use. 3                              lightning strikes the body, the current travels the
                                                     path of least resistance to the ground. Because
Pathophysiology                                      of the extremely limited duration of contact with
There are five types of lightning strike: (1) di-    the body, much of the current passes over the
rect strike that occurs when the victim is struck    skin in a “flashover” pattern. This flashover ef-
directly by the lightning discharge. Most fatali-    fect is protective to the body. Because much of
ties and severe injuries occur after this type of    the current passes over the skin causing super-
lightning strike. (2) side flash that occurs when    ficial injury, less voltage penetrates the internal
a nearby object such as a tree is struck and         structures; the result is less internal cardiac in-
current then traverses through the air to strike     jury or muscle necrosis. Wet skin may actually
the victim. It is usually the underlying mecha-      decrease the risk of internal injury, helping the
nism when multiple lightning fatalities occur        current travel though the outside of the body.
among persons or animals grouped closely to-         When current enters the body, it flows through
gether (Figure). (3) contact strike that occurs      structures that pose the least resistance. Tis-
when lightning strikes an object the victim is       sues with high fluid and electrolyte content, such
holding and current is transferred from the ob-      as nerves, blood vessels, muscle, and connec-
ject to the person to the ground. Common con-        tive tissue are most commonly affected.
tributors to lightning contact are a golf club, an          Immediate cardiac arrest from lightning
umbrella, or a set of keys in the person’s hand.     strike results from direct current depolarization
(4) ground current that occurs when lightning        of the myocardium and sustains asystole. Im-
hits the ground and current is transferred through   mediate respiratory arrest after lightning strike
the ground to a nearby victim. This ground cur-      is a result of depolarization and paralysis of the
rent creates a stride potential or step voltage      medullary respiratory center. Although cardiac
between the victim’s separated feet. (5) A weak      automaticity may spontaneously return, con-
upward streamer does not become connected            comitant respiratory arrest may persist and lead
to the completed lightning channel.4                 to a secondary hypoxic cardiac stoppage. The
       Lightning is an extremely high-voltage di-    duration of apnea, rather than the duration of
rect current (DC) electrical discharge. When         cardiac arrest, appears to be the critical prog-
                                                     nostic factor.

                                                     Clinical Features
                                                     Although lightning injuries may involve all or-
                                                     gan system, injuries to the cardiovascular sys-
                                                     tem and central nervous system are usually most
                                                     devastating. 5,6

                                                     Cardiovascular injury
                                                     The most common cause of death in lightning
Figure. Lightning-shock cows                         strikes is cardiopulmonary arrest. This condi-

                                                                   Ann Disaster Med Vol 3 Suppl 1 2004
S3 Lightning Injuries

tion results from both the direct current to the       ally classified as (1) immediate and transient,
heart and paralysis of the respiratory center in       (2) immediate and prolonged or permanent, (3)
the brain. Persons who have been hit by light-         delayed, and (4) traumatic lesions secondary
ning and are in respiratory arrest may need only       to falls and blast effects. Transient effects that
artificial respiration to prevent the secondary        typically resolve in 24 hours include loss of
hypoxic arrest. Almost all persons hit by light-       consciousness, confusion, amnesia, and extrem-
ning who do not have cardiac and/or respira-           ity paralysis (keraunoparalysis). Immediate and
tory arrest at the scene survive, even though          prolonged or permanent injury means that pa-
they may be seriously injured. If multiple per-        tients have structural lesions that are often seen
sons are struck by lightning, triage priorities must   on imaging studies or on postmortem
be reversed.7 Victims in cardiac and/or respi-         examination. Post hypoxic encephalopathy is
ratory arrest must be treated first. Persons who       the most common of the major intracranial ca-
are conscious after being struck by lightning can      tastrophes that afflict patients with lightning
wait for treatment, because they will survive.         strike. It is a complication of cardiac or respi-
Patient may suffer a variety of other cardiovas-       ratory arrest. Patients struck by lightning can
cular effects, including direct myocardial             present with intracranial hemorrhages, includ-
damage, coronary artery spasm, cardiac con-            ing intracerebral and subarachnoid
tusion from blunt trauma, acute global                 hemorrhages. Intracranial hemorrhages in light-
dysfunction, transient hypertension and                ning strike patients often appear in two suscep-
tachycardia. The electrocardiogram (ECG) may           tible locations: the basal ganglia and the
show acute injury with ST-segment change,              brainstem. Delayed neurologic disorders attrib-
prolonged Q-T intervals and premature ven-             uted to lightning include motor neuron disease
tricular contractions. Electrocardiography             and movement disorders. It included seizure,
changes generally resolve within a few days.           spinal muscular atrophy, amyotrophic lateral
Although myocardial infarctions do occur, they         sclerosis, parkinsonian syndrome, progressive
are rare.                                              cerebellar ataxia, myelopathy with paraplegia
                                                       or quadriplegia, and chronic pain syndrome. This
Respiratory injury                                     sequela has followed lightning strikes by days
Paralysis of brain stem respiratory center may         to months to years. Lightning bolts can cause
result in apnea, but this central apnea may be         trauma secondarily when the patient is thrown
temporary and a patient may survive if venti-          or falls. Blast effects related to thunder or va-
lated until cardiac and respiratory activity return.   porization of water on the body can damage
Other respiratory injuries include immediate and       the brain and other organs. Epidural, subdural,
delayed pulmonary edema, pulmonary                     and subarachnoid hemorrhages result from falls
contusion, adult respiratory distress syndrome,        linked to lightning. These patients require usual
and pulmonary hemorrhage.                              trauma care. 8

Neurological injury                                    Vascular injury
Neurological injury after lightning strike is usu-     Vasomotor spasm in an extremity is seen as a

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                                                                              Lightning Injuries S4

local response. It may induce by sympathetic       detachment or hemorrhage, and optic nerve
nervous stimulation, local arterial spasm, and     damage. Cataracts are the most common in-
ischemia of peripheral nerves. Skin color          jury and may form weeks to years after the light-
changes from white to blue to red. Severe vaso-    ning injury. Dilated unresponsive pupils may be
constriction may induce loss of pulses, mottling   due to transient autonomic dysfunction and
of skin, coolness of extremities, loss of          should not be used as a sign of brain death.
sensation, and paralysis. This calls
keraunoparalysis phenomenon.                       Auditory injury
                                                   Auditory injuries range from transient hearing
Dermatologic injury                                loss and vertigo to complete disruption of au-
The six main dermatologic manifestations of        ditory system. Tympanic membrane rupture is
lightning injury are Lichtenberg figures, flash    relatively common in lightning injury and may
burns, punctuate burns, contact burns, superfi-    result from the explosive forces of the strike,
cial erythema and blistering burns, and linear     basilar skull fracture, direct trauma to the ear
burns. Lichtenberg figures are considered          canal, or direct lightning burn to the canal. Vic-
pathognomonic for lightning strike. They dem-      tims sustaining lightning strike along a conven-
onstrate the superficial ferning or feathering     tional corded telephone are at higher risk for
pattern, resulted from electron showering over     otologic injury, including persistent tinnitus, sen-
the skin. They disappear in 24 hours. Flash        sorineural deafness, ataxia, vertigo, and
burns appear as mild erythema and may involve      nystagmus.3
the cornea, and are similar to those found in
arc welders. Punctuate burns look similar to       Musculoskeletal injury
cigarette burns with usually smaller than 1 cm     A variety of musculoskeletal injury can be seen
full-thickness burns. Contact burns occur when     from the blunt force injury associated with light-
metal close to the skin and the skin is heated     ning strike, including fractures and soft tissue
from the lightning current. Superficial erythema   injury. Intense myotonic contractions can pro-
and blistering burns are usually transient, and    duce posterior shoulder dislocation, cervical
superficial skin loss may occur. Linear burns,     spine fractures, compartment syndrome, and
less than 5 cm wide, occur in areas of skin fold   muscle rupture. Rhabdomyolysis after lightning
such as the axilla or groin. Entrance and exit     strike is unusual, so routine forced diuresis and
wounds, characteristic of electrical injury from   alkalinization of urine is not recommended in
human sources, are not commonly seen in light-     lightningvictims.
ning injuries. Cutaneous wounds are treated with
standard or burn care.                             Psychosocial problems
                                                   Lightning victims may suffer from long-term
Ocular injury                                      congnitive dysfunction, depression, and anxiety.
Half of all lightning victims will have ocular     Posttraumatic stress disorder and storm pho-
injuries, including cataracts, hyphema, vitreous   bias are known to develop. Anxiety, storm
hemorrhage, corneal abrasion, uveitis, retinal     phobias, and recurrent nightmares are more

                                                                  Ann Disaster Med Vol 3 Suppl 1 2004
S5 Lightning Injuries

common in children.                                   with advanced cardiac and trauma treatment
                                                      principles are required. Reverse triage is ap-
Pregnancy                                             propriate in the case of multiple lightning-injury
Although maternal outcome are general good,           victims. 7 In contrast to multiple-victim events
there is about 50 percent of fetal death, pre-        caused by mechanical trauma, persons with
sumably because amniotic fluid serves as a pref-      lightning injury who appear to be dead (in res-
erential path of current flow. Fetal monitoring       piratory arrest, with or without cardiac arrest)
and uterine/fetal ultrasonography should be per-      should be treated first. Such victims often have
formed on all pregnant lightning-strike victims.      little physical damage, and they may survive if
Maternal uterine activity and fetal heart rate        ventilated until cardiac and respiratory activity
monitoring is recommended for 4 hours after a         resumes. Victims of a lightning strike should be
lightning strike to a pregnant female. 9              transported in spinal immobilization, due to the
                                                      possibility of traumatic injuries.
Diagnosis and Management
Care at the injury scene                              Care in emergency department
Emergency medical service personnel and by-           Standard advanced cardiac and trauma prin-
stander safety must be the first priority, since      ciples should be followed. Intravenous access,
lightning can frequently strike twice in the same     supplemental oxygen, and continuous cardiac
place. Power lines may fall to the ground as a        monitoring should be instituted. Lightning vic-
result of high winds or lightning-related dam-        tims in cardiac arrest have a better prognosis
age to power poles or to the lines. It is impor-      than those in cardiac arrest from acute myo-
tant that rescuers visually survey the area.          cardial infarction, so aggressive resuscitative ef-
Everyone’s safety may be improved by a brief          forts are indicated. 10 Hypotension is not an ex-
survey looking for burns on the ground or             pected finding from lightning injury. Occult
nearby objects, melting of metal objects on or        hemorrhage, such as intra-abdominal or intra-
near the person, and unusual sounds, smells, or       thoracic hemorrhage, and pelvic or long bone
smoke. If a downed power line is found, safety        fracture should be searched.
precautions are important.                                  Once the primary survey is completed, a
      Information about the scene of the acci-        careful head-to-toe examination should be per-
dent may be more informative than examina-            formed to identify occult injuries. 10 Cutaneous
tion of the patient, because physical examina-        burns may help determine the path of the cur-
tion findings suggestive of lightning injury may      rent and locate potential organ injury. A careful
be subtle or nonexistent. Important information       neurologic examination should be performed to
including: history of an electric storm in the area   detect motor and sensory deficits. Ophthalmo-
at the time, blast effects on nearby objects, area    logic and otologic examinations should be done
of burned vegetation, melted or magnetized            to rule out visual and hearing disturbances. All
metal objects, and melted nylon underclothing.        patients should have a completed ECG per-
      The standard airway, breathing,                 formed to evaluate for arrhythmias and injury
circulation, disability, and exposure protocols       pattern. Laboratory tests include blood counts,

Ann Disaster Med Vol 3 Suppl 1 2004
                                                                               Lightning Injuries S6

coagulation studies, serum electrolytes, calcium,    cal injuries without rapid resolution, and
magnesium, blood urea nitrogen, creatinine,          myoglobonuria.11 For patients with minor
CK, CK-MB, arterial blood gas, and urine             injuries, admission for observation is recom-
myoglobin level. Imaging studies (plain              mended for the potential delayed sequela. For
radiography, ultrasound, or computed                 the rare patient with no neurologic injuries and
tomography) should be obtained for suspected         normal cardiovascular evaluation, a period of
injuries. A chest X-ray should be obtained to        observation in emergency department is
evaluate for aspiration, pulmonary edema, pul-       recommended. Discharge may be considered
monary contusion, rib fractures, and                 if no new abnormal symptoms or sign develop,
pneumothorax. Cervical spine films should be         and neurologic and ophthalmologic referral
obtained in patients with suspected spinal inju-     should be arranged.
ries or trauma secondary to falls. Computed
tomography of the head should be performed           Prevention
in patients with an altered or deteriorating con-    Many of these people incur injuries or are killed
scious level or evidence of head injury.             by lightning because of misinformation and in-
                                                     appropriate behavior during thunderstorms.
Disposition                                          Few people really understand the dangers of
The majority of lightning-strike victims will have   lightning. The first step in solving this problem
moderate to severe injuries that require admis-      is to educate people so that they become aware
sion for specialized care. Conditions associated     of the behavior that puts them at risk of being
with serious mortality and morbidity include         struck by lightning, and to let them know what
cardio respiratory arrest, cranial burns, leg        they can do to reduce that risk. 12,13 Individuals
burns, ECG changes and arrhythmias, any CNS          are ultimately responsible for their own safety
lesions or loss of consciousness, any neurologi-     decisions and should take appropriate action

 Table. Guidelines for prevention of lightning injury during thunderstorm
 1. Do not touch the telephone, a computer with a modem, or electric appliances,
      and stay out of the shower and bathtub.
 2. Seek shelter in a building with plumbing and electrical wiring or a closed,
    all-metal motor vehicle. Do not touch any metal objects in the buildings and
 3. Avoid open fields. Do not lie flat. Present the smallest “target” possible.
 4. Do not seek shelter under a lone tree or other tall object or under any isolated
      shelter. A thick forest is considerably safer.
 5. Put down metal objects such as golf clubs, fishing rods, and umbrellas. Stay
      away from metal objects. Remove shoes with metal cleats.
 6. Get out of the water immediately, and stay away from it.
 7. Avoid hills or mountain peaks, metal fences, or aboveground pipes.

                                                                   Ann Disaster Med Vol 3 Suppl 1 2004
S7 Lightning Injuries

when threatened by lightning. Each person must        7. O’Keefe Gatewood M. Zane RD. Light-
be familiar with and follow lightning safety rules.       ning injuries. Emerg Med Clinics North
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houses, schools, office buildings) and fully en-          182-5
closed metal vehicles (e.g., cars, trucks, buses,     9. Fish RM: Electric injury. part III. Monitor-
enclosed farm vehicles) are safer areas. It is            ing indications, the pregnant patient, and
important to roll up windows and avoid con-               lightning. J Emerg Med, 2000;18:27
tact with metal or conducting surfaces inside or      10. Cooper MA. Emergency care of lightning
outside the metal vehicle. Fully enclosed metal           and electrical injuries. Semin Neurol 15:
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trees, and those near water or open areas.2 The           1980.
lightning safety rules are listed in Table. Expo-     12. Lightning Injury Research Program. Avail-
sure to the lightning threat during thunderstorm          able at: URL:
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implementationoflightningsafetyguidelinescan          13. National Weather Service’s Lightning
decrease injuries.                                        Safety. Available at: URL: http://www.
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