Lightning Injuries in the Backcountry Remote Areas Emergency Medicine and Survival

Content Lightning Fact and Figures Lightning Myths Epidemiology Mechanism of Injury Pathophysiology Management Prevention

Lightning Facts There are 1,800 thunderstorms on the earth at any moment Equates to 16 million storms each year An average of 25 million strokes of lightning from the cloud to ground every year in the U.S.

Lightning Facts Lightning temps ~8, ,000° C Leader stroke travels one-third the speed of light Leader stroke est. 3-8 cm in diameter Lasts of a second 10 to 200 million Volts Up to 200,000 amps

Lightning Facts

Lightning can strike even if it is not raining Lightning can strike even if it is not raining Can strike in front of or behind storm Can strike in front of or behind storm Known to strike as far as miles from the storm Known to strike as far as miles from the storm Bolts from the Blue Bolts from the Blue Out of the Clear Blue Sky Out of the Clear Blue Sky Can strike in sunny conditions after storm Can strike in sunny conditions after storm

Lightning Myths

If it is not raining, there is no danger from lightning If it is not raining, there is no danger from lightning Rubber soles of boots or rubber tires on a car will protect you from being struck by lightning Rubber soles of boots or rubber tires on a car will protect you from being struck by lightning People struck by lightning carry an electrical charge and should not be touched People struck by lightning carry an electrical charge and should not be touched

Lightning Myths Lightning is always fatal Lightning is always fatal Lightning turns victims into crispy critters Lightning turns victims into crispy critters Lightning never strikes the same place twice Lightning never strikes the same place twice Victims bodies remain in suspended animation Victims bodies remain in suspended animation

Lightning Myths If caught in a lightning storm outside, it is better to seek shelter under an isolated or small group of trees than to remain out in the open. If caught in a lightning storm outside, it is better to seek shelter under an isolated or small group of trees than to remain out in the open. Heat Lightning is harmless and poses no threat to anyone Heat Lightning is harmless and poses no threat to anyone

Epidemiology

Epidemiology

Epidemiology 84% M, 16% F 84% M, 16% F June, July, August June, July, August Wed/Sat/Sunday Wed/Sat/Sunday 2-6 pm 2-6 pm

Odds of Becoming a Victim Odds of being struck by lightning in a given year (reported deaths + injuries)1/700,000 Odds of being struck by lightning in a given year (estimated total deaths + injuries) 1/400,000 Odds of being struck in your lifetime 1/5000 (Est. 80 years) Odds you will be affected by someone being struck 1/500 (Ten people affected for every one struck)

Mechanism of Injury Factors determining Injury –Type of circuit –Resistance of tissues –Amperage and voltage –Current pathway –Duration –Environmental Factors –Size of contact point –Clothing

Heat = current x resistance x time Very short duration of exposure …a short circuit… Mechanism of Injury

Duration of Exposure Longer the contact duration, the greater the intensity and thus increased injury The major difference between lightning (DC current) and high-voltage electrical injuries (AC current) Electricity takes most direct route to exit to ground Lightning – flashover effect Hot Lightning – lasting up to 0.5 sec acts like high voltage energy

Mechanism of Injury Tissue Resistance Humidity affects skin moisture and thus resistance Humidity affects skin moisture and thus resistance Resistance drops significantly when surface is wet Resistance drops significantly when surface is wet Higher resistance can ignite clothes and cause thermal burns Higher resistance can ignite clothes and cause thermal burns Metal objects increase risk thermal burns Metal objects increase risk thermal burns

Mechanism of Injury Tissue Resistance Least: –Nerve, blood, muscle Intermediate: –Dry skin Most: –Tendon, fat, bone

Mechanism of Injury Direct Strike - most common to the head and shoulders Contact Injury - touching object in pathway Side Flash - jumps from object to victim Step Voltage – travels through the ground Blunt Injury - fractures and muscle contractions

Direct Strike

Contact Flash

Step Voltage

Pathophysiology

Clinical Presentation Brain, heart and skin most commonly affected Brain, heart and skin most commonly affected Immediate cardiopulmonary arrest is primary cause of death from lightning strike Immediate cardiopulmonary arrest is primary cause of death from lightning strike

Cardiopulmonary Arrest Effects to the respiratory center Effects to the respiratory center apnea apnea Effects to the conduction pathway in the heart Effects to the conduction pathway in the heart Asystole Asystole V-fib V-fib Spontaneous conversion to NSR may occur Spontaneous conversion to NSR may occur MI rare MI rare Autonomic instability Autonomic instability

Cardiopulmonary Arrest Apnea persists causing hypoxia May outlast cardiac arrest May cause secondary hypoxic arrest

Feathering burns… Lichtenberg Figures Feathering burns… Lichtenberg Figures Linear burns Linear burns Punctate burns Punctate burns Thermal burns Thermal burns Skin

Feathering Burns

Linear Burn

Punctate Burns

Thermal Burns

Skin Skin 2º-3º burns 2º-3º burns Thermal Burns

Neurologic Injuries LOC: –anterograde amnesia CNS: –Infarction –Hematoma –Encephalopathy –Degeneration Peripheral: –autonomic instability

Neurologic Injuries Similar to after effects of electroconvulsive therapy Similar to after effects of electroconvulsive therapy Pupillary dilatation may be secondary to autonomic injury Pupillary dilatation may be secondary to autonomic injury Intracranial bleeding, cerebral edema, seizures, anoxia Intracranial bleeding, cerebral edema, seizures, anoxia

Keraunoparalysis Intense vascular spasm in extremities Intense vascular spasm in extremities temporary loss of pulses temporary loss of pulses mottling mottling absence of sensation in an extremity absence of sensation in an extremity usually resolves spontaneously usually resolves spontaneously

Miscellaneous Trauma Renal…rare Renal…rare Ophthalmic: Ophthalmic: cataracts less common cataracts less common entire axis injury noted entire axis injury noted Otologic: Otologic: TM rupture TM rupture Musculoskeletal: Musculoskeletal: injury secondary to trauma injury secondary to trauma Blunt Trauma Blunt Trauma Post-Traumatic Headaches Post-Traumatic Headaches

Management

Managing Lightning Strike Survey scene for safety Activate EMS -depending location in the backcountry Move victim to safer location Evaluate ABCs and treat accordingly -Use reverse triage principle -CPR is very effective in these victims -ACLS with good ventilation

Managing Lightning Strike Evaluate and treat for hypothermia and shock Evaluate and treat for hypothermia and shock Evaluate for blunt trauma and treat for fractures Evaluate for blunt trauma and treat for fractures Evaluate and treat for burns Evaluate and treat for burns Plan evacuation methods Plan evacuation methods ambulatory or litter ambulatory or litter air evacuation air evacuation overnight shelter overnight shelter

Long-term Management Survivors are an even greater tragedy! Survivors are an even greater tragedy! ~ 70% Long-Term Medical Problems ~ 70% Long-Term Medical Problems ~ 30% Suffer Debilitating Problems ~ 30% Suffer Debilitating Problems Elusive Data % Under-Reported Elusive Data % Under-Reported Support group is recommended Support group is recommended

Lightning Strike and Electric Shock Survivors International Jacksonville, NV Jacksonville, NV

Lightning Safety STAY INDOORS! STAY INDOORS!

Lightning Safety If you can see lightning or hear thunder, activate your safety plan. If you can see lightning or hear thunder, activate your safety plan. Resume activities only when lightning and thunder have not been observed for 30 minutes. Resume activities only when lightning and thunder have not been observed for 30 minutes. If you can see it (lightning), flee it; if you can hear it (thunder), clear it. If you can see it (lightning), flee it; if you can hear it (thunder), clear it.

Lightning Safety These are some key facts to remember about lightning safety: These are some key facts to remember about lightning safety: No place in the out of doors or the wilderness is absolutely safe from lightning. No place in the out of doors or the wilderness is absolutely safe from lightning. The safest location is inside a substantial building, away from all windows and doors. The safest location is inside a substantial building, away from all windows and doors. The next best location is inside a hard top automobile with windows rolled up. The next best location is inside a hard top automobile with windows rolled up.

Lightning Safety Indoor Lightning Safety Indoor Lightning Safety Avoid using telephone (remember the wires) Avoid using telephone (remember the wires) Avoid using water – sink, tub, etc. (plumbing) Avoid using water – sink, tub, etc. (plumbing) Unplug appliances (remember the wires) Unplug appliances (remember the wires) Inner rooms are the best Inner rooms are the best

Lightning Safety Vehicles: car, bus, etc. Vehicles: car, bus, etc. close windows close windows keep hands on lap its not the rubber tires that make a vehicle safe; its the metal cage keep hands on lap its not the rubber tires that make a vehicle safe; its the metal cage Convertibles or canvas type (soft) tops offer no protection Convertibles or canvas type (soft) tops offer no protection

Lightning Safety If you remain outdoors If you remain outdoors Stay away from rivers, lakes, or other bodies of water Stay away from rivers, lakes, or other bodies of water Be aware of the potential for flooding in low-lying areas Be aware of the potential for flooding in low-lying areas NEVER stand under an isolated tree NEVER stand under an isolated tree

Lightning Safety Stay away from tall trees Stay away from tall trees keeping twice as far away from a tree as it is tall to minimize a side strike and step voltage. keeping twice as far away from a tree as it is tall to minimize a side strike and step voltage. Avoid being the tallest object around Avoid being the tallest object around Get as low as you can but do not lie prone on the ground Get as low as you can but do not lie prone on the ground

Lightning Safety Stay away from natural lightning rods and tall structures such as: –towers –tall trees –telephone poles/lines –tents with metal supports

Lightning Safety Stay low (crouch) in a ditch or depression Stay low (crouch) in a ditch or depression a low area, ravine, or foot of a hill. a low area, ravine, or foot of a hill. DO NOT lie flat on ground DO NOT lie flat on ground Conductors should be removed from body Conductors should be removed from body communication devices with antennas communication devices with antennas

Lightning Safety In the mountains In the mountains On by noon, off by two On by noon, off by two Move off ridges and summits - descend Move off ridges and summits - descend Get below tree line into a grove of small trees Get below tree line into a grove of small trees Stay clear of cave entrance and walls Stay clear of cave entrance and walls Avoid rappelling when lightning imminent Avoid rappelling when lightning imminent

Lightning Safety Boating Safety Boating Safety First, make sure your boat is properly grounded. First, make sure your boat is properly grounded. Secondly, stop using anything that could be a potential lightning rod. Fish later. Secondly, stop using anything that could be a potential lightning rod. Fish later. Thirdly, get below deck if possible. Dont touch the mast or any metal objects. Water conducts electricity across its surface. Thirdly, get below deck if possible. Dont touch the mast or any metal objects. Water conducts electricity across its surface. Swimming during a thunderstorm is not safe. Swimming during a thunderstorm is not safe. Wear life vest at all times Wear life vest at all times

Indications of Imminent Lightning Crackling noise or ozone smell Hair may stand on end St. Elmos fire

Detection Equipment

Sky Scan Portable lightning/ storm detector Portable lightning/ storm detector Four ranges Four ranges miles miles 8-20 miles 8-20 miles 3-8 miles 3-8 miles 0-3 miles 0-3 miles

Strike Alert LED and alarm sound warnings: <6 miles 6-12 miles miles miles

ThunderBolt Provides three warning methods: Audible, LED and text Three models Max detection is 75 miles

Resources