A 28 y.o. male was brought to the ED after being found unconscious on the sidewalk in a rainstorm.
It was noted that something was wrong with his shoe.
what do you notice? He spontaneously woke and complained of decreased hearing.
Our patient had been struck by lightning. He was carrying an umbrella and the electricity passed through his body and out his shoe. He was found unconscious but spontaneously recovered and was in normal sinus rhythm when he came to the hospital.
Lightning is a discharge of electricity with a single stroke heating the air around it to 54,000 degrees Fahrenheit. In the US 1 in 10,000 people are hit by lightning in their lifetime. Lee Trevino was struck by lightning 3 times. His golf bag was hit by lightning during a lightning delay in a match and it jumped to his back and shoulder causing severe burns.
Benjamin Franklin is credited with associating lightning with electricity. He flew a kite into a storm picking up the ambient electric charge which was transmitted down a hemp rope to a key. He did not touch the key but a static charge was transferred to his nearby finger.
Ben Franklin was actually standing in a doorway out of the rain when he did the experiment.
Lightning injuries are divided into:
Direct strikes- only 5% of lightning injuries are caused by direct strikes. It is common with a direct strike to lose consciousness.
Side splash- lightning jumps from one person through the air to someone nearby.
Ground current- lightning current travels through the ground. A good example of this is a dead herd of cows standing near a tree that is hit by lightning.
It is common with a lightning strike to lose consciousness and even have cardiac arrest. The heart frequently restarts spontaneously but sometimes it is accompanied by a respiratory arrest which is prolonged. This can lead to a secondary cardiac arrest. Complications include: hearing loss, cataracts and memory defects. A transient paralysis can result which is called keraunoparalysis with motor and sensory loss in the extremities. This resolves over a period of hours.
Lightning strikes are characterized by a unique pattern of skin lesions. They resemble a fern and are called Lichtenberg figures. They are a temporary effect caused by a rupture of capillaries under the skin.
Lichtenberg figure
THE PHYSICS
Most commonly lightning is a method of transferring the negative charge of the bottom of the cloud to the positive ground below. It begins with an ascending leader that originates on the ground and propagates up to a cloud where a descending leader connects with it allowing a visible return stroke which we call lightning. This is called negative lightning but there is also positive lightning where a positive charge is transferred to a negative ground charge. It originates high in a cloud and is more powerful than negative lightning; up to a billion volts. It is this type of lightning that gives rise to “sprites and elves” which are smaller electrical discharges 18-60 miles in the atmosphere. Since positive lightning is more powerful the strikes can occur up to ten miles from the cloud. “A bolt from the blue”
sprites are seen high above a thunderhead. They are a plasma effect similar to auroras
FUN FACT
A typical lightning flash is about 300 million Volts and about 30,000 Amps. In comparison, household current is 120 Volts and 15 Amps.
Our patient suffered no burns and was observed in the ED for several hours. His hearing returned, he remained in sinus rhythm and was discharged.
The arch is struck 1-2 times per year on average.
https://www.youtube.com/watch?v=tGPQ5kzJ9Tg
https://www.audacy.com/kmox/articles/news/gateway-arch-struck-by-lightning-3-times-during-storm
Dwyer J. Uman M. The physics of lightning. Physics Reports 534(3014)147-241.
Rodger, C. J. (1999). "Red sprites, upward lightning, and VLF perturbations". Reviews of Geophysics. 37 (3): 317–336. doi:10.1029/2001JA000283
Mallinson T (2010). "Lightning Injuries". Focus on First Aid (16): 15–16.
Jensen JD, Vincent AL (January 2019). "Lightning Injuries". StatPearls.