Lightning Strikes! - The Original Kings of County

This months wilderness medicine club meeting discussed a great paper talking about lightning strikes. You can download the paper here:

lightning

Zina was also nice enough to put together a fast summary of the highlights of this article. Here they are:

Wilderness Medical Society Guidelines for the Prevention and Treatment of Lightning Injuries.

Davis C, Engeln N, Johnson E, McIntosh S, et al. Wilderness & Environmental Medicine, 23, 260-269 (2012)

Background

– Thunderstorms are a result of moisture, warm air, and a lifting wind; as water condenses and freezes into particles on top of clouds, the movement of these particles forms an electical gradient that is discharged as lightning.

– Wordwide, central Africa has the greatest incidence of lightning strikes

– In the US, the northeast and south have the highest incidence, with rural populations being at greatest risk

– Approximately 400 lightning injuries occur every year, with about 10% of these resulting in death.

Mechanisms of Injury

– Lightning injuries are classified as: direct strike, contact injury, side splash, or ground current

– A fifth, recently reported mechanism is the “upward streamer”, when lighting passes through the ground without a nearby lightning strike

Prevention

– “When thunder roars, go indoors” – if you can hear thunder, there is a risk of lightning strikes and you should seek shelter immediately

– If far from the indoors, seek shelter inside a deep cave, far in a dense forest, or in a deep ravine; staying in an open, exposed area puts you at highest risk

– Avoid shallow caves, solitary trees, and open shelters (such as dugouts and lean-to’s) because of the risk of side-splash.

– If lightning strike is imminent and you’re indoors, take the “lighting position”

Sit or crouch with knees and feet close together to create only one point of contact with the ground
Try to insulate yourself from the ground – sit on a pack (after removing metal), dry coiled rope, or rolled foam sleeping pad

– If in a group, separate from each other by at least 20 feet

Triage and Resuscitation

– Reverse triage: Lightning strike victims classically suffer initial asystolic arrest caused by simultaneous depolarization of all myocardial cells; Ventricular fibrillation can also occur.

– Victims of lightning strike do not carry residual electrical charge – it’s safe to resuscitate them!

– Have high suspicion for injury and low threshold for admission in high risk patients:

Complications

– Neurological: Keraunoparalysis – transient paralysis after lightning strike, typically resolves within several hours

– Derm: “Lichtenberg figure”

– Eyes: Cataracts can form, often over several days

– ENT: Eardrum rupture

– Psychiatric, neurocognitive complications may develop weeks to months afterwards

– Pregnant patients do not have higher mortality but fetal mortality is 50%, due to being surrounded by highly conductive amniotic fluid

The views expressed on this blog are the author's own and do not reflect the views of their employer. Please read our full disclaimer here. Any references to clinical cases refer to patients treated at a virtual hospital, Janus General Hospital.