When lightning strikes: tips for emergency management

Dr. Robert McMickle, an emergency physician at Harbor UCLA Medical Center in Los Angeles, delves into the topic of lightning injuries.

Clinical case: a lightning in a park during a thunderstorm

Some people are spending the afternoon in a park when a thunderstorm breaks out. As it starts to rain, a group of four people decide to hide under a tall tree. They notice intermittent flashes of lightning, but the situation does not seem to be getting worse. As they are planning to leave the park, the tree is struck by lightning and the group is hit by a side splash of electricity. When the first rescuers arrive, all four are breathless and pulseless. A 30-year-old woman can be resuscitated, although she goes into cardiac arrest again for 10 minutes on the way to the hospital. She recovers again (ROSC), while the other three members of the group fail to be resuscitated.


Lightning is not an uncommon environmental cause of injury and death worldwide. Approximately 24,000 fatal accidents occur each year and almost ten times as many accidents in which people are struck and survive. In the United States, there are about 400 lightning injuries and 40 deaths per year, and most lightning strikes occur from May to September in the afternoon or early evening hours in states near the Gulf of Mexico1.

Lightning carries an impressive amount of energy (30-110 thousand amperes) and voltage (10 million volts) that is delivered in a massive pulse within a few milliseconds. For reference, a typical household current measures 110-120 volts and 15 amperes, and a typical power line can deliver >7,000 volts. Lightning is neither direct nor alternating current, but rather a massive pulse of electrons moving in one direction1,2.

The temperature is usually around 8,000°C, but it can reach 50,000°C and can therefore cause significant thermal burns1.

Mechanism of the discharge1,2

  1. Direct strike (5%): lightning makes direct contact with subjects, most commonly fatal.
  2. Contact injury (15%): lightning strikes an object that the victim holds or touches directly with a direct current flow.
  3. Side splash (30%): lightning strikes an object (e.g. a tree, pole, building) and the current 'jumps' towards the victim.
  4. Ground current (50%): the current passes through the ground and reaches the victim, whose body has less resistance than the ground.
  5. Blunt trauma: secondary to the force wave generated by the lightning.
  6. Electrical flux: lightning that rises to the sky and discharges a charge that passes over the victim, not as powerful as lightning from the sky.


Injuries occur through a variety of mechanisms and can affect all organs.

Effects on the cardiovascular system

Effects on the pulmonary system

Apnoea may persist after return of spontaneous circulation (ROSC), so early and continuous ventilation is important to prevent secondary cardiac arrest from hypoventilation.

Effects on the skin

Neurological effects

Other effects


A thorough head-to-toe physical examination is crucial to assess the presence of trauma, burns and other injuries.

On-site management

In contrast to most mass casualty incidents, where apnoeic and non-ambulatory patients are considered 'waiting' to succumb to their severe injuries and should not be prioritised in a situation of limited resources, the concept of 'reverse-triage' is of crucial importance and should be used in mass casualty events with relief.

This scheme identifies victims who appear to be in cardiac and respiratory arrest and prioritises their treatment, as they can have good results if identified and treated immediately. Victims who are unresponsive, not breathing or gasping are immediately given CPR and assisted breathing. If a pulse is obtained, continue to provide assisted ventilation to prevent 'secondary cardiac arrest' due to inadequate ventilation. Those who survive the initial stroke rarely die before or after arrival at hospital1,2, although up to 77% of victims do not respond to CPR. If victims do not regain a pulse within 20-30 minutes of starting CPR, it is reasonable to discontinue resuscitation efforts4. Remember to also consider hypothermia before discontinuing efforts.

When patients arrive, aggressive resuscitation is recommended for those in cardiac arrest, as lightning-induced cardiac arrest has a better prognosis. Hypotension is not typical and suggests another injury. After ROSC, hyperthermia should be avoided.

General guide for management in the emergency room

The best treatment is prevention

General provisions

High-risk characteristics warranting observation and/or admission for telemetric monitoring

  1. Direct hit
  2. Loss of consciousness
  3. Focal neurological deficit
  4. Chest pain
  5. Dyspnoea
  6. Major trauma
  7. Cranial or significant burns
  8. Pregnancy (fetal mortality approaching 50%)1

In all other patients, discharge is safe if the patient has normal vital signs, appears well and has no other injuries requiring hospitalisation.

Myths about lightning

Main take-aways

  1. References: Della-Giustina D, Ingebretsen R, eds. Advanced Wilderness Life Support : Prevention, Diagnosis, Treatment, Evacuation. Wilderness Medicine Society; 2011:122-132.
  2. Jensen JD, Thurman J, Vincent AL. Lightning Injuries. [Updated 2021 Jul 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441920/
  3. Kaji A, Pedigo RA. Emergency Medicine: Board Review. Elsevier; 2022.
  4. Cooper, MA., Andrews, CJ., Holle, RL., Blumenthal, R., Navarrete Aldana, N. Lightning-Related Injuries and Safety. In: Auerbach P, ed. Auerbach’s Wilderness Medicine. Elsevier; 2017:71-117.
  5. US Department of Commerce NOAA. Lightning myths. National Weather Service. https://www.weather.gov/safety/lightning-myths. Published April 20, 2018. Accessed February 15, 2022.
  6. McMickle RJ. Lightning Strike Injuries. emDOCs. Aug 29th 2022