Lightning injuries: reverse triage and cardiac arrest

During a late afternoon storm, lightning strikes near a group of four people returning from a trail. When the rescue team arrives, three of them are on the ground. Two are awake, confused, with leg pain and difficulty hearing. A third is motionless, not breathing and without a pulse. The fourth person, who stayed on their feet, says their legs "won't obey" and that they are cold and pale. The first reaction of those arriving is to attend to whoever is screaming in pain. The scene is fictional and was written for teaching. This text uses this picture as a clinical reasoning scenario: why triage is reversed in lightning injuries, why ventilation can save those who appear dead, which findings call for observation and what to look for in the eyes, ears, skin and heart.

NEXO is a daily medical diagnosis game: one clinical case a day, up to six progressive clues, and ICD-10 proximity feedback across five levels.

This text is not a wilderness rescue protocol. On-site care, transport and hospital care follow their own guidelines and practical training. The interest here is reasoning: how to organize the assessment after a lightning strike, which clues indicate severity and why the usual logic of triage does not apply to this scenario. If you play the case of the day on NEXO, you will recognize the move: sometimes the most important clue is precisely the victim who is silent.

Key points

• After a lightning strike, those in cardiac and respiratory arrest should be attended first, because those who survive the initial impact rarely die afterwards.
• The heart can start beating again before breathing returns, and the lack of ventilation can lead to a new arrest.
• Victims do not retain an electrical charge and can be touched safely.
• A transient paralysis of the legs, with a pale limb and no pulse, is common and usually improves within hours, but it requires care with the spine and assessment of other causes.
• Eyes, ears, heart, skin and mental health need assessment and follow-up.

Why lightning injuries are a reasoning scenario

Lightning injuries are infrequent in the practice of most professionals and therefore challenge habits. The Wilderness Medical Society guideline on prevention and treatment of lightning injuries gathers the available recommendations and notes that the evidence is limited, with much of the guidance based on case series and expert opinion (Davis et al., 2014). Ritenour et al. describe lightning injuries as uncommon but potentially devastating, with unusual symptoms, high mortality and important long-term sequelae (Ritenour et al., 2008).

What the scene teaches

In the opening scene, the quietest victim is the most severe, and the victims who scream will probably survive. The person with pale, weak legs appears to have a severe spinal injury, but may have a transient paralysis typical of lightning. Each clue leads to a different question. The post on signs, symptoms and history shows how context changes the weight of each finding.

How lightning reaches people

Davis et al. describe different mechanisms of injury (Davis et al., 2014). Direct strike is relatively rare. In contact injury, the person is touching an object that was struck. In side splash, which accounts for about one third of injuries, the current jumps from a nearby object, such as a tree, to the body. Ground current, which accounts for almost half of injuries, travels through the ground from the point of impact to the victim. The authors also describe upward current, which rises from the ground through the body without lightning striking nearby.

Reversed triage

In the usual triage of multiple casualties, people in cardiac arrest are often given low priority, because the chance of survival is small and resources need to go to those who can be saved. In lightning injuries, the logic is the opposite. Davis and colleagues recommend reverse triage, prioritizing victims in cardiac and respiratory arrest, because death is rare among those who survive the initial strike (Davis and colleagues, 2014). Those who are awake and screaming will probably survive, even with pain, burns or confusion. Cooper analyzed severe cases of lightning victims and found a worse prognosis among those who had cardiorespiratory arrest, head burns or leg burns (Cooper, 1980). The author recommended starting resuscitation immediately in victims who lost consciousness, since they are the ones at greatest risk of dying. Van Ruler and colleagues systematically reviewed the reviews and guidelines on lightning injuries, rated the available evidence as low to moderate and stressed that, on scene, care should start with those who appear dead (van Ruler and colleagues, 2022).

Why the arrest may be reversible

Davis and colleagues explain that lightning can cause cardiac and respiratory arrest at the same time (Davis and colleagues, 2014). The heart has its own automaticity and can start beating on its own again, but the respiratory center may take longer to recover. If breathing is not supported, the lack of oxygen can lead to a second arrest, this time harder to reverse. The authors note that mortality from lightning arrest is lower than that of cardiac arrest in general. Zafren and colleagues, in the guideline for mountains and remote areas, note that victims who are not breathing can often be resuscitated and should be treated first, and that respiratory arrest may be prolonged, but the prognosis can be excellent if breathing is supported (Zafren and colleagues, 2005).

Touching the victim is safe

Davis and colleagues note that lightning victims do not retain residual electrical charge and can be touched safely (Davis and colleagues, 2014). The risk to rescuers comes from the storm that is still going on, not from the victim. The recommendation is to follow usual advanced life support, with special attention to ventilation, and to move the group to a safer place while the storm is still active. Zafren and colleagues add that rescuing lightning victims can be dangerous, including for helicopters in flight, and that it is prudent to wait for the risk of further lightning to pass (Zafren and colleagues, 2005).

Ventilation at the center of resuscitation

For reasoning, lightning arrest looks more like a respiratory arrest that drags on than like a common sudden cardiac arrest. Davis and colleagues recommend maintaining ventilatory support even after the pulse returns, because spontaneous breathing may take time to come back (Davis and colleagues, 2014). A victim with a pulse and no breathing needs continuous ventilation, not just observation.

Central pulse before compressions

Davis and colleagues note that transient paralysis can leave a limb with no palpable pulse, pale or purplish (Davis and colleagues, 2014). For this reason, the guideline recommends checking a central pulse, such as the carotid or femoral, before starting compressions. An absent pulse in the foot or wrist does not, on its own, mean cardiac arrest. This detail avoids unnecessary compressions in someone whose central circulation is preserved.

Who needs assessment and observation

Davis and colleagues list findings that identify high-risk victims (Davis and colleagues, 2014). Among them are suspected direct impact, loss of consciousness, focal neurological complaint, chest pain or shortness of breath, major trauma, burns on the head or legs, burns on more than ten percent of body surface area and pregnancy. The authors recommend immediately removing these victims from the scene for care at a health service. Pfortmueller and colleagues reviewed a decade of lightning-related care at a trauma center and found the nervous system most affected, followed by the cardiovascular system and the skin (Pfortmueller and colleagues, 2012). The authors note that reports are scarce and argue for an international registry to better understand the pattern of these injuries.

The heart

Davis and colleagues recommend screening electrocardiogram and echocardiogram in high-risk victims and cardiac monitoring for at least twenty-four hours after direct impact or after changes on the electrocardiogram or echocardiogram (Davis and colleagues, 2014). The authors consider the usefulness of routine measurement of cardiac injury markers limited. They also recommend advising the patient to return if symptoms appear that suggest inflammation of the pericardium or weakness of the heart muscle.

The head

Davis and colleagues recommend a head CT for anyone who had loss of consciousness or has an altered neurological exam (Davis and colleagues, 2014). Confusion after lightning can have several causes, such as the direct effect of the current, lack of oxygen, trauma from being thrown or a fall. The post on differential diagnosis with clues shows how to keep several hypotheses open when the picture has more than one possible explanation.

Transient paralysis

Davis and colleagues describe a transient paralysis typical of lightning, which affects the legs more than the arms (Davis and colleagues, 2014). The affected limb may have no palpable pulse, be pale or purplish, with loss of movement and sensation. In most cases, the picture improves within a few hours. Jacob and colleagues reported a case of paralysis on one side of the body after lightning, in which tests and imaging showed no other cause and improvement began in the first hours, with complete resolution in about a week (Jacob and colleagues, 2024).

Why waiting is not enough

Davis and colleagues note that transient paralysis can mimic a spinal cord injury and recommend maintaining spinal protection and requesting imaging when the deficit persists (Davis and colleagues, 2014). The victim may have been thrown or may have fallen, and a true fracture must be ruled out. The guideline also recommends hospital observation for anyone with this picture. Jacob and colleagues note that the diagnosis can only be made after ruling out the other causes of neurological deficit (Jacob and colleagues, 2024).

Symptoms that appear later

Davis and colleagues describe that most neurological manifestations of lightning are transient and begin immediately, such as loss of consciousness, seizure, headache, tingling, weakness, confusion and memory loss (Davis and colleagues, 2014). The authors also describe immediate permanent injuries, such as brain injury from lack of oxygen after cardiac arrest, and late pictures, such as weakness or loss of sensation that appear weeks to months later. The relationship of these late pictures to lightning is not well established, but the guideline recommends that anyone with late neurological symptoms see a neurologist.

Skin, eyes and ears

Davis and colleagues describe the Lichtenberg figure, a fern-like pattern on the skin that is characteristic of lightning and is not a burn (Davis and colleagues, 2014). It appears within up to one hour and disappears in about a day. The authors also describe linear burns, caused by the electric arc that passes over the skin, punctate burns, sometimes on the toes, and, more rarely, deep burns. Burns on the head were associated with higher mortality.

Burns that mislead

Davis and colleagues explain that linear burns are usually superficial and appear where there is more sweat, such as the armpits and under the breasts, because sweat turns to steam when the current passes over the skin (Davis and colleagues, 2014). Larger deep burns appear where the skin was in contact with synthetic fabric that melted or with heated metal objects, such as watches, buckles and necklaces. The authors report that few victims needed a skin graft in a case series treated in a burn unit, and that small superficial burns usually heal quickly with routine care.

Samia and colleagues recall that skin manifestations after a lightning strike are usually superficial and transient, but that superficial burns do not rule out serious injury to other organs (Samia and colleagues, 2023). For the reasoning, little skin damage should not be reassuring. Lightning passes through the body differently from household or industrial electric current, and internal damage does not match the size of the mark on the skin. Davis and colleagues also report that, in a case series, burns on the head were associated with a higher risk of death and cardiac arrest (Davis and colleagues, 2014).

The eyes

Davis and colleagues recall that cataract is a known complication of lightning and can appear from days to years after the event (Davis and colleagues, 2014). The authors therefore recommend an ophthalmologic evaluation for high-risk victims. For the clinician, this means that eye evaluation does not end at discharge and that the patient needs to know that blurred vision, even months later, may be linked to the lightning strike. Pradhan and colleagues reviewed the literature and described a case series with injuries ranging from the cornea and lens to the retina and optic nerve, with frequent involvement of the macula (Pradhan and colleagues, 2020). Optical coherence tomography helped detect and monitor these injuries, and recovery was usually good when referral was prompt.

The ears

Davis and colleagues report that, in a case series, most victims had a ruptured tympanic membrane, and they recommend examining the tympanic membrane of all lightning strike victims (Davis and colleagues, 2014). The authors recall that a simple tympanic membrane rupture usually heals on its own, but that fluid draining from the ear may indicate a fracture of the skull base, and they recommend follow-up with an otolaryngologist for those with hearing loss. Modayil and colleagues reviewed the literature and found that the most common hearing loss after a lightning strike is conductive, caused by rupture of the tympanic membrane, and that transient dizziness is the most frequent vestibular symptom (Modayil and colleagues, 2014).

In the opening scene, the difficulty hearing of the two awake victims is a clue that deserves otoscopy, not just reassurance. Hearing loss also hinders communication during care and can be mistaken for confusion.

Pregnancy and mental health

Davis and colleagues found few reported cases of pregnant women struck by lightning, with no maternal deaths, but with fetal mortality close to half (Davis and colleagues, 2014). The authors recommend fetal monitoring when the pregnancy is more than twenty weeks along. Pregnancy is among the high-risk findings that call for immediate removal from the scene and evaluation at a health service.

After discharge

Davis and colleagues recall that lightning victims may have psychiatric and cognitive sequelae, such as problems with memory, attention and mood, and recommend advising the victim and the family to seek a mental health professional if these symptoms appear (Davis and colleagues, 2014). Davis and colleagues describe that these conditions usually appear days to weeks after the lightning strike, often when the person has already returned home, and include loss of memory and concentration, difficulty solving problems, depression, sleep changes, emotional instability and aggressiveness (Davis and colleagues, 2014). Andrews and colleagues proposed diagnostic criteria for a syndrome after electrical or lightning injury, with cognitive and memory changes that may be late or progressive (Andrews and colleagues, 2017). The authors argue that, without clear criteria, many patients were assessed incompletely and treated only in part. Ritenour and colleagues also highlight the significant long-term morbidity of these injuries (Ritenour and colleagues, 2008). For the clinician, the follow-up visit should ask about sleep, memory, concentration, chronic pain, hearing and vision, and not only about the skin.

High-risk findings: a table for care

The table below summarizes, in a didactic way, common findings after a lightning strike and what the cited guideline usually recommends. It simplifies a complex topic and does not replace current guidelines or practical training.

Finding	What weighs on the decision	Frequent approach
Cardiac and respiratory arrest	Real chance of reversal	Top priority, resuscitation with prolonged ventilation
Loss of consciousness or altered neurological exam	Brain injury or trauma	Head CT and observation
Chest pain, shortness of breath or direct impact	Cardiac injury	Electrocardiogram, echocardiogram and monitoring
Pale legs, no pulse and no strength	Transient paralysis or spinal injury	Central pulse, spinal protection, observation and imaging if it persists
Difficulty hearing	Ruptured eardrum	Otoscopy in all victims
Pregnancy	High fetal risk	Immediate assessment and fetal monitoring after twenty weeks

Prevention: what to advise

Davis and colleagues recall that no place is absolutely safe during a storm and that, if you can hear thunder, there is a risk of lightning (Davis and colleagues, 2014). The authors recommend seeking shelter in a large, closed building, away from doors and windows, or in a vehicle with a metal roof and the windows closed. Open shelters, isolated trees, shallow caves and tents do not protect.

Groups and position of last resort

Davis and colleagues recommend waiting at least thirty minutes after the last thunder before returning to outdoor activities and suggest that groups spread out to reduce the number of victims from the same lightning strike (Davis and colleagues, 2014). The crouched position, with feet together, is described as a last-resort strategy, when lightning seems imminent and all other measures have failed. In the opening scene, a more spread-out group might have had fewer victims.

The biases that get in the way of care

Lightning injuries are rarely mismanaged for lack of knowledge. They are usually mismanaged because of predictable habits and biases:

1. Applying the usual triage and leaving those in arrest for last.
2. Stopping ventilation as soon as the pulse returns.
3. Starting compressions only because a peripheral pulse was not found.
4. Attributing all paralysis to the lightning strike without protecting the spine and without ruling out other causes.
5. Forgetting to examine the ears, the eyes and pregnancy.

Croskerry describes anchoring and premature closure among the most frequent cognitive errors in diagnosis (Croskerry, 2003). The post on diagnostic pause shows how a short moment of checking helps to notice what was left out. The post on heuristics in clinical reasoning helps to recognize when a usual rule does not fit the scenario.

What to ask and examine

A few questions and observations organize the care:

• Who is silent, not breathing or without a central pulse?
• Was there a direct impact, loss of consciousness, a fall or being thrown?
• Is there chest pain, shortness of breath or a change on the electrocardiogram?
• Are the legs pale, cold, without pulse or without strength?
• Are the eardrums intact and is hearing preserved?
• Is there pregnancy, burns on the head or legs, or extensive burns?

Back to the scene

In the opening scene, the rescuer who organizes the reasoning first goes to the silent victim. He confirms the absence of a central pulse, starts resuscitation with ventilation and, when the pulse returns, keeps ventilating until breathing returns. Then he assesses the person with pale legs: he checks the central pulse, maintains spinal protection and sends the person for observation and imaging. The two awake victims receive assessment of ears, heart and consciousness. Everyone is moved to a safer place while the storm continues. The reasoning starts with the silent victim, not the one who screams.

How NEXO helps train this reasoning

In NEXO, the case of the day is fictional, with a real clinical presentation and up to six progressive clues. You propose a diagnosis by searching for the ICD-10 code and receive feedback on proximity in five levels, which shows whether the guess stayed at the exact code, the same category, the same group, the same chapter or a different chapter. This format connects with the theme of this text: a discreet clue can change the priority of the whole case.

To use the case of the day as training, try three habits. Before each guess, ask whether a usual rule applies to that scenario. When a dramatic finding appears, ask whether it is dangerous or merely striking. After the result, note which clue would have anticipated the diagnosis.

Three exercises with cases

Invert the priority. In each case, ask which silent finding may be more serious than the loudest one.

Separate the transient from the permanent. Reread a case asking which symptoms should improve on their own and which call for investigation.

Think about what comes after. Faced with a diagnosis, list what needs to be followed in the weeks and months ahead.

The post about learning based on clinical cases shows how cases help fix patterns that rarely appear in daily practice.

The limits on use of the game are described on the NEXO Economy page. If you research the teaching of clinical reasoning, the page for Researchers explains how to get in touch. Professionals who write or review cases find information on Curator and on Creators, and institutions can learn about the proposal on the partnerships page.

Frequently asked questions

What is reverse triage?

It means giving priority to victims in cardiac and respiratory arrest, because, after a lightning strike, those who survive the initial impact rarely die later.

Is it safe to touch a lightning victim?

Yes. The victim does not carry an electrical charge. The risk to rescuers comes from the storm that continues.

Why keep ventilating after the pulse returns?

Because the heart can start beating again before breathing, and the lack of oxygen can cause another arrest.

Is paralysis after a lightning strike permanent?

In most cases, the transient paralysis improves within hours, but the spine must be protected and other causes must be ruled out if the deficit persists.

Is the mark on the skin a burn?

The Lichtenberg figure is not a burn. It is characteristic of lightning and usually disappears in about a day.

What follow-up is needed after discharge?

Assessment of the eyes, ears and heart when there were changes, and of mental health, with attention to memory, sleep and mood.

Final checklist

• I prioritized victims in cardiac and respiratory arrest.
• I kept ventilating until breathing returned.
• I checked the central pulse before starting compressions.
• I protected the spine in those with paralysis or trauma.
• I examined eardrums, eyes, heart, skin and pregnancy.
• I gave guidance on warning signs and follow-up after discharge.

Want to practice reasoning with progressive clues? Play the case of the day.

References

1. Andrews CJ, Reisner AD, Cooper MA. Post electrical or lightning injury syndrome: a proposal for an American Psychiatric Association's Diagnostic and Statistical Manual formulation with implications for treatment. Neural Regen Res. 2017. PMID 29089977.
2. Cooper MA. Lightning injuries: prognostic signs for death. Ann Emerg Med. 1980. PMID 7362103.
3. Croskerry P. The importance of cognitive errors in diagnosis and strategies to minimize them. Acad Med. 2003. PMID 12915363.
4. Davis C, Engeln A, Johnson EL, et al. Wilderness Medical Society practice guidelines for the prevention and treatment of lightning injuries: 2014 update. Wilderness Environ Med. 2014. PMID 25498265.
5. Jacob NE, M R. Keraunoparalysis: fleeting paralysis following a lightning flash. Cureus. 2024. PMID 39493204.
6. Modayil PC, Lloyd GW, Mallik A, Bowdler DA. Inner ear damage following electric current and lightning injury: a literature review. Eur Arch Otorhinolaryngol. 2014. PMID 23649510.
7. Pfortmueller CA, Yikun Y, Haberkern M, et al. Injuries, sequelae, and treatment of lightning-induced injuries: 10 years of experience at a swiss trauma center. Emerg Med Int. 2012. PMID 22666596.
8. Pradhan E, Khatri A, Ahmed AA, et al. Lightning injury to eye: brief review of the literature and case series. Clin Ophthalmol. 2020. PMID 32184548.
9. Ritenour AE, Morton MJ, McManus JG, et al. Lightning injury: a review. Burns. 2008. PMID 18395987.
10. Samia AM, Thanikachalam S, Dermer H, Maddy AJ. Cutaneous manifestations of lightning injury: a review of the literature. Skinmed. 2023. PMID 37634096.
11. van Ruler R, Eikendal T, Kooij FO, Tan ECTH. A shocking injury: a clinical review of lightning injuries highlighting pitfalls and a treatment protocol. Injury. 2022. PMID 36038387.
12. Zafren K, Durrer B, Herry JP, Brugger H. Lightning injuries: prevention and on-site treatment in mountains and remote areas. Official guidelines of the International Commission for Mountain Emergency Medicine and the Medical Commission of the International Mountaineering and Climbing Federation (ICAR and UIAA MEDCOM). Resuscitation. 2005. PMID 15919576.