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Lightning Injuries

This page focuses on understanding the pathophysiology, assessment, and treatment of lightning injuries. The material on this page is summarized for field use in the Environmental section of the Wilderness Medicine Handbook.

Contents

The Physics of Lightning

Thunderstorms and lightning are created when water molecules within the rising warm air become ionized (negatively charged) as they enter the cooler air in the upper atmosphere. Between 5 and 10 kilometers negatively charged water vapor condenses and turns to water droplets and ice crystals. When heavy enough to overcome the updraft, the droplets or crystals fall as rain or hail, bringing the cooler air and their negative charges with them. As negative charges accumulate at the bottom of the cloud, a step leader shoots at 150-foot (45.7-meter) intervals toward the ground. Because like charges repel one another, the negative charges at the bottom of the cloud force the electrons in all objects below the cloud deep into the ground, leaving positive charges to accumulate directly below the cloud. As the positive charges increase in strength, they create electron streams known as "dart leaders," which move upward towards the cloud and connect with the negative step leader moving down to complete the circuit. This initial upward stroke is followed by a massive return stroke.

Thunder is the result of super-heated air abruptly expanding outward from the completed circuit. The process continues until the charges are equalized. A single lightning bolt is really a series of sequential strokes one immediately after the other. The multiple strokes are responsible for the characteristic flickering and branching.
There are three basic lightning scenarios:
  • Mountainous regions with cool nights and hot days. Mountain storms tend to develop during the hottest part of the summer. Falling cool air from the high mountains feeds developing storms as it dives under the warm air at lower elevations pushing it upward. Local lakes increase the moisture content of the system and the severity of the storms.
  • A cold front moving in under an existing warm air mass forces warm air upward causing lines of thunder storms to form behind it.
  • Dark land masses surrounded (or partially surrounded) by cooler water. Water retains its relative coolness from the winter due to its tremendous mass. The darker land heats up in the hot summer sun and heats the air close to the ground causing it to rise and form thunderstorms.

Strike Types & Pathways

Types of Lightning Strikes
  1. Direct Hit: As the lightning travels down the tree, the sap changes from a liquid to a gas and the tree explodes, splits, or scars. The expanding air and/or involuntary muscular contractions caused by the electrical current can throw a victim many, many feet.
  2. Side-arc or Splash: Current travels down the tree and jumps or arcs into the person standing close to the tree trunk.
  3. Ground Current: Current travels down the tree, through the ground and into the victim.
  4. Conducted Current: Current travels along a wire fence (or shroud) and into the victim.
Electrical Pathways
Regardless of the type of strike—direct hit, splash, ground current, or conduction—the primary electrical pathway in the human body is peripheral and flashes over the victim’s skin, turning water (sweat/rain) to steam and creating linear thermal burns, tearing holes in clothes and blowing shoes off. In rare cases it can ignite sections of the victim’s clothing and cause thermal burns. Nerves often conduct the current deeper into the victim’s body, disrupting cardiac, respiratory, muscular, and nervous system function. Death is possible (± 20%) secondary to cardiac arrest (asystole versus ventricular fibrillation), respiratory arrest (paralysis of respiratory center), or delayed multi-systems failure. Some form of long-term physical and/or psychological disability is common among survivors.

It's important to remember that blunt injury from strong involuntary muscle contraction stimulated by the lightning and/or the rapid expansion of air near the strike site (thunder) often causes the victim to be thrown many feet. Traumatic injuries are likely and can be ruled out in the normal fashion.

Assessment of Lightning Injuries

PictureElectron Feathering
Lightning Injuries S/Sx
  • Both respiratory and cardiac arrest are possible.
  • If a lightning victim is awake, they will usually remain awake.
  • Assume any person with a severely altered mental status in the vicinity of a lightning storm to have been struck by lightning.
  • Fern-like patterns on patient’s skin indicate a positive lightning strike.
PictureEntrance & Exit Wounds (rare)
  • Traumatic injuries are likely. Assume that all lightning victims have an unstable spine; spinal cord damage is possible. Assess and rule out traumatic injuries normally. Temporary paralysis, numbness, and weakness are common.
  • If patient’s clothes have been blown off, check for superficial linear burns.
  • Small entry/exit wounds at conduction/contact points are common.
PicturePunctate Burns
  • Patient may present with punctate burns along the current pathway.
  • Patient may have thermal burns from contact with metal or plastic.
  • Ruptured ear drums are common due to the sound- and pressure waves created by rapidly expanding air; patients may be disoriented and temporarily deaf with vertigo and tinnitus.
  • Patients may be temporarily blind with corneal damage and/or develop cataracts at a later date.
  • General confusion, headaches, amnesia, and exhaustion are common and may persist for several days or weeks. Permanent personality changes, including irritability and depression may occur.
  • Patients may present with cardiac dysfunction and arrhythmias or they may develop over time.
  • Pulmonary edema is possible but rare.

​The following chart summarized potential lightning injuries by body system.
Body System
Potential Injury
Cardiac
​Hypertension, tachycardia, myocardia depression, coronary artery spasm, pericardial effusion, atrial and ventricular arrhythmias, ST-segment elevation, QT-interval prolongation, T-wave inversions, myocardial infarction (rare)
Nervous
​Loss of consciousness, coma, transient lower extremity paralysis (keraunoparalysis), seizures, intracranial injury or hemorrhage, heat-induced nerve damage, autonomic dysfunction with irregular pupils, confusion, amnesia, and other delayed diseases
Vascular
Vasomotor spasm in an extremity, local arterial spasm, peripheral nerve ischemia, skin color changes (pallor and cyanosis followed by redness), mottling of skin, cool extremities, loss of sensation, transient paralysis, compartment syndrome (rare)
Eyes
​Cataracts (bilateral), hyphema (bleeding in the front of the eye between the cornea and iris), vitreous hemorrhage, corneal abrasion, uveitis, retinal detachment or hemorrhage, macular perforations, optic nerve damage
Ears
Ruptured ear drum, tinnitus, deafness, ataxia, vertigo, and involuntary, rhythmic eye movements (nystagmus)
Musculoskeletal
Fractures, shoulder dislocation, rhabdomyolysis (rare), spinal fractures, temporary neuroparalysis of the lower extremities (keraunoparalysis)
Skin
Feathering, flash burns, punctate burns, contact burns, superficial & partial thickness burns, linear burns

Prevention of Lightning Injuries

Lightning Injury Prevention
  • Know the local weather patterns.
  • Seek shelter when you hear thunder.
  • Stay away from high, exposed places.
  • Stay away from open areas.
  • Do not take shelter directly under trees.
  • Remove all metal from contact with your body.
  • Seek shelter in dry areas not exposed to the storm’s rain shadow and insulate yourself from the ground.
  • If woken by thunder at night while in a tent, get up and squat on your sleeping pad until the storm passes.
  • Avoid shallow caves, gullies and overhangs. Caves should be dry and at least 2-4x your height in length.
  • Avoid holding onto metal fences, wires, or shrouds.
  • Move if your hair stands on end, you see or hear static electricity, or you see a blue ring around objects—a strike is imminent.
  • If caught in a strike zone, move in an organized fashion toward a safe area.


​Treatment of Lightning Injuries

It's fairly common to have multiple patients after a lightning strike. Because recovery with CPR is possible with patients who are pulseless and not breathing, and awake patients tend to remain awake, check unresponsive patients first and immediately begin CPR if a patient is in cardiac arrest. Begin—or continue rescue breathing if breathing absent and a pulse is present. It's common for lightning patients to require rescue breathing for hours before they are able to resume breathing on their own.

All WEMS Levels
  • Support the patient’s spine and rule out a spine injury as the situation warrants.
  • Treat all linear and punctate burns as partial or full-thickness (rare) thermal burns.
  • Rule out and treat all traumatic injuries as usual.
  • Ruptured ear drums tend to heal on their own within 2-3 weeks. DO NOT FLUSH. Avoid getting water in the ear (swimming, showering, etc.) until healed. Have drum visually inspected before swimming.
  • Fern-like patterns are temporary and will disappear in 24-48 hours.
  • Evacuate at Level 3: Patients who are awake with no loss of consciousness, a normal physical exam and are asymptomatic.
  • Evacuate at Level 2: Patients who are awake with an altered mental status and minor S/Sx.
  • Evacuate at Level 1: Patients who have suffered cardiac arrest, respiratory arrest, or who are currently V, P, or U with Advanced Life Support to a major trauma center.

Wilderness Paramedics & Registered Nurses
  • Shock prn; remember to resume CPR after each shock to minimize perishock pause.
  • Follow standard Advanced Cardiac Life Support (ACLS) protocols; avoid hyperventilation.
  • Manual defibrillator with electrocardiogram (ECG) capacity to monitor cardiac rhythm. ST-segment elevation and QT-interval prolongation indicate cardiac injury, T-wave inversions often accompany neurologic injury. Myocardial infarction is unusual/rare.
​
Wilderness Practitioners
  • Point-of care-labs: complete blood count (CBC), basic metabolic panel (BMP), creatinine, blood urea nitrogen (BUN), glucose, creatinine kinase, and urinalysis.
  • Ultrasound may help detect internal injury.

Check Your Understanding

Use the information on this page to answer the following conceptual questions​. Hover over a question to highlight it; click  to see the answer.
HOW LONG SHOULD YOU DO CPR ON A PULSELESS LIGHTNING PATIENT?
Consider stopping CPR after thirty minutes of pulselessness; your patient is dead.
HOW LONG SHOULD YOU DO RESCUE BREATHING ON A LIGHTNING PATIENT IN RESPIRATORY ARREST?
Potentially for hours until they begin breathing on their own, go into cardiac arrest, you are exhausted and can't continue, or they are turned over to advanced care.
WHY ARE ALL LIGHTNING PATIENTS EVALUATED FOR TRAUMATIC INJURIES?
  • The expanding air surrounding a lightning strike can throw patients many feet into surrounding trees, rocks, etc.
  • Debris from a strike can explode in numerous directions and injure anyone close to the strike.
  • If electricity passes through the muscles of a lighting patient, it often causes a strong, coordinated contraction capable of fracturing the patient's bones.
Use your handbook to assess the patients in the following scenarios. Hover over a question to highlight it; click  to see the answer.
Scenario 1
A 28-year-old was struck by ground current while hiking.​ When friends arrived on scene moments later, they were unresponsive and in respiratory arrest.
WHAT IS YOUR BLS TREATMENT?
All WEMS Levels
  • Immediate rescue breathing.
  • Protect their spine and spinal cord as necessary.

Wilderness Paramedics, Registered Nurses, & Practitioners​​
  • Manual defibrillator with electrocardiogram (ECG) capacity to monitor cardiac rhythm. ST-segment elevation and QT-interval prolongation indicate cardiac injury, T-wave inversions often accompany neurologic injury. Myocardial infarction is unusual/rare.
Your BLS treatment was successful and your patient is awake and confused, redness and minor blistering on their neck and right wrist where the skin was in contact with a necklace and watch with feathering patterns on their right shoulder and arm. They are partially deaf in their right ear with a headache [4] and general muscle soreness. Their confusion resolves after roughly ten minutes but they cannot remember what happened. After completing the third triangle [secondary survey] of your patient assessment, you are able to rule out a spine injury. ​
WHAT IS THEIR CURRENT PROBLEM?
Current problems = post respiratory arrest, moderate concussion, feathering on their right shoulder, superficial and partial thickness thermal burns on their neck and right wrist, headache, ruptured right ear drum, and general muscle soreness.
WHAT IS THEIR ANTICIPATED PROBLEM?
Anticipated problems = severe concussion, delayed or permanent neurologic, cardiovascular, psychiatric, cognitive, vision, or auditory problems.
WHAT IS THEIR FIELD TREATMENT?
All WEMS Levels
  • Rest and monitor. Acetaminophen for the headache and muscle soreness.

Wilderness  Paramedics & Registered Nurses,​
  • Manual defibrillator with electrocardiogram (ECG) capacity to monitor cardiac rhythm. ST-segment elevation and QT-interval prolongation indicate cardiac injury, T-wave inversions often accompany neurologic injury. 

​Wilderness Practitioners​
  • Point-of care-labs: complete blood count (CBC), basic metabolic panel (BMP), creatinine, blood urea nitrogen (BUN), glucose, creatinine kinase, and urinalysis.
  • Ultrasound may help detect internal injury.​
WHAT IS THEIR EVACUATION LEVEL?
Begin a level 1 evacuation.
Scenario 2
A lighting strike hits a tree roughly sixty feet from a 34-year-old. The rapidly expanding air knocks them to the ground. They are awake, disoriented, and unsure of what just happened. They recall hearing a loud, explosive noise immediately before being picked up by an unknown force that threw them into the tree. They have minor cuts and a sore left wrist from hitting the ground, ringing in both ears and a mild headache [2]. They can easily pick up and drink from a full 1-liter water bottle with their left arm and wrist. After completing the third triangle [secondary survey] of your patient assessment, you are able to rule out a spine injury. Over the next thirty minutes, their headache worsens slightly [3].
WHAT IS THEIR CURRENT PROBLEM?
Current problem = mild concussion, stable left wrist, headache, tinnitus, and minor cuts from blast injury. They were not struck by lightning.
WHAT IS THEIR ANTICIPATED PROBLEM?
No anticipated problem.​ While their concussive S/Sx may continue to worsen, they do not have structural damage that could lead to increased ICP over time.
WHAT IS THEIR FIELD TREATMENT?
All WEMS Levels
  • Physical and mental rest until their concussive S/Sx resolve. Minimize exertion during evacuation. NSAIDs for their headache.
  • Consider splinting their left wrist
  • Clean and dress all lacerations.
WHAT IS THEIR EVACUATION LEVEL?
Begin a level 3 evacuation.
Scenario 3
A 19-year-old was struck by lightning while descending a rocky ridge with friends. The group was spread out along the ridge. When friends arrived on scene seconds later, the patient was unresponsive in cardiac arrest.
WHAT IS YOUR BLS TREATMENT?
All WEMS Levels
  • Immediate CPR. Protect their spine and spinal cord as necessary. Lightning is considered a positive MOI for a spine and spinal cord injury.​
  • Shock with AED or manual defibrillator prn; remember to resume CPR after each shock to minimize perishock pause.

​Wilderness Paramedics, Registered Nurses, & Practitioners
  • Follow standard Advanced Cardiac Life Support (ACLS) protocols; avoid hyperventilation.
  • Manual defibrillator with electrocardiogram (ECG) capacity to monitor cardiac rhythm. ST-segment elevation and QT-interval prolongation indicate cardiac injury, T-wave inversions often accompany neurologic injury. Myocardial infarction is unusual/rare.
After a few cycles of CPR the patient begins to breathe on their own but remains unresponsive.
WHAT DO YOU DO NEXT?
Improvise a carry and get off the ridge. Do you best to protect their spinal cord during the descent; lightning is considered a positive MOI for spine and spinal cord injury. Once off the ridge and under an even tree canopy, stop, place them on their side in a recovery position in a sleeping bag and shelter. Contact Search & Rescue for evacuation assistance.
While removing their wet clothes and placing them in a hypothermia package you noticed feathering on their right leg and punctate burns on their right foot. They also presented with superficial burns in their arm pits, groin, and the center of their back where it came in contact with their pack. Your friend remains unresponsive. Their pulse and respiratory rates appear normal.
WHAT IS THEIR CURRENT PROBLEM?
Current problems = post cardiac arrest, late increased ICP, spine injury, feathering, superficial burns on their arm pits, groin, and back [likely from sweat].
WHAT IS THEIR ANTICIPATED PROBLEM?
Anticipated problems = death due to neurologic or cardiovascular problems, including increased ICP; psychiatric or cognitive problems; delayed vision or auditory problems.
WHAT IS THEIR FIELD TREATMENT?
All WEMS Levels
  • Keep them warm and monitor their airway until assistance arrives.
  • Package them on their side in a well-padded litter for transport. CPR is contra-indicated if they go into cardiac arrest again, as their arrest will be from neurologic or cardiovascular damage, not a primary respiratory problem.

​Wilderness Paramedics & Registered Nurses,
  • ​If they arrest again, follow standard Advanced Cardiac Life Support (ACLS) protocols; avoid hyperventilation.
  • Manual defibrillator with electrocardiogram (ECG) capacity to monitor cardiac rhythm. ST-segment elevation and QT-interval prolongation indicate cardiac injury, T-wave inversions often accompany neurologic injury. Myocardial infarction is unusual/rare.

​Wilderness Practitioners​
  • Point-of care-labs: complete blood count (CBC), basic metabolic panel (BMP), creatinine, blood urea nitrogen (BUN), glucose, creatinine kinase, and urinalysis.
  • Ultrasound may help detect internal injury.​
WHAT IS THEIR EVACUATION LEVEL?
Begin a level 1 evacuation.