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33. Lightning Strike: Thunderbolts and Lightning, Very, Very Frightening…The Cosmic DC Countershock
Keywords
LightningElectrocutionCase
Lightning Strike
Pertinent History
A 54-year-old man is brought in by EMS after a cardiac arrest. He is unable to provide any history; however, bystanders report he was struck by lightning and was immediately unresponsive. Bystander CPR was initiated and performed for 5 minutes prior to EMS arrival. On arrival, EMS continued CPR and placed a King LT airway. The patient’s initial rhythm was asystole, and he received an additional 4 minutes of CPR and 1 mg of IV epinephrine. On the next rhythm check, he was in ventricular tachycardia. Defibrillation was performed a total of three times with progressively increasing joules. He received an additional dose of epinephrine; and two amps of sodium bicarb before he had return of spontaneous circulation (ROSC). He was then transported to the emergency department (ED) without incident.
Pertinent Physical Exam
Blood pressure 86/42, pulse 42, temperature 94 degrees F, respiratory rate 20, SpO2 98%.
Except as noted below, the findings of the complete physical exam are within normal limits.
Eyes: Pupils are 2 mm in diameter, round, and nonreactive.
Cardiovascular: Bradycardia with regular rhythm, palpable pulses throughout.
Respiratory: King airway in place with color change colorimetry, clear bilateral breath sounds with manual ventilation.
Spine: Cervical collar in place, no step offs or deformities in the cervical, thoracic, or lumbar spine.
Neurologic: Unresponsive, GCS 3 T.
Skin: Four centimeter laceration with no active bleeding to the chin. Violaceous discoloration to the entire chest, shoulders, and right flank with an associated 1% total body surface area burn on the low midline chest over the sternum.
The patient’s past medical, social, and family history are unknown.
Pertinent Test Results
EKG – Junctional escape rhythm with a rate of 30
CT head, face, cervical/thoracic/lumbar spine, chest, abdomen, and pelvis – no significant traumatic injuries
ED Management
The 54-year-old male patient presented as a level 1 trauma alert after a lightning strike with associated cardiac arrest after prehospital ROSC. On arrival, a King LT airway was in place and he had palpable pulses. He was bradycardic and hypotensive on presentation and intravenous fluid resuscitation was begun. An EKG was obtained which showed a bradycardic junctional escape rhythm, and temporary cardiac pacing was initiated as well as an epinephrine infusion. These interventions increased his heart rate to the mid 80s and his blood pressure was improving. A repeat EKG was obtained and continued to show a junctional rhythm. Central access and arterial monitoring lines were placed. He was initiated on a therapeutic hypothermia protocol.
CT imaging was obtained to evaluate for associated traumatic injuries. The patient was then admitted to the surgical intensive care unit (SICU) in critical condition.
Learning Points
Priming Questions
- 1.
What is the pathophysiology of lightning-related injuries and are these similar to other electrical injuries?
- 2.
What are the first steps after a lightning strike?
- 3.
How does cardiac arrest occur and are there any special considerations for treatment following a lightning strike?
Introduction/Background
- 1.
In the United States, there are approximately 25 million lightning strikes per year with an average of 47 deaths per year from lightning strikes. Lightning strikes are one of the leading causes of weather-related death with an approximately 10% mortality rate in the United States. The lifetime risk of being struck by lightning in the United States is approximately 1 in 14,600 [1].
- 2.
Lightning is a rapid discharge of electricity between two opposite charges. Initially, the air acts as an insulator between positive and negative charges between the clouds or a cloud and the ground. When the difference in charge becomes too great, there is a unidirectional (in one direction) discharge of electrons. The potential difference that results may exceed two million volts/m. This is most similar to a DC current exceeding 50,000 amps, which when converted to heat, can generate a temperature of over 50,000 °F [2].
- 3.
There are five main types of lightning strike injuries [3].
Direct Strike: This happens when a patient is directly struck by lightning without the lightning first contacting another object. Direct strikes have the highest fatality rates.
Upward Streamers: A less common type of direct lightning injury (sometimes called the 5th mechanism) was described in the early 2000s [4, 5]. Injury happens when a person is caught in an upward streamer. Upward streamers are induced by the downward lightning leader as it approaches the ground. Multiple upward streamers can develop but usually only one connects with the downward stroke, completing the circuit. Even if the individual is not part of the completed lightning channel, the discharging of the streamer can cause injury or death. Although the upward streamers are much less powerful than a completed lightning stroke, they can still deliver hundreds of amps. The frequency of this type of lightning injury is likely underestimated.
Contact Injury: This occurs when the lightning strikes an object that the patient is touching. The current travels through the object and then into the patient.
Side-Splash: This is a phenomenon where the lightning strikes an object near a patient, and then, as it is traveling through that object, the current jumps through the air to the patient.
Ground Current Injury: This occurs when the lightning strikes the ground near a patient and travels through the ground. It then travels up into the patient through the legs, or whichever body part is touching the ground.
Blast Injury: This can occur due to a thermoacoustic blast wave that occurs from rapid superheating of the surrounding air-thunder, and can create an overpressure as high as 100 atmospheres of pressure surrounding the lightning.
Types of Lightning Strikes
Published with kind permission of © Colin G. Kaide 2019. All Rights Reserved
Physiology/Pathophysiology
- 1.
As lightning travels through the heart, it acts as a massive countershock, causing simultaneous depolarization of the entire heart, followed by a period of asystole. This is most common with a direct strike. The intrinsic automaticity of the heart may restart, leading to spontaneous return of normal cardiac rhythm. However, respiratory arrest may persist longer and hypoxia can lead to further cardiac decompensation and repeat arrest. There are numerous ongoing manifestations of lightning injury [6].
Although the immediate effects of a lightning strike are difficult to study, a patient with an implanted loop recorder had been struck with a rhythm strip recorded “live” during the event. When this patient was struck, there was immediately a large spike of electricity, followed by ventricular fibrillation for a few seconds and then ventricular tachycardia. Although he spontaneously returned to a sinus rhythm, two friends with him at the time, died immediately [7].
There are also case reports of multiple patients (with implanted cardiac devices (ICDs)) who have been struck or have been very near to lightning that have been defibrillated. Unfortunately, about half of the reports have been inappropriate shocks delivered by the ICDs. The magnetic field produced by the lightning has the ability to disrupt normal function of the ICDs [8].
In the first 3 days following lightning strikes, there may be a severely reduced ejection fraction of less than 15% and ongoing cardiogenic shock. This cardiomyopathy typically resolves within 1–2 weeks.
In a direct lightning strikes, there may also be electrocardiographic changes consistent with myocardial injury, such as ST elevation, QTc prolongation, or pericardial effusion. The source of these changes is not entirely clear and while some patients do have underlying ischemia, other patients have had normal cardiac enzymes and no evidence of myocardial infarction despite these EKG changes [8].
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