Medic 4 responds to a golf course on the report of a person struck by lightning. Upon arrival, on-scene first responders are breathing for the victim. After interviewing bystanders, the EMS crew learns that the first responders witnessed the patient collapse and applied an AED, at which time a shock was indicated. After they delivered a single shock, the patient regained a pulse and had weak and ineffective respirations.
The EMS crew supports the patient's ABCs as he is moved to the ambulance. The patient is a male in his 40s, who is unresponsive with occasional respirations. His heart rate is 40, sinus bradycardia with ST elevation. Blood pressure is 72/40. His skin is cool, pale and dry. Pupils appear to be dilated with a sluggish response to light. Aside from wounds to the patient's left hand and right foot, there are no other obvious signs of physical trauma. From bystander reports, his medical history is unremarkable and there were no ingestions of drugs or alcohol. Emergent transport is initiated. During transport, the patient remains unconscious with a heart rate in the 50s and blood pressure of 90/52. He continues to require manually supported ventilation.
Electrical burns account for 4%-6.5% of admissions to burn units in the United States and almost 1,000 fatalities every year, most of them occupationally related.1-3 Participants in sports and recreational activities are common victims, with mountain activities (climbing, hiking, etc.), golf and water activities accounting for the largest number of fatalities and injuries.4
EMS providers respond to a variety of scenarios. While many of these scenarios fall under the category of medical or trauma, electrical injuries and lightning strikes can present as a combination of both. Because of this, providers must not only address the traumatic outcomes from the incident, such as burns or blunt force trauma, they must also consider any potential medical issues, such as cardiac arrhythmias.
Electrical injuries involve the exchange of energy influenced by two laws: Ohm's and Joule's (see Table 1).5 The body's resistance to electrical current varies, depending on factors such as body moisture and temperature, as well as the path taken by the electrical current (see Table 2). In essence, the greater the tissue's resistance to the flow of current, the more likely the electrical energy will be transformed into thermal energy. Nerves, muscles and blood vessels, which have high electrolyte and water content, have low resistance and are good conductors. In contrast, bones, tendon and fat have a high resistance and tend to become heated when exposed to electrical current rather than transmitting the current.6
Electrical current can be low voltage (&llt;1000 volts) or high (>1000 volts) and direct (DC) or alternating (AC) (Table 3).5-7 Electrical injuries account for approximately 6% of admissions to burn units; approximately one-third of electrical trauma cases are job-related. Electrical injury remains the sixth-leading cause of occupational fatalities. Fewer than one-quarter of electrical injuries involve children. Electricians, construction workers, golfers and toddlers are some of the more common victims.7-9
Exposure to electricity can result in a variety of injuries, including damage to muscles, tissue necrosis and vascular damage. For example, burns can result if an individual becomes part of an electrical "arc." An arc is created when an object that is not in contact with an electrical source becomes involved. Consider the person who is standing next to a car that is in contact with a downed power line. Even though the person is not in physical contact with the car or power line, he may be injured if an arc is formed between him and the car.
A variety of injuries are possible from an arc. Burns due to arcing are influenced by factors including the heat of the arc, electrothermal heating due to the current's flow, and by the flames that result from ignition of clothing. In addition to the arc, the electrical current may splash across the entire body, resulting in burns.2