Electric shock is a terrifying phenomenon that didn’t begin with Nikola Tesla or Thomas Edison. Electricity is all around us, all the time, and comes with the possibility and reality of electric shock. Electrical burns are some of the most complex and deadliest burn injuries treated across Burn and Reconstructive Centers of America’s (BRCA) national care system due to how electric currents travel through the body. These burns are rarely only surface-level injuries. Due to the body’s ability to conduct electricity, the body itself acts as a conduit for the current to move through, causing the current to travel and injure muscles, deep tissues, nerves, blood vessels and organs. Electrical burns are deadly, and survivors often face the possibility or reality of amputation.
What causes electric shock?
Electricity is defined as the flow of electrical power or charge. When you receive a “shock,” you’ve come into contact with an electrical current. You might have experienced this phenomenon at least once through static shock. While serious injuries are highly unlikely to occur from the average static shock, other potential causes of electrical shock are much more dangerous and numerous in our everyday lives. The most common ones include:
- Electrical wall outlets
- Faulty appliances
- Powerlines
- Lightning
- Frayed or damaged cords
The difference between electrical voltage, amperage and current—how much of each does it take to kill the average person?
What makes some electrical shock hazards more dangerous than others? Electrical amperage, current and voltage decide how a shock might affect a person.
Voltage
Electrical voltage is the measure of force it takes to move a charge between two points or through a conductor. Because Voltage = Current x Resistance, if the voltage goes up, then the current is probably also going up. Voltage behaves a lot like pressure in how we see and experience it, while the electrical current is like flow. So, what does voltage look like in everyday examples? The typical voltage of a car battery is 12 V of direct current (DC), while standard household outlets fall in the range of 110-120 V of alternating current (AC). Because the human body is a high conductor of electricity, the force it would take to move electrical current through the tissue is minimal. That means a minimum voltage of 50 V is enough to be lethal.
High voltage electric shock incidents, such as getting struck by lightning, are much rarer than low-voltage injuries. More people die of a low voltage such as outlets, or during home wiring jobs because low voltage shocks can cause deadly cardiac defibrillation or heart arrhythmias. In contrast, high voltage shocks can severely damage the organs.
While an electrical burn injury may not be as significant from a low-voltage shock, these electrical shocks can cause arrhythmia or abnormal heart rhythm. The danger of low-voltage shock injuries is they can often lead to more severe complications and death due to cardiac defibrillation. Defibrillation, such as from a medical defibrillator or other sources of low voltage shock, stops your heart and acts as a restart, sometimes throwing the heart into and out of its natural rhythm. Therefore, it is common practice to administer cardiopulmonary resuscitation (CPR) on the scene of a low voltage shock to restart the heart or get the heart back into a natural rhythm.
Amperage
Between voltage and amperage, amperage poses the most significant risk. Voltage is the force it takes to move a charge; amperage measures the flow of charge through a conductor. It is measured in amperes or amps (A). So, what are amperes compared to volts? A typical car battery of 12V can be between 550 to 1,200A, while a home outlet of 110-120V is typically 15A. While care batteries have fewer volts than outlets, they have a higher amperage. However, the risk of electrocution from high amperage increases or decreases slightly depending on the type of electrical current: direct current (DC) or alternating current (AC).
Current
An alternating current (AC), invented by Nicola Tesla, is an electrical current that reverses the direction of electron flow multiple times a second. Most commercial applications use alternating current. Alternating current is the electrical current used to deliver electricity to households and businesses and high voltage electrical appliances. When under the same voltage or amperage, alternating current is considered the more dangerous of the two because it can cause tetany (spasms or seizing), cardiac fibrillation, respiratory muscle paralysis and cardiac dysrhythmia upon electrical shock. Alternating currents have contact points but no actual entrance or exit points. The inability to let go or release from an electric charge is more likely to occur with an alternating current than a direct current because an alternating current inhibits the let go response at a lower current.
Direct current (DC), invented by Thomas Edison, is an electrical current that only flows in one direction. Direct current is associated with lightning, car batteries, medical appliances like defibrillators and other low voltage applications. The rapid rate car chargers for electric cars are usually direct current. Entrance and exit wounds are common injuries for those who’ve suffered electrical shocks from direct current sources. While alternating current sources are more dangerous than direct current sources, that is not to say that both cannot be fatal. Both direct and alternating currents can cause a person to lock on (tetany), but a direct current is easier to let go of. The difference is that the body can tolerate direct current more than alternating and may be able to take more of a charge for longer with fewer injuries than alternating current.
What happens when you get shocked?
Electricity’s goal is to ground itself. The biggest conductor we experience is earth, which is why you may have learned in school that lightning is always trying to get to the ground. The human body naturally conducts electricity as the earth does. That means electrical currents can readily travel through the body. The nerves, vessels, muscles and skin are the most accessible parts of the body for electrical current to travel through, but that isn’t a good thing. Trying to get to the ground, an electric current will go around or through you, traveling through the body part closest to the source and following the path of least resistance on its way out of the body. If you are wearing rubber shoes, the current won’t be able to get out, which is why wearing rubber products while working with electricity is encouraged to help prevent injuries. So, what other injuries can occur as a result of electric shock?
For minor shocks or shocks from low power sources, the electricity most likely won’t enter the body but will incur superficial damage to the skin, such as first- to second-degree burns.
The electrical current will enter the body via an entrance wound for more severe electrical shocks. The entrance wound is typically the place in contact with the electrical source. For example, if you grab a live electrical wire, the entrance wound would likely be on the hand. Once in your body, the electrical current will travel throughout the body via the tissues with the highest conductivity (nerves, vessels, muscles). These tissues may be severely damaged from the electrical current traveling through them, so you can wind up with deep damage from a high current source because, as it tries to go through the bones, they get superheated. If the bones have been damaged and heated enough to impact the surrounding tissue and nerves, it might result in a “dead limb” and amputation. If the person cannot disconnect from the source of electricity, the steady flow of electricity will need to find a way out of the body. This is what is called an exit wound. It is the place where electricity exits the body. Some common areas for exit wounds are the feet and the opposite hand. However, If the person becomes disconnected from the source of electricity, there may not be an exit wound.
While entrance and exit wounds can be severe, it’s essential to examine the whole patient. Since entrance and exit wounds aren’t particularly easy to identify and most internal damage is hidden, electric shock patients need to be observed for a few days to understand the prognosis fully. If the patient is having difficulty moving a particular body part after an electric shock and, after a few days, can move it a bit easier, that’s a good sign. If the patient can’t move it at all a couple of days later, that’s usually irreversible damage. Limitations and functions that improve over time typically result in a good prognosis, but deficits that get worse over time often become permanent.
Effects of electric current on the human body
Electrical injuries are some of the most complex cases treated across Burn and Reconstructive Centers of America’s (BRCA) care system. They are much more involved than what is visible on the outside.
Burns: Electrical injuries often involve burns. If it is a high-voltage electrical injury, the shock will cause burns anywhere from first-degree burns (minor burns) to fourth-degree burns (severe burns) on the body. Depending on the mechanism, however, electrical shocks can also cause a person’s clothes to catch fire, incurring thermal burns that way as well. The burns may appear:
- First-degree: red or pink skin with no blistering
- Second-degree: red and moist in appearance with blistering
- Third-degree: dry, tight and leathery, brown/tan/waxy or pearly white in appearance
- Fourth-degree: black and charred in appearance with possible muscle or bone involvement
Traumatic injuries: Traumatic injuries can happen depending on where and how the electrical injury occurs. A traumatic injury such as a spinal or cranial injury might occur due to an electrical shock if the shock is powerful enough to throw a person physically or if the shock happens at a great height. Spinal injuries may also occur after sudden extension from tetany (muscular spasms or seizing), which can cause vertebral fractures. If this is the case, traumatic injuries will take precedence over burns, and the person will be taken to a trauma unit before being transferred to a burn unit.
Compartment syndrome: Compartment syndrome occurs after a severe burn when the affected areas begin to swell. The swelling (edema) can cut off the blood supply and cause even more damage. Emergency medical intervention is necessary to restore the blood supply and save healthy tissue when this happens.
Amputation: In severe electrical shock where the person has suffered fourth-degree burns, amputation may be necessary. Fourth-degree burns affect the skin, tissues, vessels and muscles and bone. Typically, electrical shock amputations involve the areas with exit or entrance wounds.
Internal damage: Most of the damage from electrical shock cannot be seen on the outside. As the current travels through the body, internal organs and tissues can be damaged. Some internal damage that can be caused by electrical shock include:
- Vascular compromise: the blood vessels, arteries and veins are highly conductive to electricity. Electric shock may damage the blood vessels, arteries and veins by causing them to burst, cutting off the blood supply, causing painful varicose veins and more.
- Lethal dysrhythmias: the heart is a muscle that pumps using electrical pulses. Electric shock can disrupt or mask these pulses, throwing the heart out of rhythm and possibly causing cardiac arrest.
- Organ failure: electric shock can cause organ failure or multiple organ failure. This may include the heart (cardiac arrest), the kidneys (renal failure) and more.
Long-term effects of electric shock
Long-term effects of electric shock on the human body are hard to diagnose or track over time. However, some long-term effects have continuously presented in burn and trauma patients that most researchers and healthcare workers attribute to the electric shock that those patients survived.
Physical effects:
- Eye problems, specifically the rapid development of cataracts
- Generalized pain that many don’t receive satisfactory relief from
- Ghost pains or itches, specifically in those suffering from amputations
- Joint stiffness, arthritis and contracture due to muscle damage
- Muscle pain and spasms
- Permanent neurological injuries such as paralysis
- Itching, possibly as a side effect of the burns
Psychological effects:
- Reduced cognitive abilities, specifically verbal recall and attention span
- Post-traumatic stress disorder (PTSD)
- Anxiety
- Depression
- Development of a phobia
- Memory loss, especially around incident and recovery
Neurological effects:
- Numbness, tingling or pins and needles sensation (paresthesia) due to nerve damage
- Carpal tunnel syndrome due to median nerve damage
- Paralysis
- Seizure disorders
- Dizziness, loss of balance or fainting spells
- Ringing in the ears (tinnitus) or progressive hearing loss
- Tremors
- Migraines
While we cannot guarantee all of these are long-term effects of electric shock, we can trust what our patients go through during their recovery. Electrical shock and burn survivor Mary Calhoun said, “I have injuries that are longer-term that are popping up that we discovered are probably caused by [the shock]. I’ve lost a lot more of my hearing. I have cataracts now; I didn’t have them the year before, and they’re rapidly, rapidly growing.”
It is to examine electrical shock victims for cataracts during the initial phase of their care to document that the cataracts are not pre-existing conditions. Since cataracts and eye problems are known long-term effects of electrical shock, an ophthalmologist should be contacted to examine the eyes and ensure they are fine, so if later effects show up, they can be documented. Burn and Reconstructive Centers of America’s burn care teams work closely with our patients and the Joseph M. Still Research Foundation to track these symptoms and the long-term effects of electric shock for the present and future creation of individualized patient care plans.
Scene control is important. If you believe someone has been in contact with an electrical source, turn off the electrical source. You can die from trying to help someone being shocked since they are acting as a conductor for the current. Shut off the electricity, if you can, before assisting the victim for the best chance of recovering them.
Further Information
Burns and electrical shock injuries are not “curable.” Instead, they are life-long conditions that require years of appointments, therapy, medications and surgeries. Our healthcare team at BRCA does what they can to limit the long-term effects of burn injuries and give our patients the best outcomes possible. For more information about BRCA locations and services, please visit our website at www.burncenters.com. If you have questions or would like to schedule an appointment, please call our burn information services at (855) 863-9595.
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