Hello everyone and welcome to this week's blog post. In this article, I will be discussing electric shocks. I will first explain what an electric shock is and how it causes damage to the body. I will then explain its causes, symptoms and treatment. I will then finish by describing how they can be prevented.
What is an electric shock?
An electric shock occurs when you touch an electrical source. This then causes an electrical current to pass through your body, which can cause major damage to your body. There are several factors which influence how damaging an electric shock will be.
The first is the current or voltage that flows through the body. This can vary greatly depending on the electrical source. When the current and voltage are higher, then the damage caused by the electric shock is greater. Currents of 60mA or voltages as low as 50V are enough to stop the heart from beating properly and thus can cause death (when this occurs, it is called electrocution).
What factors influence how damaging an electric shock is?
Knowing the amount of current or voltage of the electric shock is not enough, however, to determine how much damage or discomfort an electric shock will cause. Indeed, a static shock from walking across a carpet can result in the discharge of over 10,000V. Yet, because the current flows through the body for such a short period of time, no damage is caused. Consequently, the length of time that the body is part of the electrical circuit is also a major factor in determining the severity of the electric shock - the longer the time period, the greater the damage.
Additionally, the path that the current takes through the body is important. For example, the current could pass between one finger to the next, or it could pass through the arms and down the rest of the body to the legs. This greatly influences the damage that an electric shock can cause. For example, if the current passes through the heart, then fibrillation is likely to occur.
The severity of an electric shock is also reliant on the resistance that the body provides. The main factor in this is whether the skin is wet or dry. In dry conditions, the skin is very resistant to electricity, so the damage that the shock can cause is reduced. In stark contrast, when conditions are wet, the skin is coated in water, ions and electrolytes. This dramatically decreases its resistance, thus increasing its conductivity and magnifying the damage an electric shock can cause.
It is important to note that electric shocks can occur even if the person involved doesn't touch the electrical source. This is because, when the voltage is high enough, the air can be ionised, thus producing a path which the current can pass through to reach the body.
Electric shocks can also occur indirectly through the water. This occurs when electric currents are introduced into a body of water, which causes people in the water to experience a shock. Unfortunately, these cases are often fatal, as the electric current can quickly travel through the water and into the body. The current then causes muscle paralysis and results in drowning. Drowning due to electric shocks are more common in freshwater, due to dissolved mineral ions which increase the water's conductivity.
How do electric shocks cause injury?
There are many types of electrical injuries that electric shocks can cause. For example, electric shocks can often cause burns, whose severity depends on the factors explained above. Electrical burns can be categorised as superficial burns (when only the top layer of skin is burnt), partial-thickness burns (when the burn impacts the top two layers of the skin) and full-thickness burns (where all layers of the skin are burnt).
Electric shocks can also cause other symptoms, including hearing problems, headaches, muscle spasms, loss of consciousness, tingling feelings and vision problems.
In addition, electric shocks can also cause a syndrome called compartment syndrome. When muscles are damaged, swelling can occur. This causes a large amount of pressure to build up inside the muscles. As the fascia surrounding the muscles doesn't expand, the increased pressure can cause significant damage to the surrounding tissues. Furthermore, if this swelling persists, then blood flow to the area can be restricted, thus limiting the oxygen supply to the neighbouring tissues and resulting in cell death.
If the electric current passes through the heart, then the electrical activity of the heart can be disrupted. This can lead to a heart attack or irregular heartbeat, which can be fatal if help is not available. Moreover, electric shocks can cause other fatal consequences, such as seizures and breathing problems. When these serious symptoms occur and cause death, then this is known as electrocution.
What are the long-term impacts of electric shock?
Electric shocks can be extremely damaging to one's long-term health. These long-term impacts can be broadly split up into three categories: psychological, neurological and physical. Physical symptoms include general pain, fatigue, exhaustion, headaches, and muscle spasms. In addition, if the electric current passes through the eyes, then ocular damage can occur. Up to 6% of electric shocks result in patients developing cataracts (cloudy patches that develop on the eye's lens) in the year following injury, with a few more developing in the years after that.
Neurological symptoms of electric shock include memory loss, loss of balance, dizziness and tinnitus (a ringing sound in the ears). Psychological symptoms also occur, which include depression, insomnia, panic attacks and PTSD. It is worth noting that, according to a paper published in 2013, it is difficult to study the long term effects of electrical injuries. Consequently, evidence about the long term impacts of electric shocks is limited.
How can electric shock be treated?
There are many different options for treating electrical injuries. These options depend on the severity and location of the injuries. Minor electrical burns can be treated with antibiotic creams and sterile dressings. Pain relief can also be provided. In addition, according to the NHS.uk, a tetanus shot may also be advised. This is because tetanus bacteria can enter the body through these wounds, causing a painful and sometimes fatal infection.
Additionally, blisters (pockets of bodily fluids under the skin) can also form, as a result of superficial burns. It is recommended that the patient does not burst these blisters themselves, but instead seek medical attention. Blisters can be treated by creams or aspiration, where healthcare professions use a needle to make a small hole in the blister, thus allowing the fluid to be removed.
For more extensive burns which affect multiple layers of skin, specialist care is often required. In the UK, this care is delivered in specialist burn units. These severe burns are often treated with skin grafts. This is a type of plastic surgery in which skin is taken from another part of the patient's body and grafted over the burnt area.
Injuries to the eyes are treated by ophthalmologists. For example, if cataracts form, then cataract surgery is usually performed to improve vision. Meanwhile, broken bones and other internal injuries may require surgical treatment.
The prevention of electric shocks
While there are many potential dangers when working with electrical equipment, there are several ways that the risk of electric shock can be reduced. In domestic settings, power cords are responsible for the majority of injuries, especially amongst young children. As such, parents should keep cords out of reach of children and use outlet covers to prevent them from being misused. Additionally, people should also inspect any wiring that they have and ensure that any cord that has exposed wire is replaced.
When working on electrical systems, the power to these devices should be switched off in advance, so that electric shocks can't occur. Moreover, electric shocks commonly occur when someone cuts branches of trees, which then fall on bare power lines. This can be prevented by ensuring that the surroundings are free from power lines before beginning work.
There is also a threat of being shocked by lightning during a thunderstorm. To reduce this risk, people should go indoors if possible. If this isn't an option, then they should stay away from trees, metal objects and bodies of water.
Sources:
Wesner, M. L., & Hickie, J. (2013). Long-term sequelae of electrical injury. Canadian family physician Medecin de famille canadien, 59(9), 935–939.
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