Electric Shock

Electric Shock, in medicine, a serious, sometimes fatal physical injury caused by an accidental flow of electricity through the body. Electric shock administered in a carefully regulated dose can also be an effective medical treatment.

Most injuries from electric shock occur through accidental contact with an exposed wire or other part of a live electrical circuit such as electrical wiring or parts of an electrical appliance. Electric shock occurs less frequently through accidental contact with a high-voltage power line or a lightning strike.

Most cases of accidental electric shock involve a hand or arm in contact with a power source. Because the heart and lungs are close to this point of contact, these are the organs injured most frequently. Although electric shock can paralyze the diaphragm or interrupt nerve impulses that regulate respiration (breathing), death usually results from electricity’s effect on the heart. The electrical charge breaks the normal rhythm of the heart and induces fibrillation (a rapid, irregular fluttering) of the heart muscle, which prevents the organ from beating normally and pumping blood.

Heat generated by contact with a high-voltage current or lightning causes skin burns where the electricity enters and leaves the body. Electric shock also can cause muscles to contract suddenly, which may propel a person to the ground or across a room. A strong electric shock that is not fatal usually interferes with the function of internal organs near the point of contact.

In giving first aid to an electric-shock victim, a caregiver must not touch the victim with bare hands until the source of electricity has been removed safely or the power source shut off. If the victim is not breathing, mouth-to-mouth or mask-to-mouth resuscitation is necessary (see Artificial Respiration). If the person also has no pulse, cardiopulmonary resuscitation (CPR) should be administered until professional emergency help arrives. Burns should be rinsed with or immersed in cold water, blotted dry, and kept clean and covered until the victim can be examined by a physician. First aid also includes the prevention of shock, a reduction of blood flow to body tissues that can cause increased anxiety; pale, cool, clammy skin; rapid, weak pulse; possible fainting; or in more serious cases, coma or death.

The controlled delivery of an electric shock, called defibrillation, is used to restart the heart after a heart attack, which may result from accidental electric shock that stops the heart from beating properly. It also is used to restart the heart during open-heart surgery, and for the treatment of some mental illnesses, especially acute forms of depression, through a procedure called electroconvulsive therapy (ECT).