Pathophysiology

The effects of electricity

Electrical injuries can cause damage in multiple forms within the body. Damage occurs when the electrical energy passes through the body’s tissues, potentially resulting in:

  • Cardiac arrhythmias and arrest – A voltage as low as 50 volts applied between two parts of the human body can cause a current to flow that can block the electrical signals between the brain and the muscles. Cardiac arrhythmias and arrest can occur from the effects of an electrical current on the cell membranes and smooth muscle as it flows through the heart. Further cardiac damage and ischaemia can occur due to spasm of the coronary artery.
  • Burns – When an electrical current passes through the human body it heats the tissue along the length of the current flow. Electricity will usually follow the path of lowest resistance, presenting with an entry and exit burn. This means a potentially large amount of tissue, muscle, and organs being affected but with minor visible damage. Burns are more common with higher voltages but may occur from domestic electricity supplies if the current flows for more than a few fractions of a second.
  • Trauma – People who receive an electric shock often get painful muscle spasms that can be strong enough to break bones or dislocate joints. This loss of muscle control often means the person cannot ‘let go’ or escape the electric shock. Secondary trauma can also be caused by the situation the person is in, for example, a fall or being thrown from the electrical device.
  • Muscular Paralysis – May occur through high voltage contact affecting the central respiratory control system or respiratory muscles.
  • Further considerations will be needed for pregnancy as it can be affected depending on the magnitude and duration of contact.