Electrical burn injuries account for less than 5% of admissions to major burn centres. However, the injury is much more complex than a skin burn and the morbidity and mortality rate is considerably higher. The mortality rate ranges from 3–15% with about 1000 deaths attributed to electrical current in the US each year. More than 90% of injuries occur in males, most between ages 20 and 34.

Electrical current tissue damage

Pathophysiology

The severity of injury to tissues is dependent on the amperage, i.e. the actual amount of current, passing through the tissues. It is impossible to know the amperage because of the variability of resistance and exposure time at the accident, but one can infer amperage from the voltage of the source at least as to high or low. A low-voltage source is capable of producing major cardiopulmonary complications and death if a sufficient current passes through the body (Table 6.1).

A high-tension source is usually required to produce the severe tissue necrosis characteristically seen along the path of the current. The damage is caused by both heat production and direct current damage. The initial resistance to flow of current, namely, skin or clothing, is overcome by the heat generated from the high voltage, and subsequent tissue necrosis occurs with continued contact. A dry hand may have sufficient resistance to avoid passage of current from a low-voltage source over a short time period.