Electrosurgery

Electrosurgery (diathermy) has been in widespread use for many years. However, few surgeons understand its principles or dangers. This review explains the basic principles of electricity and electrosurgery and how the fundamental difference between them is the frequency of the alternating current. The very-high frequency (radio-frequency) of the alternating current allows it to be passed through tissue without the risk of electrocution for the purposes of cutting and coagulation, but the same high frequency is associated with other dangers. The important concepts of capacitance and current density are explained and the danger of non-contract activation with high voltages is highlighted. The contribution explains how the tissue effect achieved is influenced by several factors, including the choice of electrode and the generator output mode. Although electrosurgical equipment may be inherently safe, the dangers arising from poor technique are discussed and recommendations for safe practice are made.