ABSTRACT
Surgical diathermy involves the passage of high-frequency alternating current of 400 kHz to 10 MHz through the body tissue. In cutting mode, the diathermy generator produces a continuous low-voltage output. This causes an arcing of current between the high-current-density area established at the electrode tip, and the body tissue. Most diathermy has a blend facility that combines the coagulation and cutting waveforms to allow greater haemostasis during cutting. Most of the risks of diathermy use are associated with inadequate preparation of the patient or poor technique. Although the diathermy is often set up by other members of the theatre staff, the surgeon remains responsible for its overall use and should be familiar with the generator and circuit in use. In contrast to monopolar diathermy, in which the current is directed from the electrode tip in the surgeon's hand to the patient plate, in bipolar diathermy the patient takes no part in the electrosurgical circuit.
