Grounded Electrosurgical Systems
Electrosurgical technology has changed dramatically since its introduction in the 1920s. Generators operate by taking alternating current and increasing its frequency from 50 or 60 cycles/second to over 200,000 cycles/second. Originally, generators used grounded current from a wall outlet. It was assumed that, once the current entered the patient’s body, it would return to ground through the patient return electrode. But electricity will always seek the path of least resistance. When there are many conductive objects touching the patient and leading to ground, the current will select as its pathway to ground the most conductive object—which may not be the patient return electrode. Current concentration at this point may lead to an alternate site burn.