Obesity & Anesthesia

Microshock and macroshock hazards in the operating room are serious concerns to the anesthesiologist as a microshock of as little as 100 uA can cause ventricular fibrillation. Microshock refers to very small amounts of current applied to electrically susceptible patients, such as those with an electrical conduit directly to the heart (pacing wires, central venous catheters). Since this is above the 100uA threshold, this microshock current would likely cause ventricular fibrillation. 10uA is the maximal recommended 60 Hz leakage current in the OR. The threshold of perception through skin is approximately 1 mA (1000uA), which this is below current in this question. However, it is true that 10-20mA is considered the "let-go" current and 100-300 mA (100,000-300,000 uA) is when v-fib occurs in macroshock. In addition to ungrounded battery power supplies, double insulation of the chassis and casing, and patient isolation from equipment-connected grounds are ways to decrease the possibility of microelectrocution.