Editing Electrosurgery (section)

== '''Monopolar:''' ==

* Alternating current utilising a completed circuit from the instrument, through the patient, to the return electrode, to the machine, and back to the instrument
* Impedance causes heating. Impedance increases with resistance (impedance is technically '''resistance''' plus '''reactance''' in AC circuits - I am using impedance in this topic)
** Impedance can be increased by removing fluid, compressing arteries or putting tissue under tension.
*** Fluid conducts, and so reduces impedance, and since heat produced is proportional to impedance - fluid prevents heating
** Increasing the length of time also obviously increases thermal change
** Hence the mnemonic of how to increase thermal change at a point: 
*** A - first decrease the AREA of contact
**** Pad is high area, low impedance, low current = low heating
**** Electrode is low area, high impedance, high current = intense heating
*** R - second increase tissue RESISTANCE/IMPEDANCE
*** T - third increase TIME
*** Current/wattage can also be increased, but this should come last - it increases the risk of unwanted thermal change
* Risk of electrocution is low when AC < 100khZ is used. Monopolar is higher frequency (300-3800kHz)
* Selecting wattage
** Should be as low as possible to accomplish the task
** 20W is low - forces you to use the ART acronym
** Be aware that carbonisation occurs at 200-400 degrees - this should be avoided where possible - hallmark of non-refined technique