First Year Fellows Endoscopy Course (July 30-31)

3-Electrocautery
Pdf Summary
Electrocautery is a potentially dangerous tool used in endoscopy. It involves the use of high-frequency alternating current to produce heat at the cellular level. The heat produced can be used for cutting or coagulation purposes. The effectiveness of electrocautery depends on factors such as the voltage, current density, and waveform used. <br /><br />Electrosurgical generators are used to produce the high-frequency alternating current required for electrocautery. The patient is not electrocuted during the procedure because above 350 kHz, there is only a thermal effect, and there is no neuromuscular stimulation or formation of acids/bases. <br /><br />Different temperature and thermal effects can be achieved by changing the waveform. For example, a higher voltage and current density are used for cutting, which causes cells to boil and burst. On the other hand, a lower voltage and current density are used for coagulation, causing cells to heat up more slowly and dessicate and shrink. <br /><br />Conductors and insulators play a role in the resistance (obstacle to current flow) encountered during electrocautery. Different tissues have varying resistance levels, which affects the flow of current. <br /><br />There are different types of electrosurgical units available, and it is important for healthcare professionals to be familiar with their units and the most common settings for a particular device and therapeutic goal. Grounding pads are necessary for monopolar circuits, as they complete the electrical circuit and disperse the current. Proper placement of the grounding pad is essential, considering factors like cleanliness, musculature, vascularity, and proximity to the electrosurgical site. <br /><br />Argon plasma coagulation (APC) is a type of electrosurgery that uses ionized argon gas to deliver monopolar current to the tissue. APC offers advantages such as non-contact application, even and uniform coagulation, and thinner eschar. It can be used for various applications, including the treatment of vascular ectasias, tissue ablation, and as an adjunct to fistula closure. When using APC, several variables need to be considered, such as the intention (coagulation or ablation), anatomical considerations, water content of tissue, probe type, distance from tissue, power, argon flow rate, and frequency of delivery. Physicians should take responsibility for setting up the equipment and understanding the electrical concepts involved.
Keywords
Electrocautery
endoscopy
high-frequency alternating current
cutting
coagulation
electrosurgical generators
thermal effect
waveform
resistance
argon plasma coagulation