From the Guidelines
Capacitive coupling causes thermal injury through electric current transfer to organs touched by the metal trocar (option A). This is because electrical energy from an active electrode can create an electrical field that induces current in nearby conductive objects without direct contact 1. During procedures, the insulation of instruments can create a capacitor-like effect where the active electrode acts as one plate and the metal trocar as another, with insulation as the dielectric material between them. When high-frequency current passes through the active electrode, it induces current in the trocar, which can then transfer to tissues in contact with it, causing unintended thermal burns. The severity of electric injuries can vary widely, from an unpleasant tingling sensation caused by low-intensity current to thermal burns, cardiopulmonary arrest, and death 1.
Key factors to consider in preventing such injuries include:
- Using lower power settings when possible
- Minimizing activation time of electrosurgical instruments
- Ensuring proper insulation of instruments
- Maintaining awareness of the proximity between active electrodes and metal trocars
- Understanding the endoscopy suite’s electrosurgical generator (ESG) settings appropriate for procedures 1.
It is crucial to prioritize caution and follow best practices to minimize the risk of thermal injury due to capacitive coupling, as the extent of injury may not be apparent initially 1.
From the Research
Capacitive Coupling and Thermal Injury
- Capacitive coupling can cause thermal injury due to the transfer of electrical energy to nearby tissues or objects, even without direct contact 2, 3.
- This phenomenon can occur during electrosurgical procedures, where the use of high-current devices and techniques can increase the risk of thermal injury 4, 2.
- Studies have shown that capacitive coupling can cause significant temperature increases in tissues, leading to thermal injury and potentially severe burns 2.
Mechanisms of Capacitive Coupling
- Capacitive coupling can occur through antenna coupling, where radiofrequency energy is transferred to nearby cables or wires without direct contact 2.
- The use of monopolar electrosurgical devices can increase the risk of capacitive coupling and thermal injury, particularly when used in proximity to patient monitoring devices 2, 3.
- The risk of capacitive coupling can be reduced by using lower voltage energy devices, increasing the separation between wires, and reducing generator power 2.
Prevention and Safety Measures
- Perioperative nurses and personnel should be aware of the risks of electrosurgical injuries and take steps to prevent them, including standardizing processes and assessing risks preoperatively 5.
- The use of noncontact electrosurgical grounding devices can help reduce the risk of thermal injury and provide a safe and effective tool for surgical management 6.
- Regular safety inspections, thorough staff training, and strict procedure performance can help minimize the risks of capacitive coupling and thermal injury 3.