Electrosurgical Units

The electrosurgical unit is a surgical device used to incise tissue, destroy tissue through desiccation, and to control bleeding (hemostasis) by causing the coagulation of blood. This is accomplished with a high-powered and high-frequency generator that produces a radiofrequency (RF) spark between a probe and the surgical site that causes localized heating and damage to the tissue

An electrosurgical generator operates in two modes. In the monopolar mode, an active electrode concentrates the current to the surgical site and a dispersive (return) electrode channels the current away from the patient. In the bipolar mode, both the active and return electrodes are located at the surgical site.

During surgical procedures, surgeons use electrosurgical units (ESU) to cut and coagulate tissues. ESUs generate electric current at high frequency at the end of an active electrode. This current cuts and coagulates tissue. The advantages of this technology over the conventional scalpel are simultaneous cutting and coagulating and ease of use in several procedures (including surgical endoscopyprocedures).

The most common problems are burns, fire and electric shock. This type of burn usually occurs under the electrode of ECG equipment, under the ESU grounding, also known as return or dispersive electrode), or on various parts of the body that may be in contact with a return path for the ESU current, e.g., arms, chest, and legs. Fires occur when flammable liquids come in contact with sparks from the ESU in the presence of an oxidant. Usually these accidents begin the development of an infectious process in the place of the burn. This can bring serious consequences to the patient and usually increase the patient's stay in the hospital.

Safety

When used correctly, electrosurgery is a safe procedure. The main dangers during use of an electrosurgical unit are from the rare occurrence of unintentional grounding, burns and the risk of explosion. Unintentional grounding can be avoided by good use of the dispersal electrode and the removal of metal objects from the work area. The patient’s chair should not contain metal that could be easily touched during treatment. Work trolleys should have glass or plastic surfaces.

Burns may occur if the dispersal plate is poorly applied, the patient has metal implants or there is intense scar tissue between the plate and the leg. The danger is much less in podiatry, where anaesthesia is local and the patient is conscious. If a patient complains of heating anywhere in the body, treatment should be stopped until the source has been found and the problem solved.

Although emergency equipment should be available in case of accident, pressurised cylinders such as oxygen should not be kept in the room where electrosurgery is being carried out.

If the preoperative antiseptic contains alcohol the skin surface should be completely dry before applying the activated probe. Failure to do this will cause the residual alcohol on the skin to ignite, which may alarm the patient.