Electrosurgery - Prevention of Unintended Harm

Prevention of Unintended Harm

For high power surgical uses during anesthesia the monopolar modality relies on a good electrical contact between a large area of the body (typically at least the entire back of the patient) and the return electrode or pad (also known as dispersive pad or patient plate). Severe burns (3rd degree) can occur if contact with the return electrode is insufficient, or when a patient comes into contact with metal objects serving as an unintended (capacitative) leakage path to Earth-ground.

To prevent unintended burns, the skin is cleaned and a conductive gel is used to enhance contact with the return electrode. Proper electrical grounding practices must be followed in the electrical wiring of the building. It is also recommended to use a modern electrosurgical unit that includes a return electrode monitoring system that continuously tests for reliable and safe patient contact. These systems interrogate the impedance of a split or dual-pad return electrode and will alarm out, disabling further generator output in case of fault. Prior generators relied on single pad return electrodes and thus had no means of verifying safe patient connection. Return electrodes should always have full contact with the skin and be placed on the same side of the body and close to the body part where the procedure is occurring.

If there is any metal in the body of the patient, the return electrode is placed on the opposite side of the body from the metal and be placed between the metal and the operation site. This prevents current from passing selectively through metal on the way to the return electrode. For example, for a patient who has had a right sided hip replacement who is scheduled for surgery, the return electrode is placed on the left side of the body on the lateral side of the lower abdomen, which places the return electrode between the location of the metal and the surgical site and on the opposite side from the metal. If there is metal on both sides of the body, the return electrode is placed between the metal and the procedure site when possible. Common return electrode locations include lateral portions of the outer thighs, abdomen, back, or shoulder blades.

The use of the bipolar option does not require the placement of a return electrode because the current only passes between tines of the forceps or other bipolar output device.

Electrosurgery should only be performed by a physician who has received specific training in this field and who is familiar with the techniques used to prevent burns.

Concerns have also been raised regarding the toxicity of surgical smoke produced by electrosurgery. This has been shown to contain chemicals which may cause harm by inhalation by the patients, surgeon or operating theatre staff.