Cause of Device-Related Incident
User errors

Clinical Specialty or Hospital Department
Obstetrics and Gynecology; OR / Surgery

Device Factors
*Not stated

Document Type
Hazard Reports

External Factors
*Not stated

Mechanism of Injury or Death
Burn (electrical, thermal, chemical)

Support System Failures
*Not stated

Tampering and/or Sabotage
*Not stated

User Errors
Failure to read label; Improper connection; Incorrect clinical use

Electrodes, Electrosurgical, Return [11-500]

ESU Burns from Poor Return Electrode Site Preparation

Hazard [Health Devices Jan 1987;16(1):35-6]


ECRI continues to receive problem reports and to investigate incidents of burns occurring underneath electrosurgical dispersive electrodes. In the incident reported here, a burn was detected after the surgeon attempted to activate an electrosurgical unit (ESU) several times with no surgical effect. The burn occurred directly underneath the dispersive (return) electrode and corresponded to a charred section near the edge of the electrode's conductive adhesive surface, which indicates that arcing probably occurred between that section of the dispersive electrode and the patient's skin.


An electrosurgical burn following an ESU activation that produces little or no surgical effect typically indicates poor electrical contact between the dispersive electrode and the patient. This can be caused by poor electrode placement, inadequate site preparation, defective materials on the return electrode, or dried-out conductive gel or adhesive.

In the incident described above, the dispersive pad appeared to have been adequately attached to the patient, the electrode did not appear to be defective (other than the charred section of the pad), and the conductive adhesive was not dried out. However, the site underneath the pad had not been shaved. The patient's hair most likely inhibited complete dispersive electrode skin contact, resulting in a high patient electrode contact impedance. The burn most likely occurred at a small contact point between the patient's skin and the conductive layer of the return electrode.

We are aware of several other electrosurgical burns attributed to improper shaving of the area underneath the patient return electrode. Dispersive electrode manufacturers are aware of this problem and provide application instructions and warning labels on their packages, which typically state that the area underneath the dispersive electrode should be cleaned and shaved as necessary. However, OR scrub or circulating nurses may neglect to shave the area to save time, because they are unaware of the need for shaving, or because patients object to shaving for cosmetic reasons.

Regardless of how the return electrode is placed on the patient or how the site underneath the pad is prepared, OR staff should be aware of the warning signs of poor contact impedance. If inadequate surgical effect at the active electrode site occurs, OR staff should immediately check the return electrode for pad placement and obvious defects. If no problems are apparent, the dispersive pad should be removed and checked for dried-out conductive gel or adhesive, and the skin underneath the pad should be examined for signs of high patient electrode contact impedance (e.g., a pad placed over improperly cleaned or shaved areas). If an improperly cleaned or shaved area is suspected, it should be cleaned or shaved. Regardless of whether problems are found with the dispersive pad, a new pad should be placed on the patient before activating the ESU.

Fatty tissue or tissue directly over bone can also impede electrosurgical return current flow, and dispersive pads placed over these areas should be replaced with a new pad over a muscular area, such as the anterior thigh, which is more conductive. When this is not possible (e.g., with obese patients), a second parallel return electrode may sometimes be used to increase the overall dispersive pad surface area, decrease the patient electrode contact impedance, and reduce current density. Some ESU manufacturers provide adapters that permit users to attach two return electrodes to their units when used with obese patients.

Two manufacturers' circuits are designed to detect the quality of the contact between the patient and the pad. One circuit is built into the manufacturer's ESUs, and the other is a module that can be used with most ESUs. We evaluated these systems, called contact quality monitors, in Health Devices 14:115-31 (1985). These monitors are designed to detect insufficient contact between the patient and the return electrode (e.g., when the electrode is peeled away from the patient) or the pad is placed over poorly conductive areas (e.g., those with large amounts of hair). Although using a return electrode contact quality monitoring system is more expensive than a standard electrosurgical system, a good one may provide benefits for hospitals that experience several electrosurgical burns per year.


Regardless of what techniques are used to prevent patient burns during electrosurgery, they will not replace proper preparation of the return electrode site and proper placement of the electrode. By performing the following procedures, hospitals will greatly reduce the risk of these burns:

  1. Choose a flat or relatively flat muscular area fairly close to the surgical site that will not bear the patient's weight during surgery for dispersive electrode placement.
  2. Before placing the electrode, thoroughly clean and dry the site. It is safer to assume that you should shave the site than not shave it.
  3. Place the electrode in a location where it is not likely to come into contact with fluids.
  4. Before placing the electrode, check it for defects such as dried-out or insufficient amounts of conductive gel or adhesive.
  5. After applying the electrode, the operator should run a hand over the dispersive pad to confirm uniform placement. While smoothing, the operator's hand should move only from the outside to the inside of the pad so that no gel is forced out from underneath the pad.


Electrodes, Electrosurgical, Return [11-500]

Cause of Device-Related Incident

User errors: Failure to read label; Improper connection; Incorrect clinical use

Mechanism of Injury or Death


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