Electrosurgical Safety

Purpose

This document provides guidance to the perioperative team for the safe use of electrosurgical units (ESUs), electrocautery devices, and argon-enhanced coagulators.

An ESU includes a generator, an electrical cord and plug, and accessories. The accessories include the active electrode with tip(s), dispersive electrode, foot switch with cord (if applicable), adapters, and connectors.¹  The electrosurgical generator performs three functions. First, it converts the low-frequency alternating current received from the electrical circuit in the wall, which is at 60 Hertz, to approximately 500,000 Hertz (ie, radio frequency). The second function enables adjustment of the power setting. The third function controls the proportion of time over which a waveform is produced (ie, the duty cycle). These waveforms are known as cut, which is heating of the cellular water that leads to the cell bursting; coagulation, which causes a temperature rise in the cells leading to cellular dehydration and shrinkage; and blend, which is a modulated form of cut that results in an output with a higher voltage than cut at the same power setting.^1,2  The radio-frequency energy produced is transferred to the patient by various modalities, including monopolar, bipolar, advanced bipolar, bipolar ligating-cutting, and tripolar (ie, plasma knife) devices and argon-enhanced coagulation (AEC). These modalities are used to cut, coagulate, dissect, ablate, and shrink tissue.

The monopolar modality transfers the energy to the patient through an active electrode that usually has only a single tip. The intended current flow is from the generator through the active electrode cord to the active electrode tip, through the patient to the dispersive electrode, and then through the dispersive electrode cord back to the generator. The monopolar modality requires both an active and a dispersive electrode.^1,2 

The bipolar modality has a two-tip electrode that transfers the energy to the patient. The current pathway for this device goes from the generator through the cord to one tip of the forceps, through the tissue between the tips to the other tip, and then back to the generator. The current flows only through the tissue that is between the forceps tips. The only accessory required is the active electrode and the associated cord. Bipolar electrosurgery can be used as an alternative to monopolar electrosurgery when devices or implants would be in the current pathway between the monopolar active and dispersive electrodes.^1,2 

The advanced bipolar modality uses bipolar electrosurgery with a computer-controlled tissue feedback response system to sense tissue impedance. This allows for the continuous adjustment of the voltage and current generated by the unit. Continuous adjustment permits use of the lowest possible power setting that will achieve the desired tissue effect. The advanced bipolar modality does not require a dispersive electrode and requires less voltage. The energy flows only through the tissue that is between the forceps tips.^1,2  Some of the devices also have a cutting mechanism, allowing for cutting and coagulating of tissue between the forceps tips.³ 

The tripolar device has a tripolar tip consisting of a central pole and an outer pole on either side. The current flows from the center pole to the outer poles, creating a corona of energy that makes a blade-like incision. The primary current alternates with a second current that passes from one of the outer poles to the other, resulting in simultaneous cutting and coagulation.^1,3 

Argon-enhanced coagulation, also known as argon beam coagulation, is radio-frequency coagulation from an electrosurgical generator that delivers monopolar current through a flow of ionized argon gas. The risks related to this modality are similar to those for monopolar electrosurgery with the addition of the risk for gas emboli.⁴ 

The electrical current used by the ESU consistently flows on a pathway from the wall, through the device, to the accessories, through tissue, through the accessories, back to the device, and to the wall. Most adverse events associated with electrosurgery are related to the current trying to flow back to ground.^1,3  The majority of adverse events that result from the use of electrosurgery or electrocautery are burns. Burns may be caused by direct application that results in thermal spread beyond the intended target tissue, insulation failure, antenna coupling, direct coupling, capacitive coupling, residual heat, or inadvertent activation and may be described as alternate site injuries.^1,5-12  Adverse events have been reported to occur during various procedures and with all surgical approaches.^13-29  Burns may occur anywhere the tip of the active electrode is placed, under the dispersive electrode, inside the body during laparoscopic procedures, or at trocar sites.^1,5-12  Other types of adverse events include electrical shocks, electromagnetic interference (EMI), and fires.¹ 

Electrical shocks do not often involve the patient because they occur off the sterile field; if strong enough, however, a shock can cause injury to a person in contact with the device or the electrical cord. A shock may result in a burn, another type of injury, or no injury.¹ 

Electromagnetic interference may cause oversensing, cause a function reset, or stop the functioning of an implanted electromechanical device (IED) and could also damage a lead or the pulse generator itself.^30,31  In a retro spective study of 1,398 patients undergoing cardiac pacemaker generator replacement or upgrade surgery, Lin et al³²  found that four patients (0.3%) developed output failure or an inappropriate low pacing rate during use of electrosurgery. The researchers also reviewed the Manufacturer and User Facility Device Experience (MAUDE) database for events or patient injuries related to pacemaker malfunction and found 37 cases of pacemaker malfunction related to the use of electrosurgery. The adverse events included the pacemaker resorting to the backup pacing mode (32.4%), loss of output or capture function (59.5%), inappropriate low pacing rate (5.4%), and ventricular fibrillation (2.7%). The dates of review of the MAUDE database were not included in the report. Other authors have also reported on situations in which EMI during the use of electrosurgery led to complications, including ventricular tachycardia,³³  ventricular fibrillation,^28,34,35  and inappropriate defibrillation that occurred when an implantable cardioverter defibrillator sensed EMI from an electrosurgical active electrode as ventricular fibrillation.^36-38 

The active electrode is the most common ignition source in OR fires.¹  A fire may or may not result in patient burns.

Electrosurgical accessories, including the active and dispersive electrodes, have been implicated as the cause of injuries.^{3,15,20,39,40}  Overbey et al¹⁶  reviewed reports to the MAUDE database from January 1, 1994, to December 31, 2013, and found 3,553 injuries and 178 deaths related to energy-generating devices. The energy-generating devices were classified as monopolar instruments (n = 1,670; 44.8%), radio-frequency/microwave ablation devices (n = 728, 19.5%), advanced bipolar devices (n = 538, 14.4%), ultrasonic devices (n = 350, 9.3%), bipolar instruments (n = 270, 7.2%), plasma beam monopolar devices (n = 163, 4.4%), and other (n = 12, 0.3%). The incidents involved thermal burns (n = 2,353, 63.1%), hemorrhage (n = 642, 17.2%), mechanical failure (n = 442, 11.8%), and fire (n = 294, 7.9%). The authors concluded that the risk for injury from surgical energy-generating devices is significant and warrants further research and education.

A limitation of the evidence is that randomized controlled trials related to electrosurgical injury prevention may expose patients to harm and, as such, would not be ethical. A limited number of other types of studies have contributed valuable knowledge to the field. However, interpretation of these studies is limited by the nature of this type of research, which can only show association among study variables and cannot determine causation. Because of a lack of research on interventions to prevent injury from the use of ESUs, much of the available evidence is based on generally accepted practices and expert opinion.

The following subjects are outside the scope of this guideline:

• general fire safety (See the AORN Guideline for a Safe Environment of Care)⁴¹ ;

• surgical smoke safety (See the AORN Guideline for Surgical Smoke Safety)⁴² ;

• selection of endoscopic distention fluid (See the AORN Guideline for Minimally Invasive Surgery)⁴³ ;

• procedure-related decisions (eg, the amount of time the tissue is exposed to the active electrode);

• therapeutic diathermy;

• use of electrical dental equipment (eg, battery-operated curing lights, ultrasonic baths, ultrasonic scalers, electric pulp testers, electric toothbrushes); and

• selection of electrosurgical devices.

Evidence Review

A medical librarian with a perioperative background conducted a systematic search of the databases Ovid MEDLINE®, Ovid Embase®, EBSCO CINAHL®, and the Cochrane Database of Systematic Reviews. The search was limited to literature published in English from January 2009 through June 2019. At the time of the initial search, weekly alerts were created on the topics included in that search. Results from these alerts were provided to the lead author until August 2019. The lead author requested additional articles that either did not fit the original search criteria or were discovered during the evidence appraisal process. The lead author and the medical librarian also identified relevant guidelines from government agencies, professional organizations, and standards-setting bodies.

Search terms included ablation techniques, access control, accident prevention, accidental activation, airway fires, argon beam coagulation, argon plasma coagulation, artificial pacemaker, bipolar, burns, burns (electric), capacitive coupling, cauterization, cautery, device failure, device safety, diathermy, durable medical equipment, electric power supplies, electric wiring, electrical equipment and supplies, electrical power supplies, electrocautery, electrocoagulation, electrodes (implanted), electrosurgery, endocavitary fulguration, endometrial ablation techniques, energy device, equipment and supplies (hospital), equipment contamination, equipment defects, equipment failure, equipment failure analysis, equipment hazard, equipment malfunction, equipment safety, eye protective devices, fire extinguisher, fire management, fire safety, fires, grounding, high-intensity focused ultrasound ablation, hospital incident reporting, hospital risk reporting, implantable electronic devices, implanted electrode, ligation, medical device safety, misdirection, nurses, occupational exposure, occupational hazards, occupational injuries, occupational safety, occupational-related injuries, pacemaker (artificial), patient safety, perioperative nursing, personal protective equipment, postoperative complications, power sources, power sources and settings, power supplies, protective clothing, protective devices, radiofrequency ablation, risk management, safety, shared airway procedures, shared airway safety, surgical diathermy, surgical equipment, surgical equipment and supplies, surgical fires, thermocoagulation, ultrasonic surgery, ultrasonic surgical procedures, and ultrasonic therapy.

Included were research and non-research literature in English, complete publications, and publications with dates within the time restriction when available. Historical studies also were included. Excluded were non-peer-reviewed publications and older evidence within the time restriction when more recent evidence was available. Editorials, news items, conference proceedings, and poster abstracts were excluded. Low-quality evidence was excluded when higher-quality evidence was available, and literature outside the time restriction was excluded when literature within the time restriction was available. After evaluating the literature, the project team decided to exclude ultrasonic devices because they are not electrosurgical devices (Figure 1).

Figure 1

Flow Diagram of Literature Search Results

Adapted from: Moher D, Liberati A, Tetzlaff J, Atman DG; The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(6):e1000097.

Articles identified in the search were provided to the project team for evaluation. The team consisted of the lead author and one evidence appraiser. The lead author and the evidence appraiser reviewed and critically appraised each article using the AORN Research or Non-Research Evidence Appraisal Tools as appropriate. A second appraiser was consulted in the event of a disagreement between the lead author and the primary evidence appraiser. The literature was independently evaluated and appraised according to the strength and quality of the evidence. Each article was then assigned an appraisal score. The appraisal score is noted in brackets after each reference, as applicable.

Each recommendation rating is based on a synthesis of the collective evidence, a benefit-harm assessment, and consideration of resource use. The strength of the recommendation was determined using the AORN Evidence Rating Model and the quality and consistency of the evidence supporting a recommendation. The recommendation strength rating is noted in brackets after each recommendation.

Note: The evidence summary table is available at http://www.aorn.org/evidencetables/.

Editor’s note: MEDLINE is a registered trademark of the US National Library of Medicine’s Medical Literature Analysis and Retrieval System, Bethesda, MD. Embase is a registered trademark of Elsevier B.V., Amsterdam, The Netherlands. CINAHL, Cumulative Index to Nursing and Allied Health Literature, is a registered trademark of EBSCO Industries, Birmingham, AL.