SELF/Perioperative Nursing/Electro-Surgical Units

   ⚠️In Development: Module actively being built.

▼This page is a part of the Perioperative Nursing Curriculum by ECSACONM and SELFPlease see the Intuitive Foundation Terms of Use and do not edit without permission.

Electrosurgical units (ESUs) are used in a wide range of surgical procedures to cut tissue, control bleeding, and achieve haemostasis efficiently using high-frequency electrical energy. Safe use of electrosurgery requires more than simply operating the equipment. It requires an understanding of how electrosurgical energy interacts with tissue, how different electrosurgical systems function, how equipment should be prepared and tested before use, and how to recognize and prevent hazards that may place patients or healthcare workers at risk.

By the end of this module, learners will be able to safely set up, operate, and troubleshoot electrosurgical units in accordance with accepted clinical protocols. They will understand the principles of monopolar and bipolar electrosurgery, identify and assemble key ESU components, perform pre-use safety checks, select appropriate electrosurgical modes and settings, correctly apply the patient return electrode, safely manage active electrodes and accessories, and recognize and manage common electrosurgical hazards.

Particular emphasis is placed on preventing patient burns, operating room fires, electrical injury, equipment malfunction, and unintended tissue damage through systematic preparation, safe operating practices, effective communication, and appropriate post-procedure equipment management. Throughout the module, the learner will apply these principles within the realities of resource-constrained operating theatres where equipment, maintenance support, and staffing may be limited.

This module is designed for the trainee perioperative nurse who is transitioning from general nursing practice into the operating department. The learner has completed general nursing education and possesses foundational knowledge of perioperative nursing, including aseptic technique, infection prevention and control, sterile field maintenance, patient positioning, surgical safety principles, safe handling of surgical instruments, and effective communication within the operating room.

The learner has a basic understanding of electrical safety principles, operating room fire prevention, and the use of surgical instruments and energy-based devices. This module builds upon that foundation by developing competence in safe electrosurgical unit setup, pre-use testing, patient return electrode placement, selection of appropriate electrosurgical modes and power settings, prevention of electrosurgical injuries, recognition of equipment malfunction, troubleshooting common problems, and effective communication with the surgical team during electrosurgical use.

Training is intended for perioperative nurses working in district hospitals and similar low-resource operating theatres where equipment availability, maintenance support, staffing, and electrical infrastructure may be limited. Throughout the module, emphasis is placed on practical decision-making and safe adaptation to resource constraints while maintaining patient and staff safety.

By the end of this module, you should be able to:

1. Outline the basic principles of electrosurgery and distinguish between monopolar and bipolar electrosurgical systems.
2. Identify the components of an electrosurgical unit and describe their functions.
3. Describe safe preparation and setup of ESU equipment and supplies prior to patient draping.
4. Select appropriate electrosurgical modes and baseline power settings for safe clinical use.
5. Explain safe  return electrode placement while recognizing factors that increase the risk of burns and alternate-site injury.
6. Identify electrosurgical hazards, equipment malfunctions, and unsafe practices, and apply appropriate troubleshooting strategies.
7. Explain principles of electrical safety and operating room fire prevention during electrosurgical use.
8. Describe post-use management of ESU equipment, including cleaning, inspection, storage, documentation, and electrosurgical equipment reporting following use.
9. Describe safe adaptation of electrosurgical practice to resource-constrained operating environments while maintaining patient and staff safety.

Study each topic in the order presented. Each lesson builds on concepts introduced earlier, so understanding the previous topic will help you understand the next one. Complete the formative assessment at the end of each topic before moving on. If you answer a question incorrectly, review the relevant section before continuing.

After successfully completing all knowledge topics and assessments, proceed to the psychomotor skills practice, where you will apply these concepts while practicing safe setup of an electrosurgical unit.

Electrosurgery is one of the most commonly used technologies in modern surgery. It allows the surgical team to cut tissue, control bleeding, and achieve haemostasis using high-frequency electrical energy. Understanding how electrosurgery works is essential before learning how to prepare or operate an electrosurgical unit (ESU). A clear understanding of these principles helps you recognize normal equipment function, make safe decisions during surgery, and reduce the risk of patient injury.

This topic introduces the basic principles of electrosurgery, explains how electrical energy interacts with tissue, distinguishes between monopolar and bipolar electrosurgery, and describes the clinical situations in which each system is used. These concepts provide the foundation for the equipment setup and safety practices discussed in the following topics.

Electrosurgical units (ESUs) operate by transmitting high-frequency electrical current through tissue to produce controlled thermal effects. Unlike standard electrical current used to power equipment, the high-frequency current generated by an ESU does not stimulate muscles or nerves. Instead, the electrical energy encounters resistance within the tissue, generating heat. The amount and concentration of this heat determine the tissue effect produced.

Electrosurgery allows surgeons to perform several important functions during an operation:

• Cut tissue.
• Coagulate blood vessels to control bleeding.
• Desiccate tissue by removing water from cells.
• Fulgurate tissue by producing superficial coagulation through electrical arcing.

These tissue effects improve surgical visibility, reduce blood loss, shorten operative time, and often reduce the need for mechanical methods of haemostasis such as sutures or ligatures. Although electrosurgery is widely used, it must always be applied carefully because inappropriate energy delivery can damage healthy tissue and lead to complications.

When the active electrode is activated, electrical energy passes into the patient's tissue. The tissue resists the flow of current, converting electrical energy into heat. Different tissue effects occur depending on several factors, including the selected waveform, power setting, duration of activation, electrode size, and the area of contact with the tissue.

Higher concentrations of energy produce rapid heating that vaporizes intracellular water, allowing tissue to be divided. Lower concentrations generate slower heating, causing proteins within blood vessels to coagulate and achieve haemostasis. Throughout this module you will learn how equipment settings influence these tissue effects and why careful selection of the appropriate mode is essential for patient safety.

There are two primary types of electrosurgery: monopolar and bipolar.

In monopolar electrosurgery, current flows from the active electrode through the patient's tissue before returning to the generator via a patient return electrode (grounding pad). Because electrical current travels through the patient's body, correct placement of the return electrode is essential to disperse the returning energy safely and minimize the risk of burns.

In bipolar electrosurgery, the electrical current passes only between the two tips of a forceps-like instrument. The current remains confined to the tissue held between the instrument tips and therefore does not require a patient return electrode.

These differences influence both safety considerations and clinical application.

Monopolar electrosurgery is the most commonly used electrosurgical system. It provides rapid tissue cutting and effective coagulation over relatively large operative fields. Because the electrical circuit passes through the patient, careful attention must be paid to return electrode placement, equipment integrity, and prevention of unintended current pathways.

Monopolar electrosurgery is commonly used during general surgery, obstetric and gynaecological procedures, orthopaedic surgery, and many other open or minimally invasive operations requiring efficient tissue dissection and haemostasis.

Bipolar electrosurgery confines electrical current to the tissue grasped between the instrument tips. This limits the amount of surrounding tissue exposed to electrical energy and reduces the risk of alternate current pathways.

For this reason, bipolar electrosurgery is frequently preferred when operating near delicate structures, during microsurgery, neurosurgery, vascular surgery, or whenever precise coagulation with minimal collateral tissue damage is required. Bipolar electrosurgery is also often preferred in patients with implanted electronic devices because less electrical current passes through the body.

The choice between monopolar and bipolar electrosurgery depends on the planned procedure, the surgical objective, patient factors, and surgeon preference.

Monopolar electrosurgery is generally selected when broad tissue cutting or coagulation is required over a larger operative field. Bipolar electrosurgery is commonly selected when precise coagulation is required or when limiting electrical current through the patient's body is desirable.

Regardless of the system used, safe electrosurgery depends on selecting the correct equipment, preparing it appropriately, understanding how energy flows through tissue, and applying established safety principles throughout the procedure. These concepts form the basis for the equipment preparation discussed in the next topic.

• Electrosurgery uses high-frequency electrical current to produce controlled tissue heating.
• Electrosurgery can cut, coagulate, desiccate, and fulgurate tissue.
• Tissue effects depend on the concentration of electrical energy delivered.
• Monopolar electrosurgery requires a patient return electrode to complete the electrical circuit.
• Bipolar electrosurgery confines electrical current between the instrument tips and does not require a patient return electrode.
• The choice of monopolar or bipolar electrosurgery depends on the surgical procedure, tissue characteristics, patient factors, and desired tissue effect.
• Understanding how electrosurgery works provides the foundation for safe equipment setup and operation.

Self-Assessment

Please complete the following: ESU Fundamentals Quiz

Understanding the principles of electrosurgery is only the first step toward safe electrosurgical practice. Before electrical energy is ever applied to a patient, the electrosurgical unit (ESU) and its accessories must be correctly assembled, inspected, tested, and organized. Proper preparation ensures that the equipment functions as intended and reduces the risk of patient injury, equipment malfunction, delays during surgery, and contamination of the sterile field.

In the previous topic, you learned how monopolar and bipolar electrosurgery differ and how electrical energy produces tissue effects. This topic builds on those concepts by introducing the components of the electrosurgical unit, explaining how each component contributes to safe operation, and describing how the equipment is prepared and organized before surgery begins.

An electrosurgical unit consists of several components that work together to safely deliver electrical energy during surgery. Although the exact design varies between manufacturers, the basic components remain similar.

The electrosurgical unit consists of the generator, active handpiece (electrosurgical pencil or wand), connection cables, patient return electrode (when monopolar electrosurgery is used), footswitch where applicable, and various accessories.

Each component performs a specific function:

• Generator: Produces the high-frequency electrical current and allows selection of the desired operating mode and power settings.
• Active electrode (handpiece): Delivers electrical energy from the generator to the target tissue.
• Patient return electrode: Safely returns electrical current to the generator during monopolar electrosurgery. (Its application is covered in detail in Topic 3.)
• Connection cables: Carry electrical current between the generator and its accessories while maintaining circuit integrity.
• Footswitch: Allows hands-free activation when used instead of hand controls.
• Sterile holster: Holds the active electrode safely when it is not being used, reducing the risk of accidental activation and contamination.

Understanding the purpose of each component helps you recognize abnormal equipment function and perform systematic equipment checks before every procedure.

Every ESU component should be inspected before assembly. Equipment should never be assumed to be safe simply because it functioned during a previous procedure. Routine inspection helps identify defects before they place patients or staff at risk.

The generator casing should be intact, with controls responsive and indicator lights functioning. Power cords should be intact, and plug prongs free of bending or damage. Tubing and cables should be checked for insulation defects, kinks, or exposed wire, as these can result in arcing, equipment malfunction, or patient burns. The adhesive surface of the patient return electrode should be smooth and flexible, without curling, cracking, contamination, or dryness at the edges.

Reusable accessories should also be inspected for loose connectors, damaged insulation, bent contacts, or excessive wear. Equipment showing signs of damage should be removed from service immediately and reported according to institutional policy.

In many low-resource settings, equipment may remain in service for prolonged periods because replacement parts are not readily available. Under these circumstances, careful inspection before every case becomes even more important for maintaining patient safety.

After the equipment has been inspected, the generator should be connected to a reliable electrical outlet and powered on. The startup sequence should complete normally without displaying fault indicators or error messages.

Once powered, the generator should display baseline settings within safe ranges—typically 30–40 watts for cutting and 20–25 watts for coagulation. These values represent common starting points, although final settings are determined according to the planned procedure, patient factors, surgeon preference, manufacturer recommendations, and institutional protocols.

Before the patient is draped, the system should be tested by placing the handpiece tip on the designated test tool, confirming that generator output matches the selected mode, with a continuous tone for cutting and an intermittent tone for coagulation. If no test tool is available, the handpiece may be briefly activated at low wattage away from the patient to verify current delivery, provided this is consistent with manufacturer instructions and local policy. Any unexpected findings should be corrected before surgery proceeds.

The handpiece activation buttons should depress smoothly without sticking, and footswitches, when connected, should activate consistently without delay.

Testing verifies that the complete electrosurgical circuit is functioning correctly before patient use and provides confidence that the selected mode corresponds with the expected generator output.

The ESU generator is positioned on a stable, flat surface near a grounded electrical outlet and away from fluid sources. The power cord should be traced to confirm a direct wall connection rather than an extension cable whenever possible.

The handpiece cable is inserted into the active electrode port with the connection fully seated. Excess cable should be coiled loosely rather than tightly wrapped to prevent strain on the connectors. The sterile handpiece remains protected until use and is placed in a sterile holster secured to the surgical drape.

On the sterile field, ESU supplies should be arranged for sequential assembly. The patient return electrode and alcohol wipes are positioned first, followed by the sterile holster, sterile handpiece, connection cables, and test tool if available. Organizing equipment in a logical sequence allows the scrub nurse to prepare the system efficiently while minimizing unnecessary reaching and movement across the sterile field.

Glove selection depends on the activity being performed. Clean gloves are appropriate for non-sterile equipment preparation, whereas sterile gloves are worn by the scrub nurse when handling sterile equipment within the sterile field.

The sterile holster should be fixed securely to the drape on the surgeon's dominant side, allowing the active electrode to be returned safely between activations. Cables should be routed along the edge of the drape and secured with clips when available to prevent tension, accidental disconnection, trip hazards, or contamination.

Transitions between sterile and non-sterile areas should be carefully inspected to ensure cables do not compromise the sterile field.

Before the patient enters the operating room or before electrosurgical equipment is connected to the patient, baseline equipment checks should be completed and documented.

The make and serial number of the generator, the condition of cables, the presence of functional audio alarms, successful completion of equipment testing, and readiness of the patient return electrode represent the minimum documentation required before patient use. Additional documentation requirements may vary according to institutional policy.

These records establish accountability and provide an important reference should questions later arise regarding equipment performance, troubleshooting, or patient outcomes.

Where staffing is limited, responsibilities for equipment inspection and documentation should be clearly assigned before the procedure begins to ensure these essential safety checks are not overlooked.

• Every ESU component should be inspected before every procedure.
• Damaged equipment should never be used and should be removed from service immediately.
• Functional testing confirms that the generator, alarms, controls, and accessories are operating correctly before patient use.
• Equipment should be organized logically to promote efficient workflow while maintaining the sterile field.
• Proper cable management reduces contamination, equipment damage, and trip hazards.
• Baseline equipment inspection and testing should be documented before patient use.
• Careful preparation is particularly important in low-resource settings where equipment replacement may be limited.

Self-Assessment

Please complete the following: ESU Setup Quiz

In the previous topic, you learned that the patient return electrode is one of the essential components of the monopolar electrosurgical system and that it should be inspected before use. This topic builds on that knowledge by explaining how to assess the patient, select an appropriate application site, apply the return electrode correctly, and monitor it throughout the procedure.

Correct return electrode placement is one of the most important safety measures in monopolar electrosurgery. A poorly applied or poorly positioned return electrode can concentrate electrical current instead of dispersing it safely, increasing the risk of patient burns, alternate-site injury, equipment alarms, and interruption of the surgical procedure.

As introduced in Topic 1, the patient return electrode completes the electrical circuit during monopolar electrosurgery by providing a safe pathway for electrical current to return to the generator. Unlike the active electrode, which concentrates electrical energy into a very small area to produce cutting or coagulation, the return electrode disperses the returning current over a much larger surface area. This broad distribution minimizes heat generation at the pad site and reduces the risk of thermal injury.

The patient return electrode serves as the current's exit point in monopolar electrosurgery, completing the circuit between the generator and the active electrode. Its role is to disperse energy over a broad surface area, reducing the risk of concentrated heating and burns.

Because bipolar electrosurgery confines current between the two tips of the instrument, a patient return electrode is not required for bipolar electrosurgery.

Appropriate placement begins with careful assessment of the patient.

Sites with good vascular supply and muscle mass, such as the thigh, buttock, upper arm, or back, provide reliable contact and allow electrical current to disperse safely. Appropriate placement sites are those that provide good tissue conductivity and maximal surface contact.

The pad should be applied over well-vascularized, well-perfused muscle areas. The skin at the chosen site should be clean, dry, and intact, with no evidence of infection, wounds, burns, scar tissue, oedema, or compromised circulation. Flat, broad surfaces are preferred because they maximize contact between the adhesive surface and the patient's skin.

The return electrode should be positioned as close as reasonably practicable to the surgical site while avoiding bony prominences, joints, metal implants, ECG electrodes, prostheses, excessive hair, or other conductive devices that could alter the intended current pathway.

Selecting an appropriate site before opening the return electrode package also reduces unnecessary handling and minimizes delays during patient preparation.

Proper adhesion depends on both the pad and the skin surface. Electrodes with smooth, flexible adhesive maintain uniform contact, whereas dried or peeling edges create gaps where current density rises. Similarly, skin that is moist, oily, or covered with hair can reduce contact and increase resistance, predisposing the patient to burns. A clean, dry surface ensures that energy is dispersed evenly across the electrode.

Because electrical current spreads across the entire contact surface of the return electrode, increasing the contact area lowers current density at the skin. Conversely, if only part of the electrode remains in contact with the skin, the same electrical current is concentrated over a smaller area, increasing heat generation and the risk of burns.

Before application, inspect the return electrode package to confirm that it is intact and has not expired. Inspect the electrode itself for defects such as curled edges, cracks, contamination, or loss of adhesive integrity.

Clean and dry the selected skin site thoroughly. Remove excessive hair only if necessary to obtain complete pad contact and according to local policy. The electrode should then be applied smoothly over the selected muscle mass with its entire adhesive surface in full contact with the skin. Avoid wrinkles, folds, air pockets, or lifting edges, as these reduce the effective contact area and increase the risk of thermal injury.

After application, inspect the entire perimeter of the electrode to confirm complete adhesion.

Correct placement alone does not guarantee continued safety throughout the operation.

During the procedure, partial detachment, accumulation of irrigation fluid, patient repositioning, or prolonged pressure may alter current flow and reduce effective contact between the electrode and the skin.

Monitoring the electrode site throughout the case is therefore essential. Alarms indicating poor contact are triggered when the generator detects increased resistance at the return electrode site. These alarms are safety features and should never be ignored.

If an alarm occurs, electrosurgical activation should stop immediately until the cause has been identified and corrected. The return electrode should be inspected for lifting edges, contamination, fluid accumulation, displacement, or cable disconnection before surgery continues.

Periodic reassessment throughout lengthy procedures helps maintain safe electrosurgical function and reduces the risk of patient injury.

Certain patients require additional assessment before monopolar electrosurgery is used.

Patients with implanted cardiac devices, neurostimulators, infusion pumps, orthopaedic implants, or other conductive devices present special challenges because these devices may alter current pathways or be affected by electromagnetic interference.

Conductive implants or sensitive electronics can redirect or interfere with electrical current, increasing the risk of burns or device malfunction. In these situations, bipolar electrosurgery, which confines current to the tissue between the instrument tips, often provides a safer alternative when clinically appropriate.

Although the surgeon ultimately determines the operative technique, the perioperative nurse plays an important role in identifying these risk factors during patient assessment and communicating them to the surgical team before electrosurgery is activated.

In low-resource environments where specialized equipment or biomedical support may be unavailable, thorough patient assessment and careful return electrode placement become even more important in reducing preventable complications.

• The patient return electrode is required only for monopolar electrosurgery.
• The return electrode safely disperses electrical current returning to the generator.
• Select a clean, dry, well-perfused muscle mass with a broad, flat surface.
• Avoid scar tissue, bony prominences, excessive hair, compromised skin, metal implants, and monitoring electrodes.
• Apply the electrode with complete skin contact and no wrinkles, folds, or lifting edges.
• Inspect the return electrode throughout the procedure and respond immediately to poor-contact alarms.
• Patients with implanted electronic devices require additional assessment and communication before electrosurgery begins.

Correct placement of the patient return electrode establishes a safe electrical circuit, but safe electrosurgery also depends on selecting the appropriate operating mode and power settings. In the next topic, you will learn how ESU modes and settings influence tissue effects and how they are managed safely during surgery.

Self-Assessment

Please complete the following: Return Electrode Quiz

The previous topics explained how electrosurgical energy travels through the patient and how safe equipment preparation establishes a functioning electrosurgical circuit. Once the ESU has been inspected, assembled, tested, and connected safely, the next responsibility is selecting the appropriate operating mode and using the equipment correctly throughout the procedure.

This topic explains the differences between cutting and coagulation modes, describes safe baseline power settings and adjustment principles, and outlines safe activation techniques, communication practices, and handling of the active electrode during surgery.

Electrosurgical generators provide several operating modes that produce different tissue effects. The two principal modes used in routine surgery are cutting and coagulation, with many generators also offering one or more blend modes that combine characteristics of both.

The selected waveform influences how electrical energy interacts with tissue. As introduced in Topic 1, different waveforms produce different amounts and rates of tissue heating, resulting in different surgical effects.

Cutting mode delivers a continuous waveform that rapidly heats tissue, causing intracellular water to vaporize and allowing tissue to be divided with minimal resistance.

When activated, cutting mode is typically identified by a continuous audio tone generated by the ESU.

Cutting mode is commonly selected when the surgeon wishes to divide tissue efficiently while maintaining good visibility within the operative field.

Coagulation mode delivers pulsed electrical energy that heats tissue more slowly, promoting protein denaturation and haemostasis rather than tissue division.

The generator usually identifies coagulation mode with an intermittent or pulsed audio tone, allowing the surgical team to recognize the selected mode without continuously viewing the generator display.

Coagulation mode is primarily used to control bleeding from small blood vessels or to achieve haemostasis before further dissection.

Many modern generators also provide blend modes that combine characteristics of cutting and coagulation waveforms. The exact performance of blend modes varies between manufacturers.

Because blend settings differ among ESU models, users should always follow the manufacturer's recommendations and local protocols when selecting these modes.

When the ESU generator is prepared, default cut and coagulation settings should be reviewed at the surgeon's request. Cutting mode produces a continuous tone, while coagulation is identified by a pulsed tone. Standard initial ranges are 30–40 watts for cutting and 20–25 watts for coagulation. These values should be confirmed before patient use and documented according to institutional policy.

These baseline settings provide a safe starting point but may require modification depending on:

• the planned procedure,
• tissue characteristics,
• patient factors,
• surgeon preference,
• manufacturer recommendations.

Higher power settings do not necessarily improve surgical performance. Excessive power increases thermal spread, tissue injury, surgical smoke generation, and the risk of unintended burns. The lowest effective power setting should always be used to achieve the desired tissue effect.

Adjustments to power settings should be made only when clinically indicated and at the surgeon's request.

Power settings should be adjusted in increments no greater than 5 watts. Every adjustment should be confirmed verbally with the surgical team and visually by checking the generator display before electrosurgery resumes.

Surgeons may request changes based on tissue density or surgical progress, but unnecessarily large increases in wattage increase the risk of deep tissue injury without improving safety or efficiency.

Whenever generator settings are changed, the circulating nurse should document significant changes according to local policy.

Safe electrosurgery depends not only on generator settings but also on proper activation technique.

The active electrode should be activated only when its tip is in contact with the intended target tissue. Activation in air or near drapes, sponges, or other combustible materials increases the risk of unintended burns and operating room fires.

Activation should be limited to short, controlled bursts using the lowest effective power setting. Prolonged activation increases thermal spread, surgical smoke production, and collateral tissue injury.

When not actively being used, the handpiece should immediately be returned to its sterile holster. It should never be left resting on the patient, surgical drapes, or operating table.

Safe electrosurgery requires continuous communication between the surgeon, scrub nurse, circulating nurse, and anaesthesia provider.

Before activation, the selected operating mode and power setting should be confirmed whenever changes have been made. If both a hand-activated pencil and footswitch are connected, the surgeon should clearly indicate which activation method will be used. Unused activation devices should be disconnected whenever possible to reduce the risk of accidental activation.

When alternating between monopolar and bipolar electrosurgery during the same procedure, the generator should be placed in standby mode before reconnecting accessories.

At the completion of the procedure, all generator settings should be returned to the lowest setting or standby mode before the generator is switched off. This helps prevent unintended activation and ensures the generator is left in a safe condition for subsequent use.

Clear communication reduces the likelihood of incorrect settings, accidental activation, and equipment confusion during surgery.

Throughout electrosurgical use, the perioperative nurse should continuously monitor:

• generator audio tones,
• expected tissue effect,
• generator alarms,
• cable integrity,
• active electrode position,
• patient return electrode status.

Unexpected tissue effects, excessive sparking, absent generator tones, or repeated alarms should never be ignored. These findings may indicate incorrect settings or equipment malfunction and require immediate assessment before electrosurgery continues.

The perioperative nurse also plays an important role in anticipating hazards by ensuring cables remain organized, the active electrode remains secured between activations, and changes requested by the surgeon are implemented safely.

• Cutting mode uses a continuous waveform and is typically identified by a continuous audio tone.
• Coagulation mode uses a pulsed waveform and is identified by an intermittent audio tone.
• Blend modes combine characteristics of cutting and coagulation but vary between generators.
• Use the lowest effective power setting required for the intended tissue effect.
• Adjust generator settings in small increments and confirm all changes verbally and visually.
• Activate the handpiece only when it is in contact with the target tissue.
• Return the active electrode to its sterile holster immediately after use.
• Continuous communication and monitoring are essential throughout electrosurgical use.

Safe operation of the electrosurgical unit depends on selecting appropriate settings and using the active electrode correctly. Even when these principles are followed, equipment failures, alarms, and unexpected tissue effects may still occur. In the next topic, you will learn how to recognize common ESU malfunctions, troubleshoot problems systematically, and respond safely to electrical hazards before patient injury occurs.

Self-Assessment

Please complete the following: ESU Use Quiz

The previous topic explained how electrosurgical modes, power settings, and activation techniques influence tissue effects and support safe electrosurgical practice. Even when the electrosurgical unit has been prepared correctly, equipment malfunction, damaged accessories, incorrect settings, or unexpected changes during surgery may compromise patient safety. Prompt recognition of these problems and a systematic approach to troubleshooting help prevent patient injury and minimize interruptions during surgery.

This topic explains the common hazards, malfunctions, and safety risks associated with electrosurgical use. It also describes the principles of electrical safety and presents a structured approach to troubleshooting common ESU problems before they result in patient harm.

Safety checks precede every activation of the electrosurgical unit. The generator should power on without error codes, and audible alarms should sound when tested. The active electrode should demonstrate the expected response on the designated test tool or during the approved functional test described in Topic 2. The patient return electrode should remain securely attached, with all cables free from damage and away from pooled fluids.

A sterile safety holster should be securely attached to the surgical drape so that the active electrode can be placed safely between activations, reducing the risk of accidental burns, unintended activation, and contamination of the sterile field.

During electrosurgical activation, both the tissue effect and the generator's audio feedback should be continuously monitored. Changes in tissue response or unexpected audio signals may provide the first indication of equipment malfunction or incorrect generator settings and should always prompt immediate assessment before electrosurgery continues.

With electrosurgical use, several hazards, malfunctions, and safety risks can compromise patient and staff safety if not promptly recognised and managed. These risks arise from the interaction of high-frequency electrical energy with patient tissues, equipment components, and the operating theatre environment.

Electrosurgical hazards include thermal injury to tissue from direct electrode contact, unintended burns at the return electrode site, and alternate-site burns caused by stray energy pathways. These may result from poor return electrode adhesion, incorrect placement, excessive power settings, prolonged activation, or insulation failure in active electrodes or laparoscopic accessories.

Exposure to surgical smoke plume may reduce visibility within the surgical field and cause respiratory irritation to members of the surgical team. Patients with implanted electronic devices such as pacemakers or implantable cardioverter-defibrillators (ICDs) are also at risk of electromagnetic interference, which may affect device function if appropriate precautions are not taken.

Many of these hazards can be prevented by consistently applying the principles discussed in the previous topics, including proper equipment inspection, correct return electrode placement, appropriate power selection, and safe activation techniques.

Common ESU malfunctions include generator failure, alarm activation, damaged or disconnected cables, faulty footswitch operation, poor or intermittent return electrode contact, and insulation failure in active electrodes or accessory instruments.

Incorrect waveform selection or inappropriate power settings may also result in ineffective tissue cutting, excessive coagulation, excessive thermal spread, or unintended tissue injury.

Signs of equipment malfunction include:

• Excessive sparking during activation.
• Absence of the expected generator tone.
• Charring or excessive thermal injury despite relatively low power settings.
• Unexpected tissue effects.
• Repeated generator alarms.
• Intermittent generator output.
• Visible damage to cables or insulation.

Early recognition of these findings allows problems to be corrected before patient injury occurs.

If unexpected tissue effects occur or the generator produces an alarm, electrosurgical activation should be stopped immediately until the cause has been identified and corrected.

A structured approach to troubleshooting helps identify faults efficiently while preventing unnecessary equipment replacement.

When troubleshooting an ESU:

1. Confirm that the activation button or foot pedal is functioning correctly.
2. Inspect the generator ports and all cable connections.
3. Verify that the patient return electrode remains fully adherent and correctly connected.
4. Inspect cables and accessories for visible damage or insulation failure.
5. Replace any suspect cables, electrodes, or accessories.
6. Cycle generator power only as a final troubleshooting step if the fault has not been identified.

Electrosurgery should not resume until normal equipment function has been restored and the cause of the malfunction has been corrected.

If the problem cannot be resolved promptly, the electrosurgical unit should be removed from service and an alternative method of haemostasis considered according to the clinical situation.

Safe use of the electrosurgical unit depends on ensuring that electrical energy follows the intended pathway from the active electrode, through the patient's tissues, and back to the generator via the patient return electrode during monopolar electrosurgery.

Electrical safety begins with inspecting the ESU, cables, electrodes, and accessories before use to confirm they are clean, intact, correctly connected, and functioning properly. Damaged insulation, loose connections, faulty equipment, or exposed conductors can result in unintended current leakage, thermal injury, or equipment failure and should be removed from service immediately.

The patient return electrode must remain securely attached to clean, dry, intact skin throughout the procedure to maintain low electrical resistance and ensure even dispersal of returning current. The active electrode should only be activated while in contact with the intended target tissue and should always be returned to its non-conductive safety holster immediately after use.

Activation should be limited to short, controlled bursts using the lowest effective power setting necessary to achieve the desired tissue effect. Cables should remain organized to prevent damage, tangling, accidental disconnection, or contamination. Metal objects, ECG electrodes, and other conductive devices should be kept outside the intended electrical pathway whenever possible to reduce the risk of alternate-site burns.

Maintaining these electrical safety practices throughout every procedure significantly reduces the likelihood of electrosurgical injury.

Persistent malfunction requires removal of the electrosurgical unit from clinical service.

Any persistent alarm, unresolved equipment fault, damaged insulation, repeated unexpected tissue effect, or suspected equipment failure should be reported immediately to the surgical team and managed according to institutional policy.

Faulty equipment should be clearly identified, labelled, and removed from clinical use until it has been inspected and repaired by appropriately qualified personnel or biomedical engineering services.

In low-resource settings where replacement equipment may not be immediately available, damaged electrosurgical equipment should never continue to be used simply because alternatives are limited. Patient safety must always take priority.

• Safety checks should be completed before every electrosurgical activation.
• Continuously monitor tissue effect, generator tones, and alarms throughout the procedure.
• Common hazards include thermal injury, alternate-site burns, smoke plume exposure, and electromagnetic interference.
• Unexpected tissue effects, excessive sparking, or repeated alarms require immediate assessment.
• Troubleshoot equipment systematically before replacing components.
• Electrical safety depends on maintaining the intended current pathway throughout the procedure.
• Remove faulty equipment from service immediately and report persistent faults according to institutional policy.

Electrical safety prevents many electrosurgical injuries, but another important hazard remains: fire. Because the electrosurgical unit is an ignition source, it can ignite flammable skin preparation solutions, drapes, sponges, or oxygen-enriched environments if appropriate precautions are not taken. In the next topic, you will learn how operating room fires occur, how to prevent them, and how the surgical team works together to minimise fire risk during electrosurgery.

Self-Assessment

Please complete the following: ESU Troubleshooting Quiz

The previous topic explained how equipment malfunction and electrical hazards can compromise patient safety during electrosurgery. Even when the electrosurgical unit is functioning correctly, another significant risk remains: operating room fire. Because the electrosurgical unit produces heat and electrical sparks, it acts as a potential ignition source whenever flammable materials and oxygen are present.

This topic explains how surgical fires occur, identifies the components of the fire triangle within the operating room, and describes practical strategies for preventing and managing fire risks before and during electrosurgical use.

Fire prevention is an essential aspect of electrosurgical safety because the electrosurgical unit provides an ignition source within the operating room. Fires can occur when electrical sparks ignite fuels in the presence of an oxygen-enriched atmosphere or other oxidizers.

Although uncommon, operating room fires may cause severe burns, airway injury, equipment damage, surgical delays, and even death. Understanding how these fires occur allows the surgical team to identify and eliminate risks before electrosurgery is activated.

Every member of the surgical team shares responsibility for recognising and reducing fire hazards throughout the procedure.

Three elements must be present for a fire to occur:

• Ignition source
• Fuel
• Oxidizer

Removal or control of any one of these three elements significantly reduces the risk of fire.

During electrosurgery, the active electrode is the primary ignition source. Electrical arcs generated during activation are capable of igniting combustible materials if appropriate precautions are not taken.

Other potential ignition sources include lasers, fibre-optic light cables, and other energy-based surgical devices.

Common fuels found in the operating room include:

• Alcohol-based skin preparation solutions.
• Surgical drapes.
• Surgical sponges and gauze.
• Endotracheal tubes.
• Disposable plastic equipment.
• Packaging materials.
• Hair and body tissues under certain conditions.

Although many of these materials are routinely present during surgery, they become hazardous when exposed to an ignition source.

Oxygen-enriched atmospheres and nitrous oxide significantly increase fire risk by supporting rapid combustion.

High oxygen concentrations beneath surgical drapes or around the patient's airway are particularly hazardous during head, neck, facial, and upper chest procedures.

Communication between the anaesthesia provider and the surgical team is essential whenever supplemental oxygen is being administered.

Most electrosurgical fires are preventable through careful planning and consistent teamwork.

Before activating the electrosurgical unit:

• Allow alcohol-based skin preparation solutions to dry completely according to the manufacturer's instructions.
• Prevent pooling of skin preparation solutions beneath the patient or drapes.
• Remove soaked materials before electrosurgery begins.
• Minimise oxygen concentration whenever clinically appropriate.
• Keep combustible materials away from the active electrode.
• Confirm that the active electrode is placed safely in its holster between activations.
• Verify that all team members are aware that electrosurgery will be used.

These simple precautions substantially reduce fire risk without interrupting normal surgical workflow.

Fire prevention depends on continuous communication between the surgeon, anaesthesia provider, scrub nurse, and circulating nurse.

Before electrosurgery is activated, the team should confirm:

• that alcohol-based skin preparation solutions have dried completely,
• whether supplemental oxygen or nitrous oxide is being administered,
• that combustible materials have been positioned safely,
• that the active electrode is functioning correctly and safely stored when not in use.

During surgery, any team member who identifies a potential fire hazard should communicate the concern immediately.

Open communication allows hazards to be corrected before electrosurgery resumes.

If smoke, unexpected flame, burning odour, or other evidence of fire is observed, electrosurgical activation should stop immediately.

The surgical team should immediately:

1. Stop electrosurgical activation.
2. Remove the ignition source whenever safe to do so.
3. Alert the entire surgical team.
4. Discontinue oxygen delivery if clinically appropriate and directed by the anaesthesia provider.
5. Remove burning materials when safe.
6. Extinguish the fire using the appropriate fire-extinguishing method according to institutional protocol.
7. Assess the patient for injury before surgery continues.

Every healthcare facility should have established operating room fire response protocols, and all perioperative personnel should be familiar with them before participating in procedures using electrosurgery.

In low-resource operating theatres, replacement equipment, specialised fire suppression systems, or biomedical engineering support may be limited.

These constraints make prevention even more important.

Routine equipment inspection, careful cable management, complete drying of skin preparation solutions, effective communication, and continuous observation become the primary defences against fire-related incidents.

When institutional resources are limited, adherence to basic safety principles becomes the most effective strategy for protecting patients and staff.

• The electrosurgical unit is an ignition source capable of causing operating room fires.
• Fire requires an ignition source, fuel, and an oxidizer.
• Alcohol-based skin preparation solutions, drapes, sponges, and oxygen-enriched atmospheres increase fire risk.
• Allow alcohol-based preparations to dry completely before activating the ESU.
• Maintain continuous communication between the surgical and anaesthesia teams regarding oxygen use and fire risk.
• Stop electrosurgical activation immediately if fire or smoke is suspected.
• Fire prevention depends primarily on preparation, vigilance, and teamwork.

Safe electrosurgical practice does not end when the surgical procedure is completed. Proper shutdown of the electrosurgical unit, equipment inspection, cleaning, documentation, storage, and reporting of faults are essential to ensure the equipment remains safe for future patients. In the final topic, you will learn the post-use responsibilities associated with electrosurgical equipment and how appropriate maintenance supports long-term patient safety.

Self-Assessment

Please complete the following: ESU Fire Prevention Quiz

The safe use of an electrosurgical unit extends beyond its use during surgery. Once electrosurgery is no longer required, the equipment must be safely deactivated, inspected, cleaned, documented, and prepared for future use. Proper post-use management helps maintain equipment performance, prevents damage, supports infection prevention, and ensures that equipment defects are identified before the next procedure.

This topic explains the post-use responsibilities of the perioperative nurse, including safe shutdown of the electrosurgical unit, handling of reusable and disposable accessories, cleaning, maintenance, documentation, and reporting of equipment faults. Together, these activities support long-term equipment reliability and patient safety.

Following completion of the surgical procedure, the electrosurgical unit should be deactivated and disconnected according to institutional policy and the manufacturer's instructions. Before switching the generator off, all generator settings should be returned to the lowest setting or standby mode to reduce the risk of unintended activation and prepare the equipment for its next use.

The active electrode should remain in its safety holster until the generator has been switched off. Once the generator has been deactivated, cables, handpieces, footswitches, and accessories should be disconnected carefully to prevent unnecessary wear or damage.

Cables should always be disconnected by gripping the connector rather than pulling on the cord. Pulling on cables may damage internal conductors, insulation, or connectors, resulting in equipment malfunction or electrical hazards during future procedures.

After disconnection, all electrosurgical accessories should be handled according to whether they are intended for single or multiple use.

Single-use items, including disposable patient return electrodes and other single-use accessories, should be discarded immediately into the appropriate waste stream according to institutional policy.

Reusable handpieces, footswitches, cables, and accessories should be handled according to the manufacturer's instructions and local reprocessing requirements. Before transfer for reprocessing, reusable instruments should undergo point-of-use cleaning in accordance with local protocols to remove visible blood and tissue debris and prevent biological material from drying on instrument surfaces.

Following point-of-use cleaning, reusable equipment should be transported safely to the designated decontamination or sterile processing area using approved handling procedures.

After each procedure, the generator should be cleaned using a lint-free cloth lightly dampened with an approved disinfectant according to the manufacturer's instructions. Care should be taken to prevent liquids from entering ventilation openings, electrical ports, or connectors.

Connection cables should be wiped clean and inspected for cracks, exposed conductors, damaged insulation, loose connectors, or excessive wear before being loosely coiled for storage. Tight wrapping or sharp bends should be avoided because they may damage cable insulation and internal wiring.

Reusable handpieces should be cleaned and sterilized according to the manufacturer's instructions and institutional reprocessing protocols.

All reusable ESU components should be inspected carefully for signs of damage, including:

• Cracked or damaged insulation.
• Exposed wires or conductors.
• Loose or damaged connectors.
• Bent or damaged electrode tips.
• Excessive wear or deterioration.

Damaged or malfunctioning equipment should be clearly identified, removed from clinical use immediately, and reported for repair or replacement before being used again.

After cleaning, equipment should be stored in a clean, dry location where it is protected from dust, excessive heat, moisture, and physical damage.

Accurate documentation is an essential component of safe electrosurgical practice and provides an important record of equipment performance throughout the procedure.

Before patient use, the circulating nurse should document the generator's baseline condition, patient return electrode placement site, initial generator settings, and completion of required pre-use equipment checks.

During the procedure, any changes to generator settings, together with the reason for the adjustment, should be documented according to institutional policy. Generator alarms, equipment malfunctions, troubleshooting steps, corrective actions, and replacement of equipment or accessories should also be recorded.

At the completion of the procedure, the final generator settings, condition of the patient return electrode site, and any adverse findings should be documented as part of the patient's permanent surgical record.

Accurate documentation provides accountability, supports quality improvement, facilitates future troubleshooting, and provides an important reference should questions arise regarding equipment performance or patient outcomes.

Routine preventive maintenance helps ensure that the electrosurgical unit continues to function safely and reliably.

Regular inspections should include confirmation that audible alarms function correctly, generator controls move smoothly, displays operate normally, and connection cables remain free of damage. Inspection findings should be recorded in the maintenance log assigned to each generator. Dates, inspection findings, maintenance performed, and signatures provide traceability of equipment checks and repairs.

Preventive servicing, calibration of generator output, and verification of safety systems should be arranged according to the manufacturer's recommendations and institutional maintenance schedules whenever these services are available.

In facilities where biomedical engineering support or external servicing is limited, careful nurse-led equipment inspection, accurate documentation, proper cleaning, and appropriate storage become the primary means of maintaining equipment safety and reliability.

Every perioperative team member shares responsibility for maintaining electrosurgical equipment in a safe condition.

Equipment that develops persistent alarms, insulation failure, unexpected performance, or unresolved faults should be clearly labelled, removed from clinical use, and reported according to institutional policy. Equipment should not be returned to service until it has been inspected, tested, and, where necessary, repaired by appropriately qualified personnel.

Information collected through maintenance records, incident reports, equipment inspections, and documentation contributes to continuous quality improvement by helping identify recurring equipment problems, training needs, and opportunities to improve patient safety.

• Return the generator to the lowest setting or standby mode before switching it off.
• Disconnect cables by holding the connectors rather than pulling on the cords.
• Separate single-use items from reusable equipment immediately after the procedure.
• Perform point-of-use cleaning before reusable equipment is transferred for reprocessing.
• Inspect all reusable equipment for damage before cleaning and storage.
• Document baseline equipment condition, generator settings, alarms, troubleshooting, and post-procedure findings.
• Record routine maintenance and equipment inspections in the maintenance log.
• Remove damaged equipment from service immediately and report faults according to institutional policy.

You have now completed the knowledge component of the Electro-Surgical Units module. The next stage is to apply this knowledge through psychomotor skills practice, where you will assemble, inspect, prepare, and verify an electrosurgical unit using the safe practices presented throughout this course. Continue to the psychomotor skills practice and assessment activities to develop practical competence in ESU setup and management.

Self-Assessment

Please complete the following: ESU Maintenance Quiz

Self-Assessment

Please complete the following: ESU Cumulative Knowledge Assessment

Self-Assessment

Please complete the following: Clinical Decision-Making Assessment