SELF/Perioperative Nursing/Electro-Surgical Units

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▼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.

By the end of this module, learners will be able to safely handle and set up electrosurgical devices in accordance with clinical protocols. They will understand the principles of electrosurgery, identify key components, and ensure proper functioning and safety checks to support effective surgical use and prevent complications.

• Describe the principles of monopolar and bipolar electrosurgery and the function of ESU components.
• Explain the proper arrangement and preparation of ESU equipment and supplies prior to patient draping.
• Describe the purpose of the patient return electrode, appropriate placement sites, and risks of poor adhesion.
• State safe baseline settings for cutting and coagulation modes and explain how adjustments are managed during surgery.
• Identify common signs of ESU malfunction, safety risks, and troubleshooting steps.
• Explain the requirements for cleaning, inspection, and documentation of ESU equipment and intraoperative use.

Electrosurgical units (ESU) operate by transmitting high-frequency electrical current through tissue to cut or coagulate during surgery. There are two primary types of electrosurgery: monopolar and bipolar. In monopolar mode, current flows from the handpiece into the patient’s tissue and exits via a patient return electrode (grounding pad). In bipolar mode, the current passes between the two tips of a forceps-like instrument, eliminating the need for a return pad. A surgeon typically uses monopolar electrosurgery for broad cutting and coagulation across larger areas, and bipolar electrosurgery for precise coagulation in delicate or confined tissues where minimal collateral damage is needed.

The electrosurgical unit consists of the generator, active handpiece, connection cables, and a return electrode when monopolar energy is selected. Each component should be inspected before assembly. 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 or burns. The adhesive of the return electrode should be smooth and flexible, without curling or dryness at the edges.

Once powered, the generator should display baseline settings within safe ranges—typically 30–40 watts for cutting and 20–25 watts for coagulation. Before the patient is draped, the system is tested by placing the handpiece tip on the 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 pencil may be briefly activated at low wattage away from the patient to verify current delivery, and any unexpected results should be corrected before surgery proceeds. The handpiece activation buttons should depress smoothly without sticking, and footswitches, if connected, should respond consistently.

Baseline equipment checks should be recorded before patient arrival. The make and serial number of the generator, condition of cables, presence of functional audio alarms, and readiness of the return electrode form the minimum standard for documentation - refer to ESU Maintenance and Documentation section. This provides both accountability and a reference point should questions arise about equipment performance or patient outcomes.

The ESU generator is positioned on a stable, flat surface near a grounded outlet, away from fluid sources. The power cord should be traced to confirm a direct wall connection rather than an extension. The handpiece cable is then inserted into the active electrode port, the connection seated firmly, with excess length coiled loosely to prevent strain. The sterile handpiece is capped until use and placed in a sterile holster secured to the drape.

On the sterile field, ESU supplies are arranged for sequential assembly. The patient return electrode and alcohol wipes are placed first, followed by the sterile holster, sterile pencil, connection cables, and test tool. These items are positioned on the back table in a linear arrangement, allowing the scrub nurse to progress step by step without unnecessary reaching. Gloves worn during ESU setup depend on the task: clean gloves for non-sterile equipment connections and sterile gloves worn by the scrub nurse when placing items onto the sterile field.

The sterile holster is fixed to the drape on the surgeon’s dominant side, ensuring the handpiece can be returned safely between activations. Cables are routed along the drape edge, held flat with clips if available, to prevent them from trailing across sterile zones or hanging loosely into non-sterile space. Transitions from sterile to non-sterile areas are examined to ensure no points of tension or contamination.

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. Sites with good vascular supply and muscle mass, such as the thigh, buttock, or back, provide reliable contact, while scars, tattoos, or bony areas can interfere with adhesion or conductivity and increase the likelihood of injury.

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.

During a case, monitoring the electrode site is essential because partial detachment, pooling of fluids, or uneven pressure can alter current flow. Alarms indicating poor contact are triggered when the generator senses increased resistance at the pad site. These signals serve as safeguards, drawing attention to conditions that could cause thermal injury. Observation of pad placement and periodic reassessment help maintain safe function throughout the procedure.

Patients with implanted cardiac devices or orthopedic hardware present special challenges. Conductive materials or sensitive electronics can redirect or interfere with the current path, increasing the risk of burns or device malfunction. In these circumstances, bipolar electrosurgery, which restricts current flow to the tissue between instrument tips, often provides a safer alternative. Awareness of these considerations guides appropriate energy selection and helps protect patient safety.

Self-Assessment

Please complete the following: Quiz 1: ESU - ECSACONM

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 are recorded in the operative documentation before patient use.

Adjustments to power settings are made in increments no greater than 5 watts. Each adjustment should be confirmed verbally and visually with the displayed setting. Surgeons may request changes based on tissue density, but excessive increases in wattage elevate the risk of deep burns and uncontrolled bleeding. Tone changes provide an additional safeguard that the selected mode is correct.

Activation methods should be clarified before surgery begins. If both a footswitch and hand-activated pencil are connected, the surgeon is informed which device will remain in use. Unused activation devices should be disconnected to reduce accidental activation. When monopolar and bipolar modes are alternated during a case, the generator should be placed in standby mode before reconnection.

At case completion, all settings are returned to the lowest or standby levels before the generator is switched off.

Safety checks precede every activation. The generator should power on without error codes, alarms should sound when tested, and the active electrode should demonstrate response on the test tool. The patient return electrode should be secure, with cables free of fluid contact. A sterile holster is attached to the drape so that the ESU pencil can be placed securely between activations, preventing accidental burns or contamination.

During activation, tissue effect and audio feedback are continuously monitored. Signs of malfunction include excessive sparking, absence of expected tone, or charring at low settings. If alarms sound, activation must be paused immediately. Cables and connections are examined first, followed by the electrode site and handpiece. Function should be restored only once the cause is identified.

Common faults include loose connectors, defective return electrodes, and malfunctioning handpieces. A structured approach to troubleshooting is followed:

• confirm button or pedal function
• inspect generator ports
• verify pad adherence
• replace suspect cables
• cycle generator power only as a last step

Persistent malfunction requires removal of the unit from service.

At closure, the generator is powered down and unplugged. Cables are detached by gripping connectors, not cords, to prevent insulation damage. They are coiled loosely for storage. Any alarms, malfunctions, or abnormal tissue effects are recorded in the case notes, and faulty equipment is tagged for service.

After each procedure, the generator is cleaned with a lint-free cloth dampened in disinfectant, avoiding liquid entry into vents or ports. Cables are wiped with alcohol and inspected for cracks or exposed conductors before coiling. Handpieces, if reusable, undergo sterilization according to manufacturer instructions.

Weekly inspections include confirmation of functional audio alarms, verification of smooth dial or switch movement, and review of cable integrity. Results are entered in a maintenance log specific to each machine. Dates, findings, and signatures provide traceability of checks and repairs.

During cases, the circulating nurse records the generator’s baseline condition, pad placement site, initial settings, and any intraoperative changes and their rationale. Alarms and corrective actions are included. At closure, final settings, pad site condition, and any adverse findings are documented. These notes become part of the patient’s permanent surgical record.

At monthly intervals, preventive servicing should be arranged when available. Calibration of outputs and verification of safety systems reduce the risk of failure during surgery. Where external servicing is unavailable, detailed nurse-led inspection and accurate documentation serve as the frontline of preventive safety.

In environments with limited staff, roles should be clearly designated before the procedure. Where a circulating nurse is unavailable, the scrub nurse may need to assume responsibility for basic ESU setup before gowning, ensuring equipment is tested and documented prior to handling sterile instruments. Careful sequencing prevents lapses in either aseptic practice or equipment safety.

When equipment is scarce, meticulous inspection of each reusable component becomes critical. A single return electrode, if reusable, should be applied with thorough skin preparation to maximize adhesion. If a test tool is unavailable, a brief low-wattage activation check should be performed away from the operative site to confirm function. Detailed documentation of these adaptations ensures that limitations are acknowledged and that safety remains the guiding principle.

Self-Assessment

Please complete the following: Quiz 2: ESU - ECSACONM

Cumulative Test

Please complete the following: Module Test: ESU - ECSACONM

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