RDT Hospital, Dept of Gen Surgery Electrosurgery Dr sumanth

Objectives Describe the principles of the ESU and purpose for its use Describe Monopolar & Bipolar ESU’s and associated equipment Describe the types of dispersive electrodes (grounding pads) and appropriate use, including proper anatomic placement Identify special considerations for the use of the ESU

Often “electrocautery” is used to describe electrosurgery Often “electrocautery” is used to describe electrosurgery. This is incorrect. Electrocautery refers to direct current (electrons flowing in one direction) whereas electrosurgery uses alternating current. During electrocautery, current does not enter the patient’s body. Only the heated wire comes in contact with tissue. In electrosurgery, the patient is included in the circuit and current enters the patient’s body.

“Proper care & handling of electrosurgical equipment is essential to patient and personnel safety.” “Electrosurgery is used routinely to cut, coagulate, dissect, fulgurate, ablate, and shrink body tissue with high frequency (i.e. radiofrequency) electrical current.” AORN (2007) Standards, Recommended Practices, and Guidelines

History Lesson The first electrosurgical unit was developed in 1926 by Dr. Harvey Cushing (a neurosurgeon) and Dr. William Bovie, a Harvard physicist The name “Bovie” has been associated with electrosurgical units ever since

Electrosurgery Involves using a high-frequency electric current to cut tissue and coagulate bleeding The flow of electricity requires a complete pathway (circuit)

System components: Generator (electrosurgical unit) Inactive dispersive electrode (grounding pad) Active electrode (“Bovie” pencil)

The electrosurgical generator is the source of the electron flow and voltage. The circuit is composed of the generator, active electrode, patient, and patient return electrode. Pathways to ground are numerous but may include the OR table, stirrups, staff members, and equipment. The patient’s tissue provides the impedance, producing heat as the electrons overcome the impedance.

Frequency spectrum nerve and muscle stimulation cease at 100,000 cycles/second (100 kHz), electrosurgery can be performed safely at “radio” frequencies above 100 kHz. An electrosurgical generator takes 60 cycle current and increases the frequency to over 200,000 cycles per second. At this frequency electrosurgical energy can pass through the patient with minimal neuromuscular stimulation and no risk of electrocution.

Types of ESU Units Monopolar Bipolar (Some ESU units have both monopolar & bipolar capability)

Monopolar ESU Electrical energy flows from the generator (ESU unit), to the active electrode (cautery pencil). The energy then passes through the patient to the dispersive cautery pad, thus completing the electrical circuit.

Monopolar ESU Copyright© Valleylab, a division of Tyco Healthcare Group LP: All rights reserved

Monopolar Modes Cut Coag Blend- produces cutting effect with hemostasis

cut Electrosurgical generators are able to produce a variety of electrical waveforms. As waveforms change, so will the corresponding tissue effects. Using a constant waveform, like “cut,” the surgeon is able to vaporize or cut tissue. This waveform produces heat very rapidly.

coagulation Using an intermittent waveform, like “coagulation,” causes the generator to modify the waveform so that the duty cycle (on time) is reduced. This interrupted waveform will produce less heat. Instead of tissue vaporization, a coagulum is produced.

blend A “blended current” is not a mixture of both cutting and coagulation current but rather a modification of the duty cycle. As you go from Blend 1 to Blend 3 the duty cycle is progressively reduced. A lower duty cycle produces less heat. Consequently, Blend 1 is able to vaporize tissue with minimal hemostasis whereas Blend 3 is less effective at cutting but has maximum hemostasis.

REM System(renewable energy management systems) Most ESU units on the market today have REM technology. REM system continually monitors the heat build-up under the grounding pad If the system detects excess heat build-up it will shut off the current flow to prevent patient injury

Bipolar Electrosurgery Bipolar electrosurgery uses 2-tined bipolar forceps One tine of the forceps serves as the active electrode, and the other tine serves as the return electrode The electrical current is confined to the tissue between the tines of The bipolar forceps

Bipolar Electrosurgery Copyright© 2003 Valleylab, a division of Tyco Healthcare Group LP: All rights reserved

Bipolar Surgery A grounding pad is not needed for bipolar-only cases

ESU Grounding Pads Available in infant & adult sizes Infant size: follow grounding pad manufacturer’s recommendation for appropriate weight range NEVER cut a grounding pad to fit a patient, always use the appropriate size pad

Function of the Patient Return Electrode A return electrode burn occurs when the heat produced, over time, is not safely dissipated by the size or conductivity of the patient return electrode.

Dangerous Return Electrode Contact with Current Concentration In the case of reduced contact area, the current flow is concentrated in a smaller area. As the current concentration increases, the temperature at the return electrode increases. If the temperature at the return electrode site increases enough, a patient burn may result. Surface area impedance can be compromised by: excessive hair, adipose tissue, bony prominences, fluid invasion, adhesive failure, scar tissue, and many other variables.

Placement of Grounding Pad When considering grounding placement it is important to know that electric current travels easily through muscular & vascular tissue Electric current does not travel well through bone, scar or adipose tissue

Best Grounding Pad Site Over a well-vascularized muscle mass Avoid placing grounding pad over bony prominences, hairy sites, scar tissue,excess adipose tissue

Grounding pad site Pad site should be free from lotions or oils In some male patients it may be necessary to remove hair from the desired pad site using clippers

Placing Grounding Pad Place grounding pad as close to the surgical site as possible Grounding pad should be placed so that the entire surface of the pad is in uniform contact with the pad site Avoid any tenting or gaps where parts of the pad are not in contact with the patient

ESU Safety Inspect machine for frayed or broken wires before use. Active electrode wire should be free of kinks Use lowest setting that is effective

ESU Safety Avoid using the ESU unit as a table-when doing this setting buttons may be inadvertently changed or liquid may be spilled into machine If alcohol-containing prep solutions are used (ex: Duraprep, Prevail) allow prepped area to dry completely before using ESU to minimize fire risk

ESU Safety Recommended practice: keep ESU pencil in non-conductive holder when not in use- this prevents accidental activation Prep or irrigation solutions should not pool near the grounding pad Don’t allow ESU pedal to stand in pool of liquid

ESU Safety No part of the patient should be touching any grounded metal objects (IV pole, Mayo stand, metal surfaces of OR bed) Electrical current always seeks the path of least resistance—patient might have an alternate site burn where their body is in contact with metal

ESU Safety When surgeon requests that the ESU setting be changed, audibly repeat new setting Do not turn ESU activation sound completely off—sound also alerts surgical team to accidental activation of ESU

ESU Safety If it is necessary to change patient position intraoperatively, always check grounding pad site after patient is re-positioned If ESU pencil falls below the level of the sterile field, disconnect it from the generator to prevent accidental activation

ESU Safety If there is any suspicion of patient injury related to the use of an ESU unit: Immediately remove generator from service, and send to biomed along with the grounding pad & used active electrode

Surgical Smoke NIOSH (the National Institute of Occupational Safety and Health) and the CDC (Center for Disease Control) have also studied electrosurgical smoke at length. They state: “Research studies have confirmed that this smoke plume can contain toxic gases and vapors such as benzene, hydrogen cyanide, and formaldehyde, bioaerosols, dead and live cellular material (including blood fragments), and viruses.”

Smoke evacuation device

Troubleshooting If surgeon makes repeated requests to increase ESU power or complains that the “Bovie isn’t working”: Check dispersive pad contact Check all connections No resolution after taking above steps- change out ESU pad, pencil and/or machine

Special Considerations: Patients with-- Implanted pacemaker Implanted automatic defibrillator Cochlear Implant Implanted Bone Growth Stimulator Body Jewelry Offender monitoring ankle bracelets Orthopedic implants (total hips, etc)

Metal Implants (Orthopedic implants, etc) Metal is an excellent conductor of electrical current Any metal between the surgical site and the grounding pad can attract the electrical current, and cause alternate site burns

Pacemakers Bipolar electrosurgery is recommended in patients with implanted pacemakers who must undergo surgery If monopolar surgery is required, place the grounding pad on a site where current will be directed away from the heart & pacemaker generator

Implanted Defibrillators Implanted defibrillators should be deactivated before the surgical procedure, and reactivated immediately after the procedure After defibrillator is deactivated the ESU can be safely used for the procedure

Cochlear Implants Monopolar electrosurgical instruments should not be used on the head or neck of patients who have a cochlear implant- damage to the implant or surrounding tissue can occur Bipolar ESU may be used, depending on type of implant electrodes- contact manufacturer for info

Argon-Enhanced Electrosurgery Also known as “Argon Beam Coagulator” Combines argon gas with electrical energy to increase the effectiveness of the electrosurgical current Argon gas acts as a pathway to carry the electrical current to the target tissue- coagulates tissue without direct contact

References Conmed Corporation Web site: http://www.conmed.com/ Rothrock (2007) Alexander’s Care of the Patient in Surgery Valleylab Web Site: http://www.valleylab.com/