Electrosurgical Unit

Overview History Components Placement of active and inactive electrode. Monopolar/Bipolar Functions Safety considerations

Electrosurgical Unit Used to apply electrical current through the patient’s tissue to cut and/or coagulate the tissue. Monopolar mode may cut or coagulate. Bipolar mode is used for coagulate only.

History By the late 1800’s D’arsonval and Tesla applied high frequency energy to the human body to generate heat. 1908 electromagnetic waves are used to cut tissue called surgical diathermy. Results were highly unsatisfactory.

History Cushing and Bovie collaborated to produce a device that used radio frequency electric current for coagulation. Worked much smoother than the spark gap generator, allowing the cutting of tissues.

History In the 1970’s solid state generators were developed. Modern electrosurgical units are equipped with safety features to reduce the chance of burns. Although many changes have been made to the original design, most electrosurgical units are still referred to as a bovie.

Components Generator Provides source of electrical current to the active electrode. Control panel allows for power level and blend adjustments.

Components Active electrode Referred to as the electrosurgical pencil. May be hand or foot controlled.

Components Dispersive electrode Also known as the grounding pad or inactive electrode. Placed on the patient to return the electrical current to the generator.

Placement Active electrode Packaged sterile, with a protective holster. Once the patient has been draped it is secured with a non penetrating clamp. End is passed off to circulator that is plugged into the generator.

Placement Inactive electrode (grounding pad) Available in adult and pediatric sizes. Disposable, although metal plates and gel are occasionally used. Placed on a large fleshy area, close to the incision site. Must be clean and dry. Relatively free of scars or hair. Not to be placed over a joint, metal prosthesis, or bony prominence.

Placement Inactive electrode (grounding pad) Errors in placement may result in a patient burn.

Monopolar Electrosurgical pencil. Various interchangeable tips. Blade Needle Ball Hand or foot controlled. Dispersive electrode is necessary in monopolar mode.

Bipolar Uses a reusable Forcep tip with a disposable cord. Dispersive electrode is not necessary in bipolar mode.

Current Flow Monopolar Generator Active electrode Patient’s body Inactive electrode

Current Flow Bipolar Generator Active electrode One prong of the Forcep. Patient’s tissue Inactive electrode Other prong of the Forcep.

Principle of Electrosurgery High frequency current is produced and applied to tissues to cut or coagulate. Advantages include: Reduced blood loss Reduced surgical time Using the cutting feature allows you to dissect tissue without stopping to control bleeding.

Coagulation and Cutting Functions Coagulation function allows the surgeon to individually coagulate blood vessels by applying the tip directly to the tissue or by grasping the tissue with a forcep and applying the tip to the forcep.

Coagulation and Cutting Functions Cutting function allows the surgeon to make scalpel like incisions and simultaneously control hemostasis. Control panel offers “spray” or “blend” configurations to control the amount of coagulation.

Coagulation and Cutting Functions The active electrode blade must be free of charred tissue to work efficiently. Special abrasive tip cleaners are placed on the sterile drape near the operative site.

Safety Considerations Flammable prep solutions must be allowed to completely dry, and not be allowed to pool under the patient. Flammable anesthetics should not be used during the procedure. EKG electrodes with metal tips should be placed carefully to avoid burning the patient.

Safety Considerations Patients with pacemakers or internal defibrillators may malfunction. All jewelry must be removed from the patient before surgery to prevent burns.

Safety Considerations Burns to the surgical team may result by a hole or weak spot in the surgeons surgical gloves. Example: If surgeon applies a hemostat onto a bleeding vessel and then applies the bovie pencil to the instrument, with a hole or weak spot in their glove.

Review History Components Placement of active and inactive electrode. Monopolar/Bipolar Functions Safety considerations