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SURGICAL MODALITIES EL PASO COMMUNITY COLLEGE SURGICAL TECHNOLOGY PROGRAM MARGARET M. RODRIGUEZ, INSTRUCTOR UNIT TITLES ELECTRICITY, ELECTROSURGERY AND FIRE SAFETY IONIZING AND NON-IONIZING RADIATION ULTRASONIC AND HYDRODISSECTION DEVICES ENDOSCOPY/MINIMALLY INVASIVE SURGERY UNIT TITLES MICROSCOPES AND MICROSURGERY ROBOTICS AND GUIDED IMAGERY I. ELECTRICITY, ELECTROSURGERY AND FIRE SAFETY GLOSSARY OF TERMS ELECTRICITY – a fundamental entity of nature usually used as electric current CONDUCTOR Any substance, medium, or material that allows the transmission of electricity (flow of free electrons) Examples: metals, carbon, salt water, humans INSULATOR A medium that does not allow the transmission of electricity by inhibiting the flow of electrons. A non-conductive material such as rubber, glass, porcelain, or wood. ELECTRICAL CHARGE ALL MATTER CONSISTS OF ATOMS ATOMS ARE COMPOSED OF: Protons – positively charged particles Neutrons – particles with no charge, neutral Electrons - negatively charged particles ELECTRICAL CHARGE When electrons move from one atom to another, an imbalance occurs. An atom which has lost electrons will carry a positive charge. An atom which has gained electrons will carry a negative charge. ELECTRICAL CURRENT THE MOVEMENT OF ELECTRONS THROUGH A CONDUCTOR Example: a light bulb illuminates because electrons move through the conductor of wires and metal base to the tungsten filament in the bulb. The filament heats up and brightens – producing light. ELECTRICAL CURRENT Current The rate at which electricity flows. Measured in amperes. TYPES OF ELECTRICITY Alternating Current (AC) – a current that periodically reverses its direction of flow. Power from external power plant Direct Current (DC) – a current flowing in only one direction. Battery power ELECTRICAL TERMS PATH OF LEAST RESISTANCE - electricity or the flow of electrons will act like water and always seek a path from highest concentration to lower concentration via the easiest route. ELECTRICAL TERMS CURRENT LEAKAGE - all electricity can leak causing the potential for shock. ELECTRICAL TERMS Ampere – the practical unit of current strength. The amount of current flowing in a circuit. The rate of flow. Ohm – the unit of electrical resistance of a conductor Measurement of the ability of a material to receive flow of electrons. ELECTRICAL TERMS Volt – the unit of electromotive force that moves electrons through a material. It induces current to flow in one direction. The higher the number of volts, the more direct the current Voltage – the potential energy of electrons. Electromotive force of an electric current expressed in volts. ELECTRICAL TERMS Resistance – the opposition to the passage of a current. impedes or restricts the flow of electrons Measured in ohms ELECTRICAL TERMS GENERATOR – creates a force or voltage and moves electrons from one point to another. Like a plumbing system that utilizes a pump to create water pressure and move water from one place to another ELECTRICAL TERMS CIRCUIT - A moving or traveling around. In electricity, the entire course traversed by an electric current. When complete, it is a closed circuit, when interrupted, it is a broken circuit. ELECTRICAL TERMS POWER – the rate of the movement of electrons from point to point or current flow. Power = amps or current x voltage Power is measured in watts ELECTRICAL TERMS LOAD – the device that uses the electricity to perform some type of function The load can change the amount of energy delivered from the power source Examples: surgical lamps, ESU, video monitors ELECTRICAL TERMS SWITCH – a device used to open or close a circuit and controls the flow of electricity. ELECTRICAL TERMS HOT WIRE – the wire that connects to the switch. In polarized plugs, hot wire is smaller prong Often the hot wire is colored red ELECTRICAL TERMS NEUTRAL WIRE – serves as the pathway for the electrons to return to the energy source and completes the circuit. In a polarized plug, it is the larger of the prongs Wire is often colored green ELECTRICAL TERMS GROUND – the connection of an electrical current or circuit with the earth through a conductor. Safely conveys any leaking electrons to alternate path to ground. Ground wires are often colored black ELECTRICAL TERMS Hertz – a unit of electromagnetic wave frequency, equal to one cycle of alternating current (AC). Each cycle starts at zero – flows in the positive direction, changes to negative, then back to zero ELECTRICAL TERMS FREQUENCY – the number of waves passing through a given point per one second. This is measured in hertz. TYPES OF ELECTRICITY STATIC ELECTRICITY – caused by friction and accumulates on objects When two static-bearing objects come in contact, the one bearing the higher potential discharges to the one with the lower potential creating SPARKS. STATIC ELECTRICITY An electrostatic charge or spark between two objects can occur only when there is no pathway of conductivity between them; therefore the chief aim is to provide a manner of dissipating the static accumulation. STATIC ELECTRICITY Common environmental hazard in the OR Does not cause patient shock or burns However, its production of an electrostatic spark is its main hazard because this provides a source of ignition for a fire. STATIC ELECTRICITY Risks have diminished because explosive anesthetic agents are no longer used. STATIC ELECTRICITY PREVENTATIVE MEASURES INCLUDE: Good conductive floors prevent accumulation by providing a pathway of conductivity between persons and equipment coming in contact with the static electricity. STATIC ELECTRICITY PREVENTATIVE MEASURES Safe furniture is made of electrically-conductive materials or contact to the floor is made through electricallyconductive leg tips, casters, or wheels. STATIC ELECTRICITY PREVENTATIVE MEASURES Operating room floors are cleaned with materials that do not reduce conductivity. STATIC ELECTRICITY PREVENTATIVE MEASURES Avoid wool and synthetic fabrics that have not received anti-static treatment. Use cotton blankets, towels, etc. STATIC ELECTRICITY PREVENTATIVE MEASURES Use special anti-static liners in trash and linen hampers and kick buckets. STATIC ELECTRICITY PREVENTATIVE MEASURES Maintain room humidity level at 50-60% STATIC ELECTRICITY PREVENTATIVE MEASURES Dissipate charges by frequently touching metal surfaces and avoid friction causing activities. example: avoid movement around patient’s head, especially if his/her hair is uncovered. ELECTRICAL SHOCK ELECTROCUTION – the most severe case of electrical shock, often lethal. Occurs when a person becomes part of the circuit or closes the circuit. ELECTRICAL SHOCK MACROSHOCK – requires a substantial voltage to drive electrons through a highly resistant skin path. Can range from small tingling to electrocution Due to things such as frayed electrical cords, spilling of liquids on generators, radio with no back covering, or removal of ground plug. ELECTRICAL SHOCK MICROSHOCK – electrical shock below the level of sensation so can come from undetectable sources. Requires only a small amount of current but must involve passage through the heart to cause damage. If so, can also be lethal. Incidents usually arise from equipment failure, wet floors, ungrounded stretchers, or indwelling catheters/monitors, etc. ELECTRICAL HAZARDS PRECAUTIONS INSPECT THE POWER CORD AND PLUG BEFORE EVERY USE PRECAUTIONS DO NOT USE EQUIPMENT ON WHICH LIQUIDS HAVE BEEN SPILLED. PRECAUTIONS NEVER STACK THINGS ON OR BEHIND ELECTRICAL EQUIPMENT WHICH MIGHT INTERFERE WITH PROPER VENTILLATION OF THE DEVICE. PRECAUTIONS TWO-PRONG EXTENSION CORDS OR ADAPTORS SHOULD NOT BE USED IN THE OR. PRECAUTIONS USE THREE-PRONG EXTENSION CORDS ONLY WHEN NECESSARY PRECAUTIONS DO NOT RUN OVER POWER CORDS WITH WHEELS OF EQUIPMENT PRECAUTIONS DO NOT TIGHTLY COIL OR KINK CORDS. PRECAUTIONS ALWAYS PLUG PORTABLE EQUIPMENT INTO THE WALL OUTLET AND TURN POWER ON PRIOR TO MAKING ANY CONNECTION TO THE PATIENT. REMOVE ANY PATIENT CONNECTIONS BEFORE TURNING OFF POWER OR UNPLUGGING FROM WALL. ISOLATED SYSTEMS ISOLATE O.R. ELECTRICAL SYSTEMS FROM GROUNDED CIRCUITS IN THE POWER MAIN OF THE HOSPITAL Current flows from one isolated line to another Line isolation monitors check the degree of isolation by continuously measuring resistance and capacity between two isolated lines and ground ISOLATED SYSTEMS If the current leakage exceeds safe levels, an alarm sounds Unplug the last piece of equipment plugged in and tag for repair ELECTROSURGERY Application of electrical current to coagulate or cut tissue The electrosurgical generator provides the power for electric current to travel directly to tissue and utilizes alternating current (AC) ELECTROCAUTERY Term often used to mean electrosurgery but is distinctly different Electrocautery utilizes direct current (DC) via heated wire to burn tissue. No electricity passes through patient’s body HISTORY OF ELECTROSURGERY In ancient times, people used hot pokers, etc. to burn bleeding flesh to stop the flow. HISTORY OF ELECTROSURGERY In 1926 Harvey Cushing, a neurosurgeon and William Bovie, a biophysical engineer developed an electrosurgical unit for neurosurgical procedures. HISTORY OF ELECTROSURGERY By the early 1930’s, the first commercial “Bovie” units were produced and being used in operating rooms. BENEFITS OF ELECTROSURGERY Reduction of intraoperative and post-operative hemorrhage Decrease in operating time Reduction of patient morbidity It has become one of the most commonly used surgical devices in all surgical specialties ELECTROSURGERY Energy produced is high frequency radio waves in excess of 100,000 hz Produces approximately 2000 degrees F of heat when met with resistance (such as human tissue) ELECTROSURGICAL MODES MONOPOLAR – electrical energy flows from a generator to an active electrode such as Bovie (ESU) pencil and tip to the patient with some result on tissue Then out via the inactive electrode (or dispersive ground pad) and back to the generator MONOPOLAR MODE The path of electrical energy in a completed ESU circuit is: Wall plug > ESU generator > active electrode (pencil tip or endoscopic inst) > patient > inactive electrode (ground pad) > ESU generator > wall plug MONOPOLAR MODES Monopolar energy of the ESU can be set for pure cutting, pure coagulation, or a blend of cutting and coagulation. Cutting mode – can achieve effects by using less voltage because the frequency is higher It vaporizes tissue but does not dissipate heat to surrounding tissue. MONOPOLAR MODE Coagulation mode – uses more dissipated heat to cause hemostasis of blood vessels by producing coagulum and char to seal off. Causes more damage to tissues and may inhibit healing of tissues if used too much Current may be applied to hemostat placed on bleeding vessel to cauterize Is not appropriate for large bleeding vessels MONOPOLAR MODE BLENDED MODES voltage and frequency are changed Tissue results are a mix of cutting and coagulation MONOPOLAR MODE Endoscopic instruments may be electrified by attaching a cord to a metal prong on the instrument Power is activated by foot pedal May be used for either cutting or coagulation modes The patient MUST be grounded when monopolar current is used MONOPOLAR MODE Capacitive coupling – unintended electrical energy delivered to non-target tissues. Occurs during laparoscopic procedures where visibility is limited Occurs as a result of insulation failure May be prevented by shielding devices Burns to internal organs are potentially fatal PERSONNEL HAZARDS Electrical shock may be delivered to surgeon or assistant due to: Tiny hole in latex surgical gloves High setting on ESU causing hole in glove and subsequent burn – called dielectric breakdown PERSONNEL HAZARDS VAPORIZED TISSUE PLUME – may contain hazardous ingredients such as carcinogens, bloodborne pathogens, and viral particles Smoke evacuators should be utilized when large amounts of plume expected Special filtration masks should be worn for laser plume cases BIPOLAR MODE Electrical current passes only between the two prongs of the instrument and through any tissue in between. Used for delicate procedures to reduce possible nerve damage. Patient does not need to be grounded because the entire patient is not included in the circuit, only tissue between tines of instrument GROUNDING PAD Also known as inactive electrode or dispersive pad Must be in complete contact with patient to prevent electrical burn to patient Should be placed over a large muscle mass, NEVER over bony prominence, joint with prosthetic replacement, or over metal implants Should be located as close to surgical site as possible GROUNDING PAD Keep as far away from pacemakers as possible Should be placed after final positioning to prevent change in contour Should be removed following case after drapes are removed Pad site must be inspected postoperatively and result charted Pads are available in different sizes appropriate to size of patient (pediatric, neonatal, adult) GROUNDING PAD Must NEVER be cut Must NEVER allow prep solutions to pool under pad Ground pads sites are the major area where ESU burns occur ECG leads provide second most common burns due to alternate exit pathway of electrical current