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By Kelly M. Pyrek
Itis estimated that more than 3 million laparoscopic surgical procedures areperformed annually in the United States, with approximately 85 percent ofsurgeons using electrosurgical instruments in these procedures.1 Theubiquitous nature of these procedures has the members of many endoscopic suitespaying particular attention to reducing the risk of inflicting thermal burns topatients during minimally invasive surgeries. While minimally invasive surgerytechnology is revolutionizing healthcare -- reflected in the tremendous advancesmade in science -- it may exact a greater price for the benefits it yields.These burns can cause patient injury, serious post-operative complications, evendeath.
These burns are often caused by faulty equipment, such as electricalgenerators and electrodes, or by incorrect usage by healthcare workers (HCWs).Unintended tissue damage can result from stray electrosurgical burns caused byinsulation failure and capacitive coupling during laparoscopy. An elementalunderstanding of electricity is key to avoiding burns. Since electrical currentflows toward the ground and it follows the path of least resistance, it standsto reason that monopolar electrosurgery creates a complete electrical circuitfrom the active electrode to the targeted tissue, to the dispersive returnelectrode, and back to the generator.2
George Vilos, MD, professor of obstetrics and gynecology and the director ofendoscopic surgery at the University of Western Ontario in Canada, writes,"Because surgeons now work through keyhole incisions and manipulateelectrodes and instruments through long, narrow channels, it is more difficultthan ever to prevent the electricity from traveling outside this path andburning or vaporizing nontargeted tissue."3
Many burns during electrosurgery can be traced to direct coupling betweensurgical instruments, insulation failure and capacitive coupling. Insulationfailure can occur when the insulation along the shaft of the active electrodebreaks down and electrical currents "leak" from the instrument andburn nearby tissue. Causes of insulation defects can range from normal wear andtear, to contact with sharp instruments such as trocar cannula, to stress placedon the electrode from high voltages. Capacitive coupling occurs when electricalcurrent is induced from the active electrode to nearby conductive materialthrough intact insulation. In electrosurgery, the charge on the active electrodeswitches from positive to negative at a very high frequency. The varyingelectrical field around the active electrode can transfer high levels ofelectrical current to nontargeted tissue and cause burns.
Voltage can affect the performance of the electrosurgical electrode, sincethe higher the peak voltage, the greater the chance for capacitive dischargethrough the electrode insulation or the radio frequency cable. For this reason,more than two decades ago the American Association of GynecologicalLaparoscopists (AAGL) developed voluntary standards to prevent patient injuries.Within these standards, which were published in the Federal Register Feb. 26,1980, is the recommendation that unipolar output power be limited to 1,200 voltsand 100 watts at maximum generator output.4 According to surgicalinstrument manufacturer Richard Wolf, the maximum output power of theelectrosurgery unit must be matched to the surgical application. Forgastroenterology, gynecology and rhinolaryngology procedures, the companyrecommends unipolar output power should not exceed 120 watts and units withincorporated coagulation current source for blended current, 170 watts.5Electrosurgical generators operate between 500,000 cycles per second (500 KHz)and 3 million cycles per second (3 MHz), with the capacitive effect greater at 3MHz. Therefore, generators that operate at these extremely high frequencies willbe subject to more RF-current leakage through insulated instruments, cables andcannulae, meaning a more probable opportunity for injuries.
While technology and gadgetry can lend an air of heightened patient and HCWsafety, there is increased need for caution. "More important than flashymeters is the realization that surgery during the last decade has becomeenormously sophisticated," Hausner says. "Therefore, a speciallydesigned electrosurgical unit should be utilized for surgical procedures such asendoscopic polypectomy and laparoscopic procedures. The surgeon who has beenusing electrosurgical equipment empirically for a long time must retrain on theselection and use of electrosurgical equipment for laparoscopy."
Didactic education is imperative, say Michelle Carpenter, BSN, RN, CGRN,hospital supervisor at St. Joseph's/Candler Health, and Lisa Miller, LPN, CGN,staff nurse with Gastroenterology Consultants of Savannah (Ga.). They say it'snever too elemental for endoscopy team members and risk managers to review thebasics. "Electrosurgery is the basic component for anything that's donetherapeutic in an endoscopy suite," Miller says. "There are monopolarand bipolar generators, and HCWs must understand the whole process as well asthe mechanics of the units -- especially the older models because there are nosafety mechanisms in place. If you have a pad misplaced, the older ones willstill fire; the newer models won't fire if you don't have everything hooked upproperly. A lot of the education about current flow really needs to come fromreading the unit's manual, and HCWs need to know the individual machine;however, they also need the didactic education of learning from peers andeducators."
With so many older electrosurgery generators and instruments circulating inhospitals, Miller and Carpenter emphasize that HCWs need to be familiar with thefeatures of older and newer models, and be able to adjust surgical prepping andprocedure accordingly.
"The newer models have safety features that prevent firing if the pad ismisplaced, or if the cord is not hooked up to the machine properly," Millersays. "The older models will fire and you will get burned. A lot ofhospitals have both older and newer models, so that's when you really have topay attention to the unit and know what you are using. There's so much scienceinvolved with electrosurgery. In our education process, we start with thebackground, such as what a generator is, how electrodes work and what the sourceof radio frequency energy is and how it works."
"Electrosurgery and endoscopy are booming but it's challenging to findthe time to provide up-to-the-minute education," Carpenter says. "Itreally takes a manager or a director to say, 'We're going to have thisorientation process in place and we're going to make sure HCWs meet all of thesecompetencies in electrosurgery technology before we put them out on the floor.'I think there are sufficient opportunities for endoscopy suite members to geteducated."
With regard to formal best practices protocol for electrosurgery, Carpentersays there's very little that specifically addresses patient safety. She adds,"Safety is a big thing with Joint Commission on Accreditation of HealthcareOrganizations (JCAHO), and it's up to individual endoscopy teams and theirhospitals to examine their clinical practices carefully." Carpenter andMiller emphasize that there's no such thing as too much education when it comesto ever-changing technology.
"Education is critical," Miller says. "HCWs must be familiarwith whatever equipment and instruments they are using because they are not allthe same. The difference between cut and coagulation is big because everyonegets confused on that concept. Even the physicians ask, 'What happens if I turnthis (dial) up... does that mean I have more cut or more coagulation?'"
"To really be sure that the insulation is not compromised, I recommendimplementing an electrosurgical unit that employs active electrode monitoringtechnology, which virtually eliminates these type of electrical burns,"Vilos says. "AEM encases the insulated electrode in a protective metalshield that is connected to the generator; the entire probe also is covered withan extra layer of insulation. The extra conductive and insulating layers ensurethat stray current is contained and flows right back to the generator. Thesystem monitors the electrical circuit so if stray energy reaches dangerouslevels, the unit shuts off automatically and sounds an alarm before a burn canoccur. This is presently considered the standard of care in endoscopicelectrosurgery."6
Manufacturers of electrosurgical products using AEM technology say itrequires no change in clinical practice or surgical technique. Othermanufacturers are turning to argon-enhanced electrosurgery that introduces a newelement of precision and control in electrosurgical applications. The clinicalbenefits demonstrated by argon-enhanced coagulation include quick and efficientcoagulation; a thinner, more flexible eschar; less charring; and less tissuedamage.
Carpenter and Miller say HCWs should take several factors into considerationwhen evaluating electrosurgery products. "Criteria for selecting a brandwill differ from hospital to hospital, but we recommend endoscopy team leadersconsider what kind of patients they see to determine product needs,"Carpenter says. "They also should consider the total number ofelectrosurgery procedures performed, which will dictate what kind of equipmentis needed, for instance We do 1,400 to 1,600 procedures a month. They alsoshould think about how many physicians use the facility and the age of theirinstruments."