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Education in Electrosurgery Technology is Key for Endoscopy Team Members
Kelly M. Pyrek
12/01/2001
It is estimated that more than 3 million laparoscopic surgical procedures are performed annually in the US, with approximately 85% of surgeons utilizing electrosurgical instruments in these procedures.1 The ubiquitous nature of these procedures has the members of many endoscopic suites paying particular attention to reducing the risk of inflicting thermal burns to patients during minimally invasive surgeries. While minimally invasive surgery technology is revolutionizing healthcare--reflected in the tremendous advances made in science--it may exact a greater price for the benefits it yields. These burns can cause patient injury, serious post-operative complications, even death. Burns often are caused by either faulty equipment, such as electrical generators and electrodes, or by incorrect usage by healthcare workers (HCWs). Unintended tissue damage can result from stray electrosurgical burns caused by insulation failure and capacitive coupling during laparoscopy. An elemental understanding of electricity is key to avoiding burns. Since electrical current flows toward the ground and it follows the path of least resistance, it stands to reason that monopolar electrosurgery creates a complete electrical circuit from the active electrode to the targeted tissue, to the dispersive return electrode, and back to the generator.2 George Vilos, MD, professor of obstetrics and gynecology and the director of endoscopic surgery at the University of Western Ontario in Canada, writes, "Because surgeons now work through keyhole incisions and manipulate electrodes and instruments through long, narrow channels, it is more difficult than ever to prevent the electricity from traveling outside this path and burning or vaporizing non-targeted tissue."3 Many burns during electrosurgery can be traced to direct coupling between surgical instruments, insulation failure, and capacitive coupling. Insulation failure can occur when the insulation along the shaft of the active electrode breaks down and electrical currents "leak" from the instrument and burn nearby tissue. Causes of insulation defects can range from normal wear and tear, to stress placed on the electrode from high voltages. Capacitive coupling occurs when electrical current is induced from the active electrode to nearby conductive material through intact insulation. In electrosurgery, the charge on the active electrode switches from positive to negative at a very high frequency. The varying electrical field around the active electrode can transfer high-levels of electrical current to nontargeted tissue and cause burns. A common culprit in electrosurgical injury is the dependence by HCWs upon wattage indicators, which are trusted to significantly eliminate improper power output selections. Wattage, which is a measurement of the power obtained when voltage is multiplied by amperage, may not be accurate in a given application, in that a HCW could be utilizing insufficient voltage or excessively high voltage even if the number of watts is low. For example, 20 watts from a low-voltage bipolar generator could contain 200 volts or up to 10,000 volts if the bipolar unit is improperly designed.4 Another caution about wattage indicators is that they only show the power delivered to the generator's output socket under a given impedance load. When the electrical current is discharged from the unit through the attached RF (radio frequency) connection cable, it can be affected by not only the capacitance levels, but the environment in which the procedure is performed. Karl Hausner, president of Elmed Incorporated, says, "The long, insulated instruments and the associated instrument cannulae used in endoscopic surgery create a significant amount of capacitance in the electrosurgical circuit, making the higher voltage current extremely hazardous, both to patient and personnel. This also renders the wattage indicator less useful."5 Voltage can have a dramatic effect on the performance of the electrosurgical electrode, as the higher the peak voltage, the greater the chance for capacitive discharge through the electrode insulation or the RF cable. For this reason, more than two decades ago the American Association of Gynecological Laparoscopists (AAGL) developed voluntary standards to prevent patient injuries. Within these standards, which were published in the Federal Register on Feb. 26, 1980, is the recommendation that unipolar output power be limited to 1,200 volts and 100 watts at maximum generator output.6 According to surgical instrument manufacturer Richard Wolf, the maximum output power of the electrosurgery unit must be matched to the surgical application. For gastroenterology, gynecology, and rhino-laryngology procedures, the company recommends unipolar output power should not exceed 120 watts, and units with incorporated coagulation current source for blended current, 170 watts.7 While technology and gadgetry can lend an air of heightened patient and HCW safety, there is increased need for caution. "More important than flashy meters is the realization that surgery during the last decade has become enormously sophisticated," Hausner says. "Therefore, a specially designed electrosurgical unit should be utilized for surgical procedures such as endoscopic polypectomy and laparoscopic procedures. The surgeon who has been using electrosurgical equipment empirically for a long time will have to retrain with respect to the selection and use of electrosurgical equipment for laparoscopy." Didactic education, say many HCWs, is imperative. Two such proponents are 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. They say it's never too elemental for endoscopy team members to review the basics. "Electrocautery or electrosurgery is the basic component for anything that's done therapeutic in an endoscopy suite," Miller says. "There are monopolar and bipolar generators, and HCWs must understand the whole process as well as the mechanics of the units--especially the older models because there are no safety mechanisms in place. A lot of the education about current flow really needs to come from reading the unit's manual, and HCWs need to know the individual machine; however, they also need the didactic education of learning from peers and educators." With so many older electrosurgery generators and instruments circulating in hospitals, Miller and Carpenter emphasize that HCWs need to be familiar with the features of both older and newer models, and be able to adjust surgical prepping and procedure accordingly. "The newer models have safety features that prevent firing if the pad is misplaced, or if the cord is not hooked up to the machine properly," Miller says. "The older models will fire and you will get a burn. A lot of hospitals have both older and newer models, so that's when you really have to pay attention to the unit and know what you are using. "I've developed the nurse clinician role here at St. Joe's/Candler about six years ago and we really focused on education," Carpenter says. "GI is booming and so is electrosurgery and endoscopy, and it's challenging to find the time to provide up-to-the-minute education. It really takes a manager or a director to say, 'We're going to have this orientation process in place and we're going to make sure HCWs meet all of these competencies in electrosurgery technology before we put them out on the floor.'" Regarding formal best practices protocol for electrosurgery, Carpenter says there's very little that specifically addresses patient safety. She adds, "Safety is a big thing with Joint Commission, and it's up to individual endoscopy teams and their hospitals to examine their clinical practices carefully." Carpenter and Miller emphasize that there's no such thing as too much education when it comes to ever-changing technology. "HCWs must be familiar with whatever equipment and instruments they are using because they are not all the same," Miller says. The difference between cut and coag is a big one because everyone gets confused on that concept. Even the physicians ask, 'What happens if I turn this (dial) up... does that mean I have more cut or more coag?'" Healthcare personnel are not the only ones scrutinizing current electrosurgery technology from a safety standpoint. Many medical malpractice insurance companies encourage physicians to consider using active electrode monitoring (AEM) technology, as used in products from manufacturer Encision, to enhance patient safety and reduce risk electrosurgical risk in laparoscopic surgery. One such group is the State Volunteer Mutual Insurance Company (SVMIC) in Boulder, Colo. "We encourage each of our physician policyholders to go to their respective hospitals and request the AEM system be utilized to improve patient safety," says Jackie Hough, vice president of risk management for SVMIC. She says the company provides physicians a 10%discount off their insurance premium for participating in the group's seminar on the avoidance and management of complications in laparoscopic surgery. Insurance groups in Arizona and Wisconsin, as well as the American Physician Insurance Exchange, have followed suit in championing the use of AEM technology. "To really be sure that the insulation is not compromised, I recommend implementing an electrosurgical unit that employs active electrode monitoring technology, which virtually eliminates these type of electrical burns," Vilos says. "AEM encases the insulated electrode in a protective metal shield that is connected to the generator; the entire probe also is covered with an extra layer of insulation. The extra conductive and insulating layers ensure that stray current is contained and flows right back to the generator. The system monitors the electrical circuit so if stray energy reaches dangerous levels, the unit shuts off automatically and sounds an alarm before a burn can occur. This is presently considered the standard of care in endoscopic electrosurgery."8 Manufacturers of electrosurgical products using AEM technology say it requires no change in clinical practice or surgical technique. Other manufacturers are turning to argon-enhanced electrosurgery that introduces a new element of precision and control in electrosurgical applications. The clinical benefits demonstrated by argon-enhanced coagulation include quick and efficient coagulation; a thinner, more flexible eschar; less charring, and less tissue damage. Carpenter and Miller say HCWs should take several factors into consideration when evaluating electrosurgery products. "Criteria for selecting a brand will differ, but we recommend that endoscopy team leaders take a look at what kind of patients they see to determine product needs," Carpenter says. "They also should consider the total number of electrosurgery procedures performed, which will dictate what kind of equipment is needed. We do 1,400 to 1,600 procedures a month, for instance. They also should think about how many physicians utilize the facility as well as the general age of their instruments. The cost of technology and the safety of HCWs and patients never seem to meet at the same place, so it's a balancing act." Did You Know? While heat or fire has been used as a crude method of hemostasis for more than 5,000 years, it wasn't until the early 20th century that the vacuum tube was invented and used to produce heat at the site of an electrode. Just teetering on the edge of the electrosurgery era, in 1875, electric current was passed through wire loops until they were red-hot and heat was transferred to the tissue. While this was an example of early electrocautery, it wasn't considered true electrosurgery, which involves the cutting or coagulation of tissue by passing a high-frequency current through the target tissue. This method was first practiced in 1924 by famed neurosurgeon Harvey Cushing, MD. Cushing had recruited assistance from Harvard physicist William Bovie, whose name ultimately became synonymous with electrosurgical units (ESUs). These ESUs developed by Cushing and Bovie consisted of two small metal-conducting pieces separated by an air gap that worked like an automobile spark plug. When the voltage rose enough to jump across the air gap, the air became ionized and functioned as a conductor. In 1928, Cushing published a study of 500 cranial procedures in which tumor removal and hemostasis were performed using his ESU. In the 1970s, the vacuum tubes in earlier models of ESUs were replaced by solid-state circuit boards and transistors. The advancement of medical technology has since then improved the safety and versatility of ESUs. Information from www.eddesign.com. Additional resources for electrosurgical product information Anthony Products, Inc., (877) 428-1610, www.anthonyproducts.com
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