Choosing Your Active Electrodes with Care


A review of the pros and cons of reusable and disposable electrodes.

As surgeons from more and more specialties use monopolar and/or bipolar electrosurgery, the risk of electrosurgical burns increases. In laparoscopy, for example, electrosurgical burns account for 5.4% of all injuries, according to data compiled by the Physician Insurers Association of America. When you consider that an estimated 3 million laparoscopies will be performed annually in the United States by 2010 and that nearly nine out of 10 laparoscopic surgeons routinely use monopolar electrosurgery, electrosurgical safety becomes a primary concern. Electrosurgical burns from active electrodes result in three different ways:

  • Direct coupling. Usually a result of "pilot error" by the surgeon, direct coupling is when the active electrode touches (or comes into very close proximity with) a non-insulated metal instrument -- such as a laparoscope - and the current from the active electrode gets transferred to the other instrument. The transferred current can severely burn the patient.
  • Insulation failure. This is when current escapes through weak or broken insulation in the active electrode, causing it to burn unintended tissue.
  • Capacitive coupling. Capacitive coupling is a phenomenon of electricity. If the instrumentation is delivered in a specific way or if tissue becomes part of the capacitor, the energy will transfer and electrify the surface of the instrument and may burn non-targeted tissue. Both insulation failure and capacitive coupling are beyond the control of even the most skilled surgeon. These accidents are due to instrument failure - specifically, the active electrodes.

Calculate cost efficiency
If reusable instruments last only a year, there is virtually no difference in cost between the reusables and the disposables, as the reusable instruments are much more expensive.

In practice, however, most facilities continue to use their reusable active electrodes for up to two years. If you replace the instrument's cord - the part that plugs into the generator - within a year or so - you often can use them even longer. From a pure cost standpoint, this usually makes reusable electrodes the most cost-efficient option by roughly 10% over a two-year period. Reposables (active electrodes intended for several uses before disposal) fall second in line when you cost them out over the span of a couple years.

The best opportunities for economizing, I have found, lie in standardization. For example, we used to have nine different types of active electrodes on our lap-chole trays. But in talking with our surgeons, we learned that most of them only used a couple of electrosurgical instruments on the tray and used the others for grasping and retracting without using any current. Reducing the number of active electrodes we ordered saved us a bundle without affecting patient care.

Factor in sterilization
This is an area where disposable electrodes have an advantage, as sterilization is a moot issue. Consistency with product quality during the procedure is more or less guaranteed. Additionally, many facilities, especially hospitals, outsource the routine maintenance of their electrosurgical instruments, which adds cost.

There is no conclusive scientific evidence that I know of to indicate the "best" way to sterilize reusables and reposables. Purely anecdotal evidence suggests that steam sterilization seems to have the harshest effects on the reusable instruments. The insulation can crack and the electrode tips can break off sooner. Gas sterilization generally seems to be gentler on the instruments. Manufacturers should give you clear sterilization parameters for their instruments.

Regardless of the sterilization method, if you can get ten uses, on average, from a single reusable active electrode tip before it becomes too brittle to use, you've gotten your money's worth out of it.

Assess insulation failure risks
If you do not use an electrosurgery unit with AEM (active electrode monitoring) technology, the insulation of the electrodes is your only line of defense against stray tissue burns. Thus, the integrity of the insulation is absolutely vital.

Insulation failure can occur with any electrode as a result of the constant introduction and removal of the instrument during surgery, damage caused by high voltages, general handling, and, in the case of reusables and reposables, cumulative stress caused by sterile processing. If the surgeon uses a high voltage waveform during the procedure, there is a greater chance that, if there is a small hole in the insulation to begin with, the current will cause it to tear further.

Reusable active electrode manufacturers often claim that the chance of insulation failure is higher with disposable electrodes. Indeed, a study published in the August 1995 Journal of Reproductive Medicine concluded that the disposables generally had thinner insulation and posed greater risk of insulation failure intraoperatively. Since then, manufacturers of the disposable and reposable electrodes have strived to improve insulation quality and performance.

Even a tiny insulation defect is dangerous, and, in fact, it may be more dangerous than a large one. The smaller the defect, the higher the current density that can be transferred to nearby non-targeted tissue.

Visual inspection of the instruments before and after each use helps to reduce the risk but cannot eliminate it. At one of my facilities, we tested a batch of nine laparoscopic electrosurgical instruments that passed careful visual inspection. We ran each instrument through one of the insulation testing devices that are available on the market (specifically, the InsulScan from Medline). Three of the nine instruments failed, and we took them out of circulation. Unfortunately, most facilities have no formal insulation testing protocol.

Reduce the risk of capacitive coupling
Capacitive coupling, a relatively uncommon phenomenon, can occur when an insulator separates two electrical conductors in close proximity. In the case of laparoscopic electrosurgery, for example, the trocar, the active electrode and tissue are often in close proximity. Even if the insulation is intact, thermal energy can sometimes be transferred to non-targeted tissue.

Unfortunately, as other aspects of electrosurgery have gotten safer, the risk of capacitive coupling has not decreased. Here's why. As the number of laparoscopic procedures has increased, the need to lessen the costs of reprocessing instruments has obliged facilities to mix and match reusable and disposable instruments. The mixing of reusables and disposables during a procedure (which brings conductive and non-conductive materials in close proximity) can facilitate capacitive coupling.

Take safety precautions
Anything you can do to make the procedures safer is well worth the investment. The cost of treating a single stray electrosurgical burn accident is astronomical in purely financial terms, not to mention physical and psychological trauma to the patient and potential litigation from the case.

Fortunately, electrosurgical technology has come a long way and has become much safer. Most electrosurgical generators today use very high frequency current (at least 300 KHz), meaning that surgeons can use much lower voltages of electricity than in the past, which helps reduce the risk of patient burns. If you don't have a "modern" electrosurgical unit, it's time to upgrade.

Secondly, there are several extremely useful technologies that are designed to ensure that the electrodes function properly. There is contact quality monitoring (CQM) for return electrodes, which greatly reduces the risk of burns at the return site in monopolar electrosurgery. Active electrode monitoring (AEM) does the same for the active electrodes. The technology can ensure that burns cannot occur due to stray energy (either via insulation failure or capacitive coupling).

The drawback to AEM? Cost, but instrument acquisition is a yearly purchase with reusable instruments, and that cost remains constant. You do have to buy a generator with the AEM technology, and you must also purchase active electrodes (available in both reusable and disposable varieties) that interface with the AEM. The technology is endorsed by AORN and I am also personally a big believer in using AEM. It reduces the risk of active electrode failure to virtually nil, although the risk of user error still exists.

Lastly, you can purchase an insulation testing system to detect even the tiniest defects and cracks.

Reach a verdict
You can perform electrosurgery safely whether you choose reusable or disposable monitored active electrodes.

Given the high stakes, it is imperative that when you choose your electrodes, you consider the big picture of cost, convenience, and, most importantly, safety.

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