To the naked eye, even during close inspection, an electrosurgery instrument may look intact. But continued use, cleaning, and sterilization can cause the layer of insulation covering the shaft of the active electrode to break down. Minute, visually imperceptible tears in the insulation can go unnoticed during routine cleaning and sterilization. During surgery the defective insulation could allow 100 percent of the electrical current (averaging 700? C) to flow from the defect to the surgical site, burning tissue and organs. The smaller the crack, the more dangerous the effects, because the current escaping from small holes is more concentrated. And because 90 percent of the active electrode is outside the surgeon's field of view, the incident could go unnoticed.

To prevent electrode burns and detect insulation degradation, you need to have a comprehensive system for examining, testing, and caring for electrodes. Following are some techniques and devices that may help you do so.

The electrode
"The term active electrode is really a concept, rather than a description of a physical part," according to Bob Baxter, RN, CNOR, Abdominal Laparoscopic Specialist at Providence Everette Medical Center, Everette, Wash. "An electrode has a function, like scissors or a grasper, and it becomes an active electrode when it is used to cut tissue with electricity. The type of electrosurgery often used is monopolar, which means energy is transmitted to the body from an instrument connected to the generator. The electricity then travels through the body to a grounding pad. From there it returns to the generator, which completes the circuit."

A typical electrosurgery instrument has a handle, an exposed "pin" to which you attach the cord to the generator, and a shaft. At the tip of the shaft is an insert, which holds the "jaws," or the business end of the instrument. This insert is surrounded by an insulation sheath. The insulation must endure the wear and tear of repeated use and sterilization, and it could get cracked or nicked if the instrument is dropped, if several other instruments are placed on top of it, or if it is dumped in a pile in the decontamination area.

Some experts say that the insulation should hold up for at least twenty cases, but this depends on how well you take care of your instruments. One way to protect the insulation is to keep the generator temperature settings low. Some experts claim that staying within 270-275? F is safe, but it is best to contact the instrument's manufacturer to see what the company recommends. Using the "cut" rather than "coagulation" setting may also preserve the insulation, as coagulation uses significantly higher power than cut. Another stress on the insulation is char buildup on the electrode tip. Because char is a poor conductor, it causes excess energy in the electrode to be retained in the insulation, weakening it. Continuous activation of the electrode under these conditions could cause even new insulation to degrade.

Some manufacturers are making it even easier to detect insulation wear with the naked eye. One example is Megadyne's reusable Indicator Shaft, which features a patented dual insulation. The inner layer of insulation is bright yellow, and it is covered by a black layer of insulation. If the outer layer breaks, even if the defect is small, the inner layer shows through, alerting the user to replace the instrument. The indicator shaft can be sterilized with standard or flash steam cycles, or with ethylene oxide. It comes in 32 cm and 38 cm lengths and fits the Megadyne Disposable MegaTIP electrode.

When to test
When testing devices first became available, most facilities stationed them in central processing areas. This was a logical way to integrate these units into the cleaning and sterilization process. After the instruments were cleaned, they were tested and then sterilized. This is still the simplest way to adapt a testing device into your facility's routine, and many facilities feel that testing before sterilization is sufficient to detect defects.

Some testing device manufacturers, such as Mobile Instrument Services and Jac-Cell Medic, however, are recommending that facilities test instruments in the OR, immediately before use, to detect damage that may have occurred during sterilization or transport. They also recommend testing disposables before every use. These manufacturers also recommend testing instruments immediately after use to determine if they were nicked or cut during the case. Immediate follow-up testing could allow the surgeon to detect electrosurgical burns that the patient may have sustained during the procedure, which would have otherwise gone undetected.

Cleaning and sterilization
"Our staff performs a series of steps to ensure the safety of laparoscopic electrodes," says Robert Henry, CEO of American Endoscopy Services, which provides reusable medical equipment as well as service and technical support for laparascopic surgery and electrosurgery equipment. He recommends a simple five-step process to detect electrode defects:

1. Carefully examine each instrument directly after use during the cleaning process and set aside instruments with any obvious cracks or holes.

2. Clean the instruments with a soft brush and a gentle cleaning agent.

3. Check the instruments' insulation under a microscope.

4. Use an insulation testing device to detect defects invisible even under magnification. His staff usually performs this step twice to be certain the insulation is intact.

5. Steam sterilize the instruments.

Testing Devices
A number of testing devices can help you detect insulation defects. Two of note:

The InsulScan from Mobile Instrument Service