Your standard electrosurgical device, still called a "Bovie" by most of us after its inventor, William T. Bovie, MD, has been around since the late 1920s, and for decades the technology remained pretty static. It's really been only in the past 15 to 20 years that we've seen a radical shift toward energy-driven surgical devices that can cut and seal tissue with more precision and less thermal spread than the traditional electrosurgical unit (ESU). These newer, improved devices are becoming increasingly commonplace in the operating room, but it's important to remember that they're very different from the traditional ESU — and from each other. Even with all the advances we've made, electrosurgery is still potentially dangerous if not handled properly. Here's a review of how the new energy sources function and how to operate them safely.

Bipolar sealing devices
While not exactly new, devices like Covidien's Ligasure and Ethicon Endo-Surgery's Enseal are more recent additions to the surgical toolbox than the standard ESU. These devices, and others like them, use radiofrequency energy like the ESU does, but with a combination of heat and compression that both cuts and seals tissue, all in a matter of seconds. Typically the device consists of a handle with controls, a wand and a "jaw" at the end of the instrument that grasps tissue, bites down on it and releases energy to cut and seal via the dual action of compression and heat.

These sealing devices are similar in that they don't use the patient to complete the electrosurgical circuit and therefore don't require plating to protect patients from stray current. But these devices aren't interchangeable: Each has a unique design, means of delivering energy and other specifications that impact their safe use. Examples:

• Lateral thermal spread. How far will the heat from the device travel when activated? Limiting the lateral thermal spread around the area of tissue to be desiccated and better concentrating the heat inside the configuration of the jaw lets you spare more of the surrounding tissue from damage.
• Compression pressure and distribution. When you grasp or clamp down on tissue with the jaw of the instrument, does the compression spread evenly throughout the jaw? Some devices are shaped more like scissors, creating an uneven distribution of pressure, while others have a component incorporated into the jaw of the instrument that distributes pressure evenly throughout the bite.
• Grasping capacity. How much tissue and vessel diameter can the instrument grasp and still effectively cut, seal and coagulate?
• Speed. How quickly does the instrument completely seal the tissue once activated? Some work faster than others (although the difference may be a matter of seconds), and it often depends on the type and thickness of the tissue you're working with.
• Waveforms. A waveform is a duty cycle or frequency of the electrical energy delivery to produce the effects of cutting, coagulation or vaporization of tissue. All of these devices have proprietary waveforms.
• Design, length and size of instrument. These features may determine whether one device is preferable over another for a certain type of surgery, such as a laparoscopic vs. open procedure.

Ultrasonic scalpels
Ultrasonic energy uses electrical current that's converted into rapid vibrations (several thousand times a second) to generate heat. That heat is then used to cut, create a cavatational effect and coagulate tissue with a high level of precision, which is why ultrasonic energy devices used in surgery are typically referred to as ultrasonic scalpels. These instruments can be used in procedures such as hysterectomies, thyroidectomies, tonsillectomies and other soft-tissue dissection procedures. They don't create a lot of tissue destruction and can have a much smaller depth of penetration than standard electrosurgery (less than a millimeter vs. around 3.5 to 4mm), which helps to reduce the potential for complications associated with unintentional heat distribution. Much like the bipolar cutting and sealing devices, ultrasonic scalpels can serve multiple functions: gripping, cutting and coagulating.

When evaluating new technology and devices and training your staff and physicians, you'll want to consider the configuration of the blade specific to the type of procedure, the techniques used to create a cutting or coagulating effect to tissue, the speed and depth of its cutting and vessel sealing power, and how the technology works with different types of tissue. With ultrasonic energy, the tissue tension and grip force of the instrument can determine whether the device cuts or coagulates tissue.

Plasma energy
One of the more recent newcomers to the surgical cutting and coagulating field, plasma kinetic energy is marketed as an alternative to electrosurgery because it doesn't involve any electrical current flow to the tissue. Rather, a low voltage of electrical energy is applied to a low flow of argon gas within the device to create argon plasma that's then emitted from the tip of the device to cut tissue and seal vessels without deep penetration. Because it doesn't emit electrical current, the device carries less risk of interference with pacemakers and other electronic devices in or near the patient. Through a combination of light, heat and kinetic energy, plasma can be used both to cut tissue and create a thin layer of coagulation to prevent bleeding. This technology is ideal for liver resections, mastectomies and other procedures where it's particularly important to control bleeding.

Patient safety steps
The biggest safety benefit of these newer devices is that they don't use the patient to complete the circuit, therefore reducing the risk of patient complications as a result of extraneous energy and the need to use grounding plates and capacitive pads necessary during standard monopolar electrosurgery usage. But regardless of the energy source used, take these steps to prevent patient burns, OR fires and other safety hazards:

• Let prep solutions dry fully before activating the energy source.
• Keep electrosurgical tips and handpieces off drapes and other textiles, even when not in use. Place them in a protective holster or define a process to prevent inadvertent activation.
• Identify processes to either decrease the amount of oxygen or discontinue oxygen sources used during surgery.
• Evacuate surgical smoke generated at the source (see "Thinking of Buying Surgical Smoke Evacuation Devices," May, page 62).

Simply holding a one-time in-service with the vendor or sales rep right after purchasing a new electrosurgical device probably won't do much to clear up the confusion over the growing diversity of energy sources used in surgery. While the vendors and reps can be a great educational resource, your staff may respond better to repeat training and education delivered by your clinical manager, clinician or some other respected and authoritative member of your nursing staff. And don't forget to include surgeons in your educational efforts when possible. They can be just as susceptible to confusion with these devices as your nurses and techs, and it's important to keep all surgical team members on the same page when it comes to electrosurgery safety.