Safety is the driving force behind the development of today's electrosurgery generators, which not only help to minimize tissue damage and skin burns but also let surgeons select different waveforms for cutting and coagulation. Here are the factors you should consider to determine which device will best protect your patients and provide optimal performance for your OR staff.
Built-in safety indicators should be the No. 1 factor you consider when deciding what type of generator to purchase.
- Alarms. Is there a visual and audible plate placement alarm that alerts you when a plate is coming loose? Does the generator automatically decrease the voltage and make the necessary correction if it senses resistance (such as activation before touching the tissue)? Does the generator read tissue resistance?
- Test mode. Your generator should have a test mode that lets staff test the generator's functions before a case, as well as a self-assessment mode so the machine can diagnose any kind of functional problem itself.
- Isolation feature. A generator should be isolated from the ground to prevent electrical interference or alternate-site burns as a result of electrical transfer, which can result in fires.
- Smoke evacuation. Because electrosurgery generates hazardous smoke, it's also helpful to have a built-in smoke evacuator that automatically activates when the machine is in use. You could also purchase a stand-alone smoke evacuator.
- Discrete output technology. With traditional non-discrete output, if two pencils are hooked up to the generator, they're both activated with the same amount of current, which can cause alternate-site burns if the one that's not being used touches the patient. With discrete output technology - also known as discrete simultaneous on-demand or first-come, first-served activations - the current is based on the tissue resistance of whichever pencil is activated first. This decreases the risk of burns.
Choice of current
Electrical current can be delivered two ways: monopolar or bipolar. In monopolar electrosurgery, there are three basic components: the generator, the active electrode and the return electrode. These components, along with the patient, provide the circuit and the route for the current to flow back to the generator.
In contrast, bipolar energy delivery doesn't require the use of a return electrode (patient plate) the electrical current is delivered and returned to the same site. The surgeon grasps the tissue between bipolar forceps, in which one prong acts as the active electrode and the other acts as the return electrode. The current path doesn't travel through the patient; it's confined only to the tissue that is grasped between the forceps.
The bipolar mode is an excellent tool for surgeries that may have oxygen delivery, such as dental, ophthalmic, neurological and ENT procedures, because the current is confined to the immediate area surrounding the electrode. There's also no risk of return electrode burns and inadvertent thermal burns from alternate electrical paths. Although bipolar electrosurgery is an excellent coagulator, keep in mind the lateral thermal spread of energy to tissue.
While the majority of surgical procedures use monopolar mode, most manufacturers sell generators that have both modes, which lets the surgeon switch between monopolar and bipolar currents during the surgical procedure. Neurosurgery is one of the surgical specialties that still mostly use bipolar generators exclusively.
Frequency and waveform
Most generators have varying frequency levels and operate at a minimum of 300kHz, so as to not stimulate nerves or muscle. The amount of frequency creates what is referred to as waveform and affects the rate of how energy can cut, coagulate and vaporize tissue. The amount of thermal spread to tissue is dictated by the waveform of the energy in use as well the physician's surgical technique. There are also ultra-high frequency generators, which are said to cause less neuromuscular trauma, but most surgeons believe that there is a leveling-off effect as long as the frequency is above 100kHz.
Generators produce a variety of waveforms; different waveforms produce different cutting and coagulation effects on tissue. What happens to the tissue depends on how long each waveform is on or off. Surgeons will use varying levels of cutting and coagulation depending on the procedures they perform, so it's vital to buy a generator that offers many different waveforms; however, simplicity is important. You don't want the waveforms to be too complicated for staff to understand the impact they have on your patients' tissue and safety.
If your center does a lot of specialty procedures, such as urology or other surgeries in which the electrical delivery will be present with fluid, you might want to consider buying a specialty ESU designed specifically for those types of procedures in addition to a universal generator (if your facility can afford it). Specialty generators have more precisely tuned waveforms geared to specific procedures. If you have a single-practice office or a freestanding surgical center, a customized-current generator may be the way to go.
How much voltage do you need?
Different generators produce different levels of power, especially in terms of voltage. Universal generators span a wide range of voltage outputs in terms of cutting and coagulation because different procedures vary widely in the required levels of voltage. It's important to know how much power you need for the types of coagulation or cutting you do at your facility. For example, there is "pinpoint" coagulation, "low-voltage" coagulation, fulguration coagulation and desiccation coagulation, and each type's different effects delivers different amounts of voltage.
Because even universal generators vary in terms of their output, you should ask the company which procedures the unit is recommended for and which ones it isn't. This way you can know whether a certain generator will work for your facility.
Displays and controls
With displays and controls, you want to keep things as simple as possible; you may have many different nurses and staff rotating from place to place, so by keeping your generator controls simple, you can help to eliminate user confusion and error.
Having presets can be a good idea, as they let a surgeon choose the setting (such as frequency, waveform, cutting, coagulation) based on the procedure and reduce the need to change between settings. Too many presets, though, can be overwhelming and reduce the ability of the surgeon to perform the procedure as he wants. The switch for the monopolar/bipolar mode should be easily identifiable, as should the controls to switch between the different cutting and coagulation currents. It's also a good idea to have a generator with both hand and foot controls, as this option lets surgeons choose which control they are more comfortable with.
An easily readable display is a must, as nurses will generally be the ones most frequently looking at the displays. Something simple will make the generator easy for both doctors and nurses to use.
Cost of disposables
When you're purchasing an electrosurgery generator, you're also purchasing the electrodes that deliver the electrical current to the tissue. You'll need various different active electrode devices for both monopolar and bipolar modes, such as bipolar forceps, pencils and loop electrodes.
Most electrodes are manufactured to be compatible with an array of generator makes and models, but don't take it for granted. Always validate per the generator manufacturer's written instructions the machine's compatibility with various disposable products so you know which electrodes go with which units before you purchase or use electrodes.
Many generator manufacturers offer programs that roll the capital expense of the ESU into the cost of their brand of disposable supplies. Participating in such a program might get you a new ESU without any out-of-pocket expenses, but the manufacturer will bind you to using that company's supplies for a set period of time or cost. However, this type of agreement could work for your facility if it's in your budget to do so.
Or you could opt to buy the generator apart from any supply agreement and negotiate pricing on both the generator and the disposables while maintaining the flexibility to change supply vendors. Just make sure to investigate all avenues and don't enter into a long-term agreement until you've read the fine print.
Training and evaluation
When purchasing any type of surgical equipment, don't overlook the training that you and your staff receive. AORN classifies the electrosurgical unit as the most hazardous device used on a daily basis, and continuous staff development and competencies should never be compromised. Because there are many types of generators with various differences, it's important that the company provides some form of training and education, such as a self-study module or workshop. Evaluation and trials are also crucial when making a purchasing decision. Make sure to consider OR nurses' input as well as surgeons', as the nurses will be the ones programming and assessing the equipment and placing the return electrode.
FYI: Bovie Medical's ICON GI electrosurgical generator for gastroenterological procedures features an intuitive touchscreen interface and a physician preference database, and has all the connectors necessary to integrate it into the GI suites of the future, says the company. The ICON GI accepts all standard active accessories (monopolar and bipolar) and features a pulsed output mode specifically tailored for polypectomy and ERCP procedures.
System 2450 Electrosurgical Generator
Price: Not disclosed
FYI: ConMed's System 2450 Electrosurgical Generator offers "dynamic response" technology, which provides surgeons with smooth cutting, powerful coagulation and precise bipolar desiccation, says the company. The system is also easy to set up and operate, adds ConMed.
DRE Medical Equipment
Price: Not disclosed
FYI: DRE Medical's ASG 200 unit uses digital hardware instead of a general-purpose controller for processing data. This hardware allows parallel data processing and generates very high data processing throughput, measuring tissue impedance 5000 times per second, says the company. All data is sampled and processed digitally, converted to analog only in the output stage.
Ellman Radiolase II
(800) 835-5355 ex. 6412 or ex. 6414
Price: $4,995 to $6,500
FYI: Ellman's Radiolase II incorporates the high frequency of 4.0MHz to minimize heat dissipation and thus cellular alteration. The device lets general surgeons use both monopolar and bipolar modes in terms of tissue preservation and safety. Clinical benefits include reduced post-operative discomfort, minimal scar tissue formation, maximum readability of histologic specimen, enhanced healing and excellent cosmetic results, says the company.
ERBE VIO System
Price: Not disclosed
FYI: This ceiling-mountable workstation combines full ESU function, argon plasma coagulation and reusable BiClamp vessel fusion, says the company. It also features a compact, space-efficient design, modular scalability and upgradeable software, new monopolar and bipolar cut and coag modes, and enhanced APC functionality.
Gyrus ACMI G400 Generator
Price: Not disclosed
FYI: Gyrus ACMI's G400 Generator offers a powerful solution in surgical tissue management: PK Technology, which delivers a proprietary RF energy waveform to create a broad range of tissue effects for a multitude of surgical applications, says the company. The generator provides advanced sealing and cutting with superior hemostasis, delivering a minimal amount of energy to achieve the desired tissue effect, adds Gyrus.
Karl Storz Endoscopy-America
Autocon II 400 Electrosurgical Unit
Price: Not disclosed
FYI: Karl Storz's Autocon II 400 ESU offers surgeons a single unit capable of powering both bipolar and monopolar instruments while featuring automatic output regulation and optimal hemostasis, says the company. The energy path is shallow and consistent, resulting in minimal thermal damage, reduced complications and faster healing time, according to Karl Storz.
Premier Medical Products
Model 2001e Electrosurgery Unit
FYI: Premier's Model 2001e Electrosurgery Unit includes five distinctive output modes, isolated output and patient circuit monitor, digital diagnostic error codes and an optional foot control, says the company.
Richard Wolf Medical Instruments
Wolf Bipolar Generator
Price: $3,450 to $4,450
FYI: The Richard Wolf Bipolar Generator is the latest digital bipolar generator to be equipped with a proprietary audible and visual ammeter that clearly indicates the endpoint to coagulation, says the company. The "smart" bipolar technology measures tissue impedance and adjusts the power to optimize performance. The generator is specifically designed for use with the Kleppinger Bipolar Forcep, PowerBlade and PowerGrip forceps.
Universal Power Supply (UPS)
FYI: Starion's new Universal Power Supply weighs three pounds and is designed to hang from an IV pole. It incorporates all of the advantages of previous models and is compatible with all Starion instruments, says the company. In addition, this enhanced model has an adjustable hanger that allows 360-degree rotation and push-button volume and power controls.
Force FX Electrosurgical Generator
Price: Not disclosed
FYI: Valleylab"s Force FX Electrosurgical Generator provides Instant Response Technology, which gives improved performance at lower power settings, minimizing the risk of tissue damage and neuromuscular stimulation, says the company. The generator adjusts automatically, responding to tissue changes, maintaining power delivery and minimizing drag.