Electrosurgical smoke evacuation makes good sense, as we now know that the electrosurgery plume contains respiratory irritants, mutagens, carcinogens and pathogens that may put the OR team and surgical patient at risk (see "The Health Risks of Surgical Smoke" on page 67). Modern systems are also quieter and more streamlined, making them easier to use than ever before. Perhaps one of the biggest remaining challenges, then, is to figure out which system is right for your facility. To help you sort through the many options, here are some things you need to know about surgical smoke evacuation systems.

Stationary vs. portable
There are two types of surgical smoke evacuation systems: stationary and portable.

• Stationary (or centralized) systems are integrated into the facility in that the piping is built into the walls. The OR team controls the system from the OR, and there are several possible configurations. You can equip each OR with a fully independent system; you can centralize suction, filtration and exhaust; or you can centralize just the suction and exhaust while housing the control and filtration components in the OR. These systems can also exhaust air in one of four ways: back into the OR, outside the building, into the interstitial spaces or through the HVAC system (the latter two options can be technically challenging to implement). Stationary systems can also preserve floor and cart space and eliminate cable clutter, since the control unit mounts on the wall or integrates into the surgical boom.
• Portable systems house the control, suction, filtration and exhaust components in one unit. They can mount on a cart, table or wall. Some units are quite compact and, despite their small size, are just as effective as stationary units.

Plume capture and filtration
The most important feature of a smoke evacuation system is how well the system captures the plume, followed by how well the system filters particulates and gases. The performance of each model depends on airflow and tubing parameters.

• Airflow. Since airflow creates the suction, it is usually a key measure of a system's ability to capture the plume. In general, the higher the airflow, the better the plume capture. Not all systems, however, rely solely on airflow to create suction. I.C. Medical's smoke evacuation system for electrosurgery plume captures smoke in part by creating a vortex around the tip (akin to water going down a drain), due to its rotary vein pump and tip design.
• Tubing diameter and length. Electrosurgery typically requires small-lumen tubing, and laparoscopic procedures may require long tubing. Small-diameter long tubing can reduce air flow around the outside of the tip and inhibit plume capture. In these cases, the suction must be powerful enough to create sufficient air movement around the tip.
• Portable systems. Since all portable systems exhaust air back into the OR, they must perform a high level of filtration. They typically filter particulates with high-efficiency filters like HEPA or ULPA filters first, then filter gases with activated carbon filters. Some systems also require an additional prefilter for larger particulates and small amounts of liquids, although this is typically needed during laser procedures.

At high airflows, the activated carbon may not be able to absorb all noxious gases, and odor may be evident. For this reason, it can help to use a coconut-based charcoal filter, which has better absorptive qualities than a wood-based charcoal filter.

• Stationary systems. With these systems, filtration needs differ depending on exhaust location. When air vents back into the OR, you need the same high level of filtration as portable systems. When air vents outside, you can exhaust the unfiltered smoke, although air vent location is important in this case. The other venting options (interstitial spaces or HVAC) require filtration.

Your purchasing considerations
Before the advent of quieter, more streamlined systems, many surgeons resisted smoke evacuation because it necessitated another device and an assistant's hand in the surgical site. Older systems also tended to be noisy and cumbersome. Here are a few features to consider:

• Combination handpiece. Systems are available with integrated electrosurgery unit (ESU) pencil/smoke evacuation handpieces or as wands that attach to standard ESU pencils. Both of these combination handpieces give the surgeon much greater control than the separate smoke evacuation systems, which require an assistant. A system that's not too bulky will help minimize the surgeon's hand strain and enable access to small sites. As these handpieces use small-lumen tubing, evaluate their plume-capturing capability.
• Automatic evacuation. Some systems come equipped with a sensor that automatically activates the smoke evacuator when the surgeon turns on the ESU pencil.
• Quiet operation. Continuous whining or high-pitched noises may cause some staff members to stop using the systems. Automatic and foot-pedal activation help limit noise.
• Laparoscopic application. Some smoke evacuators are designed to work with the insufflator during laparoscopic procedures to ensure removal of smoke without losing the pneumoperitoneum.
• Blade options. Some ESU/ smoke evacuation systems offer a fixed electrosurgery blade, while others let the surgeon select from various blades.
• Extendability. Some ESU/ smoke evacuation wands extend for use in deeper cavities with ESU pencil extension blades.
• Tissue protection. Smoke evacuation tubings can suction tissue or sponges during a plume-producing procedure. Consider a nozzle design that doesn't let tissue enter into the tubing or a system that offers automatic, temporary suspension of suction when the tube becomes obstructed.
• Ease of maintenance. Maintenance is an important consideration for portable units, as filter life varies from single use to 35 hours to six months. See what type of filter replacement indicator manufacturers offer. Systems may come with timed indicators, filter-life indicators or none at all. Indicators are good for helping the staff remember to replace filters, and filter-life indicators are ideal. While timed filter indicators simply show when the filter's running time has lapsed, filter-life indicators sense the amount of airflow and thereby provide evidence of filter function. This can maximize filter life, especially if surgeons keep smoke evacuators on continuously, even when they're not evacuating plume.

Stationary systems have longer-life filters and require less day-to-day maintenance, although when problems do occur (piping leaks, for example), they can have a greater impact on the facility. They also require periodic valve adjustments and, according to ECRI, may involve more than one maintenance contractor (piping as well as component maintenance). The in-wall piping also requires regular flushing to prevent buildup of particulate matter from the surgical smoke.

Cost considerations
When evaluating costs, consider disposable costs as well as the life of the unit.

Filters, tubing and other disposables add greatly to the cost of operating a smoke evacuation system. According to an ECRI analysis, a portable unit that cost $2,995 was 50 percent less expensive to operate on a per-case basis than a portable unit that cost $950 - rendering the more expensive unit more cost-effective in the long run. Shop for the best price you can on disposables and avoid locking yourself into long-term supplier contracts.

While stationary systems are more expensive to buy and require permanent installation, they can last twice as long as their portable counterparts, and can reduce filtration needs when you exhaust air outside. Stationary systems cost about $5 to $6 per use, whereas portable systems cost $7 to $14 per use - an approximate savings of $6,000 per OR per year.