Innovative Whole-Room Disinfection Options

Colder air circulation and UV lighting systems are gaining traction among forward-thinking ASCs.

Our health system acquired part of an under-utilized shopping mall and converted it into a surgery center.

Installing state-of-the-art pathogen control systems was a top priority for the institution. One of the eight operating rooms constructed within the UR Medicine Orthopaedics & Physical Performance Surgery Center in Rochester, N.Y., includes a temperature-controlled airflow (TcAF) system — the first of its kind in a U.S.-based surgical center. The facility opened in February 2023.

The unit, manufactured by a European company, is designed to deliver the air over the table within the sterile zone three degrees cooler than the air outside the sterile zone. This feature makes the air heavier and denser as it comes out of the diffuser, and then drops to the floor without requiring higher delivery pressures. The cooler air travels flat along the floor, minimizing eddy currents as it meets the warmer air outside the sterile field. The colder sterile air requires less velocity to reach the ground, creating better airflow throughout the room. This creates a tighter seal at the floor level, an advantage over traditional systems that require a higher velocity to push the air to reach the ground entirely.

Modified airflow

Traditional laminar airflow (LAF) systems work well. However, the discharge within the sterile field hits the floor, which can create turbulence and wash back into the sterile field. With its cooler temperatures within the sterile field, this engineered system is a further improvement to a decades-old design.

The TcAF systems are based on temperature control, employing the laws of physics rather than solely higher air velocities. These systems are also designed around advanced air distribution, wider sterile fields, return air grill placement, thermostat and other design elements to remove particles and pathogens from the operatory effectively.

The TcAF systems also help reduce the transmission of dust particles, pathogens and skin cells caused by people entering and exiting the OR or the sterile field. The cooler air helps to prevent the re-entrainment of potential pathogens and improves the system’s ability to wash the room of potential containments. Most TcAF systems have four air return placements instead of two, as in most traditional systems. This helps to effectively carry away any stray particles or bacteria from the table into the next zone, then back to the return air plenum and away from the room.

The new system relies on the laws of physics rather than high pressure.

We reviewed a lot of data surrounding the new system before purchase, and what impressed us the most was the low infection rates of less than one percent. When looking at similar retrofits in Europe, surgical centers with standard LAF systems had higher infection rates. In contrast, the ones that converted to this TcAF system went from rates over three percent to less than one percent when other contributing factors were accounted for.

Another fact that impressed us was when we took preliminary particle counts of the operating room shortly after installing the new system. At this point, the room had only been broom-cleaned. This OR was still incomplete, yet initial air samples met an ISO 5 classification due to the performance of the TcAF system. That impressive result speaks to how well the TcAF system captures the dust particles and other potential airborne materials and moves them out of the room. Because our surgical operating rooms are new and this is the first application of this system in a major operating room, we were visited by a nationally recognized infection preventionist for a tour. They were impressed with the setup and asked us to turn on the system so they could see it in action. We were surprised by this request and explained that the system was currently running at full capacity. Initially, they did not believe the system was operational as it was so quiet compared to a traditional LAF system. We went over to the system’s control panel and return grills, and showed them it was in fact “turned on” and producing over 30 air changes per hour. The multiple cone-shaped diffusers not only produced an extremely quiet airflow, they also created an environment most surgeons prefer working in with the cooler temperatures and gentler air flows immediately over the surgical table. Obviously, pathological organisms can also be transmitted by touch, so we combined the new air delivery system with a fixed set of ultraviolet lights at ceiling height along the top of the OR walls. These fixed UV lights supplemented our ability to drive down our risk of infections by allowing for complete surface disinfection between cases. Room surfaces are cleaned, and supplemental use of these UV lamps can perform an effective surface disinfection in only three to four minutes.

This provides an extra layer of protection before the next surgical case and is also used as supplemental terminal cleaning at the end of the day.

Keeping potential pathogens out

The center will have additional ORs for other service lines in the future, but we felt it was important to explore the latest air systems for our orthopedic rooms because joint replacements and other procedures carry the possibility of higher rates of potentially serious infections.

The traditional high-end laminar airflows in our other operating rooms work perfectly fine. But I think our pilot room with the thermally controlled advanced laminar flow is one of the safest ORs out there. It’s a better way of cleaning the room to take care of any kind of airborne dust, particles and bacteria and wash them away from the sterile field where surgeries are being performed. In my view, it simply does a better job of capturing and washing potential pathogens out of that space. OSM