Brand-new ORs feel clean, don’t they? The floor squeaks, the walls shine and those expensive LED lights hanging over the soon-to-be sterile field don’t pick up a speck of dust.

It’s a picture-perfect scene worthy of appearing in marketing brochures and surgical magazines. Enjoy it while it lasts. Bacteria is waiting to grow on the room’s shiny new surfaces and airborne contaminants are hanging around to settle onto instruments, incisions and implants. It’s important to consider the following factors as you’re designing an OR to keep the bugs at bay because the plans you put on paper will face the ultimate test as soon as the first patient arrives.

ORs are designed to be positively pressurized to prevent infiltration of airborne particulate into the room or, worse, into the sterile field. But if the OR’s main door is opened, room air can escape into the adjoining hallway, causing the air pressure in the OR to drop. That pressure drop disrupts the regular currents of the laminar flow, potentially causing airborne contaminants to settle in the sterile field. Installing built-in cabinets or investing in mobile storage units to ensure often-used supplies are always within arm’s reach will help limit foot traffic into and out of ORs.

Plus, less is more when outfitting your ORs. “Keep it simple,” stresses George R. Tingwald, MD, AIA, ACHA, director of medical planning, design and construction at Stanford (Calif.) Health Care. He’s a surgeon and an architect, so he knows a thing or two about designing ORs with infection control in mind. “Store fewer pieces of equipment and fewer carts in the rooms, and certainly nothing that cannot be cleaned, if not between each procedure, then on a very regular basis. All equipment in the room should be used regularly.”

Dr. Tingwald says hanging equipment on ceiling-mounted booms is a space-saving design but warns that many turnover teams don’t clean the equipment — and the wires connected to it — often or well enough. “Just because the equipment isn’t on the floor doesn’t mean it doesn’t get dirty,” he adds.

Speaking of carts and equipment (and waste cans), do you routinely place them in front of floor-level exhaust grills? Well, don’t. Blocking the grills alters air flow in the OR, and possibly even in the sterile field, says Larry Lee, CIH, a certified industrial hygienist and owner of Pacific Industrial Hygiene in Kirkland, Wash. He suggests you tape off a 3-foot “no parking zone” on the floor in front of exhaust grills to keep the area clear and OR air flowing as intended.

Storage cabinets, shelving and back tables are regularly disinfected, so they should be easy to wipe down and shouldn’t absorb moisture. “Cleaning agents are getting very caustic, so a lot of materials that have been used previously just don’t hold up well to them,” says Dr. Tingwald. “And that creates surfaces that are very porous and susceptible to harboring transmittable agents.”

He suggests you stick with high-density materials and finishes — aluminum, chrome and stainless steel — that can be maintained for long periods of time and after multiple cleanings with highly corrosive materials.

OR floors should be solid surfaces with welded seams, according to Dr. Tingwald, who says many suites are being designed with walls made of solid-surface materials that are easily washable, very durable and free of crevices where bacteria can hide.

Airflow and air purification are vital to infection control in the OR. Surgeries involving implants are particularly risky in terms of contaminated air leading to surgical site infections, says Sue Barnes, RN, CIC, FAPIC, a board-certified independent infection control consultant, former national program leader for infection prevention and control for Kaiser Permanente and a fellow of the Association for Professionals in Infection Control and Epidemiology (APIC). Contaminants in the air can settle on hardware before they’re implanted and during the process of implantation before the wound is completely closed, she points out.

“The body’s immune system focuses on implants as a foreign body,” she says. “It’s not as quick to respond to any invading bacteria, and it doesn’t take much bacteria — as few as 100 colony forming units — for biofilm to begin forming on implants.”

Laminar airflow has long been essential for keeping the sterile field free of contaminants by sweeping them away from the operating field in one direction. Some ORs employ vertical laminar flow, where HEPA-filtered air is pushed downward from above the surgery area. Others employ horizontal laminar flow, where HEPA-filtered air is pushed from behind the work area and absorbed into the ventilation system.

Additional technologies to keep air free of contaminants are still evolving, according to Ms. Barnes, who says a gentler form of vertical air flow is now in favor in many ORs — a directional pattern of air flowing over the operating room table and then directed to vents in the corners of the room.

You can also opt to invest in devices that are positioned adjacent to the sterile field and send HEPA-filtered air horizontally across the incision site to push airborne contaminants away from the surgical field and reduce surgical site infection risk. Ms. Barnes says, intuitively, the concept is a great idea. However, she says, make sure the solution you choose has a small footprint so it’s unobtrusive as possible in a crowded area already filled with other equipment, instruments and members of the surgical team.

Air quality considerations go beyond which type of laminar flow system you use, says Dr. Tingwald. He believes the best way to avoid contaminating the air in the OR is through designing a dual-entrance philosophy: patients enter through one door from a public corridor, which also is the way out for used equipment, while another door serves as a sterile entrance for staff. “Keeping that separation of flow is really critical,” says Dr. Tingwald.

That’s not all. Mr. Lee says it’s a good idea to make sure all wall and ceiling penetrations are properly sealed. “Some ORs can even become negatively pressurized for a brief time when air from adjoining areas infiltrates the OR through electrical outlets, data ports, unsealed light booms, and other penetrations,” he explains. “This is highly troubling because ceiling light booms are commonly situated within the sterile field, so dust and particulate matter can become deposited in the surgical site.”

Ultimately, says Dr. Tingwald, preventing infections goes beyond how well your ORs are built and what technologies you use. It’s just as important to ensure proper infection prevention practices are followed during every case and for every patient. “From a patient’s standpoint, they want to know that it’s the safest room possible,” he says.

Build it right and maintain it right. The fight against infection never takes a day off. OSM