October 19, 2017

Room-cleaning robots use UV radiation to zap microorganisms

Germ-killing robots are being enlisted to further safeguard Vanderbilt University Medical Center (VUMC) patients from health care-associated infections.

New decontamination robots at Vanderbilt University Adult Hospital use ultraviolet radiation to kill microorganisms that may linger on surfaces after routine disinfection. (photo by Anne Rayner)

Germ-killing robots are being enlisted to further safeguard Vanderbilt University Medical Center (VUMC) patients from health care-associated infections.

The robots will be deployed in selected inpatient areas, starting this month with the burn unit at Vanderbilt University Adult Hospital.

After a patient is discharged and routine room decontamination with liquid disinfectants is complete, a robot will be wheeled in to flood the room with ultraviolet radiation (UV) in amounts sufficient to kill microorganisms that may linger on surfaces, including drug-resistant organisms like MRSA (methicillin-resistant Staphylococcus aureus) and VRE (vancomycin-resistant enterococci).

According to the Centers for Disease Control and Prevention (CDC), on any given day in the United States about one in 25 hospital patients has at least one health care-associated infection.
In a large randomized trial sponsored by the CDC, the robots were shown to reduce common health care-associated infections by 30 percent.

“We’re starting in the burn unit because that’s a very vulnerable population and we never want those patients to have trouble with infections,” said Thomas Talbot III, M.D., MPH, professor of Medicine and Vanderbilt’s chief hospital epidemiologist.

Vanderbilt has purchased two of the robots, manufactured by Memphis, Tennessee-based Tru-D SmartUVC. The second robot will be assigned to a unit early next year, to be selected based on population data from Vanderbilt’s clinical lab.

“We’ll deploy the second machine wherever it can be of greatest use,” Talbot said.

The robots work alone in vacated rooms, with cabinets and drawers opened and curtains and hallway doors closed. From the hallway an environmental services tech uses a handheld computer to turn on the robot remotely. UV bounces around the room to reach all exposed surfaces, not just those in the machine’s direct line of sight.

Infection control robots began appearing on the market earlier this decade as health care payers began penalizing hospitals with higher infection rates.

The machines help eliminate guesswork, shutting themselves off once their sensors have registered set amounts of UV reflected back from surfaces in the room. In testing at Vanderbilt they required an average 25 minutes to decontaminate a patient room at their normal setting.
A higher setting is used for rooms where a c. diff (Clostridium difficile) infection has occurred.

“For UV to be of benefit you have to continue to clean rooms correctly and continue to follow all infection control practices, like good hand hygiene,” Talbot said.

The hospital will monitor effects of the robots not only on infection rates but also on unit efficiency and workflow.

“We’ll be developing protocols to help optimize use of the robots without delaying patients arriving from the emergency department or the recovery room,” Talbot said.