Researchers from Boston’s Brigham & Women’s Hospital and Pennsylvania’s Heraeus Medical tested five different bone cement mixing systems and types of air flow strategies in the OR to determine which strategy or combination of approaches reduced exposure to harmful bone cement fumes.
The results of their study, “Bone Cement Fumes Generated in Laminar Airflow Versus Conventionally Ventilated Operating Rooms: Does the Mixing System Matter?” was published in the November 1, 2023, edition of The Journal of Bone and Joint Surgery.
Bone cement, a staple of many ORs, contains a colorless, clear, flammable liquid known as methylmethacrylate monomer. Considering five cement-mixing systems, the researchers looked at two different operative settings—an OR with conventional ventilation (CV) and an OR with laminar airflow—and compared the methylmethacrylate monomer vapor levels emitted.
First author Matthew P. Jamison, M.D. of the Department of Orthopaedic Surgery at Harvard Medical School and Brigham and Women’s Hospital, told OTW, “There have been long-standing concerns regarding exposure to the fumes generated from bone cement in orthopaedic surgery. We wanted to identify available cement mixing devices that would prove effective at minimizing methylmethacrylate monomer fume levels, with and without the assistance of a laminar airflow system in the OR.”
“While the concerns regarding methylmethacrylate monomer fume expose have led to some investigation into fume levels generated from various devices, the effects of different OR ventilation environments had not yet been quantified. ORs with laminar airflow are becoming more widely utilized. We wanted to contribute to this topic further by conducting these trials in two differently ventilated settings.”
The researchers calculated methylmethacrylate monomer vapor release during the cement preparation of a SAWBONES femoral canal, with five different vacuum cement-mixing systems used to mix the same cement type. Methylmethacrylate monomer vapor concentrations were measured during five phases of mixing, and each mixing system was randomly utilized 10 times in each OR.
Dr. Jamison also explained to OTW the differences that laminar airflow can make in protecting the health of operating room staff. “In an operating room with laminar airflow, filtered air is brought into the room through a large diffuser directly above the operative table, and air leaves the room through multiple vents on the walls of the room.”
“This method of ventilation, along with keeping the room at positive pressure, keeps the stream of air moving in a uniform direction and reduces turbulence. This lack of turbulence makes it much more challenging for contaminated air, particulate matter, and harmful fumes to linger in the room or in the sterile field.”
Overall, the researchers found that emissions remained higher in the conventional setting for every system and in nearly every phase. Among the five systems analyzed, System #5, the only entirely closed system, had the lowest overall emissions for each of the five phases in the CV setting.
Dr. Jamison added, “The most interesting and significant takeaway from this study were that laminar airflow is generally better than conventional ventilation at keeping methylmethacrylate monomer fume levels reduced, and that we were able to identify that using a fully enclosed mixing device is very effective in minimizing methylmethacrylate monomer fume levels in a conventionally ventilated OR. The enclosed mixing device performed well and is a great option especially when laminar airflow is unavailable.”
“We looked at five mixing devices in this study, so there is certainly room to test other marketed mixing devices. Also, it is unclear exactly how many facilities in the U.S. now use laminar airflow in the OR for arthroplasty, so knowing precisely how much the utilization of this type of ventilation has increased would be very useful to know.”
