Academics at Johns Hopkins Hospital have analyzed footfall in and out of the operating room through a form of “secret buyer” and concluded that to ensure patient health and safety, surgical staff should minimize access to the operating room. The results of the study were published in the Nov. 11, 2015, issue of Orthopedics. In the study, researchers tracked the number and timing of operating room door openings during the performance of nearly 200 knee and hip arthroplasty procedures operated at Johns Hopkins Bayview Medical Center over a three-month period. They found that in nearly one-third of the surgical operations, the number and duration of door openings were long enough to potentially render the positive pressure system, a safety measure designed to keep the air in the operating room clean and sterile, ineffective. In U.S. hospitals, most operating rooms are equipped with this system, which allows the air pressure inside the operating room to be slightly higher than the surrounding environment. This design allows the air in the operating room to escape to the outside when the door is opened, which also prevents as much air as possible from flowing into the room that could carry infection-causing germs. However, when the door is opened and closed frequently for a short period of time, or for a very long time, such a positive pressure system may be overwhelmed and lose its usefulness. The researchers said that excessive opening and closing of operating room doors is not only unique to Johns Hopkins, but that previous studies have reported frequent opening and closing of operating room doors during cardiac surgery at other hospitals. Stephen Belkoff, associate professor of orthopedic surgery and director of the International Center for Orthopedic Surgery at Johns Hopkins School of Medicine and author of the paper, commented, “This very common phenomenon may raise safety concerns, and our study provides new and definitive evidence of this and raises new questions about why operating room doors need to be opened and closed so frequently. What can we do to reduce the frequency to try to keep the operating room as clean as possible?” Since the researchers conducted this observation without informing the surgical team, they had no knowledge of being observed, Belkoff continued, adding, “We are certain that many of the frequent openings and closings of the operating room doors were unnecessary and unexplained.” In the study, which looked at excessive door openings, there was one postoperative infection out of 191 procedures observed, and Belkoff said the cause of this infection is unknown. He also emphasized that infections are rare for procedures like arthroplasty, both at Johns Hopkins and at various other hospitals. In fact, at Johns Hopkins Bayview Medical Center, the infection rates for knee and hip arthroplasty are less than 0.33 percent and 0.66 percent, respectively, well below the national averages of 0.89 percent and 1.26 percent. ”We do manage to have low infection rates, and we do do do enough to prevent them, but we can’t be complacent about it and still need to be vigilant about behaviors that could lead to risk.” Dr. SimonMears, co-host of this study, said, “Overdoing the door opening is a risky behavior.” The researchers agreed that excessive door opening during surgery is a risk factor that can be easily corrected. “There are undeniably occasions in surgery when opening and closing doors is unavoidable, but we still need to focus on addressing those behaviors that are unnecessary as well as those that can be avoided.” One way to solve this problem is to plan and have all the required equipment and facilities ready before the surgery begins, so that there is no need for such inefficient work as going back and forth after the surgery begins. To verify that over-opening of doors was occurring in his own unit, Belkoff, along with his colleagues Renee Blanding of the Johns Hopkins School of Medicine’s Department of Anesthesia and Critical Care, and Mears, looked at knee and hip replacement surgeries performed at their hospital from May to June 2011. The researchers used sensors placed inside and outside the operating room doors so that they would sense and time when the doors were opened. They likewise recorded the time from incision to suture for each procedure, as well as the actual operative time for the patient to remove the starting prep and cleanup. They then examined and counted patients who eventually developed post-operative infections. A total of 100 knee replacements and 91 hip replacements were counted in the study, and the average intraoperative door opening time was 2.5 minutes per procedure, compared to an average of 9.6 minutes per procedure for a procedure that took an average of 1.5 hours to perform. Belkoff mentioned that in 77 of the 191 surgeries, the door opening time was long enough to offset the pressure provided by the positive pressure system in the operating room, allowing outside air to flow into the room. In addition to the possible contamination from the air flow, the excessive foot traffic in and out may also distract the surgical operators and imply inefficiencies in staff management, making it necessary to identify the underlying causes behind the frequent door openings. Because the infection rates seen in the above study were low, researchers will have to obtain sufficient data from additional procedures to determine whether the amount of footfall in and out actually affects the postoperative infection rates of patients.