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Patient Safety Tip of the Week

June 8, 2021

Cut OR Traffic to Cut Surgical Site Infections




We’ve done many columns on the likely contribution of OR traffic and opening/closing OR doors to surgical site infections (SSI’s). Way back in our March 10, 2009 Patient Safety Tip of the Week “Prolonged Surgical Duration and Time Awareness” we noted a study (Lynch 2009) that suggested increased foot traffic may be factor related to prolonged procedures that increases the likelihood of surgical site infections.


In our November 24, 2015 Patient Safety Tip of the Week “Door Opening and Foot Traffic in the OR” we discussed a study from Johns Hopkins that formally studied how often OR doors are opened during joint arthroplasty surgeries and the impact on OR air flow (Mears 2015). The researchers measured how often and for how long OR doors were opened during 191 hip and knee arthroplasty procedures. They also measured air pressures in the OR and adjacent corridors. They found that, on average, OR doors were open 9.5 minutes per case and the average time between door openings was 2.5 minutes. As you’d expect the number and duration of door openings correlated with the length of surgery. In 77 of the 191 cases positive pressure within the OR was defeated. The implications are obvious. While they found only one surgical infection in the 191 cases, the effects of the door opening on OR pressure and air flow theoretically would predispose to surgical infections. OR’s have positive pressure to avoid flow of air and airborne pathogens from nonsterile adjacent areas.


Our April 23, 2019 Patient Safety Tip of the Week “In and Out the Door and Other OR Flow Disruptions” discussed multiple other studies identifying common reasons for OR door opening/closing.


A recent report on a quality improvement project to reduce OR traffic (Parent 2021) was successful in both reducing OR traffic and reducing SSI’s. But perhaps its biggest contribution is identification of the barriers and challenges to success.


Parent implemented the project in 2 orthopedic OR’s. There were four principal interventions:


Signs were intended to warn the staff about entering the OR, particularly after the initial surgical incision had been made. The original “sign” was a safety strap across the doorway but, for several reasons, that was abandoned and replaced by a sign placed on the door. The sign was green on one side, stating that the sterile field was open, and that staff should enter only if necessary. The other side of the sign was red and stated that the incision had been made and that the person should call into the OR before entering.


The second intervention, batching of staff breaks, proved impossible to implement (see barriers below).


The third intervention was review of surgeon’s preference cards to help ensure that all required supplies and instruments were available and minimize the need to exit the OR to procure more supplies or instruments. Parent found that the preference cards were actually in good shape but the supplies and instrumentation for the first procedures of the day appeared to be less accurate than subsequent procedures. That was because sterile processing staff members who prepare the supplies and instruments for the first procedures of the day were not necessarily familiar with the intricacies of each procedure and surgeon preferences.


The fourth intervention occurred after the project had begun. OR staff members suggested moving the waterless scrub from the scrub sink area to inside the OR. Staff members could now perform the surgical hand scrub within the room. (OR staff members liked this intervention and adopted it for all the OR’s, not just the orthopedic OR’s.)


Results were quite encouraging.  At week six of the project, the number of door openings dropped from an average of 1.96 door openings per minute. to an average of 1.04 per minute, a decrease of 46.9%. The SIR (standardized infection ratio) during the planning stages of the project was 1.75. dropped to 0.44 at week 6, and by the end the project, the number of infections and the SIR were 0,


There were other ongoing interventions aimed at reducing SSI’s during the implementation of this project, so the improvement in SSI rates cannot be fully ascribed to this project. Nevertheless, the results of the project were encouraging enough that staff have adopted the measures to their general surgery OR’s as well.


Parent provides a table of the reasons for OR door openings at Weeks 1 and 6. The biggest reductions after implementation were in patient-related factors, hand scrubbing, instruments, supplies and equipment.


Parent also analyzed who was entering and leaving the OR. Vendors remained the largest reason for OR traffic, especially after the incision was made. Vendors typically did not bring their carts with implants into the room until after the sterile field was open. Vendor-related door openings did decrease 34% (from an average of 23 door openings per day to 15 per day). Staff member relief was the second most common reason for OR traffic. RN circulator exiting the room did not change (average of 13 times both before and after the interventions). Entering the room after scrubbing was the third most common reason for OR traffic, and it improved dramatically after moving the scrub product into the OR.


Regarding the barriers to implementation, one big challenge related to vendors. Because this was an orthopedic OR, vendors often entered the room with the necessary implants for the procedures. Those implants were typically housed outside the OR. Often there were last-minute modifications to the surgical plans, so the vendor had to leave the room to retrieve the new implant. Another stated challenge was that “Operating room personnel have limited control over vendors because they are not hospital employees.” Several of the studies discussed in our April 23, 2019 Patient Safety Tip of the Week “In and Out the Door and Other OR Flow Disruptions” also noted the vendor issue as a major barrier to reducing OR door openings.


A second major challenge was that there was “pushback” to the project from the anesthesia group and the vendors. Parent notes that their lack of willingness to fully participate in the project was limiting. Apparently, OR leaders did speak with the vendors but with limited to no success.


Another barrier related to union rules. Parent had hoped to “batch” breaks by members of the OR team so the doors would be opened and closed less frequently. However, timing of staff member breaks was prescribed by union contractual obligations. But there were other barriers that rendered this intervention impossible. It was difficult for the anesthesia staff members to go on break during induction of anesthesia or emergence from anesthesia (handoffs at these critical would have been unsafe) so anesthesia personnel could really only go on break after incision. Nursing staff relief patterns were dependent upon relief staff members arriving at different times to relieve the day shift staff members.


Another study looked at decreasing OR traffic during orthopedic surgery (DiBartola 2019). DiBartola and colleagues implemented a bundle, including education, OR signage, team-based accountability and behavioral interventions. Average door openings per minute decreased by 22% after intervention. All surgical groups excluding anesthesia had significant reductions in OR traffic following the intervention.


Input from multiple stakeholders was collected prior to implementation for suggestions and helped identify unnecessary OR behavior and processes. A practice guideline for room traffic reduction was implemented. The guideline consisted primarily of staff education concerning the potential risks associated with a high volume of OR traffic, decreasing staff break frequency, creating rules for door openings, and placing signs on the doors to remind people to open the door only if necessary. Another product of the intervention was the installation of electronic door counters. (Note that we consider that a key to any such implementation project to reduce OR traffic. We always say “You don’t know what you don’t know”, meaning you can’t improve what you don’t measure. People are astonished when they actually see how often OR doors are opening and closing. See our April 23, 2019 Patient Safety Tip of the Week “In and Out the Door and Other OR Flow Disruptions” for further details.) DiBartola et al. did not used the door counters as a means to collect data. Rather, they served as a constant and real-time reminder to reduce room traffic.


The results were based upon a relatively small number of observations (35 cases before and 42 cases after the intervention). Total door openings in the pre-intervention group were 124.3 openings per case and 86.7 in the postintervention group. There was a statistically significant difference in room traffic rate (openings per minute) from 0.58 openings/min before to 0.45 openings/min after the intervention. Although pre-incision room traffic rates remained largely unchanged by the intervention, post-incision room traffic rates were significantly different (preintervention door openings of 0.41 per minute, postintervention 0.12 openings per minute).


Nursing staff, surgical staff, vendor, and radiology team members all had significant reductions in postintervention room traffic when compared to preintervention traffic. Only the anesthesia team did not have a significant change in room traffic, but that team had overall low room traffic prior to intervention strategies.


The DiBartola study did not attempt to link OR traffic to surgical site infection rates, though it notes that orthopedic SSI rates have traditionally been low to start with.


Our April 23, 2019 Patient Safety Tip of the Week “In and Out the Door and Other OR Flow Disruptions” noted that purely educational interventions are seldom successful in reducing OR traffic.


Our December 2017 What's New in the Patient Safety World column “A Fix for OR Foot Traffic?” noted a study which looked at the impact of an audible alarm on reducing OR foot traffic during total joint arthroplasties (Eskildsen 2017). Researchers placed an audible alarm on the substerile operating room door that sounded continuously when the door was ajar. This resulted in a significant difference in the overall mean door openings per minute between the period with no alarm and with an alarm. However, this effect slowly decreased over the time of the intervention. We suspect alarm fatigue likely set in there. Also, we’d be very concerned distractions due to the alarm could potentially lead to other surgical mishaps.


Signs have also had a limited impact. Sometimes they are simply ignored and other times they may be removed. Rovaldi et al. (Rovaldi 2015) went to a pull-down shade that was pulled down at the time of incision to warn outsiders not to enter the OR. This was a shade that, when pulled down, covered half the window on the door and stated “Incision” and would be seen from the sterile inner core area. Worried you might forget to pull down the shade? Add this to your timeout/safe surgery checklist! That sign is basically a version of one of the interventions we’ve recommended in several of our columns – a sign akin to the “On the Air” sign in TV, radio, or recording studios that lights up when the case is in progress.


We’ve also discussed in multiple columns the importance of pre-op huddles and post-op debriefings. The pre-op huddle can help ensure you have all the equipment and supplies you’ll need during a case, reducing the need to exit and re-enter the OR. And, in the post-op debriefing you can discuss events or circumstances that led to more OR door opening so that you might avoid similar ones in the future.


So, why are short-term reductions in OR traffic not sustainable? The answer is simple: that outcome is not important to clinicians. What is important is the rate of surgical site infections. So, it is critical that you tie your QI project to your SSI rate.



Our prior columns focusing on surgical OR foot traffic and door opening:






Lynch RJ, Englesbe MJ, Sturm L, et al. Measurement of Foot Traffic in the Operating Room: Implications for Infection Control. American Journal of Medical Quality 2009; 24: 45-52



Mears SC, Blanding R, Belkoff SM. Door Opening Affects Operating Room Pressure During Joint Arthroplasty. Orthopedics 2015; 38(11): e991-e994



Parent, M. (2021), OR Traffic and Surgical Site Infections: A Quality Improvement Project. AORN J, 113: 379-388



DiBartola AC, Barron C, Smith S, Quatman-Yates C, Chaudhari AMW, Scharschmidt TJ, Moffatt-Bruce SD, Quatman CE. Decreasing Room Traffic in Orthopedic Surgery: A Quality Improvement Initiative. Am J Med Qual 2019; 34(6): 561-568



Eskildsen SM, Moskal PT, Laux J, Del Gaizo DJ. The Effect of a Door Alarm on Operating Room Traffic During Total Joint Arthroplasty. Helio Orthopedics 2017; 40(6): e1081-e1085



Rovaldi CJ, King PJ. The Effect of an Interdisciplinary QI Project to Reduce OR Foot Traffic. AORN Journal 2015; 101(6): 666-681






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