For the sake of patient safety, OR teams might want to stay put more often, according to a study by researchers at Johns Hopkins analyzing foot traffic in and out of operating rooms.
For the “secret shopper-style” study, published online Nov. 11 in the journal Orthopedics, investigators tracked the number and length of door openings during 191 knee and hip arthroplasty surgeries performed at Johns Hopkins Bayview Medical Center from March through June 2011. They found enough door openings in nearly one-third of the procedures to potentially defeat the safety effects of positive pressure systems meant to keep germ-contaminated air out of sterile ORs.
Most operating rooms in U.S. hospitals are fitted with systems that keep them at an atmospheric pressure slightly higher than the surrounding corridors. The design allows air to flow out of the OR when doors open, which prevents air potentially contaminated with infection-causing germs from flowing into the OR. However, positive pressure systems can become overwhelmed when doors open too many times in quick succession or stay open too long.
Excessive OR traffic, the researchers said, is believed to be a common occurrence not unique to Johns Hopkins, and past studies have documented frequent OR door openings during cardiac surgeries performed elsewhere.
Potential safety concern
“Our findings add to a growing body of evidence of a relatively common practice that could be a potential safety concern, and raises questions about why doors get opened and how we can prevent or minimize the frequency and duration of behaviors that could compromise OR sterility,” study senior author Stephen Belkoff, PhD, MPH, said in a news release. Belkoff is an associate professor in the Johns Hopkins University School of Medicine’s department of orthopaedic surgery and the director of the International Center for Orthopaedic Advancement.
Because the research team monitored door openings without the knowledge of OR staff, it’s impossible to say why the door openings occurred.
“What we know for sure is that there was a whole lot more traffic in and out of the OR than seems necessary or easily explained,” Belkoff said in the release.
The researchers used sensors inside and outside ORs to measure when a door opened, how long it stayed open, pressure in the OR and pressure in the surrounding corridors. They also tracked the total time patients were actively operated on, excluding setup and cleanup time. Researchers checked for patients who developed postop infections.
Of the 100 knee arthroplasties and 91 hip arthroplasties in the study, doors opened on average every 2.5 minutes, researchers found. That’s a door-open time of 9.6 minutes per average case, which lasted about an hour and a half, the results showed. And it accounted for about 9% of the total active operation time, Belkoff said in the release. In 77 of the 191 cases, doors were open long enough to compromise the ORs’ positive pressure systems, allowing air from surrounding corridors to flow inside.
There was a single case of postop infection in the 191 surgeries monitored for excessive door openings, Belkoff said, emphasizing the cause of that infection was unknown. According to Belkoff, infections are quite rare for arthroplasties, both at Johns Hopkins and in general. Infection rates for knee and joint replacement at Johns Hopkins Bayview Medical Center stand at less than 0.33% and 0.66%, respectively, well below the national averages of 0.89% for knee replacement and 1.26% for hip replacement, he said in the release.
“Yes, we have low infection rates, and yes, we take great many precautions, but we cannot be complacent, and we must remain vigilant about practices that pose risk — theoretical or otherwise,” study co-investigator Simon Mears, MD, PhD, said in the release. “Excessive door opening is one such practice.”
Easily modified practice
Door openings during surgery, the researchers said, could be an easily modifiable risk factor.
“Undoubtedly, a handful of door openings during surgery are necessary and unavoidable,” Belkoff said in the release. “What we ought to figure out next is what’s causing the unnecessary and avoidable ones.”
Part of the solution, the researchers said, could be planning better to ensure all necessary materials and equipment are pre-stocked before surgery starts so there’s no need to shuffle in and out of the room once the procedure begins.
Excessive foot traffic also could suggest distraction among OR staff or simply logistical or personnel management inefficiencies, the researchers said, underscoring the need to find out the reasons behind frequent door opening.
Because the infection rates for these procedures are so low, Mears said, researchers would need to study data from many more such surgeries to determine whether variations in foot traffic could affect patients’ postoperative infection rates.
Full study: http://bit.ly/1Oe2jb8