Poor Cleaning, High Traffic to Blame For OR Bacterial Contamination
Chicago—Despite increased awareness and various national guidelines on the subject, hospital ORs remain dirty, a study has concluded. Investigators at University of Iowa Healthcare hope their findings will provide motivation for improved intraoperative infection control practices nationally.
According to Valerie Renkor, BSE, a clinical research assistant at the Iowa City institution, previous research has identified several sites as potential reservoirs of intraoperative bacterial cross-contamination, including patients, health care providers and the surrounding patient environment (Anesth Analg 2012;114:1236-1248). Exacerbating the problem are increasing antimicrobial resistance and OR throughput pressure, as well as inadequate environmental decontamination (including for equipment), hand hygiene and vascular care practices, all of which combine to pose a threat to patients.
“So, our goal with this study was to assess the efficacy of the Association of periOperative Registered Nurses’ intraoperative infection control guidelines in controlling bacterial entry to the ORs,” Ms. Renkor said. “In addition, we wanted to see if we could track bacterial transmissions in the OR.”
The investigators used reservoir collection kits to pre-, intra- and postoperatively obtain bacterial cultures from patients, providers and environmental surfaces at the institution, including surgical equipment and intravascular devices. Laboratory analysis and reporting were guided by software technology (OR PathTrac, RDB Bioinformatics).
The case-pair study comprised 27 units (54 cases), for a total of 1,543 culture specimens. Reservoirs were assessed using standardized swab and culture techniques that were quantified in colony-forming units (CFUs).
“We plated our reservoirs and established them as ‘very clean,’ ‘clean’ or ‘dirty,’” Ms. Renkor explained. Very clean plates had less than 10 CFUs; clean plates had 10 to 20 CFUs; and dirty plates had more than 20 CFUs.
The researchers hypothesized that standard environmental cleaning, hand hygiene and vascular care practices performed at their institution would see nearly 90% of the tested reservoirs rated as clean. Their findings, however, were not in line with their hypothesis.
OR Throughput Part of the Problem
As Ms. Renkor reported at the 2018 annual meeting of the International Anesthesia Research Society (abstract PS38), only 761 of the 1,543 sites tested were clean (49%). “From there we looked at our ‘never events,’ things that we or [the Association of periOperative Registered Nurses] decided should never be dirty: the surgical tray at the beginning and end of the case, and the stopcock lumen in the patient’s intravenous line,” Ms. Renkor said.
The results showed that internal lumens of patient IV stopcock sets were contaminated in 11% of cases. Moreover, 3.5% of surgical trays were found to be dirty during the first case, and as much as 10% were dirty for second cases. Indeed, the researchers concluded that terminal cleaning at the end of the day (using baseline environmental samples for the first case) and interval cleaning between cases (using baseline environmental samples for the second case) were often ineffective, leaving residual contamination.
“So we’re bringing in all this bacteria; we’re increasing the bacterial burden in the OR; and invariably it ends up in places where it shouldn’t be,” Ms. Renkor said.
In a separate part of the study, the investigators used dedicated software to help track bacterial transmission patterns in the OR. This analysis found a troubling trail of transmission with the potential for patient harm. “In one case, the surgical assistant (the resident) brought in some bugs, and then they were dropped onto the patient,” Ms. Renkor described. “Anesthesia picked it up, and it was eventually injected into the lumen.”
Whether transmission patterns such as these resulted in direct patient infection has yet to be determined. “We’re still looking through their charts to see if they ended up with infections,” she added. “I believe there were a couple who showed up with infections after surgery.”
The software also produces a heat map of bacterial hot spots in selected hospital locations, a feature that enabled the researchers to target particularly dirty rooms. “At our institution, for example, we have cleaning robots that are supposed to do a thorough job getting rid of the bacteria. So, we’re hoping we can use the heat map to see which rooms need extra cleaning and send them there.”
Nevertheless, the fact remains that common hospital environments are far dirtier than expected, despite adherence to guidelines. “We’re hoping we can take some evidence-based steps to reduce OR contamination,” Ms. Renkor said.
A new study planned by the researchers may help in that regard. “We’re getting ready to start a follow-up study that’s taking place at the University of Iowa, Georgetown [University] and Denver Children’s Hospital,” she said. “Each site is implementing a different cleaning bundle to see which one best reduces contamination in the OR.”
Such efforts may spur other institutions to examine their infection control practices, despite throughput targets. “It’s even harder to keep things clean given all the throughput pressure to push so many cases through the OR,” Ms. Renkor said.