In the Aftermath of an Outbreak, Processes, Device Design Come Under Scrutiny


By Kelly M. Pyrek

In the May 2012 print issue of ICT, we explore the dialogue in the sterile processing community that was sparked by a report in the mainstream media on dirty surgical instruments. In actuality, the genesis of The TODAY Show segment and a report from the Center for Public Integrity is rooted in a study in the December 2011 issue of the journal Infection Control and Hospital Epidemiology by Pritish Tosh, MD, of the Mayo Clinic Division of Infectious Diseases, and colleagues, who reported on organ/space surgical site infections (SSIs) that occurred after arthroscopic procedures and were due to Pseudomonas aeruginosa of indistinguishable pulsed-field gel electrophoresis (PFGE) patterns occurring at a Texas hospital from April through May 2009.

Tosh, et al. (2011) report that cultures of environmental and surgical equipment samples were performed (samples included those taken from sink drains in the ORs and instrument reprocessing areas, samples of water sources in the ORs and in instrument reprocessing areas, and samples from equipment, such as the suction channels of shaver handpieces), and selected isolates were analyzed by PFGE. Surgical instrument reprocessing practices were reviewed, and surgical instrument lumens were inspected with a borescope (a 3-mm clinical endoscope) after reprocessing to assess cleanliness. The investigators report that their case-control study did not identify any significant patient-related or operator-related risk factors. P. aeruginosa grew from 62 of 388 environmental samples. An isolate from the gross decontamination sink had a PFGE pattern that was indistinguishable from that of the case patient isolates. All surgical instrument cultures showed no growth; however, the investigators say that endoscopic evaluation of reprocessed arthroscopic equipment revealed retained tissue in the lumen of both the inflow/outflow cannulae and arthroscopic shaver handpiece. No additional cases occurred after changes in instrument reprocessing protocols were implemented. After this outbreak, the Food and Drug Administration (FDA) released a safety alert about the concern regarding retained tissue within arthroscopic shavers.

Tosh and colleagues concluded  that these SSIs were likely related to surgical instrument contamination with P. aeruginosa during instrument reprocessing and that retained tissue in inflow/outflow cannulae and shaver handpieces could have allowed bacteria to survive sterilization procedures. The investigators emphasize that they observed the hospital's surgical procedures in their entirety, including infection-prevention processes such as preoperative cleaning of the operating room (OR) following the previous procedure; preparation of the patient in the OR for the surgical procedure; preparation of instruments in the OR for the surgical procedure; and the surgical procedure itself. To completely rule out a surgery-related problem, the investigators arranged for a simulation of knee arthroscopy using a cadaveric leg, to allow for closer inspection and manipulation of the surgical process without risking patient safety.

They also observed the facility's instrument reprocessing practices from the time that the instruments left the OR, through each reprocessing step, to packaging and storage for reuse. Autoclave and reprocessing logs from the main reprocessing areas and from each surgical pod (for flash autoclaving) were reviewed. The investigators also interviewed surgeons, circulators, scrub technicians, instrument reprocessing personnel, infection preventionists, microbiologists and administrators. Two flash autoclaves were located in the surgical pod where the majority of the case procedures were performed, and were used up to six times daily during the outbreak period. The investigators report that two of the case patients and four of the control patients had instruments that required flash autoclaving during their procedures. They found that logs of the flash autoclaves were not always complete with regard to the patient name, OR number and instrument name. Interviews of OR and instrument-reprocessing personnel revealed that the flash autoclaves had been used on rare occasions for routine sterilization.

Low-temperature sterilization with hydrogen peroxide gas plasma was used for reprocessing of the arthroscope, the arthroscope light cord, and the arthroscope camera/power cord in accordance with manufacturer instructions for the recommended duration. The sterilizer logs from revealed deficiencies in the documentation of biologic and chemical indicators that were performed on each load. After sterilization, packaged instrument sets were stored in a designated room adjacent to the instrument-reprocessing area. Before and during the outbreak period, it was common practice to place instruments on a rack within the OR pod on the evening before the procedures.

The investigators say that the reprocessing procedures used on the shaver handpiece were consistent with the manufacturer’s instructions, including brushing of the suction tube channel with a disposable bristled brush, immersion of the handpiece in enzymatic solution for more than one  minute (per enzymatic solution manufacturer recommendation), and autoclave sterilization. However, endoscopic examination of the shaver handpiece suction channel after reprocessing revealed remnant tissue and brush bristles that were not visible on routine visual inspection in each of the evaluated handpieces. Endoscopic examination of shaver handpieces from a different manufacturer that were obtained from another hospital within the health system also revealed remnant bioburden. Of note, reflux of irrigant solution through the shaver handpiece during surgery at times of suction tube compromise as a result of kinking of the tube or external compression was noted by surgeons at hospital X and documented during a simulated arthroscopic procedure that was performed using a cadaveric knee. More easily compressible suction tubing had been substituted into the arthroscopy kit, without notice to the facility, before the spring of 2009 by the medical supply company.

The arthroscope-cleaning procedure involved wiping down the instrument following a brief submersion of the instrument in enzymatic solution before high-level disinfection. The manufacturer-recommended procedure for arthroscope reprocessing included gross decontamination with submersion in enzymatic solution for 10 to 15 minutes before low-temperature sterilization. The distal ends of the shaver handpiece and the camera/power cord were wiped down with enzymatic solution. The manufacturer-recommended reprocessing instructions for gross decontamination included capping the distal end (with the electrical contact points) and submerging the entire device in enzymatic solution for 10 to 15 minutes.

Lessons Learned
Louise-Marie Dembry, MD, MS, MBA, a board member of the Society for Healthcare Epidemiology of America (SHEA) and Yale-New Haven Hospital epidemiologist, says that the Texas cluster of SSIs is a wake-up call for continued diligence in the sterile processing department as well as all areas of the hospital related to infection prevention.

"It's a reminder of how complex our medical instruments and devices are, how difficult they are to clean, and also how important the cleaning step is," Dembry says. "It's another call to vigilance when cleaning, disinfecting and sterilizing these devices. A member of the general public   who hears about outbreaks related to dirty surgical instruments may say, 'How hard is it to clean these items?' but they don't always understand the challenges of making sure it's done right. In this study, when they visually  inspected the instruments, they looked clean, but when they examined the channels of the shaver more closely with a borescope, they could see retained tissue. The study also reported there were some steps in the reprocessing protocol that were not taken. It's hard to know whether people consciously made decisions to not do certain things, or whether they were not well trained. It's a constant reminder of how important every step is in reprocessing, especially cleaning, and it is not one to be shortchanged. Sterile processing is complicated, and personnel need to be well trained, in addition to having the time and the right tools to perform their work properly.  And in this case, technology in the form of a borescope was used to see if the device was really clean -- that's a step that isn't on the radar in many sterile processing department. Technicians must realize that retained tissue may be there even if they visually examine the device -- it's something people hadn't thought about before."

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