Duodenoscopes are intricate, snakelike instruments used in more than 500,000 procedures each year in the U.S. The trouble is, they're made up of many tiny, moving parts and are difficult to properly clean and disinfect. This problem has garnered national attention after outbreaks of antibiotic-resistant superbugs, which have affected at least 250 patients across 10 states and four countries between 2012 and 2015, were linked to the devices, according to a U.S. Senate health committee report.
One outbreak of a resistant form of E. coli, the spread of which was associated with duodenoscopes, occurred at VirginiaMasonMedicalCenter in Seattle beginning in November 2012. In the aftermath of that outbreak, medical center clinicians took a hard look at the manufacturer-provided guidelines for cleaning the scopes, and published research that suggests, oftentimes, those cleaning guidelines don't work.
"The defect rate is about 1.9 percent," Andrew Ross, MD, section head of gastroenterology at Virginia Mason, says. "That's a big deal. What that tells us is that in a percentage of cases the guidelines as they have existed with the scopes … up until recently don't do what they're supposed to and what we've been told they were doing."
In light of this realization, Virginia Mason expanded its scope-cleaning protocol to ensure the devices were bacteria-free before being used in patient care. By March 2014, the medical center had fully implemented cleaning and disinfecting measures that included a strict culture and quarantine process in addition to the existing protocol, which entails a manual and an automated cleaning.
"I think the most important part to recognize is by doing this we've extended the endoscope reprocessing procedure from an hour-long process to something that takes over two days," says Dr. Ross.
Currently, when scopes fail Virginia Mason's high-level disinfection and culture and quarantine process three times, they are considered defective and are decommissioned.
Dr. Ross spoke with Becker's Hospital Review about Virginia Mason's culture and quarantine process, why standard guidelines for cleaning fall short and why hospitals are in a tough position when it comes to scope reprocessing.
Question: How do you define high-level disinfection?
Dr. Andrew Ross: I think there is a bit of confusion in the industry about what the reprocessing process is — including what the term "high-level disinfection" really means. To me, high-level disinfection refers to the entire process of reprocessing an endoscope, and it's divided into two parts.
The first is a manual clean where the scope is actually manually cleaned to get rid of all of the bioburden and proteinaceous debris that gets left inside of a scope after a procedure. The second component is the automated endoscope reprocessor. When these scopes initially go through [the Food and Drug Administration] for a cleaning clearance, what they have to be able to prove is that you can actually manually reprocess the entire instrument. What the automated endoscope reprocessor does is cut out a significant number of the manual steps and automates them.
That's the process as a whole and for all intents and purposes in the United States today high-level disinfection is really a manual clean followed by using the automated endoscope reprocessor, then drying. Those are the typical guidelines that are put forth. The main difference in our scenario is that after we go through that we add on the culture and quarantine process as a successive check to ensure to the best of our ability there are no pathogenic bacteria on that scope before it goes back into the patient.
Q: How does Virginia Mason Medical Center's culture and quarantine process for medical scopes work?
AR: It begins at the end of a case. An endoscope comes out of a patient and gets reprocessed in the standard fashion according to the manufacturer's guidelines. We use Olympus scopes and specialized tools from Olympus to follow their reprocessing guidelines. Once those scopes finish the high-level disinfection process they go into drying, and once they're thoroughly dried they get cultured.
We use a liquid culture media to brush all of the difficult-to-reach areas, like the elevator mechanism which seems to be the implicated area in these outbreaks. The liquid culture media helps to produce the high burden of bacteria we need for a culture. After culturing, the scope is put through the automated endoscope reprocessor for one more cycle and is then held for 48 hours, during which time we wait for culture results to come back. If the scopes grow any potential bacterial pathogens, they then we start the clock all over again, meaning they go through the entire high-level disinfection process again and get re-cultured and re-quarantined for 48 hours. If at the end of 48 hours the scope grows no pathogens on it, it's then re-released for use in patient care.
Q: Do you think all hospitals using scopes that have been linked to outbreaks should adopt a culture and quarantine program for reprocessing?
AR: There are a couple of answers to that question. First, this is not necessarily a procedure that is reasonable for hospitals to adopt for a variety of reasons. The costs incurred are astronomical; to add the culture and quarantine process we had to purchase 20 additional scopes in order to accommodate our clinical volume. That's a huge burden, and the reality is why should we have to buy three endoscopes to make one work the way that it was sold to us that it was supposed to work and be reprocessed?
I don't think it's incumbent on everyone to implement this type of program and I think, again, the biggest criticism has been that not everybody can do this. The cost will be prohibitive in many places. This is what worked for us at a time where we had an outbreak, this is what we needed to do in order to keep our patients safe, and it's continued to be able to provide them with a medical care that they need. But I think if you look to the FDA, they've recommended adjunctive measures beyond standard reprocessing, culture and quarantine being one of them, but with the limitation that the cost-prohibitive nature of that is not insignificant.