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The incidence of scope-related infections is rare. Only a handful of outbreaks have been reported recently in the literature. Of note, the majority of these outbreaks are related to bronchoscopies, not endoscopic procedures related to the gastrointestinal (GI) tract.
One exception occurred in May 2001, when a physician notified the New York City Department of Health of seven patients who had acute hepatitis C virus infections after undergoing endoscopic procedures at the same office in March 2001. The office voluntarily ceased performing such procedures in late April 2001.1
After receiving media attention, the incidents were subjected to a retrospective case-control study, which found that the ultimate cause of infection was due to poor infection control and injection practices. After the office corrected its infection control practices, it was allowed to resume providing gastrointestinal services and performing procedures. However, other incidents have been truly related to endoscopic procedures, often the result of incomplete or inadequate cleaning.
In another community hospital, bronchoscopes were found to be contaminated with Pseudomonas aeruginosa and Serratia marcescens; patients may have been infected with these bacteria after undergoing bronchoscopy with said scopes. “All 20 P. aeruginosa isolates were associated with procedures performed with three of four new bronchoscopes from the same manufacturer. Contrary to manufacturing specifi- cations, the biopsy-port caps on all four bronchoscopes were easily removable, and P. aeruginosa was cultured from the biopsy ports of the three implicated bronchoscopes. The manufacturer reported a design change instituted in 1997, and production problems may have resulted in the distribution of bronchoscopes that did not meet specifications,” according to an article published in the New England Journal of Medicine.2
A review by Douglas Nelson, MD, explored the recent advances in epidemiology and prevention of gastrointestinal endoscopy related infections. Nelson is a staff physician in gastroenterology at the Minneapolis VA Medical Center, and a professor of medicine at the University of Minnesota Medical School. He also serves as a physician spokesperson for the American Society for Gastrointestinal Endoscopy (ASGE), regarding the issues of infection control and endoscopy.3
Nelson reviewed recent publications related to endoscope reprocessing and the potential for infection transmission during GI-related endoscopy. “There have been a number of established reprocessing failures of gastrointestinal endoscopes at various healthcare facilities across the U.S. resulting in patient notifications,” he writes. “These episodes have been associated with user errors and reprocessing equipment failures. Although peracetic acid has been promoted as superior to aldehyde-type liquid chemical germicides with regard to soil fixation, it may only be a modest improvement. Electrolyzed acid water is an emerging liquid chemical germicide that may be equivalent to currently accepted disinfectants. There appears to be no benefit to an additional reprocessing cycle before use for endoscopes that have been appropriately cleaned, disinfected, and stored.”
The incidence of these types of infections is low, he agrees, but there are three possible explanations for why they receive such public interest when they do occur. “When there are outbreaks, there are huge publicity splashes. When something goes wrong with reprocessing, a lot of letters go out, and there is a lot of media attention,” Nelson says. “But if you actually look at the episodes, there aren’t that many infections. In [an incident on] Long Island, when they sent out letters, and they did baseline testing, they found out that there were no infections. The fact that the reprocessing was not done perfectly doesn’t necessarily mean there is an infection, and it doesn’t mean it gets less publicity. There is a tremendous margin of safety, such that when things go wrong, we still have a margin of safety, and that’s why we’re not seeing many infections.”
He adds, “I don’t think our compliance is perfect; I think studies have shown it’s not perfect and we’re trying to get there, but when people don’t fully meet the guidelines, there is a margin of safety built in so that it does not necessarily result in the transmission of infection. We don’t eat sterile food; we don’t eat off sterile plates. Everything in our stomach isn’t sterile; the gut is designed to deal with nonsterile intrusions. The colon is the most nonsterile place on the planet. I’m not saying that excuses noncompliance; I don’t think it’s OK not to follow the guidelines. I’m just explaining how, in the absence of perfect compliance, we have such a startling low infection rate. I would like to say that it’s because we’re perfect, and we’re just better than every other field of medicine. That certainly is one explanation, that we’re so much more compliant. If that isn’t the answer, I suspect it’s because we have a greater safety margin.”
The low risk of transmission of infection isn’t a reason to be complacent, Nelson continues. “I think compliance with the guidelines is very important. The purpose of the multi-society guidelines that were written in 2003 was to ensure there was not a lot of confusion. There are a number of organizations and societies that deal with endoscopy and reprocessing, and we wanted to make sure all these guidelines on how to reprocess scopes weren’t causing confusion. We had one resource, one set of guidelines that everyone could agree we should follow. Those are endorsed by every major GI, nursing, and infection control society in addition to the Joint Commission on Accreditation of Healthcare Organizations (JCAHO).
“In Belgium in 2001, there was an inactive batch of glutaraldehyde sent to Belgium. These scopes got glutaraldehyde concentration between 0 percent and 2 percent. They found about 35,000 patients that they sent notifications to, that they had to give serologic testing for disease, and found that the incidence of hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B virus (HBV) was no greater than the population, which would tell you that maybe it’s not the disinfecting — it’s the cleaning we do, which is probably the single most important thing we do to prevent the transmission of infection. Cleaning alone will reduce the bacterial bioburden by 3 to 5 log, or provide a 99.999 percent reduction in bacteria. But if you don’t clean it, you can defeat the high- level disinfection process,” he continues.
The importance of cleaning cannot be overstressed; the mechanical cleaning before endoscopes are disinfected is perhaps the single most important step endoscope reprocessors take. “There are studies showing you can remove all HIV from an endoscope just by cleaning it, without necessarily disinfecting it, so cleaning is a critical part of it,” Nelson adds. “If you fail to clean an instrument, you can defeat a disinfection or sterilization process. Conversely, if you do the cleaning right, you can have a failed disinfectant process and still not have a problem. I’m not suggesting that we don’t disinfect our instruments; I’m just saying that if you look at the relative contributions [of each step], cleaning is a hugely important aspect.”
Debate still continues over whether “first case reprocessing” is necessary in the morning, for the first patient of the day. “I think that depends on the system you use, and how you reprocess the instrument,” he states. “If you leave it wet and store it, we know that an instrument, — no matter how you reprocess it, whether it’s going through a high-level disinfection cycle or a sterilization cycle — the instrument is only as good as the water, quality you rinse it off with. If you store a wet instrument, I think you are obliged to reprocess it first thing in the morning. If you high-level disinfect it and use forced air drying with alcohol and leave it as a ready-to-use instrument and you store it, there are studies showing you don’t get contamination if you have proper storage. I think if you disinfect it appropriately and dry it and store it well, these are non-issues.
“It’s not my practice to store it wet. I know that one of my manufacturers insists the finished instrument not be exposed to alcohol and forced air. In that circumstance, you’re left with water. Unless you’re checking the water quality, you have no guarantee of the reliability of water. In every other aspect of medicine, you don’t assume something is sterile because it’s been through an autoclave. We have biological indicators, and if they don’t prove it’s sterile, you assume it’s not. I don’t think we should assume because the water has gone through the reprocessor, and there’s a claim about the water quality — if we’re not testing it — we should not assume that it’s sterile. The guidelines suggest that we rinse the endoscopes with sterile filtered or tap water, but then you are obliged to dry with alcohol and forced air. That may change in future issues of the guidelines. The ASGE is in the process of planning another consensus to revise the guidelines, probably in 2007.”
There is not one specific common error that stands out relating to infections from endoscopes. However, Nelson observes, “The most recent issue was in California. There was an accessory channel on a certain model of endoscope that technicians were not cleaning, either because they didn’t know the channel existed, or for some reason they felt that if you didn’t use the channel, it didn’t need to be cleaned. I think this affected approximately 10,000 people in California. And that shows not a great understanding of the mechanics of the scope. To me it’s obvious — whether you use the channel or not, you have to disinfect and clean every channel every single time. I think that the technicians tasked with reprocessing the endoscopes need to be familiar with every make and model that they’re reprocessing, and every accessory channel.”
Design Is Not Conducive to Easy Cleaning
“There are a number of reasons why reported infection rates related to endoscopy are low,” says Victoria Fraser, MD, professor of medicine and co-director of infectious disease at Washington University School of Medicine in St. Louis. “Number one, there are very complicated multistage processes involved for the cleaning, decontamination, disinfection, and sterilization of endoscopes to prevent cross-contamination from patients. The second reason is that there are no systems in place to do surveillance to actually track endoscope-related infections. Most of what we know about endoscope-related infections come about because of either breaks in technique or outbreaks in which infections are identified, but we don’t currently have organized systems to do surveillance and tracking to determine if infections occur. The third reason is that for most GI endoscopy procedures, it’s not an incredibly infection-prone procedure because the GI tract is not a sterile body site, so it’s already contaminated with bacteria.
“Now, on the other side other argument, though, is that the system for disinfection, decontamination, and sterilization of endoscopes is difficult and complicated, because these instruments are not easy to disinfect and sterilize. They have multiple lumens, they’re long and narrow, and they are susceptible to biofilm formation and potential breaches in the integrity of the instrument, which then can increase the risk of infection.”
The ability to clean, decontaminate, disinfect, and sterilize instruments relates to the shape, size, and nature of the equipment that you’re trying to sterilize, as well as the material of which it is composed. “The easiest thing to sterilize is a metal object that is completely solid, small in nature, and that has areas without small nooks or crannies, without ridges or without areas that are hard to reach. With a perfectly square cube, you can easily reach all the surfaces to remove biofilm and biologic materials, and when you expose it to disinfectants or chemicals for disinfection or sterilization, it’s very easy for the disinfectant or sterilizing material to reach all the surfaces. Long, narrow, lumened instruments are notoriously difficult to disinfect and sterilize because it’s actually hard to penetrate the lumen and to ensure that you have adequate direct contact with all the surfaces,” Fraser says.
“There are different systems for the different steps in the complex, multistage process. And all the steps are essential if you want to have adequate disinfection or sterilization. There has to be incredibly effective cleaning initially to remove organic material, and then there has to be appropriate leak testing, to make sure the instrument is intact and that there haven’t been any tears or leaks developing in the lumenal surface through which fluids or other organic materials could escape disinfection process.”
Training Is Everything
Pat Holland, RN, BSN, CGRN, is a former president of the Society of Gastroenterology Nurses and Associates (SGNA), and a staff nurse and PRN at Lakewood Endoscopy Center in Denver. She also provides consulting services via Holland Consulting on education regarding infection control and care and handling of endoscopic equipment.
The manager responsible for the sterile processing staff must, first and foremost, familiarize herself with the scopes, with their manuals, and with the cleaning and reprocessing protocols associated with them, Holland says. “She should also be familiar with the SGNA standards for reprocessing endoscopes. She should make sure that the staff doing the reprocessing, handling the scopes, is trained properly. Training is probably the most important piece of the whole process, because often, someone who is trained learns how to do shortcuts, and then because they’re sometimes rushed, they develop their own fast way, and then they maybe teach someone else some bad habits. I think it’s important for new people to be trained not by other reprocessing staff, but by the person in charge who has done the training of the staff, so everyone is trained exactly the same way. The other big thing is a competency review annually. The SGNA video and guidelines are excellent for that.”
Reprocessing of scopes is certainly not just left to the technicians; nurses may also be responsible for cleaning, decontaminating, disinfecting or sterilizing endoscopic instruments. “Nurses who are handling the scopes, at least a portion of them, should be trained as well to do the reprocessing, because if cases go late and the reprocessing staff is off, the nurse might be the last person handling scopes at the end of day or setting up at the beginning of day. In the facility I work in, all the nurses have to go through the basic infection control training and be familiar with the components of the scope. Everyone has to know how to do the precleaning step, but I think the critical piece is that everyone is trained exactly the same way, and that no steps are ever skipped or shortcuts taken,” Holland adds.
If a new endoscope is purchased for the facility, the manager in charge of training all the personnel in reprocessing must be familiar with any new channels or reprocessing guidelines associated with that particular instrument. However, Holland says, “There is some responsibility with the scope manufacturer — they need to say, ‘This is different from the scopes that you currently have.’ Certainly, there have been incidents of infection with scopes when people were not familiar with the fact that there was an extra channel. That training has to happen as soon as you get the equipment, but then you have to look at the manual, and make sure there’s not something different in that manual than with your other scopes.”
It’s also important to remember that different reprocessing machines perform in different ways. “Scope reprocessors are not scope cleaners for the most part,” she observes. “There are some that do a portion of the cleaning, but the manual mechanical cleaning always needs to be done separately. The important pieces, when you are manually cleaning, are the proper brushes. They have to be the proper size for the channels. You have to make sure your brush is right, and there are other brushes for cleaning in the ports and the nozzle. There are also the adapters for cleaning internal channels, because you can only brush one of the three major channels in the scope, and the other channels have to be purged with a flushing mechanism. You have to make sure you have the correct adapters for all of that. Then the reprocessors do specific steps. For example, the STERIS reprocessing system doesn’t do any precleaning or preflushing of the scopes, so you have to know that you have to do the cleaning and rinsing before you put it into the processor. Some of the processors do a purge of enzymatic or purge of rinse water or purge of air, so you need to know what steps your reprocessor does, and which steps of the manual cleaning process they can replace.
“The first cleaning step is done with an enzymatic cleaner. When I started in endoscopy, we didn’t have cleaners that were specific for scopes, and they just said that you could use a detergent. Some people used dishwashing liquid. But now they’re very specific, and they say that you need to use an enzymatic cleaner for the precleaning and the cleaning steps. It has to be mixed at the right concentration. If it’s mixed too strong, it can be damaging to the equipment, but if it’s mixed too weak, it can actually not dissolve the patient materials. Of course, for disinfectants, you have to use the ones that have been approved for endoscopes — high-level disinfectants.”
New technology can make the reprocessor’s job easier. Leak testing must be performed for every endoscope every time it is reprocessed. “Verimetrix has an automated retester — a revolutionary new technology for endoscopy,” Holland points out. “Leak testing is something that’s very subject to the skill level and knowledge and training of the technical person who is leak-testing the scope, so it’s very subject to human error. It’s something that typically should take about a minute, and in my experience, I’ve seen people do leak testing in 10 to 15 seconds. That’s not enough time, so they can’t identify leaks. The Verimetrix leak testing system is able to detect any leaks in the scope with certainty, and it also is a time-saving factor, because it can be leak testing one scope while someone is cleaning another scope.”
“The reason you want to detect these leaks and breaks is because then you can get the scope repaired more quickly, and you don’t try to disinfect the scope and use it on next patient,” Fraser concurs. “If there is a leak or break in the scope, you can’t disinfect it correctly, no matter how hard you try. The more you clean and disinfect a scope with a leak, the more damage you do to the scope, and the more expensive it ultimately is to repair.
“People test for leaks by measuring the pressure inside of scopes, using what looks like a turkey baster, a bulb syringe, and inflating air into the scope and then holding it under liquid or water usually, and looking for bubbles to come up,” Fraser says. “But a human’s ability to see these bubbles and this process is not ideal.
It’s easy to miss the bubbles unless you have perfect eyes, and it’s easy not to wait long enough to detect the bubbles coming up, and this turkey baster equivalent is not very precise. The Verimetrix system takes away the turkey baster syringe and the human eye by hooking it up and by forcing a known volume of air and pressure into the scope and electronically measuring if there is a difference in pressure that is a sign of a leak or a break.”
The failures in endoscope reprocessing are not just attributed to the need for better technology; some of the other requirements are better understanding and training of exactly how to follow reprocessing instructions.
Getting Manufacturers on Board
“Olympus America is a corporate partner of the ASGE,” says Thomas Gilmore, product manager for cleaning, disinfection, and sterilization, Olympus America Inc. “As such, we support the ASGE’s published national multisociety guideline for reprocessing gastrointestinal endoscopes, for the cleaning and high-level disinfection of GI endoscopes (Gastrointestinal Endoscopy 2003; 58(1):1-8). This guideline represents the best protection for the prevention of transmission of infection during GI endoscopy.
Transmission of infectious organisms during gastrointestinal endoscopy is an extremely rare event. In fact, according to the ASGE, the reported rate of the transmission of infectious organisms during GI endoscopy is estimated at 1 in 1.8 million procedures. When bacterial and viral transmissions have been reported, every such instance has resulted from failure to adhere to established guidelines. There are no reported cases of transmission of infection when these guidelines are followed.”
Since flexible endoscopes ordinarily do not break the mucosal barrier, the Spaulding Classification System categorizes them as semi-critical devices. “Following the Spaulding system, the standard of care for flexible endoscopes is typically high-level disinfection,” observes Gilmore.
“Because flexible endoscopes are high-level disinfected, they are usually reprocessed in an area close to where the procedure is being performed, rather than in the sterile processing department. The manufacturer’s reprocessing manual and the multi-society guideline provide step-by-step instructions for reprocessing. Following these steps are the best practices.”
To ensure that the incidence of infections is reduced, nurses and technicians can do the following, he suggests:
Vision-Sciences Inc. offers a unique product for endoscope safety; the Slide-On™ EndoSheath® System is designed to allow rapid scope turnaround time, increased staff productivity, decreased dependency on germicides, and enhanced protection of patients, staff and equipment.
The Vision-Sciences Web site discusses the Slide-On ENT (ear, nose, and throat) Sheath, which provides a sterile, disposable barrier between the scope and the patient. Its design permits fast and simple placement on — and removal from — a flexible ENT scope.
This reduces the time to reprocess endoscopes, as the scopes require an “intermediate” level of disinfection rather than high-level disinfection after using the sheath. Because this disinfection level reduces the length of contact with germicides, it may also extend the life of the scope and reduce the number of repairs due to damages during reprocessing.
The sheaths, which are latex-free, are FDAcleared and CE-marked; each sheath is individually packaged, sterile, and single-use — and each sheath undergoes leak testing before it is packaged.
There are also sheaths designed for transnasal esophagoscopy; the sheaths allow air, water, and suction capabilities. The sheath forms a barrier that can block microorganisms as small as 27 nanometers in diameter. Certain sheaths even include an integrated channel for biopsy. The working channel isolates the esophagoscope, suction valve, and control mechanisms from patient fluids. And a sheath for sigmoidoscopes allows all patient materials, suction and biopsy, to travel through the disposable sheath, not the endoscope.
In July 1996, after undergoing testing by MicroTest Laboratories, the high-level disinfection requirement for scopes utilizing the sheath was eliminated and replaced by an alcohol wipe-down low-level disinfection, and the FDA allowed the claim that “The EndoSheath System is a proven effective barrier to microorganisms as small as 27 nanometers in diameter.” In 2002, the cleaning procedure was revised to drop the enzymatic cleaning and soaking, and was replaced with “an appropriate instrument detergent” wash.
In 1999, the FDA had performed testing on the endoscope sheaths to determine if defects purposely made in the sheath allowed contamination to pass inward through the defect to the scope, then outward from the scope through a defect in a subsequent sheath. The results of the study found that although a virus could pass inward through a sheath defect to contaminate the scope, and some of the viruses on the scope could contaminate the inside of a new sheath, no virus was found to have passed through the second defective sheath. Thus, the report states, “Use of a sheath combined with intermediate-level disinfection should provide a safe instrument for ENT endoscope.”4
The authors conclude, “Proper use of an ENT endoscope sheath, meticulous cleaning of the endoscope, followed by an intermediate-level disinfection step, combined with careful aseptic technique, will provide the practitioner with an instrument that can be reprocessed in a timely manner and provide confidence that the endoscope/sheath combination is safe for patient use.”
2. Kirschke DL, Jones TF, Craig AS, Chu PS, Mayernick GG, Patel JA, Schaffner W. Pseudomonas aeruginosa and Serratia marcescens contamination associated with a manufacturing defect in bronchoscopes. N Engl J Med. 2003 Jan 16;348(3):214-20.
3. Curr Opin Infect Dis. 2005 Aug;18(4):326- 30.
4. Baker KH et al. Evaluation of Endoscope Sheaths as Visual Barriers. Laryngoscope 1999, 109:636-639.