High-level disinfection of gastrointestinal endoscope reprocessing

High level disinfection(HLD) of the gastrointestinal(GI)endoscope is not simply a slogan, but rather is a form of experimental monitoring-based medicine. By definition,GI endoscopy is a semicritical medical device. Hence,such medical devices require major quality assurance for disinfection. And because many of these items are temperature sensitive, low-temperature chemical methods, such as liquid chemical germicide, must be used rather than steam sterilization. In summarizing guidelines for infection prevention and control for GI endoscopy, there are three important steps that must be highlighted: manual washing, HLD with automated endoscope reprocessor, and drying. Strict adherence to current guidelines is required because compared to any other medical device, the GI endoscope is associated with more outbreaks linked to inadequate cleaning or disinfecting during HLD. Both experimental evaluation on the surveillance bacterial cultures and in-use clinical results have shown that, the monitoring of the stringent processes to prevent and control infection is an essential component of the broader strategy to ensure the delivery of safe endoscopy services, because endoscope reprocessing is a multistep procedure involving numerous factors that can interfere with its efficacy. Based on our years of experience in the surveillance of culture monitoring of endoscopic reprocessing, we aim in this study to carefully describe what details require attention in the GI endoscopy disinfection and to share our experience so that patients can be provided with high quality and safe medical practices. Quality management encompasses all aspects of pre- and postprocedural care including the efficiency of the endoscopy unit and reprocessing area, as well as the endoscopic procedure itself.     

Liquid disinfecting and sterilizing reprocessors used for flexible endoscopes

In this issue, we evaluate three liquid disinfecting flexible endoscope reprocessors that can be used with a user-supplied liquid chemical germicide (LCG), primarily for high-level disinfection (HLD). Applying most of the same criteria and test methods, we also evaluated a fourth unit, presented separately, that is marketed as a liquid sterilizing reprocessor and must be used with manufacturer-supplied, single-use containers of LCG. Although the sterilizing unit can be used for rigid endoscopes, surgical instruments, and endoscopic accessories, we evaluated its application to the reprocessing of only flexible endoscopes. Our ratings are based on the following: (1) basic performance, such as compatibility with several different types of endoscopes and LCGs, inclusion of all essential reprocessing phases, and exposure of all endoscope surfaces to the LCG and rinse water; (2) safety, such as ensuring that essential reprocessing phases cannot be skipped or omitted, that personnel exposure to LCG vapors is minimized, and that the reprocessor is unlikely to contaminate the endoscope during reprocessing; and (3) human factors design, such as ease of use and installation. We did not perform microbiological testing to confirm HLD or sterilization by any of the evaluated reprocessors because, with a suitably clean endoscope that is in good condition, no evidence indicates that the LCGs used would not be effective on the surfaces that they contact; also, the results would be unique to the two flexible endoscopes that we used for our testing. We rated all four reprocessors Conditionally Acceptable. The units are Acceptable on the condition that users understand that they cannot be used to process the elevator cable channel of side-viewing duodenoscopes; additional conditions apply only to the liquid disinfecting units. However, if the conditions are met, all four units reduce the likelihood of using a contaminated endoscope on a patient and reduce personnel exposure to the LCG. Selection of a unit will be based on the needs and preferences of the individual healthcare facility. Our ratings also assume that these units will be used according to the manufacturers' instructions and the endoscope's operator's manual. Note that, although the evaluated liquid disinfecting units provide detergent-flushing, post-detergent water-rinse, and post-detergent water-rinse-removal phases, manual cleaning of endoscopes before automatic reprocessing is essential, regardless of which reprocessor is used.(ABSTRACT TRUNCATED AT 400 WORDS)     

The Steris Reliance EPS endoscope processing system: a new automated endoscope reprocessing technology

In this Evaluation, we examine whether the Steris Reliance EPS--a flexible endoscope reprocessing system that was recently introduced to the U.S. market--offers meaningful advantages over "traditional" automated endoscope reprocessors (AERs). Most AERs on the market function similarly to one another. The Reliance EPS, however, includes some unique features that distinguish it from other AERs. For example, it incorporates a "boot" technology for loading the endoscopes into the unit without requiring a lot of endoscope-specific connectors, and it dispenses the germicide used to disinfect the endoscopes from a single-use container. This Evaluation looks at whether the unique features of this model make it a better choice than traditional AERs for reprocessing flexible endoscopes. Our study focuses on whether the Reliance EPS is any more likely to be used correctly-thereby reducing the likelihood that an endoscope will be reprocessed inadequately-and whether the unit possesses any design flaws that could lead to reprocessing failures. We detail the unit's advantages and disadvantages compared with other AERs, and we describe what current users have to say. Our conclusions will help facilities determine whether to select the Reliance EPS.     

Reprocessing endoscopes: United States perspective

Endoscopes are used frequently for the diagnosis and therapy of medical disorders. For example, greater than 10000000 gastrointestinal endoscopic procedures are performed each year in the United States. Failure to employ appropriate cleaning and disinfection/sterilization of endoscopes has been responsible for multiple nosocomial outbreaks and serious, sometimes life-threatening, infections. Flexible endoscopes, by virtue of the site of use, have a high bioburden of microorganisms after use. The bioburden found on flexible gastrointestinal endoscopes following use has ranged from 10(5) to 10(10)CFU/ml, with the highest levels being found in the suction channels. Cleaning dramatically reduces the bioburden on endoscopes. Several investigators have shown a mean log(10) reduction factor of 4 (99.99%) in the microbial contaminants with cleaning alone. Cleaning should be done promptly following each use of an endoscope to prevent drying of secretions, allow removal of organic material, and decrease the number of microbial pathogens. Because the endoscope comes into intimate contact with mucous membranes, high-level disinfection is the reprocessing standard after each patient use. High-level disinfection refers to the use of a disinfectant (e.g., FDA-cleared chemical sterilant or high-level disinfectant) that inactivates all microorganisms (i.e., bacteria, viruses, fungi, mycobacteria) but not high levels of bacterial spores. The disinfection process requires immersion of the endoscope in the high-level disinfectant and ensuring all channels are perfused for the approved contact time (e.g., for ortho-phthaladehyde this is 12 min in the US). Following disinfection, the endoscope and channels are rinsed with sterile water, filtered water, or tapwater. The channels are then flushed with alcohol and dried using forced air. The endoscope should be stored in a manner that prevents recontamination. A protocol that describes the meticulous manual cleaning process, the appropriate training and evaluation of the reprocessing personnel, and a quality assurance program for endoscopes should be adopted and enforced by each unit performing endoscopic reprocessing.     

Guidance section: selecting, purchasing, and using reprocessors for flexible endoscopic applications

In this section, we summarize and expand on the significant findings from our Evaluation of liquid disinfecting and sterilizing flexible endoscope reprocessors. Below, we present factors that will help users decide whether their facility should purchase a reprocessor and which unit is the best selection for their needs. We also provide guidance intended to improve the overall safety and effectiveness of flexible endoscope reprocessing. Readers are advised to review the entire study in conjunction with this guidance material to establish a firm foundation for any selection, purchasing, or use decisions regarding flexible endoscope reprocessors in general, as well as those that we evaluated. Decisions on selecting and purchasing one of the evaluated reprocessors should not be based on our criteria, test methods, test results, or ratings alone, but on a thorough understanding of the clinical and technical issues associated with these devices, which can be gained by reading this issue in its entirety.     

Wie steht es um die Hygiene beim Endoskopieren?

Flexible endoscopy is essential for the practice of modern medicine. However, with inadequate reprocessing of endoscopes and additional instruments, infections can be transmitted. Therefore, guidelines for reprocessing flexible endoscopes have been published in many countries. The goal of the present survey was to examine the current compliance with German Guidelines in a German urban region, covering all hospitals (15 hospitals) and private practices (23 practices) of this area, without any exception. All endoscopic units in Frankfort on the Main were visited by members of the Public Health Service, using a checklist based on the recommendations of the German Guidelines. In 2004, a reevaluation of 14 hospitals and 20 private practices took place, either by analysing the written reports of the institutions or by revisiting the institutions. In 2003, compliance with the guidelines in hospitals was satisfactory. In practices, however, many problems were identified in 2003. Between 2003 and 2004, great improvements could be seen (data of 2003 in parentheses). At the end of 2004, in 90% of the practices adequate storage of the endoscope without risk of recontamination (2003:52%), correct reprocessing the bottle and the tube for air/water channel flushing including filling with sterilized water was observed (2003:74% and 52%). In 100% of the practices, ultrasonic cleaning (2003:26%) and sterilizing of endoscopic accessories was guaranteed (2003:57%) and routine tests of endoscopes after reprocessing (2003:56%) were performed. In conclusion the relevance and the effect of the advising and control of public health have been so efficient that between 2003 and 2004 most faults have been corrected. Therefore control visits of the Public Health Services should not only cover hygiene in reprocessing the endoscopes but also hygiene in reprocessing endoscopic accessories as well.     

Multi-society guideline for reprocessing flexible gastrointestinal endoscopes. Society for Healthcare Epidemiology of America.

Flexible gastrointestinal endoscopy is a valuable diagnostic and therapeutic tool for the care of patients with gastrointestinal and pancreaticobiliary disorders. Compliance with accepted guidelines for the reprocessing of gastrointestinal endoscopes between patients is critical to the safety and success of their use. When these guidelines are followed, pathogen transmission can be effectively prevented. Increased efforts and resources should be directed to improve compliance with these guidelines. Further research in the area of gastrointestinal endoscope reprocessing should be encouraged. The organizations that endorsed this guideline are committed to assisting the FDA and manufacturers in addressing critical infection control issues in gastrointestinal device reprocessing.     

Evaluation of the microbicidal efficacy of Steris System I for digestive endoscopes using GERMANDE and ASTM validation protocols.

In the light of more and more invasive procedures being carried out in digestive endoscopy using sterile devices, it appears necessary to put in place a process of endoscope reprocessing capable of ensuring the complete elimination of micro-organisms contaminating the device. We undertook a study of the microbial efficacy of STERIS SYSTEM 1 (SS1) which purports to achieve this objective. The channels of a gastroscope and a colonoscope were contaminated with suspensions of Pseudomonas aeruginosa, Aspergillus niger and Bacillus subtilis spores. Two procedures were then followed: (1) manual washing only, and (2) treatment in SS1 without prewashing. Recoveries of organisms were made from each channel according to a standard methodology to discover any survivors. Contamination controls we re assessed to measure the logarithmic reduction between the initial contamination and that recovered from the channels. Six cycles per micro-organisms, per type of endoscope, and per type of procedure were carried out. From an initial contamination leve l of 10(6) micro-organisms per endoscope, no micro-organisms were recovered in 35 of the 36 cycles with the SS1. In one cycle with the colonoscope, three B. subtilis organisms were recovered from the channels. Washing only gave microbial reductions which varied according to the micro-organism tested. The maximum reduction with washing alone was by a factor of 10(3 +/- 0.1)for B. subtilis and the minimum reduction factor was 10(3 +/- 0.3)for P. aeruginosa. Considering the results obtained with SS1 without prewashing and the efficacy obtained from washing only, the washing step offers an additional antimicrobial assurance reduction factor of between 10 and 103.1. This study shows that SS1, integrated into an overall reprocessing procedure for digestive endoscopes, is capable of delivering the complete elimination of contaminating micro-organisms in a reduced time and eliminates the toxic risk of reprocessing associated with aldehyde based disinfectants.     

内窥镜防交叉感染安全保护套的研制

目的：改善目前内窥镜消毒欠佳的状况,研制内窥镜防交叉感染安全保护套。方法：选用无毒、无害、无味、透明、有弹性的医用橡胶,加工成圆管状或圆筒状,其大小与内窥镜前部的镜身相吻合。前后端开口处设置内藏加厚圈。每只以保护套的中线为轴心搓卷成卷桶状,消毒灭菌后装袋备用。结果：保护套结构简洁流畅,能够经内窥镜的末端顺利退卷并套上内窥镜镜身且紧密贴附。结论：内窥镜防交叉感染保护套能够有效地避免内窥镜镜身沾染受检者的血液黏液以及可能存在的病原微生物,降低医源性交叉感染的风险。     

Application of environmental sampling to flexible endoscope reprocessing: the importance of monitoring the rinse water.

The routine sampling of environmental surfaces within a healthcare facility is generally not recommended by the Centers for Disease Control and Prevention (CDC), the Association for the Advancement of Medical Instrumentation (AAMI), and several other healthcare organizations. There are a few circumstances, however, for which some organizations do recommend this practice. For instance, the CDC and the Association for Professionals in Infection Control and Epidemiology (APIC) recommend environmental sampling as clinically required during an outbreak investigation. The CDC and AAMI also recommend routine sampling of the rinse water used during hemodialyzer (but not endoscope) reprocessing. The rationale for this recommendation is based in part on reports of pyrogenic responses, patient infections, and bacteremia due to waterborne, gram-negative bacteria during hemodialysis. To determine whether the basis for this rationale might similarly apply to the rinse water used during endoscope reprocessing, the Food and Drug Administration's medical device reporting database, the endoscope reprocessing literature, and other sources were reviewed. The results of this review indicate that nosocomial outbreaks linked to endoscopes contaminated with gram-negative bacteria have been frequently reported. As a result, for several reasons, including to minimize the risk of patient infection due to gram-negative bacteria following endoscopy, this article recommends routine microbiologic sampling of the rinse water used during endoscope reprocessing.     

The 'cut and push' method of percutaneous endoscopic gastrostomy tube removal

BACKGROUND AND AIMS: The standard method of removing percutaneous endoscopic gastrostomy tubes is by gastroscopy. This has implications for endoscopy time and resources, and we believe is not always necessary. Depending on the type of percutaneous endoscopic gastrostomy tube used we often used the 'cut and push' method. This involves cutting the catheter at skin level and allowing the tube and internal bumper to spontaneously pass. The cut and push method also represents a considerable resource saving compared to the endoscopic method that we think warrants further discussion. METHOD: We reviewed all the files of the percutaneous endoscopic gastrostomy tubes removed in our unit over the last 4 years. RESULTS: During the period of July 1995 to July 1999, we have inserted 384 percutaneous endoscopic gastrostomy tubes. Seven tubes have been removed endoscopically and 73 tubes have been removed with the cut and push method. Only two possible complications have been recorded (2.7%). CONCLUSIONS: We believe that we have provided further evidence that percutaneous endoscopic gastrostomy tubes can be removed safely using the cut and push method. Patients who are often frail and who have multiple medical problems are saved an often-long journey to the endoscopy unit as well as the hazards of an endoscopy. The saving in resources in what is already an overworked system by not performing endoscopies is also considerable.     

Future trends in the development of endoscopic studies of digestive tract organs

Presented in the paper are new promising endoscopic devices for examinations of the digestive tract organs. Special attention is paid to one of the important directions, the development of endoscopes for peroral examinations of hepatic passages, the intraoperation choledochoscopy. In order to improve the diagnostic capabilities of the small intestine endoscopy the development of a long controllable endoscope is advisable. A new trend in endoscopy, the endoscopic microscopy, is noted to be of great research importance. This trend calls for creation of not only new methodologic basis but of new types of endoscopes as well. They should be capable of detecting changes in both structural formations and cell structures.     

Bacteria-free endoscopy rinse water -- a realistic aim?

A number of outbreaks and pseudo-outbreaks have been associated with contaminated rinse water in endoscope washer-disinfectors. Health Technical Memorandum 2030 specifies that final rinse water should be 'bacteria-free'. In this study, results of rinse-water testing from 20 endoscopy units were reviewed over a 4-month period. Over 60% of samples were of an unsatisfactory quality (i.e. not bacteria-free) and none of the endoscopy units consistently achieved sterile water throughout the study period. Poor microbiology results caused anxiety to endoscopy staff and infection control teams who had to decide whether or not to take washer-disinfectors out of use, possibly resulting in delays to medical procedures. There was no common policy on how to react to poor results, with staff at each unit developing their own action levels. Here, it is suggested that future guidelines would be of more practical use if they specified a series of action levels of increasing severity based on the bacterial count in a water sample.     

Surgical video systems

A surgical video system (SVS) is an integration of components used to perform minimally invasive surgery (MIS). In the operating room, an SVS consists of an endoscope, an attached video camera, a light source, a video processor, and one or more video displays. A single SVS can generally be used in any type of MIS procedure (e.g., general, orthopedic, urologic), provided that it is equipped with the appropriate type of endoscope. In this Evaluation, we tested seven systems from six manufacturers. We found that, on average, three-chip systems provide better overall image quality than one-chip systems. Three systems were judged as providing image quality slightly superior to that of all the other systems; however, the level of subjectivity involved in judging performance suggests that users should perform in-house trials before purchase. All the evaluated systems performed relatively well in performance testing, but most systems were rated Fair or Poor in several human factors and safety tests. In fact, only two systems did not receive any Poor ratings in the Light Source Safety Features tests. Although users bear much of the responsibility for ensuring that light sources are used safely, most manufacturers have not made simple design changes that would make unintentional misuse less likely. We would be more likely to rate systems that still exhibit these safety issues in the future as Not Recommended or Unacceptable.     

Reassessment of the risk of healthcare-acquired infection during rigid laryngoscopy

Inadequate reprocessing of rigid laryngoscopes has been linked to nosocomial outbreaks with associated morbidity and mortality. Last year an outbreak of Pseudomonas aeruginosa in a neonatal intensive care unit was responsible for multiple infections and colonisations, and at least two infant deaths. An investigation of this outbreak identified contaminated rigid laryngoscopes as its source, demonstrating that inadequate reprocessing of rigid laryngoscopes remains a current public health concern. This article revisits and reassesses the risk of healthcare-acquired infection during rigid laryngoscopy and establishes the minimum reprocessing requirements for blades and handles of rigid laryngoscopes. Several potential risk factors for microbial transmission are identified and discussed, including the publication of inconsistent reprocessing guidelines for rigid laryngoscopes. Concern about guidelines that recommend low-level or intermediate-level disinfection of rigid laryngoscopes is expressed. The use of a sterile disposable sheath to cover the rigid laryngoscope and minimise the risk of contamination is also discussed. Regardless of whether a sheath is used during the procedure, thorough cleaning followed by high-level disinfection and drying of the instrument is recommended to prevent microbial transmission.     

Cleaning, disinfection, and sterilization of gastrointestinal endoscopes: approaches in the office

Bacterial contaimination of endoscopes can be clinically significant. While current data suggest that flexible sigmoidoscopy may entail fewer risks than upper endoscopy, these data are too incomplete to draw this conclusion. Careful cleaning and disinfection after each procedure are recommended. Gas sterilization of the endoscope and gas or heat sterilization of accessory equipment may be necessary in certain clinical situations. It must be remembered that hundreds of thousands of endoscopic procedures were performed in the 1970s using cleaning only without substantial health risk. The processes do not have to be complicated or difficult. Staff must be well trained and must understand the potential risks of working with disinfecting agents such as alkaline glutaraldehyde. It is recommended that the clinician fully understand the cleaning and disinfection steps and be able to perform them. It is important that office procedures be based on efficacy, not convenience. The procedures developed to date are not ideal and the ideal disinfectant has yet to be found. Cleaning and disinfecting machines have been developed, but they are expensive and their efficacy and safety are no better than hand-performed methods. An alternative approach to reducing transmission of infections by endoscopes may be to seek less adherent plastic substances for the endoscope sheath. The introduction of immersible endoscopes has helped with cleaning, but their use may also give rise to a false sense of security. Diligent attention to cleaning and disinfection is still necessary.(ABSTRACT TRUNCATED AT 250 WORDS)     

Contamination of an endoscope due to Trichosporon beigelli

Trichosporon beigelli was isolated from the gastric aspirates of ten patients who had undergone endoscopy. Suspecting fungal contamination of the endoscopic equipment, samples from the biopsy channel, the water bottle, aspiration catheter and the tip of the endoscope were examined. Only the sample from the biopsy channel showed fungal elements on direct examination and grew Trichosporon beigelli. The original source for the fungus was an immunocompromised patient who had undergone endoscopy earlier. This episode occurred despite adherence to apparently adequate disinfection procedures for endoscopes. Because of the risk of cross-infection, especially in immunocompromised patients, it is imperative to take special steps to prevent fungal contamination of endoscopes.     

Double-balloon enteroscopy of the small intestine

Since the introduction of double-balloon enteroscopy (DBE), the small intestine has come into easy reach for endoscopy. By the 'push and pull' technique, the endoscope can be introduced far into the small intestine. Diagnostic endoscopy can be combined with endoscopic treatment in the small intestine, for example in patients with intestinal bleeding (angiodysplasia), polyps, tumours, or stenosis of the small intestine. DBE is especially important for patients with gastrointestinal blood loss that cannot be explained by the results of gastroscopy and colonoscopy. The added value of DBE in patients with other possible diseases of the small intestine, such as refractory coeliac disease or Crohn's disease, seems certain and is currently under investigation. In patients with Crohn's disease, endoscopic dilation of strictures may eliminate the need for surgical intervention. DBE can be performed on an outpatient basis. The complication rate of diagnostic DBE seems low, but in therapeutic sessions the complication rate is higher than for therapeutic colonoscopy.     

Gastrointestinal endoscopy decontamination failure and the risk of transmission of blood-borne viruses: a review

The risk of blood-borne virus transmission with an inadequately decontaminated endoscope during gastrointestinal endoscopy remains unclear, although it is likely to be low. A systematic review of the literature was undertaken to determine previous episodes of blood-borne virus transmission in these circumstances. In total, 31 articles were included in this review. No articles relating to possible transmission of human immunodeficiency virus were identified. The articles included were generally case series or case reports and were written prior to the comprehensive endoscope decontamination guidelines in use today. The results suggest that hepatitis B and hepatitis C transmission are low during endoscopy with an inadequately decontaminated endoscope.     

Indigo carmine contrast staining in combination with high resolution electronic endoscopy

INTRODUCTION: Chromoendoscopy is an old endoscopic technique which has a renascence in the era of high resolution electronic endoscopy. Indigo carmine, this deep blue stain is not absorbed by gastrointestinal epithelium. It pools in crevices and valleys and highlights small lesions and defines irregularities in mucosal architecture. METHOD: The indigo carmine dye contrast method was introduced in author's endoscopic laboratory in 1994 and high resolution (400 k.pixels) endoscopy in 1997. 0.1-0.5% indigo carmine solution was administered to the gastric, duodenal or colonic mucosa through the biopsy channel of the endoscope. The author found the dye method gave dramatic accentuation of abnormalities of mucosal architecture (i.e. small irregularities, ulcer scars, extent of small tumours, polyps) and was suitable to evaluate villous atrophy in the duodenum. RESULTS: Using indigo carmine and high resolution electronic endoscopy it was possible to diagnose 3 times more gastric adenomas than was in the past. In the colon it was studied the surface appearance of colonic crypts and was able to discriminate between hyperplastic polyps which had a tipical "pit" pattern ("dots") and adenomatous polyps, which had a "groove" or "sulci" pattern. After histological examination the diagnostic accuracy was proved 59/64 in adenomatous and 18/23 in hyperplastic polyps. CONCLUSION: One should improve minute endoscopical observation and it is believed the administration of indigo carmine dye and high resolution endoscopy are suitable method for that.