Flexible Endoscopes

Get clinical answers to frequently asked questions about processing flexible endoscopes.

  • What is the potential for endoscopic transmission of prions?

    The collective evidence shows there are concerns about the potential for endoscopic transmission of prions and other transmissible spongiform encephalopathies (TSEs), including Creutzfeld-Jakob disease (CJD), and variant Creutzfeld-Jakob disease, (vCJD). For an endoscope to act as a vehicle for transmission of prions, contact with infective tissue is required.

    In CJD, the prions accumulate in the central nervous system and are transmitted by exposure to infectious brain, pituitary, or eye tissue. Because flexible endoscopes do not come in contact with brain, pituitary, or eye tissue, endoscopic transmission of CJD or other TSEs is unlikely.

    In vCJD, the prions accumulate in both central nervous system and lymphoid tissue. Patients with vCJD have infectivity detectable in the appendix, spleen, tonsils, thymus, and lymph nodes. The prions responsible for vCJD are found in abundance in the Peyer patches located in the terminal ileum. Aggregates of lymphoid prions are also found in the large intestine and the stomach. Transmission of vCJD via a flexible gastrointestinal endoscope is therefore theoretically possible because of the lymphatic distribution of prions. The risk for transmission is greater during invasive interventional procedures (e.g., biopsy, polypectomy, mucosal resection, sphincterotomy) than during noninterventional procedures; however, there have been no reports of such transmission described in the literature.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Is it necessary to wear gloves when handling processed flexible endoscopes?

    Yes. Personnel should wear clean, low-protein, powder-free, natural rubber latex gloves or latex-free gloves when handling processed flexible endoscopes and when transporting them to and from the storage cabinet. Sterile gloves are not required for handling processed flexible endoscopes unless the endoscope is intended to be placed on a sterile field.

    Wearing clean gloves may lessen contamination of processed flexible endoscopes by the hands of personnel. Using low-protein, powder-free natural rubber latex gloves or latex-free gloves can minimize latex exposure and the risk of reactions in both health care workers and patients. Studies related to storage of flexible endoscopes have confirmed endoscope contamination from the hands of personnel and environmental surfaces.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Does AORN recommend manual processing of flexible endoscopes?

    No. After manual cleaning and when compatible with the endoscope manufacturer's instructions for use (IFU), flexible endoscopes and accessories should be either mechanically cleaned and mechanically processed by exposure to a high-level disinfectant or a liquid chemical sterilant or should be mechanically cleaned and sterilized.

    Mechanical processing includes mechanical cleaning, mechanical high-level disinfection or sterilization, and mechanical rinsing. The collective evidence shows that mechanical processing improves cleaning effectiveness, increases efficiency, minimizes personnel exposure to biohazardous materials, and can be more successfully monitored for quality and consistency.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Does AORN recommend using rapid cleaning verification tests when processing flexible endoscopes?

    Yes. Manual cleaning of flexible endoscopes should be verified using cleaning verification tests when new endoscopes are purchased and at established intervals (e.g., after each use, daily). Visual inspection alone, even with magnification, is not sufficient to determine cleanliness of complex devices such as flexible endoscopes. Residual soil may remain and prevent effective subsequent high-level disinfection (HLD) or sterilization.

    Cleaning verification tests include adenosine triphosphate (ATP) and chemical reagent tests for detecting clinically relevant soils (e.g., protein, carbohydrate). Periodic verification of cleaning effectiveness using rapid cleaning verification tests provides an objective method for verifying cleanliness and helps assure that insufficiently cleaned flexible endoscopes are recleaned before HLD or sterilization.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Where should processed flexible endoscopes be stored?

    Flexible endoscopes should be stored in a drying cabinet. The collective evidence shows that optimal storage of flexible endoscopes facilitates drying, decreases the potential for contamination, and provides protection from environmental contaminants. Drying cabinets include a drying system that circulates high-efficiency particulate air (HEPA)-filtered air through the cabinet while filtered air under pressure is forced through the endoscope channels. The internal and external surfaces of the endoscope are continuously dried, suppressing bacterial growth. Studies related to the efficacy of drying cabinets compared with other methods of storage have shown that drying cabinets effectively limit bacterial proliferation during storage.

    If a drying cabinet is not available, flexible endoscopes may be stored in a closed cabinet with HEPA-filtered air that provides positive pressure and allows air circulation around the flexible endoscopes. Ventilation promotes drying of the endoscope. Using HEPA-filtered air may help prevent bacterial growth in the endoscope. Positive pressure may help prevent contamination of stored endoscopes.

    Flexible endoscopes should not be stored in their original shipment cases. The cases are difficult to clean, may be contaminated, and are designed for shipping only.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • How long can flexible endoscopes be stored before reprocessing is required?

    The collective evidence regarding the maximum safe storage time for processed endoscopes is inconclusive. Recommendations from professional organizations for maximum storage times for flexible endoscopes are not in agreement. Studies are also not in agreement and have shown that when correctly processed, flexible endoscopes may be safe to use for 48 hours to 56 days after processing. Safe storage times may be affected by factors unique to the facility including the type of endoscopes processed and stored, processing effectiveness (e.g., level of residual contamination), storage conditions (e.g., restricted access, drying cabinet, HEPA-filtered air), compliance with manufacturers' IFU (i.e., endoscope, mechanical processor, storage cabinet), frequency of use, and patient population. For these reasons, a multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should establish a policy to determine the maximum storage time that processed flexible endoscopes are considered safe to use without reprocessing.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Should flexible endoscopes be cultured?

    A multidisciplinary team that includes infection preventionists, endoscopists, endoscopy processing personnel, microbiologists, laboratory personnel, risk managers, and other involved individuals should evaluate the need to implement a program for regular microbiologic surveillance cultures of flexible endoscopes and mechanical processors. A program of regular microbiological surveillance culturing of flexible endoscopes and mechanical processors is advised in the processing guidelines of several international organizations; however, there are variances among the recommendations. Routine surveillance microbiological culturing is supported in the literature as an effective method for monitoring the effectiveness and quality of processing, reinforcing best practices, evaluating the effectiveness of corrective interventions, and detecting endoscopes requiring service. Routine microbiological surveillance may also help to identify the source of contamination and rectify processing methods to prevent transmission of infection.

    Notably, there are problems with microbiological culture surveillance of flexible endoscopes. The sensitivity of routine cultures may be unreliable for detecting the organisms associated with outbreaks. The use of surveillance cultures is confounded by the delay in feedback and the frequent isolation of nonpathogenic organisms resulting from environmental contamination. The need to quarantine flexible endoscopes until the culture results have been obtained may not allow for rapid reuse of the tested endoscope and could also lead to delays in patient care. Microbiological culturing is resource-intensive, and requires additional expenditures for microbiological testing and time for personnel to collect and process samples.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Should all flexible endoscopes be sterilized?

    According to the Spaulding classification, devices that enter sterile tissue or the vascular system are considered critical items that should be processed by sterilization. Items such as flexible endoscopes that come in contact with nonintact skin or mucous membranes, are considered to be semicritical, and should be processed by sterilization, or at a minimum, by high-level disinfection.

    At a meeting of the Gastroenterology-Urology Devices Panel convened by the FDA in May 2015 to seek expert scientific and clinical opinion related to reprocessing of duodenoscopes and other flexible endoscopes, Rutala proposed a modification of the Spaulding system wherein items that secondarily enter sterile tissue or the vascular system are considered to be critical items. Devices secondarily entering sterile tissue would include devices that enter sterile tissue by way of a mucous membrane, such as a bronchoscope, a cystoscope, or a duodenoscope. Requiring sterilization of items that secondarily enter sterile tissue or the vascular system may help prevent patient infection. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, sterile processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine whether items that secondarily enter sterile tissue or the vascular system (ie, via a mucous membrane) should be sterile.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Should flexible duodenoscopes be processed using enhanced methods?

    Enhanced methods for processing flexible duodenoscopes may include implementing high-level disinfection (HLD) followed by:

    • endoscope quarantine until the duodenoscope is culture-negative,
    • a liquid chemical sterilant processing system,
    • a second HLD,
    • ethylene oxide sterilization, or
    • FDA-cleared low-temperature sterilization.

    Initiating enhanced processing methods for duodenoscopes may decrease the potential for pathogenic microorganisms to remain on the endoscope after processing.

    Notably, performing HLD followed by HLD, liquid chemical sterilization, low-temperature sterilization, or ethylene oxide sterilization has not been validated by the endoscope, mechanical processor, or sterilizer manufacturers, and further research is warranted. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine the benefits compared with the potential harms of initiating one or more enhanced methods for processing duodenoscopes.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015

  • Should flexible endoscopes lumens be flushed with alcohol?

    A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine whether endoscope lumens should be flushed with 70% to 90% ethyl or isopropyl alcohol.

    Many clinical practice guidelines and experts in the field recommend manual or mechanical flushing of endoscope lumens with alcohol because it facilitates drying of the endoscope lumens by binding with residual water and enhancing evaporation. Alcohol prevents colonization and transmission of waterborne bacteria. However, flushing endoscope lumens with alcohol may not be necessary if the endoscope is effectively dried. Because of the fixative properties of alcohol, this practice is not recommended in some countries.

    Resources:

    • Guideline for processing flexible endoscopes. In: Guidelines for Perioperative Practice. Denver, CO: AORN, Inc.

    Updated December 11, 2015