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Precleaning Flexible Endoscopes: Time Is of the Essence
By Sara Freiberg

Flexible endoscopes are essential, yet complex and fragile medical devices. One only needs to view the internal schematics to note the various channels, control body mechanisms, light fibers, angulation wires, bending section, distal tip, CCD (camera chip), and more to understand the intricate work that takes place in the design process. The combination of flexibility, elasticity, strength, and torquing ability is both an art and science.1

Internal schematics of a flexible scope

As with any complex medical device, flexible endoscopes require the utmost care in cleaning to ensure patient safety and allow the device to remain in proper working order. Similar to any surgical instrument or reusable medical device, once removed from a patient, the crucial step of precleaning must be performed in a timely manner for many reasons. Patient infections and even deaths have been attributed to crucial steps that were missed in precleaning, manual cleaning, and disinfecting. In one study, microorganisms that were isolated immediately after use of the device, included Staphylococcus, StreptococcusKlebsiella, Escherichia coli, and Bacteroides.2

Bioburden and biofilm
Some flexible endoscopes can reach lengths of more than five feet, containing multiple parts, intricate channels, and various components that are an ideal hiding place for bacteria. If biological materials such as blood, debris, mucous fluids, etc. have an opportunity to dry and harden on or in the endoscope, the formation of biofilm may begin. Biofilm is a microbial community of bacteria that attach to an area and form a matrix. Molecules journal states, “Biofilm formation is influenced by both gene expression and environmental conditions, including surface properties, shear stress, quorum sensing signals, and characteristics of the aqueous medium.”3

Biofilm may impede the subsequent cleaning process by creating a highly effective barrier to the precleaning step and additional cleaning steps. Per the CDC, facilities are prompted to “Perform precleaning immediately following completion of the endoscope procedure to help prevent the formation of biofilm.”4

A race for time
Each endoscope manufacturer has performed cleaning validation studies to support when and how precleaning must occur. This language exists in each manufacturer’s IFU. We are all familiar with the term “immediately after patient use,” but let’s define “immediately.” Flexible endoscopes have a narrow margin of safety if precleaning is not performed in a timely and correct manner. Now the timer, so to speak, begins. 

One manufacturer IFU states, “Immediately after the patient procedure, with the endoscope still connected to the equipment used in the patient procedure (i.e., the light source, video system center, suction pump), perform the precleaning steps at the patient bedside.”5

Another manufacturer IFU states, “Complete cleaning of the patient-used endoscope should be started within two hours of the bedside precleaning. If transit time post patient procedure is greater than two hours, ensure that additional cleaning is performed if visible residual debris is present.”6

Yet another manufacturer IFU states, “If the endoscope and its accessories are not precleaned within 15 minutes and mechanically cleaned within one hour after the conclusion of the procedure, dried blood, mucus, or other patient debris may cause damage to the devices or interfere with the ability of the user to properly reprocess them.”7

Staff should be made aware that depending upon the endoscope manufacturer, model type, and their cleaning validations, each will have its own specific precleaning protocol. In addition to the time factor, we should ensure we are performing each of the precleaning steps in chronological order. One manufacturer IFU states, “All of the steps in the validated reprocessing protocol described in this manual are intended to be performed in rapid succession and as a single, continual procedure.” There should be “…no breaks in between steps and in the event that debris has an opportunity to dry, if drying of the endoscope occurs due to an excessive break in the reprocessing procedure, the procedure should be completely repeated, beginning with the first precleaning step.”8

Manufacturer IFUs may direct the user toward “Delayed Reprocessing Steps” if the endoscope is not precleaned or if excessive bleeding has occurred, which may require a specified soak time, stating the soak time may be up toalthough not exceed 10 hours prior to the manual cleaning process.9 It is important to note that some manufacturers state that continued soak times may also cause damage to the flexible endoscope; therefore, we also want to be mindful of using the delayed reprocessing protocol as a routine approach.

What is your facility’s protocol for precleaning flexible endoscopes?

  • Do we confirm staff is performing precleaning at bedside?
  • Does staff document the time in which precleaning occurred?
  • What occurs in the procedure room if more than one endoscope is used on the patient? Do we wait to preclean both scopes at the end of the procedure or do we ask another staff member to take the first endoscope and begin the precleaning?
  • What occurs if we have an emergency bronchoscopy in the middle of the night or during the weekend? Is the evening or weekend staff aware of the time factor for precleaning?
  • What occurs when no evening or weekend shifts exists in the department? Does the scope sit in the cleaning room until Monday morning?

Adhering to the precleaning steps in accordance with the endoscope manufacturer’s IFU is a crucial step for patient safety. Sterile processing and GI staff should have access to and review each flexible endoscope manufacturers IFU’s language for precleaning, as well as have access and review the AAMI ST91 Guidelines. It is imperative that we share with staff the importance of performing precleaning in a timely manner because time is of the essence. If a precleaning delay does occur, we should share with staff the importance of referring to the manufacturer IFU for their specific delayed reprocessing protocol. Consistent messaging is key to patient safety.

Additional Resources

  • Flexible endoscope guidance may be located in AAMI ST91, Society of Gastroenterology Nurses and Associates (SGNA).


  • The CDC and HICPAC also offer a Sample Policy Template. The sample policy document provides guidance to personnel processing various types of reusable flexible endoscopes and their accessories.




  1. https://www.sciencedirect.com/science/article/pii/S2090506814000529
  2. mdpi.com/1420-3049/17/8/9818/pdf
  3. https://www.cdc.gov/hicpac/recommendations/flexible-endoscope-reprocessing.html
  4. 5-9. https://www.onesourcedocs.com/






Sara Freiberg, CST, CBSPDT, CER, has more than 15 years experience working as a certified surgical technologist, with five of those years spent traveling to various operating rooms across the U.S. Following Sara’s time in the clinical arena, she worked as a surgical technology didactic and lab instructor at Rasmussen College. Sara holds bachelor degrees in science and business and marketing, which led to her work with various medical device companies as a clinical specialist, product manager, and clinical training manager. She has experience working on quality and regulatory teams, monitoring patient-adverse events, and postmarket surveillance activities.

Sara currently works for Northfield Medical as a clinical education manager where she provides education which is based on current manufacturer and regulatory guidelines regarding various healthcare topics for SPD, OR, and GI staff. Training entails the care and handling of medical devices to ensure patient safety, as well as targeted education addressing departmental cost concerns. Her passion is working with SPD, OR, and GI departments; providing assessments; and sharing best practices with respect to patient and staff safety, surgical instruments, and medical devices. Sara is a voting member of the AAMI ST/WG84, ST91 flexible endoscope committee, and she has developed several CEU presentations approved through CBSPD, CBRN, NCCT, and IAHCSMM. Sara also authors a biweekly healthcare article for Ultra Clean Systems.

Sara is currently studying for the Certification Infection Control (CIC) exam through APIC.

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