GI Endoscopes: Biofilm

What is Biofilm?

What is biofilm? This is a term that is commonly used in sterile processing and more specifically in flexible endoscope reprocessing. Biofilms are groups of tightly packed cells that attach to surfaces and secrete a slimy glue-like substance that protects them, allowing microorganisms to harden and adhere. You can find biofilm everywhere, including river rocks and even your teeth. These biofilms form when non-sterile water comes in contact with a non-shedding surface. If the biofilm is given the opportunity to mature, it can inhibit the effectiveness of enzymatics and detergents, making cleaning and disinfecting very difficult. In fact, bacteria within biofilms can be as much as 1,000 more resistant to antimicrobial solutions than bacteria alone.

The development of biofilm happens in 5 stages; initial attachment, irreversible attachment, maturation I, maturation II, and dispersion. Microorganisms must first come in contact with and attach to a surface. If given the opportunity these microorganisms will then begin to grow and mature. Once the biofilm has fully matured, it can then begin to disperse and colonize elsewhere.  

Effects on Endoscopes

The impact of biofilm on flexible endoscopes can be very problematic and could even result in deadly outcomes if bacteria is transmitted from patient to patient. In previous years there has been a string of deadly CRE outbreaks from duodenoscopes that were improperly cleaned, harboring bacteria in the elevator mechanism, resulting in at least 60 clinical infections.

Endoscopes have since taken centerstage in the media due to these outbreaks. As a result, some endoscope manufactures have added additional steps to the manual cleaning process, and The Joint Commission has increased its focus and attention on the endoscope reprocessing area. Due to this added pressure, many facilities prefer to hire candidates that are certified in flexible endoscope reprocessing. 

Causes

The most common reason for biofilm formation on endoscopes is due to delayed reprocessing or failure to preforming proper point-of-use (bedside) precleaning immediately after a procedure. It is imperative that reprocessing begin as soon as possible following the procedure, and this starts with precleaning. Typically, precleaning involves the initial wipe down of the endoscope and suctioning a cleaning solution or water through the scope to clear the internal channels of debris and bioburden, depending on the complexity of the endoscope more precleaning steps may be required. It is recommended that manual reprocessing take place within one hour of procedure end. Also, important to note that not all endoscopes are precleaned the same way, and that manufactures instructions are always followed. 

Biofilm formation can also occur on endoscopes while in storage, it is very crucial that endoscopes are thoroughly cleaned, disinfected, and dried before placing into a storage cabinet. Endoscopes that are not completely dry and still retain residual water can begin to form biofilm. There has also been a lot of discussion concerning the maximum storage time in which endoscopes can safely be stored before needing reprocessing. Studies have been conducted on this issue, however there has not been a conclusive answer to this question and it is recommended that each facility conduct a risk assessment to determine the maximum storage time.

Reaction

Although the goal is to eliminate the formation of biofilm, it is inevitable that it will form on endoscopes, this is unavoidable due to the rate at which biofilm forms. Biofilm can begin to form in as little as 30 seconds and can adhere to surfaces as slick as highly polished stainless steel. Endoscope manufacture, Olympus has validated studies that indicate no more than one-hour should elapse between procedure end and reprocessing start. In the event that an endoscope remains unprocessed for over one-hour post procedure, delayed endoscope reprocessing should be performed. This process is the same as standard reprocessing with the added step of allowing the endoscope to soak in a water and enzymatic solution for the appropriate amount of time, not to exceed 10 hours, to loosen and break down the biofilm, however this process may vary, and it is important that you follow the manufactures instructions for use (IFU).

Prevention

The only way to combat biofilm is through due diligence and prevention. Precleaning is the first step in endoscope reprocessing and greatly reduces the amount of bioburden and prevents the formation of biofilm. Precleaning is imperative and should never be skipped for any reason. Once precleaning has been completed it is recommend that the endoscope remain moist during transport to avoid the drying of any remaining bioburden. 

The single most crucial step in reprocessing is through manual cleaning. If an endoscope is not thoroughly cleaned, then it cannot be disinfected. The IFU’s from each endoscope manufacturer must be followed in accordance with their validated cleaning process. Simpler endoscopes can have very few steps and the cleaning process may only take several minutes, however, more complex endoscopes such as the duodenoscope can have as many as 120 steps and take up to 30 minutes to effectively clean. 

Conclusion

Biofilm is a real problem that has plagued flexible endoscope reprocessing, resulting in thousands of dollars spent and lives lost. However, with continued education and determination, we techs are up for the challenge. Every patient deserves a clean, well-functioning endoscope and it is our responsibility to provide that. The prevention of biofilm formation is a team effort, biofilm may act quick, but we can act quicker.        

This article was first published in the CBSPD Criterion winter 2018 Newsletter. This article is approved for 1 CE from CBSPD. Click on the link to access the corresponding quiz.

References

Association for the Advancement of Medical Instrumentation. Flexible and semi-rigid endoscope processing in health care facilities. ANSI/AAMI ST91: 2015. Arlington (VA): AAMI, 2015.

The Basics of Flexible Endoscope Reprocessing. Sterile Processing University, 2nd Edition. Lebanon (NJ): Sterile Processing University, LLC, 2016

Olympus America. www.olympusamerica.com. Center Valley, (PA)

American Society for Gastrointestinal Endoscopy. Multisociety guideline on reprocessing flexible GI endoscopes: 2016 update. www.giejournal.org Volume 85, No. 2