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2018 ranked ‘failure to consistently andeffectively reprocess flexible endoscopes’ as one of the biggest threats to healthcaredelivery and patient health, second only to threats to cybersecurity.5, 6

This ranking reflects the increasingawareness and recognition of the risks of endoscopy-associated pathogentransmission.5, 6 In addition, the annual list of Top 10 patient safety concerns of 2018ranked ‘Device cleaning, disinfection, andsterilization’ as number eight.5, 6

The failure to follow correct detergent and high level disinfection procedures at any point can result in both a compromiseddevice and compromised patient safety.A recent study of reprocessing, drying,

and storage procedures for endoscopes usedfor gastrointestinal or non-gastrointestinalpurposes at three hospitals in the USA foundmicrobial growth after reprocessing on 71%of endoscopes. Residual fluid was foundinside 49% of the endoscopes examined,which was associated with higher ATP levels(an indicator of microbial growth).Stenotrophomonas maltophilia, Citrobacterfreundii, and Lecanicillium lecanii/Verticillium dahliae were all found. Although the identified microbes were not

multidrug resistant; potential pathogens werediscovered. Reprocessing and drying practiceswere noted to be deficient at two of the threecentres studied, and all three sites used old,damaged devices, creating rough surfaces thatpromote residual contamination.7

A 2018 Review published in The Lancetreflects the increasing awareness andrecognition of the risks of endoscopy-associated pathogen transmission.8 32outbreaks involving almost 400 patients werereported between 2002 and 2007. Althoughmost of these outbreaks were associated withduodenoscope use, others reportedly involvedbronchoscopes and urological scopes.8

Endoscopereprocessing:Why cleaning is vital

The editorial expressed concern that “thistally is likely to increase over time due to thegrowing number of minimally invasivetechniques now being performed, and theirincreasing complexity, with the growingthreat of multidrug antibiotic resistancegiving the matter a real sense of urgency.”8

Although the risk of infection following agastrointestinal endoscopy is likely to be low,the absolute risk of infection after anendoscopic procedure remains unclear, andoutbreaks reported in the literature probablyunderestimate the true incidence given thelikelihood of under-reporting.8

It is notable that due to the increase indemand for endoscopy, many units have had to expand in limited space, with theresult that decontamination facilities havefrequently had to relocate away from theendoscopy unit. This has necessitated thetransfer of used endoscopes to thedecontamination facility, which sometimesmay be at a different hospital altogether.During the transfer of used endoscopes

to decontamination facilities, the endoscopesand their internal channels must be keptmoist. This has added another layer ofcomplexity to the challenge of effectivereprocessing.

Pre-cleaningThe BSG stipulates that thorough manualcleaning with a CE marked detergent mustbe undertaken before the endoscope isplaced in the washer disinfector. The manualcleaning stage should include the brushingand flushing of all accessible endoscopechannels.9

Cleaning is also carried out in the EWD

Endoscopic examination offers a simple, low-risk, and cost-effective means to diagnoseand treat a wide range of gastrointestinaldisorders. During the procedure, the externalsurface and internal channels of a flexibleendoscopes is exposed to bodily fluids andother potential contaminants, meaning thatreprocessing poses particular challenges. Unlike rigid endoscopes, flexible

endoscopes are heat labile devices andcannot be autoclaved. Most are classed as“semi-critical devices” as they come intocontact with mucous membranes during useand present a potential infection risk.1

The decontamination process involvesmechanical and detergent cleaning, followedby high-level disinfection, rinsing, anddrying.2 The cleaning stage when removal ofsoil and organic matter is undertaken with asuitable detergent, is essential to the efficacyof the disinfection stage.3

Infection risksAlthough the risk of endoscopy-relatedtransmission of infection is estimated to bevery low, more health care-associatedinfections are related to contaminatedendoscopes than to any other medical device.4

Endoscopy-related transmission ofinfections may occur if microorganisms arespread from patient to patient bycontaminated equipment or if microorganismsare spread from the gut lumen duringendoscopy through the bloodstream tosusceptible organs, adjacent tissues, orprostheses. Non-endoscopic transmission ofinfections within endoscopy units may alsooccur if microorganisms are transmitted frompatients to endoscopy staff.2

The narrow lumens and multiple internalchannels make the cleaning of flexibleendoscopes a complex and difficult task.4

It is therefore unsurprising that a reporton the top 10 health technology hazards of

Within the healthcare system, an ever increasingnumber of minimally invasive techniques are nowpossible. Wolfgang Merkens, Schü�lke & Mayr GmbHwarns that without effective and thorough cleaning, itis not possible to adequately disinfect the endoscope,as disinfection cannot remove gross contamination.

Wolfgang Merkens, Schü� lke& Mayr GmbH

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before high level disinfection. The selecteddetergent must be compatible with thedisinfectant used in the EWD.9

Cleaning refers to the removal of soil andorganic contamination from a device usingthe physical action of scrubbing and thechemical action of a detergent. Cleaningremoves large numbers of microorganisms,which reduces the levels of organic bioburdenon these surfaces. This process is designed toremove organisms rather than kill them.2

Cleaning which includes the use of asuitable detergent must always precedesurface disinfection, especially surfaces likeendoscopes with visible contamination, andhelps to ensure the efficacy of the subsequentdisinfection step.10

If soil and bacterial biofilms are notremoved from the endoscope, this willadversely impact on the efficacy of thedisinfectant which then increases the risk of nosocomial infection.3

HTM 01-06 (2016) warns that somechemicals may damage endoscopes thereforeany cleaner selected should be compatiblewith the range of endoscopes in use, as wellas with the EWD. All chemicals used in theEWD process should be CE-marked, whichindicates that the manufacturer has verifiedthese products meet EU safety, health andenvironmental standards. It is essential that the required

concentration can be accurately andreproducibly generated by the dosingsystem(s) on the EWD. HTM 01-06 (2016)also advises that “users should enquire aboutthe erosive or damaging characteristics of thechemical agents recommended.” Forexample, some detergents have addedcorrosion inhibitors, as water itself iscorrosive if the hardness is less than eight. Cheaper detergents may contain no

corrosion inhibitors at all, or poorer qualityingredients, which in the longer term couldlead to damage of the endoscope and/or the

automated reprocessor. This damage willtake place over a period of time and is notimmediately obvious.Flexible endoscope manufacturers will

advise on which chemicals could causedamage to their equipment. Use of suchcontraindicated chemicals is likely toinvalidate any manufacturer warranty as wellas potentially cause irreparable, or veryexpensive, damage to the endoscope.

Detergents - mode of actionDetergents act both as wetting agents - inwhich the reduction of surface tension allowscontact with all surfaces – and also as asolvent and/or dispersant of soil. They canalso degrade soil components, making themmore soluble and easier to remove.Detergents work by penetrating soil and actto reduce the surface tension (forces whichadhere soil to a surface), which allows forthe removal of the soil. Most detergents contain surfactants

(Surface Active Agents) which are a class ofmolecules that function to bind and lift soil.Suspended dirt is easier to remove from thesurface by rinsing and survivingmicroorganisms can be destroyed bydisinfection. Some types of surfactants serve as wetting agents to lower the surface tension of the cleaning solution and increase the ‘wettability’ of water.

Detergent selectionIt is important that the correct type ofdetergent is used for the appropriateapplication. For cleaning critical equipment,such as endoscopes, the choice is betweenenzymatic detergents or neutral detergents.Compared with enzymatic detergents, non-

enzymatic detergents can be used acrosswider temperature ranges and are less affectedby pH. Non-enzymatic detergents are also lessallergenic, but enzymatic detergents are moreeffective cleaning agents and are designed to

maximise the removal of residues. Enzymes are proteins that accelerate the

rate of a chemical reaction. The enzymes ina detergent break down large molecules, likefats and blood proteins, into smaller ones.Thus enzymatic detergents have anadvantage over non-enzymatic ones,although stricter personal protectionprocedures for staff handling are needed.The ideal detergent cleansing agent

should effectively permeate contaminantsthat contain proteins, lipids, carbohydratesand various chemical bases and separatesthe contaminants from the channels withoutdamaging the endoscope.11 It should also below-foaming to ensure the maximum contactwith the surface with the endoscope.11

The removal of soil is an important stepprior to the application of a disinfectant, asthe greater the degree of soiling remaining ona surface, then the lesser the effectivenessof disinfection. This is because disinfectantsare either inactivated by organic residues orthe soil creates a barrier which prevents thedisinfectant from reaching all of the microbialcells.The selected detergent must be

compatible with the disinfectant used. This is because some detergents leave residueswhich can neutralise the active ingredient incertain disinfectants thereby reducing themicrobial killing properties of the disinfectant.Additional factors which will influence the

choice of a detergent include the process ofdilution, the stability of the solution and thecost of using a particular product (these costsshould consider storage space, conditionsrequired for use, including staff protectionmeasures and material compatibility).

Switching to an alternative detergentIf a decontamination unit is considering theswitch to an alternative detergent ordisinfectant, there are many factors to takeinto account before making a decision. Switching based on cost savings should

not be based on comparative detergent costsalone. The efficacy of the detergent toremove soil and organic matter, materialcompatibility, concentration, stability, storagelife, inclusion of corrosion inhibitors are justsome of the factors to consider which will allhave an impact on the overall cost.Care should be taken to ensure that all

detergents are compatible with the EWD, andare employed at the correct temperature andconcentration. Detergents and disinfectantsmust be compatible with each other. Thesechemicals should be type tested to showcompatibility with both the EWD and theendoscope.9

ConclusionsEndoscopy-associated infection transmissionis frequently linked to inadequatereprocessing. Residual organic material andmoisture may foster biofilm developmentinside endoscopes, and an American studyfound microbial growth in 71% ofreprocessed endoscopes examined.

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It is well established that it is not possible to effectively disinfect flexibleendoscopes which are not clean. Therefore,the cleaning stage with a detergent is acritical stage in removing the microbialburden from an endoscope.Endoscopy has many major benefits

and is an essential component of agastroenterologist’s armamentarium. To maintain this key role, adherence toguidelines for reprocessing, including theselection of appropriate detergents is vital.

References1 Spaulding EH, Gro�schel DH. Hospital disinfectants

and antiseptics, p 852–857. In Lennette EH,Spaulding EH, Truant JP (ed), Manual of clinicalmicrobiology, 2nd ed. American Society forMicrobiology, Washington D.C., 1974

2 Calderwood AH, Day LW, Muthusamy VR, et al, ASGEguideline for infection control during GI endoscopy,Volume 87, No. 5 : 2018 Gastrointestinal Endoscopy

3 Vickery K, The effect of multiple cycles ofcontamination, detergent washing, and disinfectionon the development of biofilm in endoscope tubing,American Journal of Infection Control, 2009, Vol 37,issue 6, Pages 470-475

4 Kenters N. et al. Endosc Int Open. Infectiousdiseases linked to cross- contamination of exibleendoscopes 2015 Aug; 3(4): E259–E265.

5 ECRI Institute. Executive Brief Top ten patientconcerns for healthcare organisations 2018,https://www.ecri.org

6 ECRI Institute. Executive Brief: Top 10 HealthTechnology Hazards for 2018

www.ecri.org/2018hazards7 Ofstead CL, Heymann OL, Quick MR et al, Residual

moisture and waterborne pathogens inside flexibleendoscopes: Evidence from a multisite study ofendoscope drying effectiveness, 2018,Volume 46,Issue 6, Pages 689–696 American Journal ofInfection Control

8 The Lancet Editorial, Scoping the problem:endoscopy-associated infections

www.thelancet.com/gastrohep Vol 3 July 20189 BSG Guidance For Decontamination of Equipment

for Gastrointestinal Endoscopy, The Report of a Working Party of the British Society ofGastroenterology Endoscopy Committee March2014, Revised November 2016

10 Quinn M. M.,Henneberger P.K., et al, Cleaning anddisinfecting environmental surfaces in health care:Toward an integrated framework for infection andoccupational illness prevention, American Journalof Infection Control 43 (2015) 424-34

11 Lee YK, Park JB, Steps of Reprocessing andEquipments, Clin Endosc 2013;46:274-279

The three key steps in the flexibleendoscope decontamination processStep 1 - Manual cleaning and rinsing ofall exposed internal and external surfacesThis is undertaken at the sink in the ‘dirty’section of the decontamination area wherea solution such as gigazyme (enzyamtic)or gigasan ND (non-enzymatic) is used toclean the endoscope including the internaltubing, whilst also manually brushing thechannels. This cleaning stage is generallynot verifiable.

Step 2 - Automated cleaningThis stage describes the process of initialcleaning of the endoscopes when they areplaced in the EWD. A detergent such asthermosept Endocleaner (which containsenzymes and surfactants) may be used as

it must be compatible with the disinfectantselected for stage 3. This stage of cleaningis verifiable as the EWD tracks and tracesevery aspect of cleaning including watertemperature, pressure and detergent.

Step 3 – DisinfectionAfter the EWD cleaning stage, the disinfectionprocess takes place. Again, this is verifiableas all elements are controlled, recorded andreproduced at the same level every time. A peracetic acid based disinfectant such as thermosept PAA (effective againstbacteria, mycobacteria, fungi, viruses and spores including Clostridium difficilespores) may be used for this critical highlevel disinfection process.

Transfer HatchesTransfer Hatches are designed and constructed from a flexible format and offer a range of operations for the individual user to select their particular requirement from including floor and wall mounted types.

Additional features, such as air flushing and 2-way communicationssystems can be offered as extras if required. Installation options range from free standing to built-in.

For more information call 01273 516 661SPECIALIST EQUIPMENT FOR

ENDOSCOPY & STERILE SERVICES

Height Adjustable Sinks - Stainless SteelGoldsworth manufacture height adjustable HTM64 compliant single or multiple height adjustable sink units for manual cleaning of both instruments and scopes. Optional washing spray guns can be supplied. Bespoke stainless steel height adjustable sinks are designed and manufactured in our factory to suit specific applications. We work closely with our customers to ensure that we produce quality manufactured height adjustable sinks to exactly fit into the available space.

Goldsworth Medical (Felcon Ltd) Unit 11, Euro Business Park, New Road, Newhaven, East Sussex BN9 0DQ

Tel: 01273 516 661 Fax: 01273 512695 Email: sales@goldsworth.co.uk Web: www.goldsworth.co.uk www.felcon.co.uk GoldsworthmedicalFelcon Ltd