Non-endoscopic transmission of infection

Patients and staff are at risk of acquiring infections from one another and from the procedural environment itself.

The key in reducing transmission of infection lies in healthcare professionals understanding the basic principles of IPC and their application within endoscopy. Services should not rely on staffs own level of confidence or their length of experience in the role as reliable proxies of competence. In addition to mandatory training, there must be evidence of validated training and education specific to the roles that individuals undertake within endoscopy and, this must be revalidated at regular intervals when new evidence emerges, or at least annually.

Assessing for evidence of infection

Infection prevention starts at the front door. Restricting access to the clinical area to patients unless assessed for pre-existing infections is important. In addition to reducing the spread of infection, it reduces the need for high levels of PPE. Services are able to postpone procedures in those with known infections in whom endoscopy is not critical. Additionally, it reduces the need for high level cleaning between cases. Good patient information and assessment when booking procedures ensures that patients are screened for infection and know to inform the service if they fall ill prior to attending for their procedure.

Ventilation and temperature control

Critical ventilation systems and temperature should be monitored and inspected and verified annually. Ventilation must be assessed to ensure it complies with HTM 03–01.4 The core principle of these HTM’s is that the default method of ventilation should be where possible based on natural ventilation, using a mixed mode of natural and mechanical wherever feasible and avoiding purely mechanical unless absolutely necessary. Their commitment to promoting sustainable methods of ventilation means that by following the principles of the HTMs, services are using systems with the lowest lifecycle environmental cost while ensuring that infection prevention remains inherent. Ventilation and temperature control, therefore, is an area requiring close monitoring and liaison with estates and IPC teams. It is the duty of the provider to assess the risk, prevent, detect and control the spread of healthcare associated infection and so IPC aspects should not be compromised.4 Any risks should be assessed. The quality of the system in place will ultimately determine how services prevent and manage infection. From a sustainability perspective this can be costly in the need for chemical cleans and high PPE use in addition to downtime between cases.

In the HTMs,4 the basic objective in saving energy is to use less and therefore the most energy efficient policy is to ‘switch off’ systems or at least reduce output by ‘setting back’ if necessary to maintain background ventilation and temperature.

Regulating the use of fans has a real potential for energy saving and infection prevention. In ventilation systems fans account for around 40% of all electricity use.4 The recommendation here is in using electronically commuted fans, that is a fan designed to run on alternating current. They have both lower operating costs and a longer service life.

Mechanical ‘desk top’ fans are known to be linked to cross infection,5 leading to one of many recommendation that IPC teams and estates are consulted in any procurement of fans, principally to ensure that there are adequate instructions for use (IFUs) including cleaning/decontamination. From an environmental sustainability perspective getting the ventilation and heating correct will negate the need for fans altogether.

Intravenous cannulation and drug administration

Thankfully the practice of using single-use vials for multiple patients and/or reuse of needles, that led to cluster cases of hepatitis C,6 has ceased. Drawing up of multiple doses of drugs at once or opening drug administration equipment ahead of the patient entering the room still occurs in some areas. This not only poses a risk from aerosol or staff contamination but a waste of single-use equipment that, if not used is disposed of. Drug equipment and drugs should be prepared as required for each patient.

Peripheral intravenous cannulation (PIVC) may be the most common invasive procedure performed across healthcare settings but has a known associated infection risk for microbial contamination directly into the bloodstream. Infection prevention measures include using an aseptic technique when inserting PIVCs. This involves the use of single-use sterile PIVC packs. However, as shown in figure 1, some packs contain items that may not be used each time such as a rubbish bag (if a bin is nearby) or gauze. Services should critically review the PIVC packs available to see if efficiencies can be made to ensure less waste, recycling unused items where possible.

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Figure 1

Sterile PIVC packs. PIVC, peripheral intravenous cannulation.

Single-use equipment

When purchasing any single-use equipment, resist the temptation to overstock on items that you are unlikely to use before their expiry date, or find manufacturers who will remove and replace items some months before expiry to use in services with higher usage/turnaround to prevent waste. Ensure that all single-use equipment is kept stored and unopened until use to reduce the risk of splash or staff contamination rendering the item unsafe to use or equipment not being required and disposed of. If unused, items must be disposed of or recycled where possible.

Any item marked as being for single patient use should be used as such or a risk assessment undertaken if reusing. There are some items where a discussion on reuse is feasible such as the vacuum sacs used in endoscopy stacks; provided that the tubing is changed between patients.

The chief sustainability officer for the National Health Service (NHS)7 has stated that within the decade we will not purchase from any manufacturer that cannot meet or exceed the NHS’s commitment on net zero. Now, not in 10 years, is the time to think collectively with our organisations when procuring equipment and to ask the challenging questions to manufacturers, ‘what are you doing’?

Medical grade surfaces

Surfaces that are damaged, in poor repair or not adequately cleaned harbour contamination. All work surfaces should be in good repair and of medical grade wipeable quality. Adequate storage, often forgotten when designing or modifying units, should ensure that surfaces remain uncluttered and free from risk of splash or staff contamination. The practice of lining surfaces is not environmentally or microbiologically friendly. The often seen incontinence sheets are not manufactured for use as surface liners, they are not lint free and if left damp and/or not changed between cases are harborers of infection.

Privacy curtains

Privacy curtains where in use pose a high risk of cross contamination, including with multi drug resistant organisms.8 Frequently touched they are infrequently changed and often overlooked as an infection risk. The move from washable to disposable curtains including antimicrobial curtains clearly has a huge environmental impact. Washable curtains have a lifespan of 5 years whereas in most organisations the lifespan of disposable curtains is 6 months. One unpublished study,9 as part of a hospital curtain project with Brunel University, showed that based on the maximum lifespan of washable curtains of 5 years the carbon footprint in kilograms of disposable curtains was 2.5 times greater than washable curtains. Additionally, although limited, studies9 have shown that not all antimicrobial curtains are effective in preventing contamination in their lifespan. Studies are ongoing10 to look at improving sustainability by installing solar systems to reduce energy when using washable curtains and systems such as Curtainmelt that recycles single-use disposable polypropylenes into usable byproducts. Other options exist8 such as using dehumidification units to deliver dry hydrogen peroxide to reduce the microbial risk with no known environmental risk.

There are seemingly a number of solutions that both prevent cross contamination from privacy curtains and ensure environmental sustainability. Services should explore the solutions available and make it part of their organisations green strategy.

Endoscopic transmission of infection

Concerns over the infection complications linked to duodenoscopes have increased attention over recent years as to how we reprocess reusable gastrointestinal (GI) endoscopes. It has additionally led to an increased interest in single use, disposable endoscopes due to concerns that the complexity of some instruments may make absolute reprocessing impossible even with exemplary standards of practice. The environmental sustainability versus infection control of single-use endoscopes requires its own paper, once there is a more substantial body of evidence.

However, despite this and COVID-19 raising the profile of infection control, there have been no real changes to practice recommendations. Reprocessing guidance remained the same throughout the pandemic with the addition of guidance on the aerosol generating risks from some procedures. Yet, most cases of microbial transmission to patients in endoscopy are via contaminated endoscopic equipment and result from non-adherence to reprocessing guidelines. The human factors involved are a non-negligible risk and it is chiefly because of ergonomic factors that ‘risk’ is managed out. Risk that is essential to IPC but risk that does not sit comfortably when considering environmental sustainability. The earlier statement on ensuring that staff have validated competency for their role is critical when reprocessing endoscopes. As the single biggest cause of microbial contamination, recognising the ergonomic factors involved is vital.

The risk of infection is now widely acknowledged as being underestimated from the oft quoted 1:1.8 million procedures.11 It is underestimated because very rarely are cases reported in peer-review journals and rather it is the examination of government and legal documents and media reports that highlight the widespread lapses in reprocessing12 and these may represent just the tip of the iceberg. Additionally, it is very likely that outbreaks may not be identified or acknowledged because they involve commensal bacteria of the GI tract.13

Water quality

Water quality is the most contentious issue when it comes to environmental sustainability, specifically with regard to the use of sterile water for irrigation through endoscopes. Clearly, there is an environmental sustainability issue. The lifecycle of plastics and transportation impact is of concern, even with recycling of the plastics. However, it should be noted that the British Society of Gastroenterology14 European15 and endoscope manufacturers IFUs all state the use of sterile water in water bottles.

There is an evidenced ‘3-hour’ point after which there is bacterial growth within water containers and endoscopes with evidence14 that some gram negative bacteria can undergo cell division within 20–30 min. Pseudomonas aeruginosa is a gram negative pathogen and is the most commonly reported micro-organism responsible for transmission of infection in GI endoscopy. It is a biofilm producing bacterium with a preference for moist environments such as hospital water supplies water bottles and wet endoscope channels. The biofilm is notoriously difficult to remove being 10–100 times more resistant to process chemicals.16 Although small numbers of cases, transmission of P aeruginosa in endoscopy has been cited as being attributable to contaminated endoscope water bottles, the water supply to the endoscope and rinsing the endoscope channel with tap water between procedures.17

The guidance referred to in the GIRFT report for gastroenterology18 advises reducing the use of sterile water bottles by using potable water of suitable quality for manual flushes via single-use syringes. It must be noted that this refers to manual flushing only. It does not include flushing via the air/water channel from automated devices with a water bottle. Manual flushing is used via a syringe and normally through the biopsy channel. The reason why this is acceptable for manual but not automated systems is that the manual process tubing and syringes are disposed of after each case and water is not residual in these components between patients or long term. Automated processes on the other hand will have residual water in them before and after the procedure and are, therefore, more likely to suffer from biofilm formation if the microbiological quality of the water is not controlled or monitored.

Given the acknowledged limited evidence of infection in irrigation devices the report from the Healthcare Infection Society Working Party19 on final rinse water quality has now included a best practice statement that sterile water should be used or, water of at least the same quality as final rinse water. To be of the ’same quality’, therefore, the water would need to be tested weekly with limits set for the total viable count and should be free of any coliform as a minimum.

Services should, therefore, approach changing use from sterile water with care. It is imperative to ensure that reprocessing standards are followed rigorously and with evidence of tracking and traceability of each step and of staff competency. A risk assessment should be undertaken to ensure that because of IFUs organisations are comfortable with transferring legal liability to themselves, with an awareness that the reverse burden of proof20 lies with organisations to prove that it was not their actions that resulted in any adverse event.

Personal protective equipment

PPE is both an endoscopic and non-endoscopic infection risk. Covered here specifically because of the aerosol generating risk from some endoscopic procedures.

It is a legal requirement for employers to provide PPE if their risk assessment identifies it is needed to protect employees’ health and safety while at work,21 and vicariously patient’s health. High level PPE use became a feature during the pandemic, with an estimated 106 478 tonnes CO2e used in a 6-month period alone.22 It also focused many authors on the infection risks from endoscopic procedures and particularly on contamination to the faces of endoscopists and assistants as a result of aerosol generation23 and the need even postpandemic to increase the face protection used routinely. It should be noted that the PPE worn when reprocessing endoscopic equipment remains as it was prepandemic. Whether organisations and IPC teams have reviewed and revised the use of PPE postpandemic is unknown. The environmental, infection and monetary cost of incorrect or judicial use of PPE is immense in each case. Services with their IPC teams should review the PPE used throughout the patient pathway. Think about high and low risk areas, incorporating the principle of reduce, reuse and recycle and recognise circumstances where use can be reduced or stopped. For example, ensuring staff competence in maintaining standard precautions in hand hygiene can reduce the need for gloves in some areas. This includes the use of hand gels when hands are not soiled or there are no known alcohol resistant infections. Non-sterile gloves actually protect the wearer and not the patient and should not be used injudiciously. There are examples where PPE can be reused. Using washable gowns has been found to have a smaller carbon footprint,22 these must be changed between patients and/or procedures. Face visors can be worn up to five times if cleaned appropriately between cases. There is information and guidance available to build resilience into PPE use22 24 There are proof of concept studies underway to allow recycling of contaminated PPE.25