The Scottish Government

« Previous | Contents | Next »

Listen

Section 3 Results

3.1 Response

In response to the CMO letter (Appendix 2), data were received from all NHS Boards and all independent hospitals in Scotland. In the absence of any national database recording all units in which endoscopy activity occurs, however, it is not possible to determine the sample portion of the target population.

Reviews were analysed for 19 sites. Data received from sites after the extended submission date were not entered in the analysis. The site details for all analysed reports have been coded to preserve the participants' anonymity (see Table 2).

3.2 Range of clinical units that undertake endoscopy

Review reports were submitted from 153 clinical units that carry out endoscopy (Table 2). We are unaware of any existing database of all clinical units that undergo endoscopy in Scotland and therefore have no 'denominator' to quantify the extent of this response. Each clinical unit was given a unique identity number ( CUID) to facilitate further analysis of the reported data.

The contact personnel for each reported unit covered many (38) different job titles including Clinical Leads, Clinical Nurse Managers, Endoscopy Unit Managers, Senior Nurses, Specialist Nurses, Theatre Sisters, Staff Nurses, Charge Nurses, Cardiac Technicians, ECG Technicians, OPD Managers, Ward Managers, one Infection Control Doctor and one Clinical Director. This suggests a significant diversity in the management structure adopted for control of endoscope decontamination.

The range of clinical units included operating theatres/theatre suites (39%), outpatient departments (20%), endoscopy suites (15%), day surgery units (7%) and a single primary care unit. The remaining 29 'other' units included a variety of specified departments. One site submitted detailed information for a non-specified clinical unit. A clinical unit described as 'test run' with no accompanying data was excluded.

3.3 Range of clinical units that undertake reprocessing of endoscopes

Of the 153 clinical units, 123 (80%) reported that they undertook endoscope reprocessing within the unit. Of these, one unit reported that their two endoscopes "only had a social wash" and another unit reported that reprocessing of their eight endoscopes involved "occasional use of endoscopy unit facilities based on risk assessment". Neither unit gave any further responses to the review questionnaires and therefore no details of their endoscopes or reprocessing facilities were available for analysis. In contrast, an ENT unit reported that all its endoscopes received only manual decontamination in the unit but provided extensive information on which further assessment could be made.

Of the thirty units that did not reprocess endoscopes, one unit (an operating theatre) reported that reprocessing of their five endoscopes was undertaken in the central sterile services department but gave no further details of endoscopes or reprocessing method. Similarly, an operating theatre reported that their endoscopes were reprocessed in the main theatre but gave no further details.

Instances of reprocessing sites being located other than at the site of clinical use included endoscopy units (11), different theatres from the use location (9), outpatient departments (3), CSSD (1) and TSSU (1). Typically, the reprocessing locations were in the same hospital as the clinical use. In nine instances the endoscopes were reprocessed at a different hospital. The 'off-site' decontamination locations included endoscopy units, an operating theatre suite, an outpatients department and a respiratory day unit.

Forty four units received endoscopes for reprocessing from different clinical units including theatres (11), ITU (6), endoscopy units/wards (3), treatment rooms, ENT clinics etc.

The number of endoscopes reprocessed in individual units ranged from a single endoscope (in 4 units) to 60 endoscopes, with a median of 8.

Forty eight of 153 units (31%) had permanently withdrawn endoscopes from service within the last two years.

Eighty three clinical units did not borrow or loan endoscopes. Of the remaining seventy units, the endoscopes were borrowed from other clinical units (35), from the endoscope supplier (50) or from the endoscope manufacturer (36). Seven units borrowed endoscopes from all three sources. One unit borrowed from another hospital and two units described the borrowed endoscopes as 'on loan'.

TABLE 2 EDAT reports: sites and clinical units that undertake endoscopy

3.4 Range of endoscopes

Data were analysed on a total of 1494 endoscopes, each of which was given a unique identity number ( EID). Interpretation of reported data used the entries for each EID, endoscope manufacturer, type of endoscope and whether it was flexible or rigid, related to each CUID.

The data set included flexible (1403) and rigid (91) endoscopes.

The scope of Hazard Notice HAZ(SC)04/05, concerning the risks from inadequate decontamination, included both flexible and rigid endoscopes. Similarly in EDAT, information was sought on all endoscopes in use at the time of review. However, by limiting the scope of some elements in the questionnaires to thermolabile rather than thermal reprocessing equipment and to chemical disinfectants rather than steam sterilization, emphasis was placed on the decontamination requirements for flexible endoscopes.

Rigid endoscopes are typically cleaned and thermally disinfected in surgical instrument washer-disinfectors and steam sterilized in central decontamination units. The decontamination performance and technical requirements for CDUs have been the subject of previous review against the Glennie Technical Requirements ²⁶.

Given the limited time available for this review, respondents who queried the need to include data on rigid endoscopes reprocessed in sterile service departments were advised to give priority to providing data on thermolabile flexible endoscopes. The reported data on the rigid endoscopes may therefore represent a relatively small sample of these devices in current practice. However, this data has been analysed, particularly in respect of inventory records (manufacturer, model number, serial number, type of endoscope, number of channels etc).

The types of flexible endoscopes in EDAT are listed according to manufacturer (Table 3) and clinical unit (Table 4).

The data for rigid endoscopes have not been tabulated since the sample size was too small to give meaningful information.

Table 3 Endoscopes by manufacturer and type

*The name entered either did not correspond with any known manufacturer or supplier, or the listed manufacturer did not produce the type or model of endoscope recorded

Table 4 Endoscopes by type and nature of endoscopy unit

3.5 Information recorded for endoscopes

Clinical Units were asked to identify the manufacturer, supplier, model number, serial number, type and the number and types of channel for each endoscope ) Maintaining accurate records, including entry on the asset register for endoscopes is important for many reasons. These include tracking off-site for reprocessing and repair, traceability and recalls. Endoscope manufacturers may publish important information on particular types after purchase, for example, up-date information on specific models with 'difficult to clean' channels. If the endoscope cannot be identified the manufacturer's recommended action cannot be implemented. Accurate information on model number is also an essential pre-requisite to obtaining the appropriate connectors for a compatible endoscope washer-disinfector or liquid chemical disinfector.

Key indicators of good practice

Records of endoscopes

• An inventory should be maintained of all the endoscopes available for use, their location/s for use and the location/s for reprocessing;
• List to include: - manufacturer, supplier, model number, serial number, type of endoscope, date of purchase, asset number, location

Interpretation of reported data used the entries for each EID, endoscope manufacturer, supplier, model number, serial number, type of endoscope and the number of channels. This data was compared with the information supplied independently by manufacturers ( EMID).

Table 5 summarises the extent and range of deficiencies in the records held for endoscopes, as reported in EDAT. The analysis of data on endoscope channels is given later (Section 3.6).

Although the details of most flexible endoscopes (88.9%) were fully recorded and matched information supplied independently by manufacturers ( EMID), there were some deficiencies. For rigid endoscopes, full records and manufacturer recognition was found for less than half the reported endoscopes.

All manufacturers had difficulties in recognising some model numbers attributed to them, even allowing for the age of some devices (details of older endoscopes were often 'archived' but were retrieved by the manufacturers on request). 'Mis-matches' have generally been categorised as errors on the part of the user. The most frequently observed error (11% for flexible endoscopes and 45% for rigid endoscopes) was in model number recognition. In a few instances this may have resulted from mistakes on data entry (for example, recognised Olympus model numbers entered for the wrong manufacturer) but in the majority of instances the erroneous information provided was cursory ( e.g., Number 'one', Number 'two') or obscure.

In a few instances, model numbers and serial numbers were confused with the CE mark + notified body identification code ( e.g., CE 0047). This information is required to be marked by manufacturers on endoscopes for certification under the Medical Device Directive ¹¹.

Table 5 Reporting errors in endoscope recognition

* NBID : Notified Body identification

3.6 Recognition of endoscope channels

Key indicators of good practice

Decontamination process - general principles

• Identification of all channels in the endoscope is an essential pre-requisite to effective decontamination.
• All channels should be decontaminated by an agreed decontamination process after each use, irrespective of whether a specific channel has been used in the clinical procedure or not.

Channels identified in EDAT for each endoscope were compared with the data supplied by manufacturers ( EMID). This comparison was possible only for those endoscopes that had a recognised model number. Each endoscope was categorised according to the degree of match of channels to the correct specification and the results are summarised in Table 6.

Table 6 Reporting errors in channels present in endoscopes

Only 59% of endoscopes of recognised model number gave a complete match for the different channels in endoscopes overall. This varied according to the type of endoscope, for example recognition was higher for laryngoscopes (78%), bronchoscopes (69%), gastroscopes (69%) and duodenoscopes (67%) but was as low as 8% for the small number of recognised choledocoscopes.

The data in this comparison derives from information on each type of channel for endoscopes from every manufacturer. Further analyses could be made to show the level of recognition for each type of channel (biopsy, suction, air, water, auxiliary, CO₂ and elevator) in each recognised type of endoscope and for each manufacturer. It is clearly evident that there are serious deficiencies in the recognition of endoscope channels and the following analysis using information from one manufacturer is sufficient to illustrate the problem.

In response to publication by the MHRA of the Medical Device Alert MDA/2004/028 on 23rd June 2004, KeyMed issued an advisory notice to all medical facilities in the UK using Olympus flexible endoscopes, to reinforce the information provided by the MHRA and remind users of the specific reprocessing requirements for the auxiliary water and elevator wire channels found on certain models of Olympus flexible endoscope (see Appendix 7). A list was included of all the models of Olympus flexible endoscopes sold in the UK that have auxiliary and elevator channels. In response to that information, all Olympus endoscopes in the analysed data with recognised model numbers have been checked against this list and the recognition of auxiliary and elevator channels noted. The results are shown in Table 7.

It is evident from this analysis that recognition of critical channels for which guidance has been given by the endoscope supplier/manufacturer is poor. For the specific models highlighted in the KeyMed's advisory notice, this analysis demonstrates that auxiliary channels were missed in colonoscopes (56%), elevator channels missed in duodenoscopes (20%) and both channels missed in gastroscopes (53%).

Table 7 Identification of auxiliary and elevator channels in Olympus endoscopes

* added elevator channel in 1 instance ** in 2 instances
¹ Models listed in 'Important Safety Information - Reprocessing of Olympus Flexible Endoscopes' KeyMed Advisory Notice, 2/7/2004 (see Appendix 4)

3.7 Decontamination processes for endoscope channels

For each channel reported on every endoscope, responses were gathered on the decontamination methods used. This included whether the channel was flushed through while connected to the endoscopy machine, whether the channel was visually inspected to ensure free flow of water through the channel, whether the channel was manually cleaned by irrigation with detergent, whether the channel was brushed with a single-use or with a re-usable brush, whether the channel was cleaned and disinfected in an endoscope WD or whether it was manually disinfected.

Key indicators of good practice

Decontamination process - general principles

• All re-usable endoscopic devices including accessories that are available for use are capable of being decontaminated by an available and agreed decontamination process.
• An automatic endoscope washer-disinfector is available in each unit where endoscope decontamination is undertaken.
• Compatibility of endoscopes and connectors with the cleaning and disinfection process has been confirmed with both the manufacturer of the endoscope and the manufacturer of the automatic endoscope washer-disinfector.
• Endoscope channels that cannot be decontaminated in an EWD have been identified and are manually cleaned and disinfected, following the manufacturer's instructions.

Of the 123 reprocessing units, 100 units reported having one or more automatic endoscope reprocessor/s. In two instances this was a simple 'disinfection stand' which provided no automated facility for cleaning or disinfection. Thirteen reprocessing units had a liquid chemical disinfector (Steris System 1) but lacked an endoscope washer-disinfector ( EWD). In these units, all the cleaning prior to disinfection was undertaken manually. Two reprocessing units had both an EWD and an automatic endoscope disinfector. Only 85 (69%) units that reported endoscope reprocessing 'on site' had one or more EWD.

Further details on endoscope reprocessing equipment are summarised in section 3.9.

Key indicator of good practice

Preliminary flush

• There is preliminary removal of gross contamination by flushing before the endoscope is detached from the light source/video processor.
• Free flow of water through all channels to confirm freedom from blockage is checked.

The analysis of data for channels that were reported to be flushed before the endoscope is detached is summarised in Table 8. This was performed for the majority of channels, with the biopsy channel being the one that users reported most frequently as not being flushed. Visual inspection to ensure a free flow of water through the channels was again not undertaken for all endoscopes, with the exception of the auxiliary channel where the inspection was reported as 100%.

Table 8 Reported data for channels not flushed or checked for flow

However, by reanalysing the data to include the actual channels present from the recognised model number, the findings change significantly (Table 9). More than 40% of the auxiliary channels in the recognised models of endoscope were not flushed through and a similar percentage were not inspected visually to ensure free flow of water. The percentage that were not inspected for blockage was even higher for the CO₂ channels (71%) and elevator channels (51%).

Table 9 Data corrected for 'missed channels' using recognised model number

Key indicator of good practice

General

• Flushing, cleaning and disinfection phases are essential and none are ever omitted
• All channels, including those that have not been used during a procedure are flushed, cleaned and disinfected.

Brushing of channels was undertaken using single use brushes (49%) or reusable brushes (32%). Of the remainder, 12% of channels were irrigated without brushing and 7% received neither irrigation nor brushing.

Channel cleaning

The following table (Table 10) gives further analysis of the extent of channel cleaning. In some instances, channels received no cleaning i.e., were not irrigated with detergent, not brushed and not cleaned in the EWD despite being recorded as present on the endoscope. Failure to carry out cleaning was particularly high for the CO₂ channel (75%) and elevator channels (35%). Other channels were manually cleaned only and a third group received no manual cleaning before processing in the EWD. These channels were present across the range of endoscope types.

Table 10 Channels not cleaned or receiving only partial cleaning

Channels of all types and across a range of types of endoscope were excluded from different stages of the cleaning process. For the channels receiving manual cleaning only, the highest reported incidence was for the elevator channel (26%) but all channels occurred in this category.

For channels that failed to be given the recommended manual clean prior to automated reprocessing, the highest incidence was for air (14%) and water (12%) channels.

Channel disinfection

A similar shortfall was demonstrated for channel disinfection, as summarised in Table 11. Some channels of all types were reported as receiving no disinfection, others received manual disinfection only, whereas a third category received both manual and EWD disinfection.

Table 11 Channel disinfection

The data on channel cleaning and disinfection was further analysed and combined to determine how many endoscopes were processed by the preferred method of manual irrigation with detergent and water rinse, brushing with single-use brushes and then washing and disinfection by automatic process in an EWD. This method is in line with current guidance and is typical of endoscope and EWD manufacturer's instructions.

The results indicate that on average, less than half the endoscopes were cleaned and disinfected by the 'preferred method' (Table 12). Compliance varied according to the type of endoscope and ranged from 14% for laryngoscopes to 71% for bronchoscopes. However, when the endoscopes were corrected against EMID for missing channels, the overall rate of compliance fell to 17%, with a range from 0 - 36%. This analysis is a 'worst case' in that it takes no account of channels for which no information is provided but which may have been decontaminated by the preferred method.

The analysis also serves to demonstrate the effect that lack of awareness of a channel/s has on the overall outcome for endoscope decontamination.

Table 12 Endoscopes cleaned and disinfected by the preferred method

Instructions for endoscope reprocessing

Interpretation of reported data used the entries for each EID, including whether endoscope manufacturer reprocessing instructions were supplied, copy available, availability of a formal written procedure for decontamination and whether this differed from manufacturer's recommended instructions. The clinical units were not asked to provide copies of the manufacturer's instructions or their own written procedure and it was not therefore possible to compare the analysed data with this information. However, the data was compared with the analysed data for endoscope information (3.5), endoscope channel recognition including EMID (3.6), and the analysis for endoscopes cleaned and disinfected by the preferred method (Table 12).

The endoscope manufacturer was reported as having supplied written details of their recommended cleaning and disinfection methods for 93% of endoscopes (1391 of 1494). A copy of these instructions was reported as kept with the endoscope in 91% of this group (1263 of 1391). The value of these instructions may be diminished for the proportion of this group (50%, 692 of 1391) that failed to recognise the endoscope manufacturer and/or correct model and/or the number of channels .

A formal written procedure for decontamination of the endoscope was reported for 86% (1279 of 1494). In 82 instances (6%), this was reported as being different from the manufacturer's instructions.

The 'preferred method' of manual irrigation of all channels with detergent and water rinse, brushing with single-use brushes and then washing and disinfection by automatic process in an EWD was reported in only 42% (583 of 1391) of those with a copy of the endoscope manufacturer's instructions. This proportion was similar (43%, 555 of 1279) for those endoscopes for which a formal written procedure for decontamination was reported

Training on endoscope reprocessing

Interpretation of reported data on training in re-processing the specified endoscope used the entries for each EID, including whether training had been provided in respect of three categories of staff (supervisory, clinical, non-clinical) and the type of provider.

For the specified endoscope, training in reprocessing was provided for supervisory staff who manage the reprocessing activity (76%, 1142 of 1494), for clinical staff who carry out the reprocessing (90%, 1344 of 1494) and for non-clinical staff also carrying out the reprocessing (34%, 517 of 1494). For 83 endoscopes, no staff in any of the three categories were reported as receiving training and there was no reported availability of manufacturers instructions for 30 endoscopes in this group. Training in reprocessing the specified endoscope was most commonly provided by in-house staff (81%, 1216 of 1494) but was also provided by the endoscope manufacturer (78%, 1162 of 1494) and by the manufacturer of the re-processing equipment (72%, 1070 of 1494). For the in-house trainers, their own previous training had been provided by a variety of sources including the endoscope manufacturer (88%, 1075 of 1216), the re-processing equipment manufacturer (76%, 929 of 1216) and other in-house staff (84%, 1017 of 1216). Additional reported sources of training on endoscope reprocessing included chemical disinfectant manufacturers (41), the infection control team (9) and external units (8).

3.8 Manual pre-cleaning procedures

Key indicator of good practice

Manual pre-cleaning - 1

• Thorough manual pre-cleaning of all surfaces (internal and external) according to a documented procedure, using an appropriate detergent ( e.g., low-foaming enzymatic) and including brushing of all accessible channels is undertaken.

Manual washing was reported as being used for all endoscopes by 120 units (78%) and for 'selected endoscopes only' in 7 units (5%).

One clinical unit made a statement that 'no lumens were handwashed'.

Brushes were reported as being used in the entries under 'Manual Cleaning Procedure' in ninety units. One unit stated that the brush was 'single-use only, but re-used' and another unit stated that the brush was 're-usable with no treatment between uses'.

Fifty three units (35%) used a syringe in their cleaning procedure and one unit reported the use of a jet gun.

Key indicator of good practice

Manual pre-cleaning - 2

• There is a dedicated sink(s) for decontamination separate from that used for handwashing, filling kettles etc.
• There are separate sinks for washing and rinsing.
• There is a means to fill the decontamination sink to a known volume.
• There is a means to dispense detergent in known volumes.

Dedicated sink for manual washing endoscopes

Of 153 clinical units, less than half (71) had a dedicated sink for manual washing of endoscopes.

It was noted that nine of these lacked a separate hand wash basin, so it is likely that the actual incidence of sinks dedicated for manual washing is lower than 46% (or, of even greater concern, hands are not washed in some decontamination rooms). Of the remainder, 23 reported that they had 'nothing' and 8 units gave no response to the question.

Of those with a shared sink for manual washing, the activities reported included handwashing (41), environmental cleaning (40), beverage preparation (3), waste disposal (1), cleaning other instruments (2) dirty utility (1) and 'flowers' (1).

Eighty units (52%) reported that a separate wash hand basin was provided.

Other facilities for manual cleaning

Fourteen units (9%) reported that they had a separate vessel (bowl) for rinsing the washed endoscope. Forty two units (27%) reported that they had three dedicated spaces ( e.g., work surface or drainer) alongside the sink for separate accommodation of used devices prior to cleaning, for cleaned devices prior to rinsing and for rinsed devices prior to inspection. Thirteen units (8%) had only a space to accommodate used devices prior to cleaning and no space to put the device down between cleaning stages or for final inspection. Two units reported only a space for inspection of the cleaned device.

The fill-level for water in the sink was marked in 18 units (12%) but the volume that this represented was known in only 14 (9%).

Table 13 Use-concentration for detergent used in manual cleaning

About two-thirds of units (107 of 153) reported that the use-concentration of detergent was specified from various sources (Table 13) but only four in five of this group overall reported the specified concentration. The use-concentration was typically specified as 'volume of detergent /volume water' although one instance, in the group using the concentration 'specified by the detergent manufacturer', this had been converted to 'five squirts in half a sink'.

The choice of detergent for manual washing (Table 14) covered a wide range with only 44 (29%) using a detergent claimed to be formulated specifically for manual washing of endoscopes. There was clearly considerable confusion as to the intended use of various detergents. Hospec was reported as a 'washing up liquid', a detergent for 'manual washing of surgical instruments' and also as a detergent specifically for 'manual washing of endoscopes'. Surgical hand wash was used by 3 (2%) of units. These are formulated as skin disinfectants and contain a variety of additives, including dye, which may have an adverse effect on the device.

Three units indicated that no detergent was used. This would limit any removal of contamination to 'loose' material, capable of being both physically removed by irrigation and of avoiding redeposition elsewhere in the endoscope.

Table 14 Detergents used in manual washing

Key indicator of good practice

Manual pre-cleaning - 3

• Hot water mixed to optimal temperature for detergent and which will not damage thermo-labile endoscopes is used for washing.
• Good quality soft potable, de-ionised or reverse osmosis water is used for rinsing.

Water for rinsing after manual cleaning

In 95 units (62%), the water supplied for rinsing was untreated mains water. Softened water was supplied in 3 units and deionised water in one unit, with no reported use of RO water. One unit rinsed the endoscopes using bottled distilled water and six used sterile water for irrigation.

Twenty three units (15%) stated that the manually cleaned endoscopes were not rinsed.

3.9 Endoscope reprocessing equipment

Table 15 lists the range of endoscope reprocessing equipment according to manufacturer, model type and age.

Of 155 items, 123 (80%) are classified as endoscope washer disinfectors, designed to provide automated decontamination of endoscopes, including cleaning and disinfection. Of the remainder, twenty seven are 'endoscope disinfectors' which are described as 'liquid chemical disinfectors' ( LCDs) in SHTM2030. These lack many of the features of the EWD, in particular the automated cleaning stage and are intended to provide 'high level' chemical disinfection or chemical sterilization of previously cleaned thermolabile medical devices using peracetic acid. Two laryngoscope disinfection stands were also reported as being in use in outpatient departments.

The date of manufacturer was not known for 21 EWDs (17%) and six LCDs (22%). The known age of EWDs are in the range 1 year to 12 years, with a median of 4 years. For the LCDs, the age range is 2 - 7 years with a median of 3 years (Table 16).

For EWDs on which details were reported, the range of designs include single door, top loading (44), double-door, top loading (26), single-door, front loading (6) and double-door, pass through (2) (Table 17). Most commonly, the EWDs are able to process more than two endoscopes in either single or double chamber machines. (see Table 18). For the dual chamber EWDs, all were reported as allowing independent operation of either chamber.

The LCDs are all Steris System reprocessors, with a single lidded, top-loading chamber and an endoscope loading capacity of two (twenty machines) or more than two (three machines).

Table 15 Endoscope reprocessing equipment

Table 16 Age of endoscope reprocessing equipment

Table 17 Endoscope reprocessing equipment : loading and doors

Table 18 Endoscope washer disinfector : chamber capacity

Details were sought on the 'unique' EWD identifiers of serial number, asset number and designation.

Serial numbers were reported for 109 EWDs (88%) and all the LCDs. In contrast, asset numbers were recorded for only 26 EWDs (21%) and one LCD (4%). The need for an asset number was considered 'inapplicable' for six EWDs, all supplied by Sterilox Medical in 2000 to one site, possibly because of lease or hire arrangements.

The capability of sites to retrieve records of this nature varied - one site with 16 EWDs reported full details (manufacturer, model number, serial number, asset number) for 14 of 16 EWDs installed from 1998 to 2003, whereas another site with 17 EWDs over an age range from 1993 - 2003 could provide full records on only two.

The designation of EWDs ranged from the imaginative (Winnie, Piglet) to the informative, revealing possible clues about their location. Two were designated 'Store room in OPD' and three were 'Corridor', either in theatres (2) or on a ward (1). An EWD in one unit was designated 'sterilizer'.

EWD cycles and performance

Key indicator of good practice

Automatic Endoscope Washer-disinfectors - operating cycle

• the specified performance of the EWD is achieved by an operating cycle under the control of the automatic controller, to include :-
• leak testing
• cleaning (which may include several stages)
• disinfecting
• final rinsing
• drying (when appropriate)
• it should not be possible for the operator to interrupt a cycle before completion.

Leak Test

The leak test is intended to demonstrate that the endoscope will not be damaged by liquid ingress during the EWD operating cycle. The test may be carried out manually prior to processing though the EWD or incorporated as an automatic test on the EWD, completed before the endoscope comes into contact with process fluids. In some EWDs, the leak test is repeated at the end of the operating cycle to confirm that the process has been completed without damaging the endoscopes.

The analysed data for leak tests is shown in Table 19. EWDs incorporating an automatic leak test were reported in 35 of 123 (28%). Typically this feature was reported in newer machines, purchased after 2001. However, even after this date, some sites chose to purchase EWDs lacking an automatic leak test (eg Sterilox QED, Sterilox 83+ in 2002-3).

Models such as the Labcaire Autoscope Guardian range incorporate an automatic leak test as 'user selectable' - this may explain why EWDs of this type appear in both categories. The AFOSICU machine reported as having an automatic leak test was purchased in 1995, and this attribute may therefore require verification (no other similar models have this feature).

Table 19 Reported automatic leak test in EWD models

* purchased in 1995

3.10 Decontamination process stages

Table 20 Data for the operating cycle stages on the EWD.

One in five EWDs had the complete range of process stages recommended for the operating cycle of an EWD (Table 20). Of the remainder, more than half had all the process stages other than an automated air-purge and/or drying stage. All the EWDs were reported as having a disinfection and a post-disinfection rinse stage. Seven lacked a post-wash rinse stage. For five EWDs there was no wash stage recorded although one machine was cited elsewhere as having a detergent used in the process (Hospec). The 'detergent' used in the remaining four 'non-wash stage' EWDs were given as 'unknown' (1) or were confused with disinfectants (3 - Sterilox, Gigasept, Tristel). It therefore seems likely that, in at least three instances, EWDs were operated without a detergent wash cycle.

Automatic cleaning/disinfecting/rinsing of endoscope channels was typically achieved by irrigation under pressure (96%). Three EWDs were reported as irrigating the channels by suction.

The wash/disinfection/rinse action for the external surfaces of the endoscope in the chamber was either by immersion (92%), by spray action (6%) or not known (2%).

Cleaning stage : Process chemicals

The detergents used in the EWD are shown in Table 21. Most units were unable to categorise their detergents into the broad categories of acid, neutral, alkaline or enzymatic - with the exception of 'Hospec', which was widely recognised as a neutral detergent. The table provides the category of detergent as determined from the product name.

Table 21 Detergents used in EWD

The products used were predominantly enzymatic (36%) or neutral detergents (31%). Five disinfectant formulations were confused with detergents - the chlorine dioxide disinfectant Tristel was described as an enzymatic detergent, Nu-Cidex (containing peracetic acid) as an acidic detergent and product entries were given for Sterilox, Gigasept and Cidex- OPA.

Disinfection stage

The endoscope disinfection stage was at room temperature in 117 EWDs and at a controlled elevated temperature in three EWDs - the Dawmed Wassenburg (35°C) and two QED/Sterilox machines (20 - 43°C). Three EWDs were reported as having no temperature control, only five were reported as having independent temperature monitoring and four had an independent temperature recorder.

The 'Sterilox' EWD reported as operating at a controlled elevated temperature (up to 43°C) was reported as having neither independent temperature monitoring nor an independent temperature recorder. Four EWDs operating at room temperature had independent temperature monitoring and two had an independent temperature recorder.

Chemical disinfectants

Relatively few units provided details of the chemical disinfectants used in endoscope decontamination. Table 22 lists the chemical disinfectants reported for manual disinfection, automated disinfection and machine disinfection (self-disinfection).

As for the detergents previously, there is some confusion in the choice of product. In addition to a number of high level disinfectants, there are three detergents cited in error as disinfectants and one skin disinfectant/antiseptic, Sterets, that is not intended for use on medical devices . The latter is formulated for topical use and contains iso-propanol, which is not a high-level disinfectant.

The disinfectants used by clinical units include formulations containing peracetic acid (in 45 units), ortho-phthalaldehyde (in 38 units), chlorine dioxide (in 24 units), and superoxidised water (in 22 units). Eight units reported the use of glutaraldehyde.

Most disinfectants were used for automated disinfection, including self-disinfection. It was noted that three units reported the use of Steris 20, the formulation containing peracetic acid intended specifically for use in the Steris System processor / LCD for both automated and manual disinfection. Formulations used for manual disinfection in addition to automated disinfection included Cidex- OPA, Gigasept, Nu-Cidex, Steris 20 and Tristel. One endoscope disinfectant, Perasafe, was used for manual disinfection only.

Process chemicals other than detergents and disinfectants were not commonly used, other than descalers (6), a water softening agent (1) and corrosion inhibitors/polimax inhibitor (7) used in fourteen of the Sterilox QED/Sterilox System 83+ machines. Alcohol and methylated spirits were cited in two instances (probably for use in drying) and hypochlorite was cited in four instances for 'chlorination' (probably for use in the self-disinfection cycle).

Table 22 Chemical disinfectants used in endoscope reprocessing

* supplied for use in Steris System 1 automated disinfector / LCD

Rinsing

Rinsing stages were included after the wash stage in EWDs and as a final post-disinfection rinse. In most cases the water was supplied as mains water (100), with additional treatments including softened (5), deionised (6) and RO (4). The data on performance tests of rinse water quality are given in Tables 25 and 26.

Drying stage

A drying stage was reported in 46 EWDs (30%). The means of automated drying in the EWD included:-

air drawn into the EWD directly from the room (15 )

supply of compressed air (5),

filtered air (6)

by flushing with alcohol (17 )

A manual flush with alcohol was used to aid endoscope drying after processing in 45 instances, including nine where the endoscope had already been processed in an EWD with an automatic drying stage.

Cycle interruption and over-ride

In half the EWDs it was possible to over-ride the automatic operating cycle and in five instances there was nothing to prevent the settings of the key process variables from adjustment by the operator (only 88 EWDs had protection of the key process variables). It was possible to interrupt the operating cycle in nearly 90% of EWDs (110 - 89%) and the endoscope could be removed from the EWD before automatic reprocessing was complete in nearly 60% (73 - 59%).

Self-disinfection

Key indicator of good practice

Automatic Endoscope Washer-disinfectors - self disinfection

• EWD has a self-disinfection cycle, operated under the control of the automatic controller and distinct from the normal operating cycle.
• the self-disinfection cycle provides for disinfection of the chamber and all liquid transport systems.
• uses a different disinfectant from the normal operating cycle, preferably thermal and validated to remove biofilm.

A separate cycle for self-disinfection was reported for 87 EWDs, including some that were ten years old. Thirty six EWDs had no separate cycle for self-disinfection and the remainder were unknown.

For two EWDs (both Lancer (France) Fibrocleaner), the unit reported 'same cycle all processes'.

Self disinfection of the EWD, whether by a separate validated cycle or by repetition of the normal operating cycle typically used the same chemical disinfectant for both cycles.

Performance tests of cleaning efficacy

Analysis of tests on cleaning efficacy for 117 EWDs reported from the original set of 123 is shown in Table 23. Only 1 in 4 (31 EWDs - 26%) were tested for cleaning efficacy. Across the NHS Boards reported, none tested all their EWDs .

Table 23 Performance tests of cleaning efficacy

The test soils used were the HTM2030 test soil (9) and Browne's test soil (7). Other reported tests of cleaning efficacy were the Tosi flexi test (1), 'microbiological' (5) and 'Sterilox manufacturer' (1). Ten EWDs were tested but the test soil was unknown; in four of these machines the tests were performed weekly and in the remaining six machines the tests were done with an unknown test soil at an unknown frequency.

For 83 EWDs, the test of cleaning efficacy was reported as 'nothing' and in three instances 'never'.

The efficacy of cleaning after EWD processing may be further tested by detecting protein residues in the eluate after final rinsing. The findings (Table 24) show that protein residue tests were undertaken after processing on only 14 EWDs (12%). One unit reported for 2 EWDs that the test is done on the basis of 'new machine', at an unknown frequency.

Table 24 Protein residue tests on endoscopes processed in EWD

* recorded as 'new machine', no frequency given

Some anomalies were noted in the reports - one site reported for four EWDs that the protein efficacy test was 'nothing' or 'never' but then reported that these non-existent tests used the ortho-phthalaldehyde ( OPA) method at unknown time intervals.

Tests of final rinse water quality

Chemical quality

The chemical quality of final rinse water at the EWD was reported as tested and compliant with SHTM2030 in only 18 instances (Table 25 and 26). In a further 15 instances the rinse water was reported as compliant with SHTM2030 but was not tested (2) or the results of any testing was unknown (13).

A slightly higher number of EWDs (30) were reported as being supplied with rinse water of hardness value < 210 mg/l Ca CO_3. However, the rinse water quality at most EWDs (85%) was untested and unknown.

Table 25 Chemical quality of final rinse water

Table 26 Microbiological and endotoxin tests of final rinse water

3.11 Reprocessing equipment - maintenance and testing

Information on AP(S) services, initial validation, subsequent testing and maintenance schedules was sought for EWDs and LCDs, for comparison with the guidance given in SHTM 2030.

Endoscope Washer-Disinfectors

The data on AP(S) services, initial validation and subsequent test and maintenance schedules on EWDs in line with SHTM2030 are summarised in Table 27.

AP(S) services were recorded as retained on ten sites to advise on 56 EWDs in 44 clinical units. The AP(S) services were most commonly reported as being responsible for 'agreeing the programme of periodic testing', with other responsibilities being 'agreeing the programme of validation testing', 'auditing test results' and 'auditing the maintenance record'. Approximately one third of those who recorded the services of an AP(S) did not know what the retained services included.

The analysed data indicates that 1 in 5 EWDs (21%) were not validated. Installation tests were slightly less common (76%) with annual tests (22%) and periodic tests (20%) being the least common.

Only eight of the 123 EWDs (7%) had a full programme of installation tests, commissioning/validation, periodic test, and annual tests carried out by qualified test persons. Four of these (50%) were in units which recorded the services of an AP(S). The EWDs were in 6 sites and had been installed in 1995 (1), 2001 (2), 2002 (2) and 2003 (3).

Qualified Test persons (Washer Disinfectors) undertook test work on 57 EWDs of which 36 were on the sites that retained an AP(S) with the remainder of test work undertaken by engineers not known to have the TP( WD) qualification. Test records were held with the EWD (5), in the Unit (54), in the Manager's Office (1), or externally in the Estates Dept (28), Medical Physics (12) or ISS Control Centre (6).

Planned preventative maintenance was undertaken on a higher proportion of EWDs than for the validation test work. Most commonly this was done by the EWD manufacturer but on sites with an AP(S), the maintenance work was as likely to be undertaken by in-house personnel as the external manufacturer.

Nine EWDs in five clinical units on one site had no programme of validation or on-going testing and no planned preventative maintenance.

Table 27 AP(S) services, testing and maintenance of EWDs

Liquid chemical disinfectors

Engineering aspects of LCDs were reported on 24 machines by 15 units in 4 sites including one clinical unit (an endoscopy unit) with 5 LCDs, two units with 3 LCDs and one with two LCDs.

In two sites, no AP(S) services were reported as retained for the specific LCD/s in any units, including the unit with 5 LCDs. In a third site, there was awareness of provision of AP(S) services for the LCDs in only two of seven clinical units.

Where recorded, the AP(S) responsibilities were stated as agreeing the programme of validation testing, agreeing the programme of periodic testing, auditing the test results and auditing the maintenance records.

Pre-installation tests were reported for 18 of the twenty four LCDs, but only ten (42%) had been commissioned/validated and only one machine (installed in 2001) was subject to a full on-going programme of periodic, quarterly and annual testing by a qualified test person, as described in SHTM2030. In the two other units also provided with AP(S) services, commissioning but no subsequent periodic tests were reported on LCDs (installed in 2002).

Qualified test persons had undertaken periodic tests (3), quarterly tests (1) and annual tests (2) on LCDs in three clinical units on two sites - in all other instances (88%) none of the schedule of tests given in SHTM2030 had been undertaken.

It should be noted that if the LCDs are used for liquid chemical sterilization, in line with the claims made by Steris, then validation and subsequent testing should be in line with the BSENISO 14937 ²⁷.

Planned preventive maintenance was carried out on 20 of the twenty four LCDs, including the three units with AP(S) services. In the majority of instances (16), this was undertaken by the equipment manufacturer, in one instance by a specialist contractor and in three instances the maintenance was carried out by in-house staff. Maintenance records were kept in the unit in 19 instances and with the machine in one (in-house testing). Two clinical units reported no planned preventative maintenance for the LCDs and 'nothing' for maintenance records.

« Previous | Contents | Next »