GB2630294A

GB2630294A - Decontamination of a medical device

Info

Publication number: GB2630294A
Application number: GB2307528.6A
Authority: GB
Inventors: Brand Thomas
Original assignee: Tristel PLC
Current assignee: Tristel PLC
Priority date: 2023-05-19
Filing date: 2023-05-19
Publication date: 2024-11-27
Also published as: WO2024241039A1; GB202307528D0

Abstract

A method of decontaminating a medical device comprises applying a dyestuff comprising indicator composition having a first colour to a surface of the medical device101, performing a first inspection of the surface to verify that the first colour is present on the surface 102 and making a first log entry in accordance with the outcome of the first inspection 103. A disinfecting agent is then applied to the surface 104, a second inspection of the surface performed to verify that a colour change has occurred 105 and a second log entry made in accordance with the outcome of the second inspection 106. The first log entry and the second log entry are associated with the decontaminated medical device 107 e.g. linked to an identifier of the medical device. There is a kit of parts comprising the disinfecting agent, the dyestuff comprising indicator composition which has a first colour and exhibits a colour change upon exposure to a disinfecting agent, and a logbook for recording the log entries. Preferably the disinfecting agent is chlorine dioxide and the dyestuff is anthocyanin, anthocyanidin or betanin and is applied using a wipe.

Description

DECONTAMINATION OF A MEDICAL DEVICE

FIELD OF THE INVENTION

The present invention relates to a method of decontaminating a medical device using a disinfecting agent and an indicator composition.

BACKGROUND TO THE INVENTION

Within the healthcare market, decontamination procedures are widely used for disinfection and cleaning. Areas of particular importance include the reprocessing of medical devices, such as example surgical instruments, ultrasound probes, endoscopes and the like. For infection control and patient safety, it is essential that any process used for decontamination or disinfection is effective in practice, taking into account the products used for disinfection, the training and performance of the user, environmental factors, and so on.

Existing methods for reprocessing such medical devices typically include multiple process steps. For example, a first step may be performed in which the device is cleaned with a cleaning agent, for the removal of gross contaminants and soiling from the surface. In a second step, disinfection or sterilization may takes place using chemical, thermal, or radiative means. In a third step, a rinsing process may be performed to remove left over chemical residue, particularly where the disinfection step uses a chemical disinfectant. One example of a three-step decontamination system, in which a chlorine dioxide-based disinfecting agent is used, is described in WO 2005/107823 Al. Many other disinfectant compositions are also used in the art, including those based on chlorine, peracetic acid, hydrogen peroxide, hypochlorite, quaternary ammonium compounds, tertiary amines and so on. Disinfection may also be achieved for example by exposure to UV radiation, steam or heat.

The minimum requirement for device reprocessing is to disinfect the device.

Cleaning and/or rinsing stages may be required depending on the type of device, -2 -type of disinfection medium, levels of contamination/soiling, and prevailing regulatory and legislative frameworks.

Effective disinfection relies on the user ensuring that all parts of the surface to be treated are adequately exposed to the disinfecting agent. When a pre-disinfection cleaning step is required, failure to adequately clean the device prior to disinfection has the potential to markedly increase the risk of cross-contamination and post-procedure infection. By failing to remove soil, the performance of the disinfectant can be impaired. This impairment can manifest as a reduction in active strength of the disinfectant as some disinfecting capacity will be consumed via reaction with the remaining soil and secondly by shielding the surface of the device from contact with the disinfectant.

In the event of a problem arising in the reprocessing of a medical device, for example where inadequate disinfection results in a test failure or an infection incident, it is desirable to have a record of the decontamination process. It is known, for example from WO 2005/107823 A1, to log on a record sheet the batch numbers and other information relating to the products used in the process. While this can be useful in identifying the use of a defective or expired product, such information does not relate to how the process steps are performed by the user.

Against that background, it would be desirable to provide a method for decontaminating a medical device in which information relating to the performance of steps in the decontamination process is recorded. -3 -

SUMMARY OF THE INVENTION

Aspects of the invention are specified in the independent claims. Preferred features are specified in the dependent claims.

In one embodiment, the invention provides a method of decontaminating a medical device using a disinfecting agent, comprising applying an indicator composition to a surface of the medical device, the indicator composition comprising a dyestuff and having a first colour when applied to the surface and exhibiting a colour change upon exposure to the disinfecting agent; performing a first inspection of the surface to verify that the first colour is present on the surface; making a first log entry in accordance with the outcome of the first inspection; applying the disinfecting agent to the surface; performing a second inspection of the surface to verify that the colour change has occurred; making a second log entry in accordance with the outcome of the second inspection; and associating the first log entry and the second log entry with the decontaminated medical device.

In this method, the user may apply the indicator composition to the surface so that the first colour becomes detectable on the surface, and may subsequently apply the disinfecting agent to the surface. This causes a colour change that can be detected by eye and/or by electronic means. If any of the first colour remains after application of the disinfecting agent, it can be concluded that the disinfecting agent has not been adequately applied to the surface and consequentially there is a risk of inadequate disinfection. If none of the first colour remains -i.e. the colour change has occurred across the surface -then it can be concluded that the disinfecting agent has reached all of the parts of the surface to which the indicator composition was applied.

The utility of an indicator composition that changes colour upon exposure to the disinfecting agent as an aid to determine whether the disinfecting agent has been applied to the whole of the surface to be disinfected relies in part upon the -4 -indicator composition having being applied in such a way that it, too, covers the whole of the surface to be disinfected. Accordingly, a first inspection of the surface after application of the indicator composition is performed to verify that the first colour is present on the surface, and a first log entry is made in accordance with the outcome of the first inspection (e.g. to record that the first colour was or was not visible across the whole of the surface to be disinfected). Then, after application of the disinfecting agent, a second inspection of the surface is performed to verify that the colour change has occurred, and a second log entry is made in accordance with the outcome of the second inspection (e.g. to record that the colour change was observed in all areas that had previously exhibited the first colour, or that the colour change was observed in only some such areas, or that no colour change was observed).

The first and second log entries are associated with the decontaminated medical device. In this way, the first and second log entries together can be used to determine if the associated medical device is suitable for re-use, or if further reprocessing is required. For instance, the medical device may be deemed suitable for re-use only if the first log entry indicates that, at the first inspection, the first colour was visible across the whole of the surface to be decontaminated, and that, at the second inspection, none of the first colour remained visible on the surface to be decontaminated. The first log entry and the second log entry together provide an "audit trail" associated with the medical device that can be consulted during regular use, for quality/training control and/or for investigative reasons.

The first and/or second log entries may comprise one or more of: user identifier, device type, inspection composition or disinfecting agent batch used, inspection composition or disinfecting agent expiry date, inspection outcome, and other similar information.

The method may comprise linking the first log entry and the second log entry to an identifier of the medical device, such as a serial number or asset number of the -5 -medical device. The method may comprise obtaining the identifier from a machine-readable medium provided on or associated with the medical device.

The first and second log entries may be made electronically. For example, the first and second log entries may be entered into a computing device, such as a computer, smartphone, tablet or similar device. The log entries may be stored in a memory of the device and/or transmitted to another device, such as a server. The first and second log entries may be associated electronically with an identifier of the medical device.

In another embodiment, the first and second log entries are made on physical media. For example, the first and second log entries may be made in a physical logbook or journal, or on a label for a container, bag or other package into which the medical device can be placed after performing the decontamination process.

The method may comprise attaching the physical media to the decontaminated medical device, either directly, or by attachment to a container, bag or other package into which the medical device is placed.

The first inspection and/or the second inspection may be performed electronically.

For example, the medical device may be imaged by a suitable still or video camera, and the resulting image or images may be analysed using image analysis techniques. For example, the extent of the first colour and subsequent colour change may be discernible by analysis of RGB colour values in the images. In another example, a machine learning image analysis method using suitably trained neural networks may be used to determine the extent of the first colour and subsequent colour change in the first and second inspections, respectively. For example, one or more neural networks may be trained to output a "pass" or "fail" indication for each of the first and second inspections.

It will be appreciated that the indicator composition may have a starting colour that differs to some degree from colour of the dyestuff itself, and that the first colour -6 -that is exhibited when the indicator composition is applied to the surface of the device may differ from the starting colour of the indicator composition and/or the dyestuff. In other words, the first colour observed on the device may be influenced by the surface of the device, and by other effects such as drying, even though no disinfectant-induced colour change has occurred. In other cases, the first colour may correspond to the starting colour of the indicator composition and/or the dyestuff (i.e. the application to the surface has no perceptible effect on the colour).

The indicator composition may change colour from the first colour to colourless upon exposure to the disinfecting agent, or the colour change may be from the first colour to a second, different colour.

The indicator composition may include any suitable dyestuff that changes colour upon exposure to the disinfecting agent to be used in the process. The colour change may arise from oxidation of the dyestuff when the disinfecting agent is an oxidising composition, such as chlorine, chlorine dioxide, peracetic acid, hydrogen peroxide, hypochlorite and so on. In another example, the colour change may arise from a change in pH upon application of a disinfecting agent with a pH that differs from the pH of the indicator composition. In further examples, the colour change may arise due to UV-induced or thermal degradation of the dyestuff when the disinfecting agent is UV light or high temperature, respectively.

The dyestuff may selectively change colour upon exposure to the disinfecting agent used in the method, but not upon exposure to other disinfecting agents. In one example, the disinfecting agent is a chlorine dioxide disinfecting agent, and the dyestuff comprises an anthocyanin, anthocyanidin or betanin dyestuff. Such dyestuffs have been found to exhibit a colour change upon exposure to chlorine dioxide disinfectants but not other high-level disinfectants.

The indicator composition may act as a cleaning composition, so that the application of the indicator composition to the surface provides a cleaning step of -7 -the decontamination procedure. To this end, the indicator composition may comprise one or more cationic, non-ionic, or anionic surfactants. When the indicator composition acts as a cleaning composition, the first log entry may serve to record that the cleaning step has been correctly completed.

The indicator composition may have any suitable composition that permits the surface to be marked by the indicator composition. The indicator composition may comprise one or more of a silicone, siloxane, or polymer for promoting surface adhesion, and/or a lubricant. Preferably, the indicator composition remains adhered to the surface and does not immediately run or drip from the surface. The indicator composition may be in the form of a liquid, gel or wax, or may be a foam.

The indicator composition may be applied to the surface by any suitable means, such as by spraying, dipping or by using a wipe, a gloved finger or an applicator device. The indicator composition may be spread during or after application to achieve a uniform, even coating of the indicator composition on the surface.

Similarly, the disinfecting agent may be applied using any suitable method. When the disinfecting agent is a composition, the disinfecting agent may be applied for example by spraying, dipping or by using a wipe. When the disinfecting agent is UV light, the light may be applied by placing the device in a suitable IN light cabinet. When the disinfecting agent is thermal energy (heat) or steam, the heat and/or steam may be applied by placing the device in an autoclave or similar apparatus.

The invention also extends to a kit of parts for use in the method described above, comprising a disinfecting agent comprising a disinfecting agent, an indicator composition comprising a dyestuff and having a first colour and exhibiting a colour change upon exposure to the disinfecting agent, and a logbook for recording the first and second log entries and for associating the first and second log entries with the medical device. -8 -

The logbook may be an electronic logbook, in which case the logbook may be provided by an application on a smartphone or tablet device or otherwise by a computer program, and may be stored in a memory on a local or remote device or server. The logbook may instead be a physical logbook.

Preferred and/or optional features of each aspect and embodiment of the invention may also be used, alone or in appropriate combination, in the other aspects and embodiments also. -9 -

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which like reference signs are used for like features, and in which: Figure 1 is a flowchart showing a method of decontaminating a surface of a medical device; Figure 2 is a schematic illustration of a first part of the method of Figure 1 being performed; Figure 3 is a schematic illustration of a second part of the method of Figure 1 being performed; and Figure 4 shows a decontaminated medical device with associated log entries.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention provide a method for performing a high-level decontamination procedure while at the same time generating an auditable log that records the outcome of steps in the procedure.

Referring to Figures 1 and 2(a), in a first step 101 of the method, a medical device 10 having a surface 12 to be decontaminated is placed in a work area. The method can be applied to substantially any medical device 10, for example an invasive or non-invasive ultrasound probe, an endoscope, nasendoscope, transvaginal probe or any other similar device. The surface 12 to be decontaminated may be substantially the whole surface of the medical device 10, or only a part of the medical device 10.

A wipe 14 is provided that carries an indicator composition 16. The indicator composition 16 includes a dyestuff that exhibits a colour change upon exposure to a disinfecting agent 22 to be used in a subsequent step of the method. The indicator composition 16 therefore has a first colour when applied to the surface 12. As shown in Figure 2(b), the wipe 14 is used to apply the indicator composition 16 to the surface 12 to be decontaminated in accordance with instructions provided to the user. Instead of a wipe 14, a different applicator such as a cloth, sponge, gloved hand, spray or other applicator device could be used to apply and spread the indicator composition 16 on the surface 12, or all or part of the device 10 could be dipped in a tray or other container containing the indicator composition 16. In any event, it is desirable that the whole of the surface 12 to be decontaminated is covered by a uniform, complete coating of the indicator composition 16 after application, as shown in Figure 2(c).

Once the indicator composition 16 has been applied, the surface 12 can be inspected (at step 102 in Figure 1 and Figure 2(d)) to verify that the first colour is present on the surface 12. This first inspection can reveal any areas which are intended to be disinfected but are not marked with the first colour, demonstrating that the indicator composition 16 has is not present on these areas, for example due to incorrect application (e.g. missing areas of the surface 12 or not applying enough indicator composition 16). Accordingly, this first inspection serves as a useful validation tool to ensure that the indicator composition 16 has been correctly applied to the whole of the surface 12 to be decontaminated. If missed areas are identified, appropriate corrective action (such as repeating the application of the indicator composition 16 and re-inspecting) can be taken.

At step 103 in Figure 1, a first log entry 18 is made. The information recorded in the log entry is based on the outcome of the first inspection, and therefore may include an indication of whether the first colour was observed across the whole surface 12, whether any areas of the surface 12 were not coloured with the first colour, whether any corrective action was taken and so on.

The device 12 then goes forward to a disinfection stage of the method, shown in Figure 3. Here, a wipe 20 carrying a disinfecting agent 22 is provided (Figure 3(a)). In step 104 (Figure 1), the disinfecting agent 22 is applied to the surface 10 in accordance with instructions provided to the user. Again, a different applicator such as a cloth, sponge, gloved hand, spray or other applicator device could be used to apply and spread the disinfecting agent 22 on the surface 12, or all or part of the device 10 could be dipped in a tray or other container containing the disinfecting agent 22.

The dyestuff of the indicator composition 16 changes colour upon exposure to the disinfecting agent 22, as shown in Figure 3(b). Areas of the surface 12 that have not been exposed to the disinfecting agent 22 can therefore be distinguished from areas of the surface 12 that have been exposed. In this way, a user-verifiable visible change in appearance of the surface 12 occurs once the disinfecting agent 22 has been applied. If the disinfecting agent 22 has been applied to all of the areas of the surface 12, none of the first colour will remain as shown in Figure 3(c).

Once the disinfecting agent 22 has been applied, the surface 12 can again be inspected (at step 105 in Figure 1 and Figure 3(d)) to verify that the colour change has occurred (i.e. that none of the first colour is still visible on the surface 12). This second inspection can reveal any areas to which the disinfecting agent 22 has not been correctly applied. This second inspection serves as another validation tool to ensure that the disinfecting agent 22 has been correctly applied to the whole of the surface 12 to be decontaminated. If missed areas are identified, appropriate corrective action (such as repeating the application of the indicator composition 16 and re-inspecting) can be taken.

At step 106 in Figure 1, a second log entry 24 is made. The information recorded in the log entry is based on the outcome of the second inspection, and therefore 30 may include an indication of whether the colour change has occurred across the whole surface 12, whether any areas of the surface 12 were still coloured with the first colour, whether any corrective action was taken and so on.

At step 107 in Figure 1, the first log entry 18 and the second log entry 24 are associated with the decontaminated medical device 10 (see Figure 4). The first and second log entries together can be consulted to determine if the associated medical device 10 is suitable for re-use, or if further re-processing is required. The log entries provide an "audit trail" associated with the medical device 10 that can be consulted during regular use, for quality/training control and/or for investigative reasons. The first and second log entries 18, 24 may include data relating to the decontamination procedure of the medical device 10 such as: user, device type, product batch used, product expiry, and cleaning outcome.

The log entries may be logged and stored in a physical form, such as traceability book, logbook or journal. Other possibilities include making the log entries on a bag, package, envelope or other container into which the decontaminated medical device can be placed, or on a label, tag or similar for attaching to such a container or directly to the medical device.

Alternatively, the log entries may be logged and stored using a suitable electronic system. A computer program and/or a computer program product may be provided for this purpose, for execution on a suitable device such as a desktop or laptop computer, tablet, smartphone or dedicated device. The program may allow for the recording of the first and second log entries along with the serial number and/or other identifying information of the medical device, so that the log entries can be associated with the device.

The electronic system may be capable of reading information from the medical device and from products used in the method (e.g. the indicator composition and the disinfecting agent) from machine-readable media, such as bar codes, matrix codes, radio-frequency ID tags and so on, provided on or otherwise associated with the device and/or the products.

The electronic system may be capable of performing the first and/or the second inspection automatically, or providing assistance and guidance to the user in performing the inspection(s). For example, the electronic system may include a camera system for imaging the medical device, and image analysis capability for detecting the presence of the first colour after application of the indicator composition, and the colour change after application of the disinfecting agent. The medical device could be imaged at suitable points as the method is performed or, alternatively, some or all of the procedure could be captured by video, and the video analysed to perform the first and second inspections. In such cases, artificial intelligence-based image analysis methods can be employed to perform the inspections. For example, a machine learning system comprising one or more neural networks can be trained with image sequences corresponding to various outcomes of the first and second inspections.

The indicator composition 16 used in the first step 101 includes a dyestuff that exhibits a colour change upon exposure to the disinfecting agent used in step 104. Accordingly, the dyestuff may be selected for compatibility with the disinfecting agent. Many suitable dyestuffs are known in the art, and include for example dyes that are oxidised, bleached, denatured or otherwise modified by disinfectant compositions, so that they lose their colour, or that exhibit a pH-sensitive colour change, and so on. The colour change may be from the first colour to colourless, from the first colour to a second colour, or from colourless to a visible colour. It is also conceivable that the colour change may be in or include the non-visible range. For instance, the first colour and/or the colour after the colour change may be apparent only in the UV or IR range of the electromagnetic spectrum. It is however preferable that the first colour is visible to the eye in some applications, so that the presence of the indicator composition on the surface of a purportedly decontaminated device can alert a user to the possibility that the decontamination procedure has been incompletely or incorrectly performed.

By way of non-limiting example, suitable dyestuffs for use with a chlorine dioxide-based disinfectant are described in the present applicant's International Patent Application No. WO 2022/013543 A1, the contents of which are incorporated herein by reference. The dyestuff may for example be an anthocyanin dyestuff selected from the group consisting of: black carrot extract, purple carrot extract, haskapa berry extract, and blackcurrant extract. Examples of anthocyanidin dyestuffs that may be suitable for use include bilberry extract and blue pea extract (clitoria ternatea). Suitable betanin dyestuffs may be referred to as E162 food additives. Examples of betanin dyestuffs that may be suitable for use include red beetroot powder and beetroot juice concentrate.

The application of a disinfecting agent in step 104 is not limited to applying a disinfecting composition to the surface. Other disinfecting agents include, for example, ultraviolet radiation, thermal energy, steam and so on, with suitable apparatus and methods for applying such disinfecting agents being known to those skilled in the art.

In the case of disinfection by irradiating the surface with ultraviolet radiation (UVR), azo dyes may be suitable dyestuffs since they are known to undergo a colour 20 change in the presence of UVR.

The indicator composition may be in the form of a liquid, gel, a foam or any other suitable form, and may be applied to the surface by any suitable means. Non-limiting examples include application by (gloved) hand, wipe, sponge, spray, applicator, pump, nebuliser or by immersion of the surface in the indicator composition.

The indicator composition may have cleaning properties, so that the application of the indicator composition also serves to provide a cleaning step in the decontamination method. In such cases, application of the indicator composition may achieve mechanical removal of contaminants by the wipe or other applicator.

The indicator composition may include a surfactant to provide detergent properties. The surfactant may provide or enhance other properties such as foaming, surface wetting, spreading, soil encapsulation, emulsification and lubrication. When the indicator composition has cleaning properties, the first log entry may serve to record that the cleaning step has been correctly completed.

Further modifications and variations not explicitly described above can also be contemplated without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A method of decontaminating a medical device using a disinfecting agent, comprising: -applying an indicator composition to a surface of the medical device, the indicator composition comprising a dyestuff and having a first colour when applied to the surface and exhibiting a colour change upon exposure to the disinfecting agent; - performing a first inspection of the surface to verify that the first colour is present on the surface; - making a first log entry in accordance with the outcome of the first inspection; - applying the disinfecting agent to the surface; - performing a second inspection of the surface to verify that the colour change has occurred; - making a second log entry in accordance with the outcome of the second inspection; and - associating the first log entry and the second log entry with the decontaminated medical device.
2. The method of Claim 1, wherein the first and/or second log entries comprise one or more of: user identifier, device type, composition batch used, composition expiry date, inspection outcome.
3. The method of Claim 1 or Claim 2, comprising linking the first log entry and the second log entry to an identifier of the medical device.
The method of Claim 3, comprising obtaining the identifier from a machine-readable medium provided on or associated with the medical device.
The method of any preceding claim, wherein the first and second log entries 6. 7. 8. 10. 11. 12. 13. 14.are made electronically.
The method of Claim 5 when dependent on Claim 3 or Claim 4, wherein the first and second log entries are associated electronically with the identifier of the medical device.
The method of any of Claims 1 to 4, wherein the first and second log entries are made on physical media.
The method of Claim 7, comprising attaching the physical media to the decontaminated medical device.
The method of any preceding claim, wherein the first inspection and/or the second inspection are performed electronically.
The method of any preceding claim, wherein the indicator composition changes colour from the first colour to colourless upon exposure to the disinfecting agent.
The method of any preceding claim, wherein the disinfecting agent is a chlorine dioxide disinfecting agent, and wherein the dyestuff comprises an anthocyanin, anthocyanidin or betanin dyestuff.
The method of any preceding claim, wherein the indicator composition is in the form of a liquid or gel.
The method of any of Claims 1 to 11, wherein the indicator composition is a foam.
The method of any preceding claim, comprising applying the indicator composition using a wipe.
15. A kit of parts for use in the method of any preceding claim, comprising: - a disinfecting agent comprising a disinfecting agent; - an indicator composition comprising a dyestuff and having a first colour and exhibiting a colour change upon exposure to the disinfecting agent; - a logbook for recording the first and second log entries and for associating the first and second log entries with the medical device.
16. The kit of parts of Claim 15, wherein the logbook is an electronic logbook.