Evaluating Automated Dispensing Systems for Disinfectants in Hospitals

Environmental Services

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Environmental services (EVS) and infection prevention personnel consider efficacy, safety, and cost when selecting cleaning and disinfection products. Many hospitals use dilutable disinfectants dispensed from automated wall-mounted systems. While these systems can reduce costs and ensure stability, monitoring is essential to verify correct dilution.

Past studies have found variations in disinfectant concentrations, leading to potential surface contamination. Adjustments like water-pressure regulators and flow-control modifications improved accuracy. Hospitals should conduct routine testing to ensure proper dilution levels, as inconsistent concentrations may compromise infection prevention efforts. Evaluating automated dispensing systems can help maintain effective hospital disinfection practices.

A recent study, “Dilution dysfunction: evaluation of automated disinfectant dispenser systems in 10 hospitals demonstrates a need for improved monitoring to ensure correct disinfectant concentrations are delivered,” explored what is happening in 30 hospitals. Infection Control Today^® (ICT^®) spoke with Curtis J. Donskey, MD, lead author, to learn more.

ICT: What was the primary motivation or research question that led you to conduct this study, and why do you believe it is essential?

Curtis Donskey, MD: We have a long-standing interest in environmental cleaning and disinfection. We recently completed a 30-hospital study where we collected cultures after environmental services personnel had completed their cleaning, and we got a substantial amount of contamination in the environment even after the cleaning was completed. Those results stimulated us to reconsider why we see suboptimal cleaning and disinfection results, which many other studies have also demonstrated. We usually blame the EVS personnel; we believe they probably didn't wipe surfaces down adequately. But there are other potential explanations, too.

Disinfectants can be used incorrectly. If you don't apply the disinfectant but don't give enough contact time, it may not work. Sometimes, people may think you'd be using the wrong product, so you're supposed to use a sporicidal disinfectant, but someone gets confused and uses a nonsporicidal product. Then, there are some examples of issues where the disinfectants were not working as they were supposed to. We had a study many years ago where a defective product was coming from the manufacturer and losing its activity, so that product was ultimately taken off the market. So, it is always possible that products need to be fixed or could be more stable.

Then, the final thing in terms of thinking about disinfectants is that many of the disinfectants we use are diluted. They come as a concentrate, and they're diluted. Something could be wrong with our dilution mechanisms. We considered all these things, but for this project, we specifically asked our products to be diluted appropriately. Many of the disinfectants used in the hospital are dispensed from an automated dispensing system that is supposed to ensure things are accurately measured. We specifically looked at the disinfecting system—disinfected dispensing systems in hospitals.

Several companies make these dispensers. The reason for them is that it can reduce costs because you get a jug of concentrate instead of having one, and it reduces storage space. Instead of having a large amount of disinfectant, it is a very concentrated product. And some products are more stable when they're concentrated. It helps with stability as well. This is why hospitals all over the US use these dispensers. The ones we use have 4 different bottles of concentrated different types of products placed in the dispenser.

The manufacturers provide some guidance on these; some do that, so you should consider doing some monitoring. They instruct how to place these concentrate bottles in the dispenser. There is some awareness that you must set these up correctly, or they may not work correctly. And then there's one previous study that suggested there might be at least one prior study that did note some issues with these dispensers.

John Boyce and his group published a study in 2016 in which they said there was a lot of variation in the disinfectant concentrations of these dispensers, and they noted that water press and water pressure varied. You could have some variation in the concentration. Some manufacturers then made some adjustments, such as adding a regulator so water pressure wouldn't have an impact. So that's the dispenser.

Regarding the methods, we wanted to assess disinfectant concentrations that were being dispensed. But from these dispensing systems, again, we started at 1 hospital, and we continue. Overall, we did 10 hospitals. They were from four different healthcare systems in five states. Four of those were VA hospitals, and 6 of them were non-VA hospitals.

Then the methods were very simple. We went to that facility and collected disinfectant as it was being dispensed from the dispensers. We went to at least 10 different dispensers in multiple wards in each facility and collected the fresh disinfect from the dispenser. At the same time, we went out to the wards and the carts where the EVS personnel were working and collected some from their buckets of disinfectant. We tested the level of disinfectant and the pH, which you can use to assess pH and the appropriateness of the disinfectant. These are both done with just very simple, inexpensive test strips. Then we also, at the same time we were doing this, asked, as we were rounding with the EVS folks if you were doing anything to monitor whether these dispensers were working correctly.

ICT: Was it that each of these hospitals had the same dispenser from the same company?

CD: Overall, we tested 3 different types of dispensers. So, one of the most common dispensers was quaternary ammonium products. Four of the hospitals use that type of dispenser. Five used a second type of dispenser, and then we had one that used a third, so 3 different types of dispensers. There are at least 4 companies that make these types of dispensers.

ICT: What were your key findings, and how did they impact our current body of knowledge? How do they contribute to it?

CD: The findings were that none of the 10 facilities had any routine monitoring program for these dispensers. Several of the facilities told us we thought the manufacturer was that the product was working, that It would the dispensers worked correctly, and that the manufacturer, when they came in and checked, was making sure that these were working correctly so they didn't have monitoring, routine monitoring in place, nine of the 10 hospitals had at least one dispenser that was not appropriately dispensing had too low of a concentration, and 8 of the 10 hospitals had at least 1 dispenser that we tested that was dispensing solution that had no detectable disinfectant in it. So, essentially, dispensing water.

The overall summary is in the visual abstract. So overall, 29 of 107 or 27% of dispensers had a lower-than-expected concentration. Of those, 29, 15—or 14%—of all the total dispensers were dispensing water.

Also, 1 of the types of products that we tested were peracetic acid and disinfectants, and in those 5 hospitals we tested, about half of those dispensers were dispensing product where the concentration was a bit higher was substantially higher than expected, which there is some potential risk with that type of disinfectant in terms of being having an elevated concentration so, and that there was a previously unpublished study.

Still, it's available online from National Institute for Occupational Safety and Health (NIOSH), where they found the same thing: some dispensers dispensed higher concentrations of that product than expected. So, our primary focus was not on whether the concentration was too high but on whether it was too low. But that's an additional issue, an issue to consider.

ICT: Did you take this information back to them, and what did they say?

CD: All the facilities were given feedback on their results. Some of the 4 facilities were VA hospitals. In addition to alerting the local facility, we alerted the national EVS program for the VA, and they put out a bulletin to all VA hospitals that this is something you should take upon yourself to monitor for our facility. We were one of the facilities. We developed a standard operating procedure where we asked the EVS personnel to check the strips to check the disinfectant concentration every time they put a new bottle of concentrate onto the device. Infection control would also do some additional spot testing. We put in a formal process to provide ongoing monitoring.

Then, we'll give that feedback regularly through our infection prevention committee. I left some of the findings out. Let me give you a couple more surprising things. In addition to the product directly from the dispensers, we also, as I mentioned, went around to environmental services carts to check the product. And so the overall findings were the same as you would expect if you were on those wards. And 34% of samples from the carts were too low; 18% had no detectable disinfectant. And of note, 4 out of the 80 disinfectant samples we tested on the EVS carts were the wrong product.

So, instead of using a disinfectant, they were using a nondisinfectant detergent product that was typically used as a floor cleaner as their product, and that is a separate issue that we also sought to address. In some ways, our impression was that it was potentially a design issue with the dispensers because if you look at the dispensers, there are 4 different concentrates in the dispenser system, and in our facility, we were finding that they were often not in the same place. So, someone worked on the fifth floor, and they knew the disinfectant was on the upper left, and they went down to the fourth floor, and it was on the lower right; they could get confused about where what they were getting out of the machine. So standardizing, in addition to testing levels, standardizing placement is important to avoid that type of situation as well.

The obvious question is, why are dispensers releasing no detectable disinfectant? What is going on?

The most common reason we identified was that the concentrate container was not appropriately connected to the system. Someone had put it in, but if you don't lodge it in there precisely right, there is a straw that goes down into the container and pulls the disinfectant up to mix with water. If you don't get it lodged in there set exactly correctly, you're not pulling up any disinfectant. That was the most common issue. We also identified 3 of these concentrates.

The second most common reason was that the top of the disinfectant concentrate had been damaged. In talking to people, it turned out that some of the EVS personnel thought that if they twisted this a certain way, it might dispense more product when [in fact] that damaged it, and it didn't dispense any product.

For one of the dispensers, you see a low product indicator on the dispensing system, and that indicator was not functioning correctly. So the actual system was not working correctly. But most of the issues here were people’s problems. They were not getting things lodged in there correctly or were confused about what they should do with those concentrates. These are the things that led us to our solution. Since many issues arise when adding a new container of concentrate to the machine, our solution is to use one of these test strips every time you add the concentrate, ensuring you have the correct disinfectant concentration.

ICT: It can't help but be good for the companies to know too that their product is difficult to use. If it must be in a certain like this minuscule movement spot, then that's something that they need to address because if you're dealing with many people, and you must teach each one of them how to do it correctly, then make it easier. Have another fail-safe if the light doesn't come on; have another light or a beat or something to show that the dispenser is not working. So, yes, it's a human thing, but it's also a machine thing that could make it easier to use.

CD: I agree. We came up with many considerations for how you might deal with this. One issue is that the color of one of these disinfectants is not distinct enough to distinguish it from basically water coming out. You can see some bubbles anytime because that product has some detergent. So, you might be fooled into thinking it has disinfectant; however, even if the product's color were an indicator, or if there were other ways to ensure that this device correctly concentrates containers.

We spoke with the VA, and 1 type of company made most companies aware. So, the VA has had discussions with all 3 of the manufacturers who provide these products for the VA, and they are doing in servicing. Our vendor looked at all our dispensers here in Cleveland [Ohio] VA. They are in the VA, and they're having a national call where all 3 vendors will participate and discuss what monitoring needs to be done to ensure their product is working. Exactly as you say, all the manufacturers want to make sure they're being used [correctly], that they're losing money if they're not dispensing or dispensing dilute product, obviously, right? We've made the manufacturers, at least those working with the VA, aware and informed the hospitals of the other dispensers.

ICT: Did you have pushback?

CD: There was no pushback—at least from hospitals. Our EVS program was right on it. When we told them there was a problem, they immediately worked with us to assemble an standard operating procedure and help fix it. The only issue is that people are busy and must make time to do this.

ICT: What are the key takeaways?

CD: The key takeaway is that hospitals are currently assuming that these dispensers are working and not doing adequate monitoring. The key issue here is that it's essential to have some system in place to monitor whether these dispensers are working correctly. In addition to that, as you said, there are ways to design the systems better so they're a bit more fail-safe. That would be ideal. And then, as you alluded to, facilities also need to work with the manufacturer to tell them and let them know that we have these issues so they can collaborate with infection prevention and environmental services to fix the problem.

The primary manufacturer we've dealt with has been on top of it. They're eager to ensure that this is taken care of so that people continue to use their products.