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Subsequent to the events at QE Birmingham the topic of measuring chlorine (and for the sake of simplicity this includes chloramines and chlorine dioxide) was brought up at a the most recent Patient Safety Committee conference call on 5th Feb 2015. We wish to review the guidelines issued from RA/ART regarding monitoring of these products. I would strongly argue that the very minimum interval for monitoring chlorine should be daily prior to the first dialysis session, using two methods. I would like any interested party to comment so that I can collate the comments and then we can discuss how to go forward with this, even if the consensus is that weekly monitoring is enough for ART to reccommend. Comments please!
Gerry
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Hi Gerry,
At King's we measure daily using a DPD chlorometer at all sites with the nurses/HCA doing it at the satellites. The home patients test before each session using the Serim test strips. A recent exception to this is we have now set up two home HD style installations in the clinical trial building and the nurses test with the Serim strips. We always try to get the water supply direct from the municipal feed, but this is not always possible.
I know the recent Birmigham incident involved chlorine dioxide and single patient RO’s. One concern I have about chlorine dioxide is how sensitive the standard DPD test and Serim strips are to this?
I also think the incident occurred away from the main unit, hence the single patient RO’s so testing is less likely to happen.
Ian
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Hi,
We have always preferred to go over the top on reducution rather than testing.
The Serim test strips are OK but I am unsure of their consistency. DPD chlorometers are very dependent on good technique. There have been issues with Chlorosense - although they seem OK now and are my preferred method.
In units we have 2 GACs in series giving a minimum of 10 minutes EBCT. Over the years the first column has reduced incoming levels to ~zero on it's own, so sampling after the first column 1-3 times a week will indicate when breakthrough is beginning and the second column will protect until the GAC is changed. Anecdotally I would suggest that performance tends to drop off rather than suddenly change.
At home we fit 2x 20" carbons blocks in series, changed 6 monthly - which is vastly more than has been shown to be needed even with patients dialysing 6 days a week. We only test on 6 monthly visits but have never seen any sign of breakthrough. Even so we are ugrading to the latest CFB-Plus type which have even greater capacity. Looking at our results I think testing more frequently would be a waste of staff (or patient) time.
Chris
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Like Chris we overspecify on reduction, it would be good to get an agreement and recommendation on what that specification should ie what level of redundant chlorine reduction capacity should be in place to cope with unexpected increases. We use a single 10" chloramine grade filter at home changed monthly, which is probably twice or three times more frequent than we need to for our incoming levels, but it is affordable and gives me piece of mind that should we have a spike in the level there would be sufficient capacity within the filter to cope. It all depends on how high that raw water level is. Our water companies say that it would never be higher than an average of 0.5 but there is no upper limit.
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This post was updated on .
The guidelines suggest daily and I believe that to be acceptable. We could possibly argue for the ideal of live monitoring as I guess the majority of cases of chlorine breakthrough are not the result of gradual exhaustion of the media but more often the result of an unexpected spike in the raw water (RW).
Should we also monitor RW chlorine levels daily (some may already be doing this) as opposed to just post carbon and/or final product water? It would be easier to spot an uncharacteristic rise in RW chlorine levels ahead of one in the daily/weekly monitoring of a gradually increasing post carbon level.
Maybe common sense but some guidance on sampling technique could be useful. eg Not much point is sampling post carbon, 1st thing in the morning before there is any draw on the system. Likewise for single patient RO systems - sample with the dialysis machine running so results are representative of the expected contact time.
We use the DPD method weekly and I was of the understanding that, with the total chlorine test, this would show the total chlorine from both free, chloramines and chlorine dioxide. Is this correct? For the remaining treatment days, and with home patients, serim test strips are used.
Regarding the QE incident I think it would be really beneficial to us if we could get an idea of the RW levels experienced, type and age of filtration used and flow rates that resulted in the published treated water chlorine levels. It's clear that we all use different levels of carbon filtration, especially out at the home where monitoring maybe reduced. I think the QE incident could provide a good reference point to work with if we had the data.
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Administrator
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Going ever so slightly off topic perhaps we should be putting across a standard for carbon filtration in a home installation?
Insisting on 20" rather than 10", block rather than impregnated for example.
There appears to be lots of different methods around at the moment and I think it would benefit all if there was one standard that was a minimum. If you wanted to further exceed this by using a cylinder for example then that would be the individual's choice.
Ian Wilde
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Hi Chris,
I agree that spec'ing the chlorine reduction system is most important. That cannot legislate for human or technical failure though. And only frequent testing will pick that up. I have to disagree that it would be a waste of time. If we are to examine in detail the various failures over the years that have led to patients over exposure to disinfectant chemicals I wonder if the majority are due to human failure. I cannot see how you can legislate for that by spec of carbon filtration, only by having a reasonable level of carbon in association with appropriate testing.
I'd go for belts and braces.
Regards,
Gerry Gerard Boyle Section Manager Renal Services Dumfries & Galloway Royal Inf. Tel : 01387 246246 ext 31660 On 20 Feb 2015, at 11:32, Chris Bates [via ART Forum] < [hidden email]> wrote:
Hi,
We have always preferred to go over the top on reducution rather than testing.
The Serim test strips are OK but I am unsure of their consistency. DPD chlorometers are very dependent on good technique. There have been issues with Chlorosense - although they seem OK now and are my preferred method.
In units we have 2 GACs in series giving a minimum of 10 minutes EBCT. Over the years the first column has reduced incoming levels to ~zero on it's own, so sampling after the first column 1-3 times a week will indicate when breakthrough is beginning and the second column will protect until the GAC is changed. Anecdotally I would suggest that performance tends to drop off rather than suddenly change.
At home we fit 2x 20" carbons blocks in series, changed 6 monthly - which is vastly more than has been shown to be needed even with patients dialysing 6 days a week. We only test on 6 monthly visits but have never seen any sign of breakthrough. Even so we are ugrading to the latest CFB-Plus type which have even greater capacity. Looking at our results I think testing more frequently would be a waste of staff (or patient) time.
Chris
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Administrator
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For those who have non technical staff measuring the chlorine, at what point are the staff taking the measurement - from a machine drain during function checks at the start of the shift or something different?
Our water plant is 3 floors away from the main unit so popping into the plant room is not an option. Has anyone had specific sample points on the ward fitted for such testing? Perhaps this should be something considered when anyone has a new ring main installed?
What about those who have home patients testing - what is the technique for that sample?
Ian Wilde
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Our nurse use a loop run off point at our main unit, the satellite's have access to plant room run off points. Our home patients use septum ports on the product water pipework. Hospital staff take a daily reading which is meant to be prior to the first patient shift., home patients are less frequent. All use colourimeters.
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Administrator
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It appears to me that the water from the utility companies is not the danger but our own local estates and facilities teams. This is where I think we need to improve communication.
Playing devil's advocate, If you sampled at the start of a dialysis and it was fine, within 30 minutes the reading could be off the scale if the estates team have been dosing without letting people know which makes me question the validity of any sample taken? The patients have still been exposed in my made up scenario.
Preventing anyone introducing chemicals into the water without communication would be better along with a carbon setup fit to take out regular municipal supply limits in the 1 - 3 ppm range?
It would also be nice to get the details of any incidents that have taken place before any knee jerk reactions are made. We need all the facts to be able to make an informed decision surely?
Ian Wilde
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our staff test on a daily basis but it's more for trending purposes than an effort to protect patients from the type of incidents that have been reported. Maybe the guidelines should recommend online chlorine monitoring for areas where third parties are involved in the water supply? along with recommendations that renal techs should liaise with these third parties to ensure policies are in place for notification/alternative supply if local dosing is required?
Can anyone currently using these automatic monitors tell me what their sample rate is set to?
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The thing about trends is that it is valid until you include the possibility of human or technical error and then the trend data is less valid.
I agree that any of the recent problems have been due to agents out with renal and not from the water supply companies. Maybe continual measurement is the way forward but is that reliable enough, or will we just swap one set of risks and problems for another different set. Gerard Boyle Section Manager Renal Services Dumfries & Galloway Royal Inf. Tel : 01387 246246 ext 31660 On 13 Mar 2015, at 09:07, fraser gilmour [via ART Forum] < [hidden email]> wrote:
our staff test on a daily basis but it's more for trending purposes than an effort to protect patients from the type of incidents that have been reported. Maybe the guidelines should recommend online chlorine monitoring for areas where third parties are involved in the water supply? along with recommendations that renal techs should liaise with these third parties to ensure policies are in place for notification/alternative supply if local dosing is required?
Can anyone currently using these automatic monitors tell me what their sample rate is set to?
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Reviving an old thread, please help me from losing my mind! I cannot find any reference in current renal documents that refers to the recommendation of minimum of 10 minute EBCT. Please point me in the correct direction
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Administrator
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Hi Garry, I'm 99% sure it doesn't exist. Happy to be corrected though. All that matters is that chlorine level post carbon is below 0.1 and even then the RO will take some out after that although the membrane won't like it. I have a formula somewhere that companies use to decide on the vessel size so I'll try and dig it out for you tomorrow. I'm pretty sure a 10 or 20" filter in a home environment won't have a 10 minute ebct.
Ian Wilde
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This post was updated on .
Yes I've always wondered about the magic that goes on in the 20" carbon filters. They seem to work well regardless of contact time.
Thank you for putting my mind at rest regarding renal recommendation. All of our main plants are specified to at least 10 min so all is fine. I was about to quote the 10 EBCT to our estates but luckily I checked before quoting something that doesn't exist (specifically for renal at least). Edit: see update further along the thread on page 2
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Administrator
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If in the market to replace then just get the biggest you can fit/afford :-)
Ian Wilde
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Thanks for that link Chris, an interesting read and added to our library of documents.
This also answered another question for me, that being 'what exactly is a chloramine'?. I'd been a bit confused with recent literature referring to free chlorine and chloramines instead of free chlorine and total chlorine from the old days! My initial (mis)understanding of a chloramine was that it only included chlorine bound to ammonia. The explanation for organic chloramine, and a bit of further literature searching, has now clarified this.
I assume not all combined chlorine is chloramine but it is correct to assume a proportion of that contained within feed water will be depending on organic content?
Maybe a topic for another thread or an ART presentation from somebody in the know?
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On the topic of online monitoring, I spoke to the Kuntze guy at ART this year - he is a Kuntze and his sister is the chemical engineer for the company too.
Their device seemed quite different to all the others I have seen. I particularly liked the online live and historical data access through an app for a yearly fee. I believe it could send alerts automatically but am not sure.
Not sure how affordable it would be but I was impressed. www.kuntze.com
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