What is the opinion of the group of testing dialysis water for endotoxin levels as well as CFU's? Does testing for endotoxins give us any, clinically relevant, additional information?

Thank you for your help!

Edotoxins are the lipid portion of gram negative bacteria cell walls. They are produced when bacteria reproduce and when they die.

Endotoxins levels above 5EU/ml or 5 endotoxin forming units per ml are outside of the AMMI and CSA standards. Edotoxins can cause febrile reactions even if no live bacteria are present.

With the latest edition of AAMI Standards, we are required to do endotoxin testing as well as bacterial testing. Where formerly, we only had to look @ endotoxin in water for reuse, we now need to monitor endotoxin in water used to prepare dialysate or concentrates from powder or to reprocess dilayzers for multiple use. Current AAMI Standards include a limit of 2 EU (Endotoxin Units)/mL and an action level of 1 EU.

"Of the two factors (bacteria and endotoxin) for which maximum allowable concentrations are established by AAMI (1992), it is our opinion that the standard for allowable endotoxin contamination is the most important."
- Lee Bland
AAMI Standards & Recommended Practices
1996 edition

Two items which go into my (same) opinion about this are:
1) Endotoxin = pyrogen! Our patients can & do have pyrogenic reactions due to endotoxin in the water or dialysate.

2) Bacteria can hide in biofilm, and remain undetectable by Colony Count ..... All living things slough ..... endotoxin is the by-product of bacterial cell sloughing (living as well as dead bacteria create endotoxin). You will see endotoxin in the sample before you would see a significant CFU in the colony count from the same sample.

I hope this is helpful! If you need additional information, please feel free to e-mail me, or call me @ Isopure; 1-800-280-PURE(7873). You may also use my direct line; 440-946-0540.

Good Luck!

Thanks for your quick replies! The info is really useful. I keep getting conflicting opinions about endotoxin testing. Thanks, I may well be picking your brains again!
Kind Regards
Andrea

Sandie: That was a comprehensive reply!
Well said! I hope you don't mind if I keep your reply for future use. I have never heard it said quite so succinctly before.....

Cheers NOVA,

Nova;
Thanks for your kind words!
Please keep for your future reference .... and don't hesitate to call any time you would like information ..... I don't always know things, but I usually know where to find the answers!

Take care!
Sandie

On wednesday of last week, I took a water sample for a LAL test. It came back >2EU/mL, so I performed a disinfect with minncare that evening. Another test on thursday showed NO endotoxin units. I decided to take another sample on Friday, (from a different supply site) and once again it was >2EU/mL. I'm scratching my head here thinking that it must have been just a contaminated sample bottle. Still, I disinfected again over the weekend.
Any other ideas out there.

Thanks
Darren McKinnon, CET
River Valley Health

To help clarify:
Sample container MUST be sterile to be effective, and a very clean technique is also a priority here. Many people disinfect the port immediately prior to drawing the sample, or contaminate the container when drawing the sample.
Endotoxin is the byproduct of bacteria, living as well as dead ..... completing a disinfect procedure with any chemical disinfectant can create endotoxin, so RINSING is the key here. A full & complete rinse following disinfection is essential, lest we cause more problems than we prevent! MinnCare is an excellent product for disinfection, and can be effective in fighting biofilm as well. Lengthening dwell time can help break down any biofilm in the system, but often temporarily increases the amount of endotoxin circulating with the water. Proper rinsing will run the endotoxin down the drain. Please check with your lab for their recommended procedure for drawing the sample, or call me any time @ 440-946-0540. You may also leave a message for me @ Isopure, 1-800-280-7873.

Good Luck!

Sandie Monsman
Isopure; Manufacturers of Advanced Purification Technologies

[This message has been edited by Sandie Monsman (edited 06-17-2002).]

Is it true that home patients who have well water have to use RO's instead of DI's. Our center says anyone with a well has to use an
RO. I heard another unit says anyone with well water has to use DI's. Which is correct
and the reasoning behind it?

quote:

Originally posted by Water Question:
Is it true that home patients who have well water have to use RO's instead of DI's. Our center says anyone with a well has to use an
RO. I heard another unit says anyone with well water has to use DI's. Which is correct
and the reasoning behind it?

Our home patients who have had wells have used DI systems. The reasons being:

1. A RO machine will use in the vicinity of 1 gallon each minute whereas a DI system only uses what the dialysis machine needs, there is no waste. For a 4 hr tx a RO will use 240 gallons as opposed to a DI using 50 gallons.

2. A DI system will typically produce a better quality of water (chemically). Since private wells are not monitored for EPA compliance, a DI system is the prudent choice.

A RO system has the added benefit of being able to "filter" out virtually all bacteria that may be present in the water (providing the membrane and seals are intact and there is no grow-through). DI systems on the other hand are fertile breeding grounds for bacteria and must be followed by an ultra-filter.


[This message has been edited by Chuck W (edited 07-12-2002).]

To add to what Chuck had to say .....

1. Water usage is generally the reason home patients would use DI rather than RO; particularly when a cistern is used for waste water & must be periodically pumped out .... higher usage (RO) requires significantly more water in the first place, and also more frequent draining & removal which can become very costly.

2. In my experience in providing all forms of water treatment equipment nationwide, I have found that product water quality, with current equipment available, is generally not an issue in choosing one method of treatment over the other ..... both provide AAMI quality water, or the patient would be unable to use them. The issue is often with the quality and particular contaminants found in the feed water. While DI systems and ROs will provide AAMI quality water, in situations where highly contaminated feed water is present, DI tanks will exhaust more quickly and can be extremely expensive to exchange very frequently.

3. RO systems not only "filter" out (reject)bacteria, the RO can be fully cleaned and/or disinfected prior to use. DI systems cannot be disinfected. Particularly in low usage situations, my recommendation is to go with an RO whenever possible. We know that stagnant water (especially warm stagnant water) promotes bacterial proliferation. We know that especially in home care situations, the equipment is sitting stagnant more hours than it is in use; and the water flow rates for single patient use is fairly low. Especially in the event of patient vacations or hospitalizations, the normal "down" time may be greatly extended. ROs may be packed with membrane preservatives which inhibit growth, and may easily be disinfected and rinsed immediately prior to use. In a DI system, the patient would need an exchange from the supplier prior to resuming dialysis at home.

While both systems are acceptable, I always prefer the RO to the DI system unless, as stated, the cost to the patient of providing water and removing waste water would be prohibitive. I find that most facilities make these choices based on economics- hopefully, with both the facility AND the patient's interests in mind. Whether a system comes from the capitol budget or the operating budget makes a huge difference. A DI system will cost more to the facility in the long run, but an RO has a higher initial cash outlay. Staffing may also figure in to the decision, as DI systems require very little maintenance where RO systems require some amount of staff time to maintain.

I hope the information is helpful & that the patients are part of the (informed) decision-making process when determining what equipment is best for that patient's particular situation.

Please call any time you have a question or problem; I'm always available to assist in any way that I can!

Sandie Monsman
Isopure
800-280-7873 Corp. office
440-946-0540 direct line

I think the case for ever using DI instead of RO is very weak. The lower ionic content of DI water is meaningless since the acid and bicarb solutions are proportioned into the water to make dialysate. DI should never be used without an ultrafilter following it. An ultraviolet light and/or a 0.2 micron filter do nothing to stop pyrogens.

DI is also dangerous because of resin exhaustion. The deaths in Chicago a few years ago were from running a DI column past exhaustion and it then dumped high flouride concentrations into the dialysate. DI should never be used in a critical application like dialysis without proper resisitivity monitoring.

The amount of water needed by an RO can be significantly less than the 1 gallon per minute stated. On our Model PA2000, the reject flow rate (with the flush valve closed) is 1400 ml/min. Assuming the dialysis machine is using 700 ml/min, the total flow rate is 2100 ml/min. This is 0.56 gallons per minute. It also represents a recovery of just 33%. An even higher recovery and less water use would be reasonable if the feed water was soft and otherwise non-fouling.

There wouldn't be much flouride in well water, though, would there?

Usually, there would not be much fluoride in well water .... but it can be there. The significance of fluoride in the incident mentioned is that fluoride is the FIRST thing to slip through .. the first thing to be noticed ... fluoride is often used as an indicator in testing equipment, and in planning for expected "load" on membranes or resin.

In response to Stephen's comment, "DI should never be used in a critical application like dialysis without proper resisitivity monitoring." I agree 1000%; it is the responsibility of the supplier to assure that any system installed has proper monitoring, the responsibility of the base facility to train the patient and/or caregiver as to the importance of monitoring quality. One of the reasons I dislike DI systems for home patients is that the tanks are usually NOT kept near the patient, and when a quality indicator changes, the possibility that the patient will continue to run is high. Even if the tanks are kept close enough, especially with nightly nocturnal programs, no one in the home is awake to monitor quality during the treatment. Many home systems also do not follow the worker/polisher method which offers some protection as well. Most DI systems for the home have no capacity to divert poor quality water to drain, and no audible alarm. Adding everything up, I feel that while DI can and does provide adequate water for dialysis, RO systems are safer in the home.

Sandie,

Aren't the bypass and audible alarms required for 510K approval? The DI systems that we have had all had them.