Dialysis machines are able to disinfect their own flow path from their inlet solenoid valves right to the drain. Water systems are also periodically disinfected by the techs. There is one portion of the dialysis fluid system that is sometimes overlooked, or may receive disinfection less often than it should. That is the hose that runs between the dialysis machine and the water supply port. In our unit, when we disinfect our loop we turn each machine on for a short time to get some disinfectant into the water line, let it dwell and then rinse everything. This prolongs the water system disinfection process, and adds considerable work, especially as we have to shuffle in and out the spare machines in order to clean every line. The water feed line actually has much more opportunity for bacterial growth (because it is open to the environment more often, and also has no flow more often) than the water system loop and probably should be disinfected more often than the water system loop. It is just not easy and convenient on most machines.

One efficient and somewhat convenient way to disinfect the water line would be to add a port to the dialysis machine that would accept the water inlet connection. (In our unit we have replaced all the garden hose water fittings with quick connects.) During the appropriate portion of the disinfect cycle the machine can prompt the operator to place the water line on the appropriate port to allow a proper end to end disinfection. This could be easily done by the manufacturer on most machines with built in heat disinfection systems, but it would require another operator intervention, and we all know the cost of labour...

Machines using only chemical disinfection may require more modification, as they will probably need a reservoir to hold a quantity of rinse water in order to pre-rinse the water line up to the inlet solenoid valve before connecting it back to the water system. This would guarantee no reflux of chemical into the water line. Then of course you have to look after cleaning that reservoir �

If the inlet water line were to be fitted with a resistance element wrapped around it, and a layer of insulation around that, then the machine could preheat the inlet waterline in order to disinfect the line during the disinfection procedure. The machine could draw water in at a very slow rate and monitor the temperature with the inlet temperature sensor. This would guarantee no hot water going back into the water system. This method would be totally automatic and require no user intervention during the cycle. The inlet line could probably be heat cleaned with this system even if you prefer chemical disinfection for the rest of the machine.

I have seen information on some of the new water systems from Europe that incorporate heat disinfection of the water system with concurrent heat disinfection of the machines on a nightly basis, and I am sure that all things considered, that is the ultimate way to go. However, I believe my idea would be a good solution for units that cannot replace their entire water systems at this time.

It is heartening to learn that someone else realizes the extent of the problem posed by the water inlet hose of the dialysis machine. For years I have exhorted customers to flow the chemical circulated during water system disinfection through all the dialysis machines as well. This suggestion has often met hostile resistance or the retort that the dialysis machine manufacturer has not recommended it.

A bacterial slime, even algae, can be expected to grow on the inlet hose of the dialysis machine unless it is disinfected. If this hose has been disconnected since its last disinfection, it can be expected to be colonized that much faster. The dialysate drain water may still be less than 2000 cfu/ml, but the dialyser will be receiving an endotoxin load.

Equipping the dialysis machine itself with some extra heater or outlet port to connect to the water inlet hose would not necessarily be a solution. Every station outlet on the purified water loop should have disinfectant exposure and subsequent rinsing. If the dialysis machine is not connected to the outlet then some dummy piece to drain or a bucket must be connected to the outlet. It seems easier just to leave the machine connected.

The fear that a disinfectant such as the 1% Renalin or Peracidin disinfectant typically used for water systems might destroy the elastomers and other materials in the dialysis machine is misplaced. If the disinfection soak period is on the order of an hour after which it is rinsed, even Buna N rubber will give long service.

Water system distribution loops that can be disinfected separately from the upstream RO can be disinfected with safe, cheap, and effective bleach. I fail to see the overall advantage of heat or ozone.

I have storage tanks and ozone in one of my unit's water system. The system is almost foolproof, costs only a cents a day, partially sterilizes the incoming water line to the machine, NO LABOR COST!!!! I have drawn in ozonated water into the machines periodically to ensure that the entire water system is sanitized.

You know worst case senario could a guy just use a small tank or bucket of water to disinfect the spare machines if the spares were in a closet with no fitting to connect the inlet to the plumbing system? By putting the inlet hose into a bucket of bleach water? This way you wouldnt have to swap out the spare machines and would still get your inlets disinfected on all the machines....just a thought.

And after putting the inlet in the bucket/small tank, just run the machine through a rinse mode while the inlet is still in the bucket, so that you vaccum up the bleach water in the bucket.

You need adequate water pressure to allow the machine to pull up bleach water from a bucket. I use a small pump I got from Mar-Cor. I pull up 2 gallons of 10% bleach water to disinfect the incoming water lines. It works great.

About a year and a half ago we built a new dialysis clinic and installed a Gambro heat disinfectable RO system. The RO can auto heat disinfect the RO membranes as well as the entire pure water distribution loop. It cannot do these two functions at the same time so three nights a week we disinfect the membranes and the other four nights we disinfect the loop. This is all auto programmed and occurs in the wee hours of the morning. Two nights a week we program all of the dialysis machines to come on and perform a rinse while the distribution loop is disinfecting with hot water. No person needs to be there. We have been doing this since day 1 and have nothing but excellent bacteria and endotoxin results from our testing of machines and RO product. The machine incoming water lines look like new after a year and a half. System was very expensive but so far it's performance has been top notch.

Speaking strictly about incoming water lines to the dialysis machine, why not simply replace the tubing periodically?
My cost is only $0.37 per foot. You could get it cheaper with bulk orders.

For what it's worth, - we have only been disinfecting the in-coming hose on our machine monthly during the loop disinfection as well, -and we have been doing this for years now, but we've never have had any problems with machine cultures. We do have Fresenius machines with diasafe filters, -but then again, - we didn't have any dialysate culture problems before having the diasafe filters either. What kind of machines do you have and are you in fact having bad dialysate cultures???? .....and are you having bad water culture problems also????

Keep in mind that this is another 8 year old post that has become active again.

quote:

Posted 12 September 2008 09:11 AM Hide Post
About a year and a half ago we built a new dialysis clinic and installed a Gambro heat disinfectable RO system. The RO can auto heat disinfect the RO membranes as well as the entire pure water distribution loop. It cannot do these two functions at the same time so three nights a week we disinfect the membranes and the other four nights we disinfect the loop. This is all auto programmed and occurs in the wee hours of the morning. Two nights a week we program all of the dialysis machines to come on and perform a rinse while the distribution loop is disinfecting with hot water. No person needs to be there. We have been doing this since day 1 and have nothing but excellent bacteria and endotoxin results from our testing of machines and RO product. The machine incoming water lines look like new after a year and a half. System was very expensive but so far it's performance has been top notch

FYI: the CWP does not heat disinfect your membranes, just the loop. Membranes are done on your weekly chemical disnfect.
I have them too, and never have had microbiological issues in the 8 yrs I've worked on them. Plus no monthly 4 + hr disinfect for me to do

Hi, FYI, at least in Europe, there is a Gambro CWP version fully heat disinfectable, including the membranes.

quote:

Originally posted by Ktech:
Keep in mind that this is another 8 year old post that has become active again.

I wonder what became of Clarence?

I love the CWP in Europe that heat disinfects the whole shabang !!! Long story...but our reg authorities do not allow it here...
CAN YOU SAY...INTEGRATED HEAT DISINFECT FOR THE U.S. CWP SYSTEMS....Any one using this process ??
It would hit those incoming water lines nightly..I do not know anyone that uses this option.....do you?

I have three clinics with 5 CWP units out here in Northern California and none are integrated. We did try initially, but when used with Phoenix machines there are a lot of problems with hoses blowing off the hydraulics. I must say that even though the incomming water lines to the machines don't get disinfected I have never had a culture above 10 cfu's in the last 5 years.