Foaming machine drains.

[John Moore]

We've recently opened an expanded satelite unit on our County hospital, Stafford, site. We are using Nikkiso DBB-05 and FMC 4008S machines. All of the Nikkiso machine drains exhibit the foaming shown in the attached photos but only in treatment. The FMC maxchines do not have any sign of foaming and equally the Nikkisos only have it in treatment i.e. NOT in clean/rinse/preparation etc. Anyone have any bright ideas??

[Ian Wilde]

Hi John,

We have this with some of our 4008 and 5008 machines too.
Is it not linked to specific patients?

Ian

[Chris Pearson]

Hi John,
May be a daft question BUT do you keep the machines in exactly the same positions or are they moved from station to station e.g. could it be the actual drain at the station or does the foaming change if you swap machines at a particular station?
If it is definitely specifically machine related i.e. foaming stops or starts if you change machine type do you use the same disinfection/decalcification chemicals on each type of machine ie. could it be post dialyser bio-film build up in the Nikkiso's drain lines ?
BR
Chris

[Chris Bates]

Hi all,
We have seen this for years at various units. There is another thread discussing this already with no real conclusions.

We have had real problems at home patients when they have pumped waste using a saniflow type pump. They were getting badly blocked with the usual aromatic (!) white gel. We cleaned out the pump boxes and got the patients to do a weekly sporotal clean which we weren't doing before. The waste pumps remained much cleaner for quite a while after this.

I suspect the proteins or fats or whatever cause the gel build up are the cause of the foaming too and I wonder if units doing weekly bleach cleans see this problem less ?
Chris

[Chris Pearson]

Hi Chris,
I too think the cause is a lack of a cold chemical clean cycles,I think the heat sanitise using various  acids relies too much on the heat to be effective and perhaps by the time it gets down to the drain line its not even hot enough to pasturise and break down the patient by-products which slough off into the drain break tank during dialysis mode.

[Ian Morgan]

John,
While I have seen this problem with many machine types, one reason why you might see this with the Nikkiso and not the 4008 is the difference in instantaneous flow. The 4008 with it's balance chamber will have a near constant flow down the drain with only a very brief interruption when the valve change over. The Nikkiso with it's duplex pump has very intermittent flow every time the duplex pump cycles. So the flow rate when the pump discharges to drain will be higher than the average dialysate flow rate. This higher flow rate is probably creating the bubbles that generate the foam.

[Chris Pearson]

Hi Ian,
I don't think it is machine related because others are experiencing exactly the same symptoms on Baxter-Gambro machines and both 4008s and 5008's.
Another issue raised again last week is shelf life of bleach with a unit expecting a 5L can to last 3 years on the back of a machine,could it be the use of only 30ml's per week ?

[John Moore]

Hi all. Both the Nikkiso and Fresenius machines are hot sanitized using citric acid solutions between every treatment. I don't think the problem is related to the lack of a hypochlorite clean as it has been present right from day one (the unit only opened at the start of December 2015). The machines are routinely moved between stations as required and the problem goes with the (Nikkiso) machine. We are starting to see more of the yellowish colouring you can see in one of the photos. Not entirely convinced by Ian's flow theory - both Nikkiso and FMC machines have a similar pulsatile flow at the drain and the 4008S are running silmilar high (800 ml/min) flows in treatment which is the only time you see the problem!

[Chris Bates]

Hi again,
I think Ian may have a point in that the Nikkiso has a duplex pump which has a 50% duty cycle so the pressure and flow peaks will be higher than a balance chamber which more or less 100% duty cycle with brief dips at the chamber switches.
That said we have quite bad foaming at one of our units which has only ever had 5008s.
Chris

[Chris Pearson]

That's blown my theory then,wonder how many more  units are experiencing this same issue but not reporting it ?
It would be nice to build up a bigger picture with other machines,cleaning protocols and drain designs.

[Garry]

Is there any form of retractable collar on the drain outlets, I can't make it out from the photographs?

[John Moore]

No, no collar. The drain (stainless) outlet just drops straight to the hloe in the bottom of the panel. You can adjust the distance from the end of the drain (stainless) tube to the hole below but it doesn't make any difference.

[Garry]

Ok, that idea out of the window then!

We had similar at one of our units and raising the collar slightly gave a marked improvement.  We thought it may have been to do with either the distance or the fact that air was being drawn in around the collar and aerating the fluid.  I'm sure drain restriction also plays a part, either one that is inherent in the drain design, or one that occurs following build up of deposits.

[John Moore]

Update to foaming drain problem. Purite have supplied an extension pipe to bring the end of the drain closer to the fluid level in the trap, this seems to work. Purite are in the process of manufacturing and supplying a more permanent stainless steel fitting for all of the media panels. Will keep you posted.

[peter jones]

Hi John,
sorry have only glanced at the other comments.
We have had the same issue at Leeds, it appears to be a combination of the height of the drop, cleaning of the drain and the patient.
We have used Health tec's drain cleaning fluid but not as directed. Put a large claibrated 'glug' in each drain when nothing is running and left it from saturady night to monday morning. To this day approx 12 months ago the the foam has not returned.
However, At huddersfield we have one particluar drain which is still foaming and now we are moving on to a haz tab on a weekend this is still under review at the moment.
hope this helps?

[Lindsay]

Hi All,
We have had this problem here at Southmead in our new build since start-up.
We have came up with a solution - not perfect but it works.

We introduced a 'bung' with a tube into the drain. As has been noted above it sems to be partially due to the dropin the drain causing the 'foam'

If you would like to discuss I would be happy to expand on this.

For the record, we are using Nikkiso DBB-05 / 06 and 07 machines here.

We do not now see the problem(?)