Along with many units we are examining our disinfection routines to see if there's a way to save energy, emissions and money. We use 5008H for which the manual states that a delay of up to 72hrs is acceptable.
We currently run three shifts a day and disinfect 4 times. This means disinfection is done approx 06.00 11.30, 17.00 and 23.30. I've considered removing the early morning disinfection routine and would be really interested to hear people's thoughts and experiences on the subject.
We do high vol HDF treatments and change ultrafilters as per OEM instructions.
We have different equipment but same manufacturer's guidance. We do not routinely disinfect each morning, just post each treatment in centre, as operational 6 days per week. Though 72 hours is acceptable we have always used 48 hours as guidance to users, though that is purely historical.
For home patients we also ask them to do an additional disinfection if they have a a two day break.
We have a mix of HDF, DF and standard HD equipment.
No start of day disinfections at Wolverhampton but they are carried out after each session. We also carryout a double disinfect from an isolated BBV machine is to be "de-isolated" and returned to general machine pool.
I'm old enough to remember when we used to store our HDF machines in a bacteriostatic low level peroxide solution overnight, and would internally disinfect after sitting idle for 4 hours. Changed days We stopped the automatic morning disinfect some years ago. I tried requesting the evidence FMC based the 72hrs on but didn't get anything back. I'm sure they would have to validate this before stating in the manual.
We set our machines for an automatic thermal cycle mid morning so that any machines not in use will be disinfected daily and be ready for use, and not left to stagnate in a run up bay or plant room.
We did some fluid testing a long time ago as we often had equipment in storage. It was more an 'out of interest' check as opposed to something more scientific. I've searched our equipment data base but cannot find any reference to it. Our manufacturer also states 72 hours and I remember the results being fine at least a few days past this. When limits were exceeded, a single disinfection brought results back in. As I say, not very scientific and did not account for any variation in storage conditions e.g. temperature, light etc
The morning disinfection was dropped in Manchester some years ago saving in water, energy and disinfectant. We also made sure HHD didn’t do a pre dialysis disinfection.
The 72 hour break mentioned in the manual for the FMC machines refers to a safety measure for the disinfectant valves as opposed to any kind of microbiological reasons. That was my interpretation anyway. We had machines in Manchester in storage for months and never had any problems. At the end of the day if you’re feeding a machine with pure water then growth should be a minimum if at all?
"General label information according the Fresenius dialysis machines Instructions For Use (IFU), e.g, 6008 Haemodialysis Systems, provides the following information:
• Intended purpose: The device is used for the extracorporeal blood treatment of patients suffering from renal insufficiency.
• Information about disinfection after downtime: Risk of poisoning as a result of disinfectants in the dialysate. In the event of defective components, disinfectant fluid can enter the device during longer downtimes. The next treatment will then pose a risk of injury for the patient. After a downtime of more than 72 hours, the device must be disinfected before a treatment.
The validation testing determines the adequacy of the disinfection by measuring microbial count and endotoxin levels to prove that the dialysis machine provides sterile, non-pyrogenic dialysis- and/or substitution-fluid according to ISO 23500 (1). In our analyses 72 hours have been validated and were proven to be safe. The 72-hour time frame has been chosen according to practical considerations, since 72 hours may include the weekend plus possibly another day e.g., Friday. It was found to be an adequate compromise between ensuring safety and accommodating practical needs.
The information given above is the same for the three Haemodialysis Systems, the 5008S, 5008 and the 6008"
72hrs would seem to be a combination of safety precaution in the event of chemical valve failure and a validated period where the machine can still produce online infusion fluid. It's possible that a longer period in between disinfection would still be OK but they've chosen the 72hr timeframe for practicality.