Dialysate Running Out Before Meeting UF Goal

[PrimeTimer]

Never ran out of dialysate on the old cycler but sometimes do on the new "S" cycler. Thought it may have something to do with the Flow Fraction setting (hence, the reason for my thread about Flow Fraction changes) but maybe not... By the way, for those who may not know it, the new "S" cycler can be used (if needed/wanted) for higher rates/volumes but we still use the lower rates/volumes, which is ok with the Neph and it's also ok with NxStage so long as we use the right 400 series SAK's (bags are not to be used at the higher rates/volumes on the S cycler). My husband is getting just as good of labs with the new cycler as he was with the older version, so everything is ok there. For the most part, all is going well. The only thing the Neph had him change was the Flow Fraction. Went from a 40 to a 44. We use a chart dated from 2008 titled "NxStage (SAMPLE) Setting the Ultrafiltration Rate" to calculate what UF rate to use according to how much fluid my husband needs to remove and length of treatment time (almost always 3:30 hour treatments). Seems more often than not tho, that the dialysate meets it's volume goal before the UF goal is met. I have been making my own chart to figure out what Dialysate and UF rates work best together, meaning to "zero out" at the same time or as close together as possible but all this guesswork sort of takes the fun out of treatment (ha ha, joke and a bad one at that!).

Aside from calling NxStage, have any of you had this problem and what did you do to resolve it? Was it a matter of a System Setting? The Flow Fraction setting? Bad luck? A loose nut behind the wheel? I will probably be giving NxStage a call but don't think they have a new chart to go with the new "S" cycler (our nurse said they don't) but if they do, I wouldn't be surprised it's for higher rates/volumes and well, that's not going to help our situation. Thanks in advance for all who can give their input on this.

[Hemodoc]

You could simply go back to 40%FF and have your old numbers you were comfortable with. Or, increase the UF slightly by about 10% since you increased the FF by 10%. If everything else is the same, you should get back to a regular  session as before.

[obsidianom]

Never ran out of dialysate on the old cycler but sometimes do on the new "S" cycler. Thought it may have something to do with the Flow Fraction setting (hence, the reason for my thread about Flow Fraction changes) but maybe not... By the way, for those who may not know it, the new "S" cycler can be used (if needed/wanted) for higher rates/volumes but we still use the lower rates/volumes, which is ok with the Neph and it's also ok with NxStage so long as we use the right 400 series SAK's (bags are not to be used at the higher rates/volumes on the S cycler). My husband is getting just as good of labs with the new cycler as he was with the older version, so everything is ok there. For the most part, all is going well. The only thing the Neph had him change was the Flow Fraction. Went from a 40 to a 44. We use a chart dated from 2008 titled "NxStage (SAMPLE) Setting the Ultrafiltration Rate" to calculate what UF rate to use according to how much fluid my husband needs to remove and length of treatment time (almost always 3:30 hour treatments). Seems more often than not tho, that the dialysate meets it's volume goal before the UF goal is met. I have been making my own chart to figure out what Dialysate and UF rates work best together, meaning to "zero out" at the same time or as close together as possible but all this guesswork sort of takes the fun out of treatment (ha ha, joke and a bad one at that!).

Aside from calling NxStage, have any of you had this problem and what did you do to resolve it? Was it a matter of a System Setting? The Flow Fraction setting? Bad luck? A loose nut behind the wheel? I will probably be giving NxStage a call but don't think they have a new chart to go with the new "S" cycler (our nurse said they don't) but if they do, I wouldn't be surprised it's for higher rates/volumes and well, that's not going to help our situation. Thanks in advance for all who can give their input on this.

You are making it way to difficult for yourself. Just do some simple math YOURSELF. forget the graphs and flow fraction. Just figure how much fluid you want to remove. Then figure 3.5 hours treatment . Divide the total fluid by 3.5. That gives you the liters per hour of UF.  Then when you set the dialysate speed , make sure when it gives the total time it reads slightly over 3.5 hours. that gives you a few extra minutes to play with. I run ours for 3:35 to give me 5 extra minutes to play with. If I remember right the dialysate speed runs about 8.1.  I ignore the flow fraction completely.   I run the blood at 330 to 340.

[PrimeTimer]

You could simply go back to 40%FF and have your old numbers you were comfortable with. Or, increase the UF slightly by about 10% since you increased the FF by 10%. If everything else is the same, you should get back to a regular  session as before.

Last night I said the heck with it and we went back to an FF40 and sure enough, we did not run out of dialysate. We met the UF goal first with about 2 minutes of dialysate left to use. Perfect.
I understand what you're saying about using 10% increments. That makes sense. I've just been concerned that the Neph would get upset that we aren't using FF44 like we were told to when we started on the new S cycler. At this point tho, I think so long as my husband is getting good labs we won't be hearing from anybody about it.

[PrimeTimer]

Never ran out of dialysate on the old cycler but sometimes do on the new "S" cycler. Thought it may have something to do with the Flow Fraction setting (hence, the reason for my thread about Flow Fraction changes) but maybe not... By the way, for those who may not know it, the new "S" cycler can be used (if needed/wanted) for higher rates/volumes but we still use the lower rates/volumes, which is ok with the Neph and it's also ok with NxStage so long as we use the right 400 series SAK's (bags are not to be used at the higher rates/volumes on the S cycler). My husband is getting just as good of labs with the new cycler as he was with the older version, so everything is ok there. For the most part, all is going well. The only thing the Neph had him change was the Flow Fraction. Went from a 40 to a 44. We use a chart dated from 2008 titled "NxStage (SAMPLE) Setting the Ultrafiltration Rate" to calculate what UF rate to use according to how much fluid my husband needs to remove and length of treatment time (almost always 3:30 hour treatments). Seems more often than not tho, that the dialysate meets it's volume goal before the UF goal is met. I have been making my own chart to figure out what Dialysate and UF rates work best together, meaning to "zero out" at the same time or as close together as possible but all this guesswork sort of takes the fun out of treatment (ha ha, joke and a bad one at that!).

Aside from calling NxStage, have any of you had this problem and what did you do to resolve it? Was it a matter of a System Setting? The Flow Fraction setting? Bad luck? A loose nut behind the wheel? I will probably be giving NxStage a call but don't think they have a new chart to go with the new "S" cycler (our nurse said they don't) but if they do, I wouldn't be surprised it's for higher rates/volumes and well, that's not going to help our situation. Thanks in advance for all who can give their input on this.

You are making it way to difficult for yourself. Just do some simple math YOURSELF. forget the graphs and flow fraction. Just figure how much fluid you want to remove. Then figure 3.5 hours treatment . Divide the total fluid by 3.5. That gives you the liters per hour of UF.  Then when you set the dialysate speed , make sure when it gives the total time it reads slightly over 3.5 hours. that gives you a few extra minutes to play with. I run ours for 3:35 to give me 5 extra minutes to play with. If I remember right the dialysate speed runs about 8.1.  I ignore the flow fraction completely.   I run the blood at 330 to 340.

The chart we have (from our old cycler) basically uses that same formula and it worked very well (and at a FF40). But, for whatever reason it doesn't work for a FF44. I know this will make for a long post but let me walk you thru our setup procedure...When I set up the machine, I first go to the volume screen and plug in the amount of fluid to be removed (but we always use the same volume of dialysate each treatment). Then I go to the rates screen and enter the UF rate we want. Then I push the green up arrow on the dialysate rate and "max" it out or rather, press it until I get a "3" in the middle screen and see FF44 on the far left screen. But obviously that dialysate rate is too fast for the UF rates we use, at least on the new S cycler or for FF44....

Next, we don't use the same UF rate each treatment....using the chart, we set the UF rate depending on my husband's blood pressure at pre-treatment and how long of treatment he wants. We go faster if his BP is medium-high, we go slower if his BP is low-medium. Regardless, we always try for 3:15 to 3:30 hours. And sometimes I have to adjust his UF rate during treatment if his BP starts dropping. I have found that if I drop the UF rate (slow it down) and give him 1 small saline bolus, sometimes his BP will slightly go back up and stabilize, which is better than having to give him 2-3 boluses only to end up cutting his treatment short and taking him off the machine to avoid a BP crash. So, obviously when I change the UF rate during treatment, I adjust the Dialysate rate, too. If it's for the sake of his BP dropping, that's no big deal, doesn't happen very often. But ever since using a FF44 and being on this new S cycler, I have had to make adjustments to rates towards the end of treatment to avoid the dialysate from "zeroing out" and being used up first. I do this on top of taking vitals every 30 minutes, tending to my husband, making sure he's comfortable or needing anything and watching the machine like a hawk. At a FF40 and on the old cycler, I could set the numbers and not worry about having to make changes (unless his BP started dropping). Other than that, treatments were pretty boring and not so much of a guessing game. Think we will just go back to using FF40. Called NxStage and they said the old chart for the old cycler is the same one they use for the new S cycler. I didn't go into rates and Flow Fractions with them, was too tired at the time but maybe will give them a call back and see what they say. For now, we are going back to what we know works, FF40. Thanks again so very much for your input. Saves the day to hear from you more experienced folks. Greatly appreciated.