[QUOTE=Mel;12083]I agree with HemoHelper that bubbles are evident in the green line between the warmer and the cartridge.
As I’ve said elsewhere it appears the #14 alarm can be avoided by increasing the dialysate rate. We’ve been able to get through the night a few times alarm-free at 3.1 L/hour, but to do so consistently requires 3.4 or 3.5 L/hour. This does not eliminate the bubbles, but the higher rate seems to prevent them from accumulating at the air sensor and thus prevent alarms. To get the same amount of dialysis (kT/V) requires increasing the total amount of dialysate so that it will last for 8 hours and a corresponding increase in FF. I’m told that NxStage has referred this issue to their engineering department, but I’m not aware of another solution as yet.
Mel[/QUOTE]
Mel;
Yes, When I talked to NxStage about my 14 alarm Scott at NxStage told me that he was going to refer this problem to their engineering staff and don’t know if they have come up with a solution yet… Anyway my new machine is running 4.5 software the old one was 4.3 software. So something changed. As i write now I see the bubbles are there but no alarm yet. Scott mentioned that there might be a change in the cartridge. As I mentioned to him of the reduction in tubing size on the line above the air sensor traps the bubbles. Don’t know when the new changed cartridges will be available. Guess nocturnal use on the System One is beginning to be the better choice so they are beginning to gather more information of problems that happen when you run longer/slower/gentle dialysis. I will call him tomorrow and let him know that I had to increase the fluid flow rate to 3.1 to eleminate the 14 alarm… Also mentioned to him that the bubbles that go in and out of the cartridge on the dialysate line happens every 20 seconds after an audiable click in the machine… If they can eliminate this there would not be any bubbles in the system… or when the machine goes to state YEL #2 and the dialysate line pump rate increases it need to run longer to get the bubbles pulled thru the system… The bubbles are coming from somewhere in the cartridge as I have extracted all the bubbles before connecting the line to the heater and am very sure no bubbles have enter the system thru the line coming from the heater as I have watched the line for a while and see no bubbles entering the cartridge. Can’t figure how the bubbles get pushed back in the line from the cartridge towards the heater when the pump should be pulling the fluid in not pushing it back…There is a line in the cartridge that goes from the input to the pump to the other side of the pump. So the Click must be a valve that opens this line and must be where the air is entering the line… Will have to confirm this with NxStage and see if they can stop this valve from opening every 20 seconds…
I had not noticed the association with the click as you suggested. This could be an important clue as to source of the bubbles. It seems clear that speeding up the flow prevents air build up at the sensor to prevent the alarm. A better solution would be to eliminate the source of the air which may be a valve as you pointed out. If this can be done it may avoid a need to redesign the cartridge.
If you speed up the pump don’t forget to change the filtration fraction, and of course, you’ll need more bags unless you opt for a shorter treatment. Since these changes represent a change in the dialysis prescription we asked for approval from my wife’s nephrologist before making them.
My only other grievance with the machine running nocturnal is that it takes about 300 ml +/-100 ml more off than it is set for. I’m told this is within the pump tolerance so can’t be regarded as a defect. Earlier machines took off somewhat less than our setting. We just take this error into account in determining the setting. Have you encountered this problem?
I agree that nocturnal may well become the standard for home dialysis as well it should because of the additional benefits it provides. It’s unfortunate that nocturnal was apparently not the initial design goal.
I doubt the machine is taking off more, the fact is you lose water through respiration (breathing), so in 8 hours you will lose weight. Test yourself, weigh yourself when you go to bed and when you wake up, you will see that you are lighter in the morning.
I agree there is water loss from transpiration and perspiration, but we take that into account. We’re on our third NxStage machine and each one has been different – the first one took off several hundred ml less than it was set for while the current one takes off about 300 ml more. I’m convinced after talking to NxStage it is just a matter of pump tolerance.
I agree there is water loss from transpiration and perspiration, but we take that into account. We’re on our third NxStage machine and each one has been different – the first one took off several hundred ml less than it was set for while the current one takes off about 300 ml more. I’m convinced after talking to NxStage it is just a matter of pump tolerance.
Mel[/QUOTE]
Wow, interesting that you say different NxStage machines vary so much. Ours comes out right on the nose, thankfully. Wouldn’t like so much pump tolerance.
I had not noticed the association with the click as you suggested. This could be an important clue as to source of the bubbles. It seems clear that speeding up the flow prevents air build up at the sensor to prevent the alarm. A better solution would be to eliminate the source of the air which may be a valve as you pointed out. If this can be done it may avoid a need to redesign the cartridge.
If you speed up the pump don’t forget to change the filtration fraction, and of course, you’ll need more bags unless you opt for a shorter treatment. Since these changes represent a change in the dialysis prescription we asked for approval from my wife’s nephrologist before making them.
My only other grievance with the machine running nocturnal is that it takes about 300 ml +/-100 ml more off than it is set for. I’m told this is within the pump tolerance so can’t be regarded as a defect. Earlier machines took off somewhat less than our setting. We just take this error into account in determining the setting. Have you encountered this problem?
I agree that nocturnal may well become the standard for home dialysis as well it should because of the additional benefits it provides. It’s unfortunate that nocturnal was apparently not the initial design goal.
Mel[/QUOTE]
Mel;
When I did the adjustments for some reason MY FF factor did not change much… It is now 26 it use to be 25 When we were in training our FF was suppose to be set at 20… But after testing her blood it wasn’t as good as when were using tghe Fresenius so they increased it to 25. My system set-up is set at 30 so I can increase the pump speed up to 3.3. but if I do go that high I need to calculate every thing again… being that I am still using the same amount of dialysate… my time was reduced from 7.0 hrs to about 6.5 hrs. half an hour isn’t much. I did have to increase the blood pump from 200 to 220 to make sure that I processed the same amount of blood.
When you say the machine takes off 300ml +/-100 than it is set for. Takes off what??? what setting are you talking about? How are you measuring this difference? If you are talking about the dialysate in the bags… because I hang 4 bags (20 ltr) I use all of it. when I had a lot of alarm #14 some time I would run the bags dry and times I would have a little left in the bags. so when alarms happen and the fluid pump stops your volume must change… it seems that I had a problem while in training and had to change the #70 [allowable variation of therapy fluid to reach end of treatment] in the system set-up from 300 to 500.(max fluid vol for end of treatment). That was with the machine with 4.3 soft ware… the new machine with 4.5 software system set-up #70 is now (1.0). Mel don’t loose sleep or worry about 300ml of dialysate think you are running 5 ea X 5 ltr bags (25ltrs = 25,000 ml.) What software do you have on your machine? Can’t remember why NxStage suggested we change this setting. also set our dialysate volume to 19.6. think all these changes was because I was running out of dialysate before the machine reached 000’s. You should not be concerned with what volume of dialysate you have left in the bags at the end of the treatment. Be more concerned with the amount of ultrafiltration and the amount of blood processed… You know when you finish returning the blood you press the ADD FLUID button log in the time…,total dialysate Volume… Total Ultra Filtration
and blood processed… Making sure that time and blood processed are constantly the same… That way you know that you are doing the best you can… I’ve noticed that the time and blood processed change with the amount of alarms you have had during the treatment.
Interesting discussion. I get 14 when I forget to turn on my pureflow or otherwise forget to connect the dialysate. My bad. User error. No big deal genearlly I just turn on the pureflow or hook up the green clamp to the green clamp. This my friends is not rocketscience - it’s nephrology! Cheers, Erich
When I did the adjustments for some reason MY FF factor did not change much… It is now 26 it use to be 25 When we were in training our FF was suppose to be set at 20… But after testing her blood it wasn’t as good as when were using tghe Fresenius so they increased it to 25. My system set-up is set at 30 so I can increase the pump speed up to 3.3. but if I do go that high I need to calculate every thing again… being that I am still using the same amount of dialysate… my time was reduced from 7.0 hrs to about 6.5 hrs. half an hour isn’t much. I did have to increase the blood pump from 200 to 220 to make sure that I processed the same amount of blood.
When you say the machine takes off 300ml +/-100 than it is set for. Takes off what??? what setting are you talking about? How are you measuring this difference? If you are talking about the dialysate in the bags… because I hang 4 bags (20 ltr) I use all of it. when I had a lot of alarm #14 some time I would run the bags dry and times I would have a little left in the bags. so when alarms happen and the fluid pump stops your volume must change… it seems that I had a problem while in training and had to change the #70 [allowable variation of therapy fluid to reach end of treatment] in the system set-up from 300 to 500.(max fluid vol for end of treatment). That was with the machine with 4.3 soft ware… the new machine with 4.5 software system set-up #70 is now (1.0). Mel don’t loose sleep or worry about 300ml of dialysate think you are running 5 ea X 5 ltr bags (25ltrs = 25,000 ml.) What software do you have on your machine? Can’t remember why NxStage suggested we change this setting. also set our dialysate volume to 19.6. think all these changes was because I was running out of dialysate before the machine reached 000’s. You should not be concerned with what volume of dialysate you have left in the bags at the end of the treatment. Be more concerned with the amount of ultrafiltration and the amount of blood processed… You know when you finish returning the blood you press the ADD FLUID button log in the time…,total dialysate Volume… Total Ultra Filtration
and blood processed… Making sure that time and blood processed are constantly the same… That way you know that you are doing the best you can… I’ve noticed that the time and blood processed change with the amount of alarms you have had during the treatment.
HemoHelper[/QUOTE]
I wasn’t very clear. What I meant was the machine takes off about 300 ml more ultrafiltration (based on pre-post weight) than the UF is set for. We already allow 100 ml for transpiration and perspiration. This 300 is additional. Since our UF goal is usally 600-1000 ml this is a fairly significant percentage error. We, of course, can allow for it by setting our goal 300 leass than we would otherwise. We’ve never seen this on a Fresenius machine through years of use and can almost always hit our UF goal exactly or be off no more than 100 ml on that machine. We’re using 4.4 software on the NxStage machine.
Starting tomorrow we’re increasing our dialysate to 30 L which will let us run for 8 hours at a rate of about 3.6 which hopefully will avoid any #14 problems. We’re increasing the FF to 31 so we can run Qb at 200 (96 L for the night).
Hemo Helper writes:"You know when you finish returning the blood you press the ADD FLUID button log in the time…,total dialysate Volume… Total Ultra Filtration
and blood processed… Making sure that time and blood processed are constantly the same… That way you know that you are doing the best you can… I’ve noticed that the time and blood processed change with the amount of alarms you have had during the treatment. "
***I had thought blood processed had to do with the amount of fluid removed during the tx, the goal. What else determines blood processed, because looking at my run sheets, I may have the same goal, but a different value for blood processed.
Mel writes:“Starting tomorrow we’re increasing our dialysate to 30 L which will let us run for 8 hours at a rate of about 3.6 which hopefully will avoid any #14 problems. We’re increasing the FF to 31 so we can run Qb at 200 (96 L for the night).”
How many liters of dialysate did you use before going to 30L? What were you other rates?
[QUOTE=Unregistered;12183]Hemo Helper writes:"You know when you finish returning the blood you press the ADD FLUID button log in the time…,total dialysate Volume… Total Ultra Filtration
and blood processed… Making sure that time and blood processed are constantly the same… That way you know that you are doing the best you can… I’ve noticed that the time and blood processed change with the amount of alarms you have had during the treatment. "
***I had thought blood processed had to do with the amount of fluid removed during the tx, the goal. What else determines blood processed, because looking at my run sheets, I may have the same goal, but a different value for blood processed.[/QUOTE]
Heather
Blood processed is the amount of blood that will pass thru the dializer…
the amount of fluid removed is Ultrafiltration… (weight minus [dry weight PLUS rinse back] = GOAL… example:
weight is 50 kilos
dry weight is 49.0 Kilo
rinse back is 250 + 50 = 300
50.0 MINUS 49.0 = 1.0 PLUS .3 (rinse back)= 1.3 Goal
to figure how much blood would process use this formula:
Blood pump rate divided by 1000 times 60 times run time = blood processed
example:
220 pump rate
1000 is to change mililiter to liter
60 to change minute to hour
run time is how long you are on the running on the machine
220 divided by 1000= .22 times 60=13.2 times 6.5 hrs = 85.8 (86)
So the more blood you process would mean that it should be removing more toxins from your blood any way that is my logic… When we were using the Fresenius think we usually processed only 80 ltrs of blood per TX and now on NxStage we are doing 86 ltrs. Yes, I have noticed that on the Fresenius the blood pump we set at 200 but since it was turning the Knob sometime I would set it just a little higher to process 80 ltrs… On the NxStage it seems if you are having alarms and taking your time to clear it the blood pump continues to run so the blood processed is a bit more when you have alarms…
[QUOTE=Mel;12166]I wasn’t very clear. What I meant was the machine takes off about 300 ml more ultrafiltration (based on pre-post weight) than the UF is set for. We already allow 100 ml for transpiration and perspiration. This 300 is additional. Since our UF goal is usally 600-1000 ml this is a fairly significant percentage error. We, of course, can allow for it by setting our goal 300 leass than we would otherwise. We’ve never seen this on a Fresenius machine through years of use and can almost always hit our UF goal exactly or be off no more than 100 ml on that machine. We’re using 4.4 software on the NxStage machine.
Starting tomorrow we’re increasing our dialysate to 30 L which will let us run for 8 hours at a rate of about 3.6 which hopefully will avoid any #14 problems. We’re increasing the FF to 31 so we can run Qb at 200 (96 L for the night).
Mel[/QUOTE]
Mel;
So you are saying that your pre weight minus dry weight plus rinse back to get your UF goal is off by .3 kilo? Your UF goal is only .6 to 1.0? Wow that is really low…(if you have only .3 kilo to remove) My partner’s dry weight is 49.0 Kilo and she usually have .7 kilo to remove so .7 + .3 (rinse back) = 1.0 UF Volume. UF rate on the first screen would than be 1.0 divided by time (6.5) = .15 If she weigh 49.8 kilo before going on the machine, in the morning she weighs 49.0 kilo… some time if she feels like cramps is coming I turn off the UF by changing the vol to 0. then the next night we try to make it up as her dry weight would be a bit more… So if you feel cramps are just about to happen turn the UF off and you can make it up the rest of the week… DO NOT GO THROUGH THE PAIN OF CRAMPS ever again… it might be you need to adjust the dry weight… Getting healthy and FATTER.(Gaining weight). Ha HA ha…
When we used the Fresenius it was the same calculation and what ever we programmed to remove is what we got except when days that she would turn UF off because of cramps…
You keep saying ml. How are you measuring this? or are you saying that when you are getting off tha machine your dry weight is .3 kilo more that you had programmed into the machine… example: you are asying 600 ml = .6
so your PRE weight and dry weight difference is .3 kilo???/
Because if you set the rate Vol at .6 it is only taking off .3 kilo…the other .3 is from the rinse back. when you start your saline bag is Full 1000 ml. After prime it is at about 600ml. then when you return the blood after tx the bag is down to about 300 ml… Where did all this fluid go??? into the patient right… only about 300 mls. that is why .3 is added to the dry weight. Think on the Fresenius it was the same. Unless you hooked only the the aterial (red side) to the patient and ran the Fresenius until the blood appeared in the (Blue line) going to the patient and not have any added saline going to the patient. that way you did not have to add the saline into the UF formula.
As I stated earlier what is your machine set-up for rinse back???
Can you put your machine into the set-up mode and check?
You might check with your center and see what the setting is, if you do not know how the check the system set-up. it is set-up #13. When you are finish with your treatment and press STOP before disconnecting what is the top window reading?.. This is the volume of rinse back… It must be calculated into the UF volume.
This talk of the machine being off has me wondering what type of scale is everyone using to weigh themselves. The digital scale I have now is so off all the time. I can never really trust it when it says I weigh so much. The only solution we have seen is a detecto 090 mechanical scale and they are over three hundred dollars. We are saving up for one, but in the meantime I really have to pay attention to my body.
LSB
So you are saying that your pre weight minus dry weight plus rinse back to get your UF goal is off by .3 kilo? Your UF goal is only .6 to 1.0? Wow that is really low…(if you have only .3 kilo to remove) My partner’s dry weight is 49.0 Kilo and she usually have .7 kilo to remove so .7 + .3 (rinse back) = 1.0 UF Volume. UF rate on the first screen would than be 1.0 divided by time (6.5) = .15 If she weigh 49.8 kilo before going on the machine, in the morning she weighs 49.0 kilo… some time if she feels like cramps is coming I turn off the UF by changing the vol to 0. then the next night we try to make it up as her dry weight would be a bit more… So if you feel cramps are just about to happen turn the UF off and you can make it up the rest of the week… DO NOT GO THROUGH THE PAIN OF CRAMPS ever again… it might be you need to adjust the dry weight… Getting healthy and FATTER.(Gaining weight). Ha HA ha…
When we used the Fresenius it was the same calculation and what ever we programmed to remove is what we got except when days that she would turn UF off because of cramps…
You keep saying ml. How are you measuring this? or are you saying that when you are getting off tha machine your dry weight is .3 kilo more that you had programmed into the machine… example: you are asying 600 ml = .6
so your PRE weight and dry weight difference is .3 kilo???/
Because if you set the rate Vol at .6 it is only taking off .3 kilo…the other .3 is from the rinse back. when you start your saline bag is Full 1000 ml. After prime it is at about 600ml. then when you return the blood after tx the bag is down to about 300 ml… Where did all this fluid go??? into the patient right… only about 300 mls. that is why .3 is added to the dry weight. Think on the Fresenius it was the same. Unless you hooked only the the aterial (red side) to the patient and ran the Fresenius until the blood appeared in the (Blue line) going to the patient and not have any added saline going to the patient. that way you did not have to add the saline into the UF formula.
As I stated earlier what is your machine set-up for rinse back???
Can you put your machine into the set-up mode and check?
You might check with your center and see what the setting is, if you do not know how the check the system set-up. it is set-up #13. When you are finish with your treatment and press STOP before disconnecting what is the top window reading?.. This is the volume of rinse back… It must be calculated into the UF volume.
HemoHelper[/QUOTE]
HemoHelper,
We calculate just like you. Pre-weight-dry-weight + rinseback = calculated goal. On Fresenius we then enter a planned goal 100 ml less than calculated goal to allow for perspiration and transpiration losses. We usually hit the calculated goal with post-weight or come within 100 ml. With NxXtage if we do that our post-weight may be 300 ml below calculated goal so we set the planned goal 300 ml below the calculated goal. The machine is set not to automatically account for rinseback as I prefer to do that manually in our calculations.
We had #14 alarms last night even though we were running Qd of 3.7. I’m going to try a few other things tonight and see if we can get some sleep.
[quote=Leafsunbear;12188]This talk of the machine being off has me wondering what type of scale is everyone using to weigh themselves. The digital scale I have now is so off all the time. I can never really trust it when it says I weigh so much. The only solution we have seen is a detecto 090 mechanical scale and they are over three hundred dollars. We are saving up for one, but in the meantime I really have to pay attention to my body.
LSB[/quote]Didn’t you get a scale from your unit?
Hemo Helper,
I was told the higher the ultrafiltration goal, the longer the tx. when it comes to sdd on NxStage-not by a whole lot, may vary an average of about 10 min. at most. So, I was thinking, the higher the goal, the longer the tx, the more blood processed. Generally, this is true, but in checking my tx sheets this is not always the case. So, I can understand how alarms might be one thing that affect the bvp rate. There could be other things that affect it, too, but don’t know what that would be.
Regarding nocturnal txs on NxStage, when various ones say you set machine for a specific run length (i.e. 8hrs, 7 or 6.5 hrs), how do you set the machine differently than you would for a sdd tx? Because my understanding is for sdd txs, the uf goal determines how long txs run and it will vary somewhat. So, how do you get exact run times with nocturnal?
I understand what Mel means about the .3 his machine is off. It is just the way it is calibrated. In-center, machines are calibrated differently, so with one machine a patient will come out on goal whereas on another machine, it can completely throw the goal off and patient will cramp or come out fluid overloaded. As long as the machine is consistant, whether too low, on target or too high, one can figure the goal ok without problems. One does need to know the rinbseback volume rate with NxStage in order to figure the goal.
Doesn’t sound like the scale is Mel’s problem, but we were given a defective scale from the home tx supplier which was unacceptable, so we had to go out and purchase an accurate scale at a local housewares store, Tanita $100, very dependable.
Hemo Helper wrote:"some time if she feels like cramps is coming I turn off the UF by changing the vol to 0. then the next night we try to make it up as her dry weight would be a bit more… So if you feel cramps are just about to happen turn the UF off and you can make it up the rest of the week… DO NOT GO THROUGH THE PAIN OF CRAMPS ever again… it might be you need to adjust the dry weight… "
About how often must you turn off the UF as patient is feeling close to cramping? Most on nocturnal talk like they rarely run into this, because it is a slower tx. But anytime a patient gains a little weight cramping is a possiblilty, so I have wondered how often this is a concern with those on noturnal? Seems like a caregiver should be closeby as the patient might not be able to wake up and handle turning the UF off??