Thank you NxStage

[Hemodoc]

Sorry, I took your comment at face value where you said "few bubbles...". indeed all I hear from NxStage educators and tech support is a few air bubbles are OK. I get tired of it sometimes. With the issues I have been having it's a pet peeve that no one seems to want to address. NxStages official policy as I have been told is that micro-bubbles are ok. I have had an educator look at the bubbles in my lines and shrug their shoulders and say it looks fine. Reading many forum posts I can tell other patients have been told the same thing.

You hit the nail on the head. The high speeds attribute to the amount of air in the system. I've been working on prime settings which slow the whole process down and eliminates a very large amount of the air during dialyze flush. At the point where the dialyzer is being flushed all the pumps start rip roaring away and as I'm sure you've seen there develops a pretty good head in the saline bag. That along with stating with warm saline so far has worked out pretty well in keeping bubbles from forming in the first place. Unfortunately the last few days I've been inundated with bubbles due to a faulty motor. Slight set back.

Changing the prime parameters and recirculating for about 30 tends to leave the lines pretty clear. At least to an unassisted eye. The saline bag which used to be pretty cloudy is now clear. I'm having someone else try it and see what their opinion is. Keep you posted.

Sorry if I took it the wrong way.

No problem. You are quite correct to focus on the micro-bubbles issue as best as you can. Reprogramming the set up is a bit beyond my ability, but the concept is correct. Percolating water in the manner that NxStage does on its prime could be used in many an aquarium to oxygenate the water. I snap and tap when I first begin setting everything up and then do my charting, pick my scabs and then come back to snap and tap a second time. Most of the time I can completely clear any visible bubbles. However, I readily understand that there are microbubbles that I cannot see that I cannot eliminate. I believe that we need to pay more attention to this aspect of dialysis that goes largely unnoticed by researchers and dialysis companies yet has profound clinical impact on every dialysis session.

[obsidianom]

Sorry, been busy for awhile. Haven't been on here in quite some time.

My HHD nurse has been the one keeping me sane. Whether it be problems with Nxstage or Sterling, it's not just a job, it's an adventure. The quality of the machine is more dependent on DaVita than NxStage. In our area, when you get a machine it comes from a refurbishment center and they are sketchy at best. I have gotten machines which have clearly been dropped, shipped without packaging, never cleaned or sterilized, you get the idea. At best a machine in this neck of the woods will last a year. It's not uncommon to hear that we all have a batch of failures all at the same time. Every area and center has it's own issues. Ours is with equipment. Our HHD nurse is the best by far. That's my story and I'm sticking to it!

NxStage has gotten better, but there is still an ongoing issue with air which is a design and implementation issue. I'll cover that in a separate post. As I write this I just finished firing off an email to one of their senior tech's requesting another cycler. The dialysate stepper motor is making a lot of noise. It's more noticeable since I developed a new set of parameters to prime which is much better at removing air, but alas it highlights any deficiencies in the motors since it tends to raise the torque values, but I digress. I just also got my 4th Express Warmer in just over a year. Again, not a great track record, especially since it only gets used rarely.

Russ, you are not pulling air from the pressure, pod, or at least you better not be. I think it was hemodoc who got it, you are cavitating your access, which is not a good thing.

Obsidianom, I have heard that method for clearing air. While it gets rids of the current air, make sure that you are getting rid of all the air. As the saline de-gasses it will release even more air. Too many people do a quick S&T and if they don't see air, onward they go. Getting rid of dissolved air is also very important. To see if you have dissolved air, let it run for about 15 mi and check for air again. If you see the bubbles come back, you still haven't gotten rid of it all just yet. It sounds like you already let it run for awhile, so it may not be an issue.

Hemodoc, you scare me when you say there are "few" bubbles left. There should be zero, none. While the mantra is that micro-bubbles are ok since they won't cause emboli, they are actually detrimental to long term health. When a micro-bubbles(read microscopic) burst, the tissue next to where they have resided, dimples. While this is generally ok for intermittent occurrences in small quantities, large quantities as a hemo patient might see can cause cumulative damage. The tissue damage can be vascular, pulmonary or even cerebral. This is damage that would accrue over say 10-15 years. Studies recommend the use of de-gassers on hemodialysis machines. Get the air out! I have been working for several months now to develop a prime sequence which will keep as much air as possible out of the saline. On top of that a decent amount of recirculation prior to S&T will ensure a minimal amount of air/micro-bubbles in the lines. I'm waiting for results of a secondary test to validate what I have come up with and then I will publish my results.

I haven't read the studies on blood flow yet (I will), but from an engineering viewpoint if your heart is pumping at a rate of nearly 6L/min the difference between 300 or so ml/min and 500 ml/min doesn't seem significant. I promise I will go read the studies for myself. I run at 500 ml/min and it works for me. I get to process close to 90L over just about 3hrs with 30L of dialysate. I'm achieving a clearance of 2.39. However my URR is a bit lower than I'd like. At one point I was around 48. I am higher now, but I can't find the latest lab results. Darn paper mess...

On the plus side, after a little over a year on Home Hemo I am almost completely off BP med's. Fistula aside, that's an awesome accomplishment. I am still tapering the last of my med's and of course I am getting a transplant soon (fingers always crossed), but anticipate being off them hopefully sooner than later. There is always good with the bad.

With all your obvious knowledge of engineering , you are really missing the boat on biology . You are flogging your fistula as Dr. Agar calls it . Going at 500 blood speed will eventually be lethal to your fistula and can stun the heart. The tissue in the fistula reacts to this speed and the intima lining/cells in the fistula will thicken over time and can lead to stenosis and other issues. This has been proven in studies and in the differance in fistula health in Australia compared to US where they run MUCH slower. There is no reason to run that fast on NxStage. It doesnt gain much. I had Dr. Agar look at this also for me and he felt the same. There is little to gain and MUCH to lose. I never run over 340.
if you like numbers then with the 340 blood speed, we get URR of 62% and KT/V of 3.24.     That is with 30 liters.

[obsidianom]

This is interesting article on air bubbles in hemo dialysis.

http://www.ncbi.nlm.nih.gov/pubmed/23826686#

One point they made that is interesting. In the middle of the abstract they mention "turbulant blood flow " as one cause of micro air bubbles. That should make everone slow down the blood speed. A recent article Dr. Agar and I have noted discussed how the research found increase in blood speed caused increased turbulance at the venous return site needle. So to extrapolate, speed up the blood and you get MORE AIR BUBBLES.  So going at 500 blood speed is dangerous for another reason. 

[obsidianom]

Another interesting article on air bubbles.  One point made is LONGER PRIMING TIME should reduce bubbles. I beleive in that concept. I try to leave the machine for at least 20 minutes at the "23" point to reduce air before snapand tap.

http://www.ncbi.nlm.nih.gov/pubmed/18432587#

[Speedy1wrc]

Sorry, I took your comment at face value where you said "few bubbles...". indeed all I hear from NxStage educators and tech support is a few air bubbles are OK. I get tired of it sometimes. With the issues I have been having it's a pet peeve that no one seems to want to address. NxStages official policy as I have been told is that micro-bubbles are ok. I have had an educator look at the bubbles in my lines and shrug their shoulders and say it looks fine. Reading many forum posts I can tell other patients have been told the same thing.

You hit the nail on the head. The high speeds attribute to the amount of air in the system. I've been working on prime settings which slow the whole process down and eliminates a very large amount of the air during dialyze flush. At the point where the dialyzer is being flushed all the pumps start rip roaring away and as I'm sure you've seen there develops a pretty good head in the saline bag. That along with stating with warm saline so far has worked out pretty well in keeping bubbles from forming in the first place. Unfortunately the last few days I've been inundated with bubbles due to a faulty motor. Slight set back.

Changing the prime parameters and recirculating for about 30 tends to leave the lines pretty clear. At least to an unassisted eye. The saline bag which used to be pretty cloudy is now clear. I'm having someone else try it and see what their opinion is. Keep you posted.

Sorry if I took it the wrong way.

No problem. You are quite correct to focus on the micro-bubbles issue as best as you can. Reprogramming the set up is a bit beyond my ability, but the concept is correct. Percolating water in the manner that NxStage does on its prime could be used in many an aquarium to oxygenate the water. I snap and tap when I first begin setting everything up and then do my charting, pick my scabs and then come back to snap and tap a second time. Most of the time I can completely clear any visible bubbles. However, I readily understand that there are microbubbles that I cannot see that I cannot eliminate. I believe that we need to pay more attention to this aspect of dialysis that goes largely unnoticed by researchers and dialysis companies yet has profound clinical impact on every dialysis session.

While we as patients have our priorities, manufacturers have theirs. If the Fresenius takes 20 minutes to prime, it's obvious NxStage has to prime in less time. Changing the programming stretches the prime to 20 minutes, and in the scheme of things it's a minor increase. I've gotten rid of the turbulence the best I can, but there are some things I can't control so it's not perfect. I'll go grab the numbers and post them shortly.

[Speedy1wrc]

Sorry, been busy for awhile. Haven't been on here in quite some time.

My HHD nurse has been the one keeping me sane. Whether it be problems with Nxstage or Sterling, it's not just a job, it's an adventure. The quality of the machine is more dependent on DaVita than NxStage. In our area, when you get a machine it comes from a refurbishment center and they are sketchy at best. I have gotten machines which have clearly been dropped, shipped without packaging, never cleaned or sterilized, you get the idea. At best a machine in this neck of the woods will last a year. It's not uncommon to hear that we all have a batch of failures all at the same time. Every area and center has it's own issues. Ours is with equipment. Our HHD nurse is the best by far. That's my story and I'm sticking to it!

NxStage has gotten better, but there is still an ongoing issue with air which is a design and implementation issue. I'll cover that in a separate post. As I write this I just finished firing off an email to one of their senior tech's requesting another cycler. The dialysate stepper motor is making a lot of noise. It's more noticeable since I developed a new set of parameters to prime which is much better at removing air, but alas it highlights any deficiencies in the motors since it tends to raise the torque values, but I digress. I just also got my 4th Express Warmer in just over a year. Again, not a great track record, especially since it only gets used rarely.

Russ, you are not pulling air from the pressure, pod, or at least you better not be. I think it was hemodoc who got it, you are cavitating your access, which is not a good thing.

Obsidianom, I have heard that method for clearing air. While it gets rids of the current air, make sure that you are getting rid of all the air. As the saline de-gasses it will release even more air. Too many people do a quick S&T and if they don't see air, onward they go. Getting rid of dissolved air is also very important. To see if you have dissolved air, let it run for about 15 mi and check for air again. If you see the bubbles come back, you still haven't gotten rid of it all just yet. It sounds like you already let it run for awhile, so it may not be an issue.

Hemodoc, you scare me when you say there are "few" bubbles left. There should be zero, none. While the mantra is that micro-bubbles are ok since they won't cause emboli, they are actually detrimental to long term health. When a micro-bubbles(read microscopic) burst, the tissue next to where they have resided, dimples. While this is generally ok for intermittent occurrences in small quantities, large quantities as a hemo patient might see can cause cumulative damage. The tissue damage can be vascular, pulmonary or even cerebral. This is damage that would accrue over say 10-15 years. Studies recommend the use of de-gassers on hemodialysis machines. Get the air out! I have been working for several months now to develop a prime sequence which will keep as much air as possible out of the saline. On top of that a decent amount of recirculation prior to S&T will ensure a minimal amount of air/micro-bubbles in the lines. I'm waiting for results of a secondary test to validate what I have come up with and then I will publish my results.

I haven't read the studies on blood flow yet (I will), but from an engineering viewpoint if your heart is pumping at a rate of nearly 6L/min the difference between 300 or so ml/min and 500 ml/min doesn't seem significant. I promise I will go read the studies for myself. I run at 500 ml/min and it works for me. I get to process close to 90L over just about 3hrs with 30L of dialysate. I'm achieving a clearance of 2.39. However my URR is a bit lower than I'd like. At one point I was around 48. I am higher now, but I can't find the latest lab results. Darn paper mess...

On the plus side, after a little over a year on Home Hemo I am almost completely off BP med's. Fistula aside, that's an awesome accomplishment. I am still tapering the last of my med's and of course I am getting a transplant soon (fingers always crossed), but anticipate being off them hopefully sooner than later. There is always good with the bad.

With all your obvious knowledge of engineering , you are really missing the boat on biology . You are flogging your fistula as Dr. Agar calls it . Going at 500 blood speed will eventually be lethal to your fistula and can stun the heart. The tissue in the fistula reacts to this speed and the intima lining/cells in the fistula will thicken over time and can lead to stenosis and other issues. This has been proven in studies and in the differance in fistula health in Australia compared to US where they run MUCH slower. There is no reason to run that fast on NxStage. It doesnt gain much. I had Dr. Agar look at this also for me and he felt the same. There is little to gain and MUCH to lose. I never run over 340.
if you like numbers then with the 340 blood speed, we get URR of 62% and KT/V of 3.24.     That is with 30 liters.

I did not come up with my prescription. I understand your logic and don't disagree with it. Can you give me an example set of parameters with your goals and I'll see if I can get an ok to run similarly? I played with the calculator awile back and from what I came up with my prescription seemed reasonable. I'd like to compare it to yours.

[Speedy1wrc]

This is interesting article on air bubbles in hemo dialysis.

http://www.ncbi.nlm.nih.gov/pubmed/23826686#

One point they made that is interesting. In the middle of the abstract they mention "turbulant blood flow " as one cause of micro air bubbles. That should make everone slow down the blood speed. A recent article Dr. Agar and I have noted discussed how the research found increase in blood speed caused increased turbulance at the venous return site needle. So to extrapolate, speed up the blood and you get MORE AIR BUBBLES.  So going at 500 blood speed is dangerous for another reason.

I was only able to read the abstract, but the premise is spot on. The question is does 500 ml/min cause turbulent flow? Is 500 more turbulent than 340, of course. Remembering that our own little heart pump is churning out 6000 ml/min. Next time I go in to have my fistula checked I'll ask them what kind of flows they are measuring.

[Speedy1wrc]

So, without all the background, here are the settings I have changed to adjust the prime to get rid of all the turbulence. Well, as much as I can. Some thing's aren't able to be adjusted and that's the way it is. I haven't given these to NxStage yet, I will as soon as I can reach the tech I have been working with. This essentially slows the prime from 15 minutes to 20 which isn't much in the overall scheme of things, but it makes a huge difference in air.

First the usual disclaimers. Don't mess with the settings if you aren't comfortable doing it. Check with your center/nurse to see if it's ok. These settings work for me, I don't know if they will work for you. I've been working since January trying many different combinations of settings. I've been going back and forth and then when I though I had something good I needed to change something back. I'm still tweaking them, but I've been ruining these for at least two weeks now and they seem to work pretty well. They were tested on a System One with a 170 cartridge and both the PureFlow SL and bags.


Setting#     Default     New
  19               200        150
  20               450        440
  24               600        200
  29               360        300

If anyone tries these, let me know how they work.

Please Email me at mark@wetzelsracing.com

[obsidianom]

I still see the most important aspect to eliminate air is TIME AFTER prime while at step "23" . The longer you let it sit there the less air. That is absolute. I tend to tap the dialyzer tube while there a few times and clamp the red clamp and this really pushes out the air.  I dont see that cahnging the settings will do much as the final rate limiting step in the equasion is still time in step 23.

[obsidianom]

This is interesting article on air bubbles in hemo dialysis.

http://www.ncbi.nlm.nih.gov/pubmed/23826686#

One point they made that is interesting. In the middle of the abstract they mention "turbulant blood flow " as one cause of micro air bubbles. That should make everone slow down the blood speed. A recent article Dr. Agar and I have noted discussed how the research found increase in blood speed caused increased turbulance at the venous return site needle. So to extrapolate, speed up the blood and you get MORE AIR BUBBLES.  So going at 500 blood speed is dangerous for another reason.

I was only able to read the abstract, but the premise is spot on. The question is does 500 ml/min cause turbulent flow? Is 500 more turbulent than 340, of course. Remembering that our own little heart pump is churning out 6000 ml/min. Next time I go in to have my fistula checked I'll ask them what kind of flows they are measuring.

The heart pumps into a LARGE vessel , the aorta. It is huge as is the pulmonary artery. The needle in the venous line is small and the point of the article is they found turbulance at every increase in speed.  300 was better than 400 and MUCH better than 500. The needle is an artificial onject inside a vessell that creates turbulance just being there. Then add in the blood speed and you have a nasty turbulant flow getting worse with increased speed.
Bottom line is cliincally we see more fistula damage in countries like the US where the blood speed is higher than in countries like Australia where it is slower. That is really all that matters. Engineers can explain only the physics , not the biology of it.
Wolfs Law in biology can explain some of it. The increase speed causes increased forces that cause biological changes to the lining of the fistula causing it to thicken. That causes stenosis eventually. In this case biology/physiology  trumps physics.

[obsidianom]

Sorry, been busy for awhile. Haven't been on here in quite some time.

My HHD nurse has been the one keeping me sane. Whether it be problems with Nxstage or Sterling, it's not just a job, it's an adventure. The quality of the machine is more dependent on DaVita than NxStage. In our area, when you get a machine it comes from a refurbishment center and they are sketchy at best. I have gotten machines which have clearly been dropped, shipped without packaging, never cleaned or sterilized, you get the idea. At best a machine in this neck of the woods will last a year. It's not uncommon to hear that we all have a batch of failures all at the same time. Every area and center has it's own issues. Ours is with equipment. Our HHD nurse is the best by far. That's my story and I'm sticking to it!

NxStage has gotten better, but there is still an ongoing issue with air which is a design and implementation issue. I'll cover that in a separate post. As I write this I just finished firing off an email to one of their senior tech's requesting another cycler. The dialysate stepper motor is making a lot of noise. It's more noticeable since I developed a new set of parameters to prime which is much better at removing air, but alas it highlights any deficiencies in the motors since it tends to raise the torque values, but I digress. I just also got my 4th Express Warmer in just over a year. Again, not a great track record, especially since it only gets used rarely.

Russ, you are not pulling air from the pressure, pod, or at least you better not be. I think it was hemodoc who got it, you are cavitating your access, which is not a good thing.

Obsidianom, I have heard that method for clearing air. While it gets rids of the current air, make sure that you are getting rid of all the air. As the saline de-gasses it will release even more air. Too many people do a quick S&T and if they don't see air, onward they go. Getting rid of dissolved air is also very important. To see if you have dissolved air, let it run for about 15 mi and check for air again. If you see the bubbles come back, you still haven't gotten rid of it all just yet. It sounds like you already let it run for awhile, so it may not be an issue.

Hemodoc, you scare me when you say there are "few" bubbles left. There should be zero, none. While the mantra is that micro-bubbles are ok since they won't cause emboli, they are actually detrimental to long term health. When a micro-bubbles(read microscopic) burst, the tissue next to where they have resided, dimples. While this is generally ok for intermittent occurrences in small quantities, large quantities as a hemo patient might see can cause cumulative damage. The tissue damage can be vascular, pulmonary or even cerebral. This is damage that would accrue over say 10-15 years. Studies recommend the use of de-gassers on hemodialysis machines. Get the air out! I have been working for several months now to develop a prime sequence which will keep as much air as possible out of the saline. On top of that a decent amount of recirculation prior to S&T will ensure a minimal amount of air/micro-bubbles in the lines. I'm waiting for results of a secondary test to validate what I have come up with and then I will publish my results.

I haven't read the studies on blood flow yet (I will), but from an engineering viewpoint if your heart is pumping at a rate of nearly 6L/min the difference between 300 or so ml/min and 500 ml/min doesn't seem significant. I promise I will go read the studies for myself. I run at 500 ml/min and it works for me. I get to process close to 90L over just about 3hrs with 30L of dialysate. I'm achieving a clearance of 2.39. However my URR is a bit lower than I'd like. At one point I was around 48. I am higher now, but I can't find the latest lab results. Darn paper mess...

On the plus side, after a little over a year on Home Hemo I am almost completely off BP med's. Fistula aside, that's an awesome accomplishment. I am still tapering the last of my med's and of course I am getting a transplant soon (fingers always crossed), but anticipate being off them hopefully sooner than later. There is always good with the bad.

With all your obvious knowledge of engineering , you are really missing the boat on biology . You are flogging your fistula as Dr. Agar calls it . Going at 500 blood speed will eventually be lethal to your fistula and can stun the heart. The tissue in the fistula reacts to this speed and the intima lining/cells in the fistula will thicken over time and can lead to stenosis and other issues. This has been proven in studies and in the differance in fistula health in Australia compared to US where they run MUCH slower. There is no reason to run that fast on NxStage. It doesnt gain much. I had Dr. Agar look at this also for me and he felt the same. There is little to gain and MUCH to lose. I never run over 340.
if you like numbers then with the 340 blood speed, we get URR of 62% and KT/V of 3.24.     That is with 30 liters.

I did not come up with my prescription. I understand your logic and don't disagree with it. Can you give me an example set of parameters with your goals and I'll see if I can get an ok to run similarly? I played with the calculator awile back and from what I came up with my prescription seemed reasonable. I'd like to compare it to yours.

If you want  a set of parameters I need some info on you. Age , sex, weight, height, hematocrit,  then also days per week on machine, ultrafiltration per week taken off generally, and what you want for a KT/V. ( I do 3.0 for ours as I want better clearance).   

[Speedy1wrc]

Sure...

53 yrs old, male, 77 kg, hematocrit 35 (latest value I can put my fingers on), 5 days, UF generally around 1.3-1.4L/day, current KT/v is 2.49

Currently I am running 30L around 2:52 blood rate 500 (although I've had some extra free time the last couple days so I've run 450) dialysate during UF runs right around 10 post UF is 11.4 SAK 302 cartridge 170

Thank you!

[obsidianom]

I need height too please.
After I get that I will run some numbers /samples for you to consider and take to your team. I will do that early tomorrow morning.

[amanda100wilson]

Your team should be able to, and should be accessing the dosing calculators themselves.  I am another person who let's my machine sit after prime.  All the small bubbles are gone and then when you snap and tap, there are just big bubbles to get rid of.  Leaving after prime, also helps dissipate the ones that are in the saline line.  I must agree with Obsidionom.  Not sure why you are fixating on bubble removal whilst putting a strain on your heart by running so fast.

[obsidianom]

Sure...

53 yrs old, male, 77 kg, hematocrit 35 (latest value I can put my fingers on), 5 days, UF generally around 1.3-1.4L/day, current KT/v is 2.49

Currently I am running 30L around 2:52 blood rate 500 (although I've had some extra free time the last couple days so I've run 450) dialysate during UF runs right around 10 post UF is 11.4 SAK 302 cartridge 170

Thank you!

Well, I have your info. I didnt have height exactly so I guessed baased on weight to be 5ft. 9 inch.

What it came down to was THERE IS ABSOLUTELY NO DIFFERANCE IN THE PARAMATERS AT THE FIRST RECOMMENDED SETTINGS WHETHER BLOOD SPEED IS 350 OR 400 OR 450 OR 500. YOU GAIN NOTHING BY SPEEDING IT UP ABOVE 350.
I got the following for all speeds from 350 to 500.:;:   Time 3:30 , volume 35 liters , dialysate speed 10.0,  projected kt/v, 2.5.

Now if you drop to 30 liters there is a very slight differance in time and dialysate speed , with blood speed changes. Each 50 ml/min slow down from 500 adds up to 10 minutes. So 350 speed requires 4 hours , dialysate speed 7.5,  400 speed requires 3:50 , d speed 7.8 ,  450 and 500 both are at 3:40 , d speed 8.2. So going from 450 to 500 gives no change at all.

Now you ,can continue to stun your heart and damage your fistula at 450 to 500 or drop to 350 and only add a few minutes at 30 liters or no time added at 35 liters.
If it were me I would go to 35 liters and get the max. dialysate and run 350. If you dont want the hassle of 35 liters then go to 30 liters and run a bit longer. Just dropping to 400 will help save your fistula and only add 10 m inutes time. If you are willing to add another 10 minutes then 350 is better. Remeber TIME ON MACHINE IS THE BEST INDICATOR OF BETTER LONG TERM HEALTH.

REMEMBER TOO THIS IS ONLY A GUIDE. DO NOT DO ANYTHING WITHOUT DISCUSSING THIS WITH YOUR TEAM , EITHER THE NURSE OR NEPHROLOGIST. WORK WITH THEM . I AM ONLY GIVING THIS INFORMATION FOR EDUCATIONAL PURPOSES. IT IS NOT MEDICAL ADVICE.
 
If I can be of further help, please ask.

Addendum: I never ran your UF rate faster than .5 per hour as that is the fastest speed Dr. Agar beleives is safe.  It allows the fluids to move from compartment to compartment without drawing off fluid faster than it can move between compartments.  You may be doing it faster currently and that is not good for the heart or other organs.

[Speedy1wrc]

Good guess on te height. I'm actually 5'10", but you were pretty darn close.

I will talk to my nurse and see what she thinks. I think the only objection would be wasting 25L of dialysate every treatment.  I suppose it would also mean a lot more SAK changes.

The last two treatments I did run at 450. It added about 17 min overall. I do unfortunately have an issue with time. I get up at 5:55am and some times am then working till midnight. If I start right away doing setup I I am usually getting done pretty close to noon. Too often I am getting only a few hours sleep. Losing any more precious time is hard to justify. Yes, I certain do understand the risks and I try to minimize as many as I can. While testing shows that a high flow can damage a fistula, I guess I am currently an exception. My last fistula ultrasound showed it is performing the same as baseline from 9 years ago. My heart from the last echo a year ago show no changes. I am having my yearly full workup at the end of April and I'll get the latest results.

[obsidianom]

There are 50 liter saks so you would only waste 15 liters if you do 35. .  Also you can run 30 liters on a sak and then add 5 liters at the end with a 5 liter solution bag. I have done that . Its easy.

[Speedy1wrc]

I'll run that by my nurse and see what she thinks.

[Hemodoc]

Good guess on te height. I'm actually 5'10", but you were pretty darn close.

I will talk to my nurse and see what she thinks. I think the only objection would be wasting 25L of dialysate every treatment.  I suppose it would also mean a lot more SAK changes.

The last two treatments I did run at 450. It added about 17 min overall. I do unfortunately have an issue with time. I get up at 5:55am and some times am then working till midnight. If I start right away doing setup I I am usually getting done pretty close to noon. Too often I am getting only a few hours sleep. Losing any more precious time is hard to justify. Yes, I certain do understand the risks and I try to minimize as many as I can. While testing shows that a high flow can damage a fistula, I guess I am currently an exception. My last fistula ultrasound showed it is performing the same as baseline from 9 years ago. My heart from the last echo a year ago show no changes. I am having my yearly full workup at the end of April and I'll get the latest results.

Why stop at 35 liters? I do 40 liters every treatment. I tried to go to 47 liters in a 50 liter bag, but the NxStage sodium levels are too high for me at 140 mmols. But "calculating" an ideal of 35 liters is just one more absurd ploy by NxStage. I would do 60 liter treatments with NxStage if the sodium in their dialysate was 135 instead of 140 mmols. This whole low flow dialysate is a gimmick that likely will not last once other home dialysis machines start competing against NxStage. It is time for NxStage to lower their sodium levels so we can increase to higher clearances with each treatment.

[Speedy1wrc]

Do you think the new System S or 3 whichever you prefer to call it is to address the competetion by having the higher dialysate capabilities?

[cdwbrooklyn]

This is for anyone who wants to answer.

Can you measure the blood flow of 500 from NxStage to the blood flow of 500 with in-center?   In-center machines are a lot stronger than NxStage machine.  How can a blood flow of 500 damage your heart from NxStage if the blood flow is not as fast as in-center?  I’m confused regarding blood flows.   

My nurse put my prescription together according to what I was doing in-center after 11 years.  In-center, I ran at 500 blood flow as anything under that made me sick.   I’ve got my heart check in February of this year, and I was told I have a strong healthy heart.  I run at 500 blood flow and have been doing it for 14 years.  Some occasions, I run at 450 blood flow but it does not make me feel better than running at 500 blood flow.   

Anyhoo, I do believe that more dialysis per week will keep you healthier but I’m not into the length of time (6–8 hours) or low blood flows (200-350).  All cases are different and what works for one person may not work for another. 

[Hemodoc]

Do you think the new System S or 3 whichever you prefer to call it is to address the competetion by having the higher dialysate capabilities?

I believe that the 60 liter dosage possible in 4 hours with the makes NxStage a contender with any of the new machines coming on the market. However, I have recently tried to push my 40 liter treatments up to 47 liter and ran into a brick wall from the high sodium levels in their dialysate.

At 45 liters, I can taste and feel the effects of the salt load that for some reason is does not bother me at the 40 liter level. The current system one can run nearly 50 liters in about 4.5 hours. For me, I have already taken NxStage to my only personal max because they use 140 mmols of sodium instead of 135 which would allow me to get near in-center clearances at 60 liters in the same time frame.

If NxStage is going to compete with these other venders,  they must address the sodium issue. Their clearances will be very comparable and they have the advantage of ultra-pure dialysate which is one of the main reasons I went with the NxStage as well as ease of use. Sodium levels not clearance will be the biggest issue in my opinion on how far you can take NxStage.

[obsidianom]

Peter, I have been doing some research on sodium concentrations in dialysate and for the most part it is very controversial. This article was interesting to me as they could measure changes using 140 compared with 135 sodium. It appears that 135 can cause hypotension in many patients . In your case you may be better off with 135 , but many other patients wont. So it is hard to justify changing it for everyone . I guess they could come up with 1 sak with lower sodium.

Nephrol Dial Transplant. 2008 Nov;23(11):3629-34. doi: 10.1093/ndt/gfn274. Epub 2008 May 28.

The influence of low dialysate sodium and glucose concentration on volume distributions in body compartments after haemodialysis: a bioimpedance analysis study.

Ozturk S1, Taymez DG, Bahat G, Demirel R, Yazici H, Aysuna N, Sakar S, Yildiz A.

Author information

Abstract

BACKGROUND:

Despite the developments in haemodialysis, there are still some difficulties in maintaining the haemodynamic stability. Bioimpedance analysis (BIA) has been proposed for the estimation of dry weight in haemodialysis patients. We aimed to investigate the effects of dialysate sodium and glucose contents on volume distribution in body compartments after haemodialysis by using BIA, a sensitive and reliable method.

METHODS:

Seventeen chronic haemodialysis patients [11 males, 6 females, mean age: 36.9 (18-64) years] were included in the study. Patients were evaluated in three periods. The patients (period 1-P1) underwent haemodialysis with dialysate of 200 mg/dL glucose and 140 mmol/dL sodium for 4.5 h in the middle session of the first week. At the beginning and the end of the session, haematocrit, vital parameters (blood pressure, pulse), ultrafiltrated volume, plasma osmolarity and plasma renin activity were recorded. Also multi-frequency bioelectric impedance analyses (Bodystat Quadscan 4000) were applied to all patients at 5, 50, 100 and 200 kHz, including the impedance index (Z200/Z5). In the second midweek session the same procedure was repeated with same glucose concentration and 135 mmol/dL sodium including dialysate (period 2-P2), and in the third week, it was performed with a dialysate that included 140 mmol/dL sodium and no glucose (period 3-P3).

RESULTS:

The change of the ratio of the intracellular volume to total body weight (ICV/TBW) at the beginning and the end of the session was same in all periods. However, there were significant differences in the change (after/before session) ratio for the extracellular volume/total body weight (ECV/TBW) in P2 compared to other periods (P values for P1-P2: <0.001 and P2-P3: 0.007). Likewise, the same was observed in the changes of impedance (P values for P1-P2: 0.08, P1-P3: 0.44 and P2-P3: 0.063). There was a significant increase of hypotensive events in P2 against the other periods (P = 0.001).

CONCLUSION:

Decreasing dialysate sodium concentration results in important haemodynamic changes but the lack of glucose in dialysate does not result in any changes in haemodynamic and inflammatory parameters. The changes in bioimpedance parameters are parallel to haemodynamic changes in the haemodialysis patients.


PMID: 18508835 [PubMed - indexed for MEDLINE] Free full text


Publication Types, MeSH Terms, Substances

[obsidianom]

On the other hand I did find this which does show improvements when lowering sodium to 135.  So its still controversial . I would continue to push for 1 sak with sodium 135 as an alternative.


Ren Fail. 2014 Feb;36(1):23-7. doi: 10.3109/0886022X.2013.830360. Epub 2013 Sep 2.

Effect of gradually lowering dialysate sodium concentration on the interdialytic weight gain, blood pressure, and extracellular water in anuric hemodialysis patients.

Kim do Y1, Kim B, Moon KH, Lee S, Lee DY.


Author information

Abstract

BACKGROUND:

The majority of hemodialysis (HD) patients are overhydrated and have high interdialytic weight gain (IDWG) which induces increased blood pressure (BP). The positive sodium balance resulting from a high sodium diet, a high dialysate sodium concentration (DNa), or a combination of both is major causes of this disease. We evaluated the effects of lowering DNa on IDWG, BP, and volume status in anuric HD patients with dietary sodium restriction.

METHODS:

Thirty-two patients were enrolled in this study and the period was divided by phase 1 and 2 according to DNa which decreased from 140 to 135 mEq/L at a rate of 1 mEq/L per month; phase 1, 140 mEq/L; phase 2, 135 mEq/L. We compared the IDWG, BP, volume status measured by multifrequency bioimpedance spectroscopy, and adverse events such as intradialytic hypotension, cramps, and headache of both phases.

RESULTS:

The IDWG was significantly reduced by 0.39 ± 0.38 kg (p = 0.000). Pre-dialysis BP showed significant reduction (systolic pressure 146 ± 18 vs. 138 ± 22 mmHg; p = 0.012, diastolic pressure 80 ± 10 vs. 75 ± 11 mmHg; p = 0.008). Pre-dialysis extracellular water (ECW) was reduced significantly by 0.13 ± 2.22 L (p = 0.02). There was no significant increase in adverse events (all p > 0.05).

CONCLUSIONS:

This study showed that gradually lowering DNa could bring a significant reduction in pre-dialysis IDWG, BP, and ECW without increased adverse events. Large and crossover designed study will be needed to demonstrate the clear causal relationship.

[obsidianom]

Our home nurse was telling me yesterday they now have 5 more patients starting training with Nxstage. That gives us 8 in our rural area. We were the first and had to fight for it. The nurses were afraid of it at first. Now they LOVE it and are pushing it almost exclusively as the patients feel so much better on it then conventional dialysis. The other interesting aspect is that more patients then ever are doing home hemo here and that is directly because of Nxstage. It is so much easier to use and patients are doing better on it.