NxStage Gaining Ground On Growing Adoption Of Home Hemodialysis

[obsidianom]

There is no advantage at all to others who are on lower volumes and need the speed at a slower rate to get enough time on machine.
Dr. Agar talks about the "waterfall effect" which in simple terms means more time on machine gets better clearance of the middle molecules. Going too fast with shorter times loses this effect. Time is critical , not speed.

Take the example of a patient who is getting nice long times.  Does increasing the speed, without decreasing the time, offer any benefit to the patient?

That wont work on Nxstage. The whole point of the system is a set amount of volume . So with the same volume always if you increase the speed of the dialysate will automaticlly reduce the time. There is no way around that.
Again the prescription is based on your size, hematocrit, amount of fluid to be removed, and desiredkt/v/.    I use 3.0 for our kt/v by the standards used in the US we are getting better then minumum dialysis. Whether that actually means anything, I dont know. BUT I will say that we are meeting that goal on our blood work . We are getting the 3.0 kt/v.
So the prescription works. We use 30 liters. slightly over 3 hours. (we run 9.7 per hour) 
With your size you would require probably 50 liters as a guess.  So at 50 liters you could run standard speed up to 12 per hour for time of slightly over 4 hours. Or you could go faster with shorter times on the high flow.
Try it and see how you feel with gentler dialysis. AS in my previous post yopu may find you feel better on slower gentler dialysis.

[Simon Dog]

Try it and see how you feel with gentler dialysis. AS in my previous post yopu may find you feel better on slower gentler dialysis.

I am pushing to get overnight which will give the benefits of long/slow no matter what the machine.   The problem about "see if I feel better" is that I already feel great.  Dialysis (6 months PD; one year hemo) has been a mega inconvenience, however, I have been feeling better than I ever expected to based on the storied I had heard from patients.  And no, I don't have any residual left propping me up.

[obsidianom]

this article hints at faster more agresssive dialysis causes issues with osmotic changes and  hypo  tension
















Am J Nephrol. 2013;38(5):388-96. doi: 10.1159/000355958. Epub 2013 Oct 26.

Dialysis dose and intradialytic hypotension: results from the HEMO study.

McCausland FR, Brunelli SM, Waikar SS.


Author information




Abstract


BACKGROUND:

Intradialytic hypotension (IDH) is common and is associated with increased morbidity and mortality in chronic hemodialysis patients. A higher dialysis 'dose' may generate transient intradialytic osmotic gradients, predisposing to intracellular fluid shifts and resulting in hypotension.

STUDY DESIGN:

We performed a post hoc analysis of the HEMO study, a multicenter trial that randomized chronic hemodialysis patients to high versus standard Kt/V and higher versus lower membrane flux. In order to achieve dose targets, per protocol, adjustments were made in membrane efficiency, blood flow or dialysate flow before changing session length. Detailed hemodynamic and urea kinetic modeling data were abstracted from 1,825 individuals. The primary outcome was the occurrence of hypotensive events necessitating clinical intervention (saline infusion, lowering of ultrafiltration rate or reduced blood flow).

RESULTS:

Intradialytic hypotensive events occurred more frequently in the higher-Kt/V group (18.3 vs. 16.8%; p < 0.001). Participants randomized to higher-target Kt/V had a greater adjusted risk of IDH than those randomized to standard Kt/V [odds ratio (OR) 1.12; 95% confidence interval (CI) 1.01-1.25]. Higher vs. lower dialyzer mass transfer-area coefficient for urea and rate of urea removal were associated with greater adjusted odds of IDH (OR 1.15; 95% CI 1.04-1.27 and OR 1.05; 95% CI 1.04-1.06 per mg/dl/h, respectively).

CONCLUSIONS:

Higher dialysis dose, at relatively constrained treatment times, may associate with an increased risk of IDH. These findings support the possibility that rapidity of intradialytic reductions in plasma osmolality may play an important role in mediating hemodynamic instability during dialysis.

© 2013 S. Karger AG, Basel.

[Simon Dog]

That wont work on Nxstage. The whole point of the system is a set amount of volume . So with the same volume always if you increase the speed of the dialysate will automaticlly reduce the time. There is no way around that.

I have failed to properly formulate my question.

Assume I am prescribed X liters and run for 4 hours at 200ml/hour.   Now, assume I have an 18L machine at my disposal.    Is there any benefit to asking my doc to prescribe 1.5x liters at 300ml/hour to get more clearance in the same treatment time?

[obsidianom]

Try it and see how you feel with gentler dialysis. AS in my previous post yopu may find you feel better on slower gentler dialysis.

I am pushing to get overnight which will give the benefits of long/slow no matter what the machine.   The problem about "see if I feel better" is that I already feel great.  Dialysis (6 months PD; one year hemo) has been a mega inconvenience, however, I have been feeling better than I ever expected to based on the storied I had heard from patients.  And no, I don't have any residual left propping me up.

Overnight is definatly a better way to go if you can manage it. It is longer and slower. I hope you can pull it off.

[obsidianom]

That wont work on Nxstage. The whole point of the system is a set amount of volume . So with the same volume always if you increase the speed of the dialysate will automaticlly reduce the time. There is no way around that.

I have failed to properly formulate my question.

Assume I am prescribed X liters and run for 4 hours at 200ml/hour.   Now, assume I have an 18L machine at my disposal.    Is there any benefit to asking my doc to prescribe 1.5x liters at 300ml/hour to get more clearance in the same treatment time?

Basic math. Same x volume at faster speed means shorter time on machine. You may get slightly quicker clearance but lose time which causes loss of the gain so it evens out . In the end it is still VOLUME . Read my articles on speed of dialysate. I beleive it is detrimental to go faster.  Slower gentler is better

[Simon Dog]

Overnight is definatly a better way to go if you can manage it. It is longer and slower. I hope you can pull it off.

I have been told I can have overnight as soon as the local Fresenius clinic is able to offer remote monitoring for home hemo patients, or immediately if I can get a family member to agree to stay up all night to monitor me.   I haven't have much luck with the later, but I have been assured that the monitoring is coming "soon".

[obsidianom]

When you do go to nocturnal , rmember to slow down your blood flow to save your fistula. In Japan and Australia they run about 225 to 250 . Its gentler on the whole body and can save your heart and access.

[Simon Dog]

When you do go to nocturnal , rmember to slow down your blood flow to save your fistula. In Japan and Australia they run about 225 to 250 . Its gentler on the whole body and can save your heart and access.

My doc has already mentioned he will be doing that, along with moving me from a 15ga to a 16ga needle.

[Hemodoc]

Dear Obsidianom,

There are quite a few studies on solute diffusion rates. The end points of those are focussed on middle molecule clearances as well as PO4. The smaller molecules diffuse quite well. The middle molecules are most dependent on time on the machine and frequency, but they are also greatly influenced by highflux artificial kidneys and total dialysate volume. The main issue that Dr. Agar wished to communicate with his waterfall post is that volume, i.e., Ultrafiltration volumes and interdialytic fluid gains are the most important factors that kill patients. I was one of three people Dr. Agar asked to review and comment on his paper before he published it and that was the focus of our joint discussions.

So, the studies are relatively conclusive. In discussing NxStage with Dr. Agar, he is unimpressed with this machine for one reason, low dialysate flow rates. I am sure he would confirm that. If you look at my post in DSEN back in 2010, that was also the focus of my article stating to take NxStage to the max. That remains a significant detriment and reason why Australia has almost uniformly rejected NxStage. In addition, Dr. Agar points out that NxStage was designed on the failed American fast, violent dialysis session model of care that is also uniformly rejected in Australia and New Zealand. He much prefers the Baxter VIVIA system now with CE mark approval in Europe and pending FDA approval here.

So, as much as I appreciate what I have gained on NxStage the last 5 years, I cannot defend the low volume dialysate flow rates that is at the heart of their philosophy. In the end, the FREEDOM studies showing low dialysate volumes and flow rates may retard implementation of the better "HIGH DOSE" protocols with the new NxStage upgrade. I fear that people like me that desire to truly take NxStage "to the max" will never have that opportunity because NxStage has created a newer, lower "standard of care." In the end, should this occur, this will result in diminished benefits to patients. I have always believed that the NxStage low volume, low flow dialysate rates was a mistake. As you have noted, your wife felt terrible on the low volume NxStage and gained immediate benefit from increasing the dosage to 30 liters as you have documented in some posts here. That is proof in itself of the dangers of the NxStage philosophy of low volume dialysate. It is a failed paradigm that will be most difficult to rid from our system but that will be one issue that Dr. Agar will address directly next month at the ADC. Defending NxStage on this issue I believe is completely counterproductive in my opinion.

[Hemodoc]

Actually John just answered an unrelated thread at Home Dialysis Central on FB on exactly why he is not a fan of the NxStage System One and why he has rejected it for his patients in Geelong:

Now here's the next thing ... and I know some of you will have picked up that I am not fully convinced about the NxStage system. Why? Why has there been a reluctance in my part of the world (all the 'error' issues alluded to by Maz and Trevor aside) to accept this nice little portable machine? Well, the NxStage was designed (primarily) for US dialysis, for a home HD market that it (the NxStage) has almost on its own - and spectacularly - grown from nothing to a now creditable 1-1.5% of dialysis. Full marks and all credit to it that it has done so! But, it was designed principally to provide fast, hard (bad) but more frequent (good) dialysis, but in the home. To do this, but with a limited volume of bagged or batched dialysis fluid - ultra pure, as Peter rightly says .. a clear tick - it had to introduce a reversal of the standard dialysis practice of a high dialysis fluid and low blood flow ratio. It had to turn that long-standing dialysis dictum around and on its head, instead scripting a high blood flow to low dialysis fluid flow ratio - a reversal it named as the filtration fraction. In 'conventional single pass' dialysis (ie: Ian Chitty's Fresenius 4008B which, incidentally, we also use here in Geelong) - or any similar single pass system - the blood flow rate is commonly about half the dialysis fluid flow rate ... say, a Qb of 250 -300 ml/min paired with a Qd of 500-600 ml/ min. But, NxStage was (at least initially) limited to a 25-30 litre dialysis fluid batch. While it can do a bit better than that now with the PureFlow, it can still, at best, only offer a maximum dialysate volume per treatment of <60 litres. To compensate for this very low dialysis fluid volume and its associated low Qd, the counter-current pass of blood across the dialyser HAD to be ramped up! That meant reversing the Qb:Qd ratio so that Qb was 2-3 x greater than Qd ... the very opposite of conventional dialysis where Qb is only 1/2 the rate of Qd.
The problem, for us here in ANZ, is that we think this only serves to rob Peter (pun intended) to pay Paul!
To get anywhere near adequate clearance, the NxStage system and its blood/fluid flow dynamics required a very high Qb ... in turn demanding that the AVF be driven at flows that were anathema to us ... and, to be honest, they still are. We do not use high a high Qb. We think high Qb's are detrimental to good AVF care. Using the kind of Qb needed to compensate for the low flow dialysis fluid rates of the NxStage simply, to our view, introduces another 'bad' thing into the dialysis equation. Not only is a venous 'blast' back into the return vein of 350+ anathema to us, but to run a Qb of 350+, an arterial end 'suck' of the same amount is needed ... with the potential (and actual) result of structural damage to the AVF the arterial end too - at BOTH ends - venous and arterial. To be plain, we don't think that's a good trade, if you dont have to. And, in single pass systems, you dont have to!. But, turning down the pump speed on a NxStage to 300-ish (or, better, even lower - NB: our home patients on single pass systems run Qb's of 225 ml/min) would cause the filtration fraction physiology of NxStage to fail, and 'adequate' dialysis clearance would be unachievable.
So, for this, and other reasons, we have decided to stick with what we do ... at least until newer, portables appear that allow low Qb's yet provide for a high clearance by still allowing a high Qd. How might that happen. Well, sorbent regeneration of the dialysis fluid for reprocessing then re-passing the dialysis fluid around and around, would allow that ... but, we would have to be convinced of (a) safety and (b) that the sorbent would not be supersaturated such that breakthrough occurred. It's not a new concept ... some of the 'old hands' like Nancy,will recall the REDY system. Other options may also emerge, but that discussion is not for here or for now.
Meantime, we remain comfortable, here in ANZ, with providing good dialysis clearances yet at low pump speeds (low Qb's) ... and we are likely to continue to do so until something better is on offer. Dialysis is, in essence, a trade off - as no system is ideal - but we believe it best to recommend to our patients to trade what is, in truth, still difficult portability for better fistula care, optimal small and middle molecular clearance and, through longer dialysis, to ensure a low UFR that does not threaten myocardial stun and allows intra-dialytic trans-compartmental fluid equilibration. For the reasons that underpin this last point, see the HDC blog on the Dialysis Waterfall Part 1. I think that will be our collective view here, at least till something better comes along.
Dori is right, choice IS important, and while mobility DOES matter to many, it is important, too, to make sure that patients who choose mobility understand that by doing so, they may sacrifice other benefits.
Now ... I can just imagine a raft of posts coming back in response to this post ... "I have run at flow rates of 450 for decades and my AVF is fine - etc etc" ... and that may well be true, for some - but it is unlikely to be true for most or all.
Again, the weakest link in your life-sustaining dialysis is not the machine but your access. Access protection HAS to be a paramount priority. I try to live and deliver that priority.

John Agar:
Sent from my iPad

[obsidianom]

To HemoDoc(Peter)

"Our facility-based conventional patients run Qb’s of 325 on a 3 x 4.5-5 hr schedule … and her 5 x 3  hr schedule should still drive better clearances than they get at an equivalent Qb!r),"  ( From John Agar   to me via email pertaining to my wife on NxStage)

"As regards the waterfall concept – it applies equally to fluid and solute (see Part  =  just up) – though with solutes, there are greater disparities as a result of the differences between small solute clearance (ie: urea) and middle molecular clearance (ie: PO4 as a surrogate"   Quote to me from John Agar

Now I want to discuss why I disagree that NXstage is as flawed as you have posted. (I have great respect for your knowledge and experience and this is just a debate, not personnal. You have taught me a lot).

Nxstage is not perfect. I can think of many things I would do differently including more flexibility on the saks size and types. BUT, it is the best we have for home use in the US.  I have practiced medicine for 25 years and deal with realities. I run my own practice and know the business side of US medicine all too well. I am currently in the midst of a medicare RAC audit that many docs who do durable medical products are facing for items we provided patients 3 years ago. It is a terrible waste of our time . The worst part is the company medicare hired to do the audit gets a percentage of any money they can take back from us. That is like giving police a commission for every ticket they write out as their pay. It creates a system that is ridiculous. BUT that is the US medical system we live in. So its the same for dialysis.
Nxstage is a public company that has stockholders it is responsible to. That means they come before patients. That is the way of free enterprise in the US. Now I wont debate whether thnis is good or bad , as that is a whole other topic. BUT it is the reality we are in. So whiile we may want to get "perfect " dialysis from them , we have to remember they deal with economic forces that are pulling on them all the time.
Nxstage provided a way for much easier more frequent dialysis in the US. The other system form Fresenius is more labor intensive for the patient at home. It isnt as easy to use and requires special electical and plumbing lines and more space.
The big advantage of NXstage is the frequency of treatment. I know it can be done fewer times , but most patients do 5 days per week or more. The other system is done 3.5 or 4 days per week. Now in regards to John Agar and the fluid waterfall, this is a big ADVANTAGE. Less water builds up between treatments and less has to be taken off allowing slower UFF which is what the whole theory is about. He points out that 5ml/hour  times the weight in kg is the max. speed that is safe for UFF.  For example a 100 kg person would be at a max of .5 liter per hour safely. That is easier to achieve with more frequent dialysis like on Nxstage.
Now John Agar doesnt like NxStage as much as their home system in Australia. But his reality is far different then the US. They do almost exclusively nocturnal  , 6 to 8 hour dilaysis. That is not going to happen easily here in the US. It is a different mind set there. NxStage may not be better for them but in the US  we dont do that kind of time on machine they do and so comparing NXstage to  their home machines isnt a fair comparison in the US.
NxStage still offers more total time on machine then the other home system here unless the other is nocturnal. For day time use it is still superior time on Nxstage.
Now go back to my point about speed of dialysis. I still dont see any studies or even the ability to measure how fast diffusion FROM ONE COMPARTMENT TO ANOTHER takes place . I am not talking about diffusion across the dialsisis filter from the blood. I am talking about from the cells to the interstitial compartment and then from the interstitial to the blood where we finally access it in dialysis. That to my knowledge has not been or may not be measurable easily. Yes we clear the blood fast but what about the rate the molocules go from the cells to the intercell area and then to the blood. ? My best guess is that it is quite variable form patient to patient based on factors like proteins in the system and other molocules that vary greatly from patient to patient. As a surgeon I have seen how different exudate in the tissue is from patient too patient and how much this effects healing rates . Some patients have thick protien filled exudate while others are more watery and thin. This clearly will effect diffusion at the cellular level. So bottom line, we dont have proof that speed of dialysis clearance can be truly measred at the cell and intreacellular level, we just test the blood where we have access . This is just the final step in the line from compartment to compartment. We cant prove what speed is actually most efficasious as we cant measure the inner compartments . Going too fast may be detrimental to some patients. See my earlier post with the abstact article on that .
So bottom line, NxStage may in fact be more suitable for some or many patients as it is a slower dialysis . It may be less harsh on the body.
I did some checking on Nxstage with slower blood speeds as John Agar beleives we should do. I found at least for my wife I could run as slow as 250 blood speed and still get a Kt/v of 3.0 ( I realize this is an imperfect measure of dialysis but its all we have). It simply requires we run longer dialysis sessions ( long enough to get similar blood volume as at higher speeds) which is what John Agar prefers.  So according to the on line calculator Nxstage can handle slow blood speeds . I plan to keep lowering ours over time and check this out .
Now I agree that the original dialysate volumes were too low. I increased ours from 20 to 30  as I have posted. But actually with the on line calculater now available , I can see where it appears they have upped the volumes form 2 years ago . I got to 30 liters by using THEIR online calculator . It gave me the prescription of 30 liters at 5 days. I also know my wifes numbers from her blood draws pre an post show she is getting what is predicted for numbers so the calculator seems to work. I do beleive you could benefit from going to 50 liters as you have stated. That is not Nxstages fault, but the people in your clinic who wont listen to you.
So , yes its an imperfect system, but so is everything in life . All we can do is continue to strive for better. I commend you for all your efforts .
Given where we are in the US TODAY, I still prefer NXstage to anything else currently available here.  I am thankful they made home dialysis so easy for me to do for my wife, and how good she feels on it. 

[amanda100wilson]

 I admire the tireless work that John Agar dies for kidney patients. However he mentions trade offs, and how patients need to consider portability against more clinical outcomes.  At the end of the day though, he is an outsider looking him.  He clearly understands and empathizes with patients more than the majority of nephrologists, but he is not living with the reality itself and we have to consider the reality of trade offs.  The fact is that as patients we have to balance not only physical trade-offs but also the psychological aspects too. Having a huge machine that prevents travel is anathema to me.  I have a thirteen year old son and have been on dialysis for most of his life, and all of his life for the time he remembers.  To deny him the opportunity to enjoy simple pleasures of childhood is just not worth sacrificing.  Maybe I have a fatalistic attitude, but I have been dealing with this for more than twenty years.  I should have even dead twenty us years ago. I have had twenty plus years of bonus days.  I know that it is unlikely that I will have a normal lifespan.  I am at peace with that. In the meantime, I will continue to do the best I can for both my physical and psychological well
-being.  When a better portable option comes  along, I will definitely be interested.  Until then I will stick with my NxStage, together with its shortcomings, but also the benefits that I personally desire.

 
 

[Hemodoc]

NxStage is indeed a reliable and easy to use machine. It is also the choice of machines I went with back in June of 2009 understanding also the limitations of their low flow capabilities.

They have also set a new "low flow" standard that now accepted by the LDO's will be VERY hard to overcome as they now have the upgraded machine.  When Baxter and FMC with the PAK get into the market which will happen one of these days, who knows when, I was told by the ex-CEO of FMC that it would be FDA approved by January of last year. 

I won't hold my breath in getting the full 60 liter machine in a 4 hour session any time soon if ever. It sets up a choice for me when the Baxter and FMC PAK come on line of dumping NxStage. They will have to try and compete with this standard flow machines which are now called "High Dose." The marketing of the Baxter machine tells the story that NxStage has reset the dialysate flow curve standard and not to our benefit.

In that, the nephrologist of America are pretty uniform of their disapproval of NxStage. We are simply caught in a market where it is big, hard to manage, huge RO system and expensive plumbing and electrical work with the Baby K, or the simple to use NxStage that allows NxStage to expand the market.  I have been relatively silent about the deficiencies of NxStage in the last 5 years because it was the only real game in town. That is no longer true. However, I did set out the principles of what I needed NxStage to do back in my post in 2010. The volume is simple too low.

Interestingly, I had a conversation with Dennis Deneau, one of the inventors of the NxStage System One and a Vice President of the company, at the 2011 ADC in Phoenix where I spoke at the Saturday Home Dialysis Symposium. I bluntly told Dennis, give me a machine that can do 60 liters in 4 hours and I will be happy with NxStage. Their ultra-pure dialysate remains their biggest competitive factor. He told me, I don't believe we can do that, but you will be happy with our new machine coming out. I can't take credit for the new 60 liter capability, but I am sure I am not the only person that they had that request. For me to feel well, I need three days in a row of NxStage before I take my break. Two sessions leaves me a bit down as far as how I feel. That is on 40 liters. Their clearances are simply too low. For 4 hours of dialysis, I get a Kt/V of only 0.8 at best. That is a poor use of 4 hours as far as solute removal. If I can get above 1.0 in a single session, then I have taken NxStage to the max. Will I ever see that with the LDO's having studies such as the FREEDOM study showing them that 20 liters in 3 hours is all you need? I won't hold my breath.

As far as what your clearances are with short or long dialysis sessions, as I referred to you earlier in two pm's, using 30 liters of dialysate over 3 hours or 8 hours, the clearance will be exactly the same. Brent Miller of Washington Medical School in St Louis discussed that at the 2011 ADC as well.

[obsidianom]

I admire the tireless work that John Agar dies for kidney patients. However he mentions trade offs, and how patients need to consider portability against more clinical outcomes.  At the end of the day though, he is an outsider looking him.  He clearly understands and empathizes with patients more than the majority of nephrologists, but he is not living with the reality itself and we have to consider the reality of trade offs.  The fact is that as patients we have to balance not only physical trade-offs but also the psychological aspects too. Having a huge machine that prevents travel is anathema to me.  I have a thirteen year old son and have been on dialysis for most of his life, and all of his life for the time he remembers.  To deny him the opportunity to enjoy simple pleasures of childhood is just not worth sacrificing.  Maybe I have a fatalistic attitude, but I have been dealing with this for more than twenty years.  I should have even dead twenty us years ago. I have had twenty plus years of bonus days.  I know that it is unlikely that I will have a normal lifespan.  I am at peace with that. In the meantime, I will continue to do the best I can for both my physical and psychological well
-being.  When a better portable option comes  along, I will definitely be interested.  Until then I will stick with my NxStage, together with its shortcomings, but also the benefits that I personally desire.

As a doctor I absolutely see your point. Medicine is an art not a pure science. What is best on paper isnt always whats best for an individual patient. I try to practice that way. For you and many others Nxstage is a better choice because of factors like portability like you stated, or in some cases patients in rural areas with limited water(like me) who need a system that uses less water, or in many cases patients who simply need the easiest machine to use , or prefer more days on then they get with other systems.
There are always trade offs in real life medicine. Some patients have to take less medicine than ideal due to cost , or wont take optimum doses of medications due to side effects that they wont live with. There is always the quality of life issue that doctors should never forget. The patients have to live with the medicine or in this case the machine, and their quality of life cannot be discounted even if the treatment is sacrificed to some extent.
I have an inter5esting story as patient in my case rather than as doctor. When I was diagnose with stage 2 plus rectal cancer in 2006 I was told by all my treating physicians that the standard treatment would be a total perineal resection which would leave me with a permanent colostomy. Now I am an athlete and have been since I was a kid. i work out 2 hours perday even now at age 60 plus. I couldnt see myself accepting a permanent bag on my abdomen.
I did my own research and found an alternative that was common in Europe (but not in the US) and that involved less invasive surgery after chemo and radiation shrunk the large tumor. I was told by several doctors I would be risking my life and one told me I would "die needlessly". I stuck to my choice and ran my own treatment and found a surgeon who would do the local resection to save my body integrity. It is now 8 years later and I am still here. I was recently checked out by that surgeon who proclaimed me cancer free.
The moral here is that quality of life matters . As a patient I chose to go with a lesser quality procedure and risk death as quality of life is critical to me. I made a trade off knowing the potential consequences (death).  I beleive every patient should have their quality of life taken into account and allow them to make their choices accordingly.
For you and my wife, NxStage is the choice . Perhaps it isnt as "good" as standard dialysis , although I am not convinced of that. But it allows for a better quality of life for some.  Un til something better comes along, I am sticking with it for my wife.
(If I had the colostomy I am not sure I could care for my wife now and so the choice I made effected her just as yours effects your child).

[obsidianom]

NxStage is indeed a reliable and easy to use machine. It is also the choice of machines I went with back in June of 2009 understanding also the limitations of their low flow capabilities.

They have also set a new "low flow" standard that now accepted by the LDO's will be VERY hard to overcome as they now have the upgraded machine.  When Baxter and FMC with the PAK get into the market which will happen one of these days, who knows when, I was told by the ex-CEO of FMC that it would be FDA approved by January of last year. 

I won't hold my breath in getting the full 60 liter machine in a 4 hour session any time soon if ever. It sets up a choice for me when the Baxter and FMC PAK come on line of dumping NxStage. They will have to try and compete with this standard flow machines which are now called "High Dose." The marketing of the Baxter machine tells the story that NxStage has reset the dialysate flow curve standard and not to our benefit.

In that, the nephrologist of America are pretty uniform of their disapproval of NxStage. We are simply caught in a market where it is big, hard to manage, huge RO system and expensive plumbing and electrical work with the Baby K, or the simple to use NxStage that allows NxStage to expand the market.  I have been relatively silent about the deficiencies of NxStage in the last 5 years because it was the only real game in town. That is no longer true. However, I did set out the principles of what I needed NxStage to do back in my post in 2010. The volume is simple too low.

Interestingly, I had a conversation with Dennis Deneau, one of the inventors of the NxStage System One and a Vice President of the company, at the 2011 ADC in Phoenix where I spoke at the Saturday Home Dialysis Symposium. I bluntly told Dennis, give me a machine that can do 60 liters in 4 hours and I will be happy with NxStage. Their ultra-pure dialysate remains their biggest competitive factor. He told me, I don't believe we can do that, but you will be happy with our new machine coming out. I can't take credit for the new 60 liter capability, but I am sure I am not the only person that they had that request. For me to feel well, I need three days in a row of NxStage before I take my break. Two sessions leaves me a bit down as far as how I feel. That is on 40 liters. Their clearances are simply too low. For 4 hours of dialysis, I get a Kt/V of only 0.8 at best. That is a poor use of 4 hours as far as solute removal. If I can get above 1.0 in a single session, then I have taken NxStage to the max. Will I ever see that with the LDO's having studies such as the FREEDOM study showing them that 20 liters in 3 hours is all you need? I won't hold my breath.

As far as what your clearances are with short or long dialysis sessions, as I referred to you earlier in two pm's, using 30 liters of dialysate over 3 hours or 8 hours, the clearance will be exactly the same. Brent Miller of Washington Medical School in St Louis discussed that at the 2011 ADC as well.

I dont see why you are having such a hard time going from 40 to 50 liters as you are dumping the extra anyway. That makes no sense. I ran some numbers on a generic patient your size and NxStage calls for 50 liters at 5 days for a Kv/t of 3.0 which decent.  You are simply not geting enough volume . That is not Nxstages fault. That is the fault of your clinic. I think you might find you feel a whole lot better at 50 liters if you try it.
I hate going behind the backs of clinics but perhaps it is time for you. Why dont you try it for a week or 2 and see how you feel and get some labs done with it. Maybe that will convince them.
50 liters at the max. of 12 liters per hour is a 4 hour and about 10 minute treatment.  So it will only add 10 minutes to your time.
I have read several studies on the advantages of ultra pure dialysate including less inflammation and less heart damage. So that does remain a big plus for Nxstage.

[noahvale]

*

[Hemodoc]

Actually, NxStage is complicit since they have published quite a few studies in their FREEDOM series showing improved outcomes on 20 Liters. The LDO's are running with this now and as long as someone has a weekly Kt/V over 2.0, they say you don't need any more. Anyone trying to get the high flow NxStage is going to be hard pressed to provide medical justification for that to these for-profit dialysis providers. If nothing else, it will make a good opening post on my blog after not writing for about a year.

As far as my situation, it is all about control and shows the fact that they could care less about how I feel or how my outcome is long term. Pure evil really.

[Simon Dog]

Basic math. Same x volume at faster speed means shorter time on machine. You may get slightly quicker clearance but lose time which causes loss of the gain so it evens out .

We are still speaking on different wavelengths    Assume that my doctor prescribes a higher volume of dialysate since a higher flow rate allows me to use 1.5X liters of flow instead of X liters in a single treatment.     Consider a non-nocturnal treatment, and that with the 12L machine, my doc were to prescribe a volume that runs 4 hours at a 200ml flow rate.  Assume further that nocturnal is not possible, and that neither my doc or I consider a 6 hour treatment reasonable.  Would I see an improvement with 1.5X the dialysate, running at 300ml, over the same time?   We are NOT talking constant volume.

By the way - thanks to all who have replied, particularly hemodoc and obsidianom - this has been a fantastically informative thread.

[Hemodoc]

Basic math. Same x volume at faster speed means shorter time on machine. You may get slightly quicker clearance but lose time which causes loss of the gain so it evens out .

We are still speaking on different wavelengths    Assume that my doctor prescribes a higher volume of dialysate since a higher flow rate allows me to use 1.5X liters of flow instead of X liters in a single treatment.     Consider a non-nocturnal treatment, and that with the 12L machine, my doc were to prescribe a volume that runs 4 hours at a 200ml flow rate.  Assume further that nocturnal is not possible, and that neither my doc or I consider a 6 hour treatment reasonable.  Would I see an improvement with 1.5X the dialysate, running at 300ml, over the same time?   We are NOT talking constant volume.

By the way - thanks to all who have replied, particularly hemodoc and obsidianom - this has been a fantastically informative thread.

The short answer is yes, the higher you take NxStage on clearances, the better your solute clearance for you the patient. I first wrote about the NxStage clearances and WHY the standard NxStage dosage was not a correct philosophy back in January of 2009, a few months before I started on my own NxStage treatments in June of 2009.

http://www.billpeckham.com/from_the_sharp_end_of_the/2009/01/nxstage-dialysate-flow-rates.html

If you look at the pop out of the slide showing the dialysate flow graph, you will see visually that for every increase in dialysate flow rates along the entire curve, there is a corresponding improvement of clearances. I looked at the issue once again in a year later talking about taking the NxStage System One to the max.

http://www.billpeckham.com/from_the_sharp_end_of_the/2010/02/taking-nxstage-system-one-to-the-max.html

If you look at the graph in this post by Dr. John Daugirdas, you will see how single pool Kt/V measurements are correlated with frequency and the resultant weekly Kt/V. The goal of several devices known and some not known yet are to bring the weekly Kt/V to the 7-8 levels approximating 40 ml/min of renal function. One reason to set this level is that in children, if you don't get them to the 40 ml/min level, they won't grow. That is the level that Victor Gura is looking at with his latest version of the WAK. The prototype achieved 25 ml/min clearances.

So stating that a Kt/V of 3.0 is good doesn't give the whole story of where the innovative devices, many of which no one outside of the cloistered researchers have ever seen, and the direction that these researchers are heading and why they have this level of clearance as their goal. If that is what research states is the direction we should head, why wait 2, 3, 5 or 10 years until the FDA approves these devices in development today.  If I can achieve a weekly Kt/V of 4-5 by taking NxStage to the max, why wouldn't I do that now with the technology available right now?

If we don't push the LDO's to raise the limits, we will be stuck in the mortality and morbidity that has given America a black eye when it comes to dialysis issues. There is a truth in dialysis that holds true in almost all situations that more is better when it comes to improved solute clearances and increasing TIME and frequency on dialysis.

So, the short answer is yes, it will improve your clearances and the long answer following explains in part why.

[obsidianom]

Basic math. Same x volume at faster speed means shorter time on machine. You may get slightly quicker clearance but lose time which causes loss of the gain so it evens out .

We are still speaking on different wavelengths    Assume that my doctor prescribes a higher volume of dialysate since a higher flow rate allows me to use 1.5X liters of flow instead of X liters in a single treatment.     Consider a non-nocturnal treatment, and that with the 12L machine, my doc were to prescribe a volume that runs 4 hours at a 200ml flow rate.  Assume further that nocturnal is not possible, and that neither my doc or I consider a 6 hour treatment reasonable.  Would I see an improvement with 1.5X the dialysate, running at 300ml, over the same time?   We are NOT talking constant volume.

By the way - thanks to all who have replied, particularly hemodoc and obsidianom - this has been a fantastically informative thread.

First off , thanks to all who are reading this and the feedback. I enjoy adding what i can and drawing out from Peter some of his genius.
I have been ironically doing most of this while watching Nxstage work on my wife , while monitering her treatment. I marval at the engineering of dialysis machines .

Now to answer your question exactly, if you go to 300 ml per hour for the same time of 4 hours, you would get 72 liters of dialysate , which Nxstage cant do . It maxs out at 60 liters. At 200 ml per hour you get 48 liters total vloume. So in theory you gain more dialysate at a faster speed.  ____----BUT what do you really gain??
Well, if you look at Peters (Hemodoc) graph you see that with Nxstage you get 200 ml/per min clearance of urea at 200 ml/per minute dialysate rate or 1 to 1. Its a nice easy fit. What is interesting is at 300 ml/min dialysate rate , you only go to about 230 ml./min  urea clearance .  Not a big improvement. So by going up 50% in dailysate , you only gain about 15 % clearance. Not that much benefit really.
I agree with Peter that maxing out the 200 ml rate is still best. Running the standard machine at 12 liters per hour (200 ml /min) is most efficient. The high flow machine really is for larger people who need 60 liter treatments and dont want to go 5 hours . They can cut it to 3hour, 20 minutes at fastest.

[Simon Dog]

So by going up 50% in dailysate , you only gain about 15 % clearance. Not that much benefit really.

Excellent - this was the sort of answer I was looking for.  But, I don't see why I shouldn't go for the 15% gain if I am ambe to negotiate for the bigger system

The high flow machine really is for larger people who need 60 liter treatments and dont want to go 5 hours

What is the weight cutoff for "larger"?

[obsidianom]

Basic math. Same x volume at faster speed means shorter time on machine. You may get slightly quicker clearance but lose time which causes loss of the gain so it evens out .

We are still speaking on different wavelengths    Assume that my doctor prescribes a higher volume of dialysate since a higher flow rate allows me to use 1.5X liters of flow instead of X liters in a single treatment.     Consider a non-nocturnal treatment, and that with the 12L machine, my doc were to prescribe a volume that runs 4 hours at a 200ml flow rate.  Assume further that nocturnal is not possible, and that neither my doc or I consider a 6 hour treatment reasonable.  Would I see an improvement with 1.5X the dialysate, running at 300ml, over the same time?   We are NOT talking constant volume.

By the way - thanks to all who have replied, particularly hemodoc and obsidianom - this has been a fantastically informative thread.

The short answer is yes, the higher you take NxStage on clearances, the better your solute clearance for you the patient. I first wrote about the NxStage clearances and WHY the standard NxStage dosage was not a correct philosophy back in January of 2009, a few months before I started on my own NxStage treatments in June of 2009.

http://www.billpeckham.com/from_the_sharp_end_of_the/2009/01/nxstage-dialysate-flow-rates.html

If you look at the pop out of the slide showing the dialysate flow graph, you will see visually that for every increase in dialysate flow rates along the entire curve, there is a corresponding improvement of clearances. I looked at the issue once again in a year later talking about taking the NxStage System One to the max.

http://www.billpeckham.com/from_the_sharp_end_of_the/2010/02/taking-nxstage-system-one-to-the-max.html

If you look at the graph in this post by Dr. John Daugirdas, you will see how single pool Kt/V measurements are correlated with frequency and the resultant weekly Kt/V. The goal of several devices known and some not known yet are to bring the weekly Kt/V to the 7-8 levels approximating 40 ml/min of renal function. One reason to set this level is that in children, if you don't get them to the 40 ml/min level, they won't grow. That is the level that Victor Gura is looking at with his latest version of the WAK. The prototype achieved 25 ml/min clearances.

So stating that a Kt/V of 3.0 is good doesn't give the whole story of where the innovative devices, many of which no one outside of the cloistered researchers have ever seen, and the direction that these researchers are heading and why they have this level of clearance as their goal. If that is what research states is the direction we should head, why wait 2, 3, 5 or 10 years until the FDA approves these devices in development today.  If I can achieve a weekly Kt/V of 4-5 by taking NxStage to the max, why wouldn't I do that now with the technology available right now?

If we don't push the LDO's to raise the limits, we will be stuck in the mortality and morbidity that has given America a black eye when it comes to dialysis issues. There is a truth in dialysis that holds true in almost all situations that more is better when it comes to improved solute clearances and increasing TIME and frequency on dialysis.

So, the short answer is yes, it will improve your clearances and the long answer following explains in part why.

I agree with more is better with time and frquency. That makes sense as kidneys function full time and dialysis is very limited time. So more is clearly better. BUT------I am not at all sure about speed . (dialysate speed)
Lets look clinically since that is something we can all relate to.  I am hearing over and over about patients switching to the slower dialysate Nxstage system and feeling a whle lot better clinically. Again going back to my own wife it has been night and and day. Now in some cases that could be frequency as it is done more days then other systems.
But at least in some cases like my wife, we dont remove any fluid due to residual kidney function.  Going more days obviously makes UFF less stressful as less is removed daily. But if there is no UFF then we look only at solute clearances. Why does higher frequency (more days) dialysis lead to feeling better? Well the variable here is more time on machine done at slower speeds. We are getting the same kt/v but doing it slower and gentler.
My wife used to get awful headaches and feel quite ill after conventional in center dialysis. That is with NO UFF. The classic story I hear form hundreds of patients is they feel washed out and tired and often headaches after dialysis. Now on Nxstage none of that occurs for my wife (she feels energized after treatment) and for countless others. The main difference is the SPEED of dialysis or the urea cleance which runs under 200 ml/min on the graph. Conventional runs closer to 300 ml/min which is 50% faster.
Now to me as a clinician in thinking rather than a researcher , I would go with the slower gentler dialysis . Now reaearchers are working to get better systems as Peter has written. But remeber, research starts on models and then animals but cant measrure HOW IT FEELS clinically until it is tested on humans for years. Too many drugs have been developed by researchers with lab models and on animals that when used on humans either didnt work as well or caused significant, even lethal side effects later. Just because we can do something to the body doesnt mean it is in our best interest clinically.
Going back to basics. The body works on homeostasis. Basically it tries to even out or rebalance the system after any cahnges occur . this is especially true if we artificially change or perturb the system. We can effect change but the body will try to go back to its set point.
Now my point is we can clear the blood faster with conventional dialysis then with Nxstage . Say for example its 300 ml/min to 200 ml/min blood clearance. Now as the blood is cleared more of the solutes have to come from the inner 2 compartments (cell and interstitial) via osmosis /diffusion to fill the gap or vaccum that clearing the blood has caused. MY QUESTION STILL IS HOW FAST IS TOLERABLE TO THE BODY before we create side effects like cramps, headaches , fatigue and general ill feelings. As we perturb the nsystem and it tries to right itself to homeo stasis we can pay a price clinically in feeling ill.    Example ; we can technically lower blood pressure by taking off a lot of fluid and dehydrating the patient. But they will feel lousy and then homeostasis comes into play and the body will try to right it by increasing our thirst and reabsorbing water and decreasing urine output.   Eventually it will fail and blood pressure will evn out as it was before through homeostasis.
Going too fast with dialysis because we can doesnt mean we should. I still want to see long term studies (over 5 to 10 years ) on a slower dialysate model such as Nxstage.
The other issue is the kidney is a very complex organ that is not simply a filter as some seem to think. Yet we do dialysis with just 2 things going on. We filter the blood through a counter current filter system and we remove fluid via hydrostatic pressure. We use fixed dialysate chemisty that dosnt have flexibilty to regulate sodium or calcium well for example. There are articles out now questioning this and why we dont have more variable dialtsate with flexible sodium and calcium levels. So we are still very backward in our technology . This may be more important then simple solute clearance.  WE also need to look at the other basic functions of the kidney and try to mimic them.
Without getting too esoteric, the kidney transports ions and solutes across the loop of Henle with very low differentials between the osmotic pressures on both sides. So there may be a lot of filtration of blood but at the osmotic levels it is slow and gentle. Perhaps there is a lesson there for us in looking at dialysis . Perhaps NxStage has bumped into something that we should be looking at . Slower dialysis may mimic more closely what really goes on at the basic levels of kidney physiology. Clinically they seem to have a product that creates a less harsh dialysis and people feel better on it. Isnt that some of what medicine is about?  Remeber the motto "First do no harm".   
 

[obsidianom]

So by going up 50% in dailysate , you only gain about 15 % clearance. Not that much benefit really.

Excellent - this was the sort of answer I was looking for.  But, I don't see why I shouldn't go for the 15% gain if I am ambe to negotiate for the bigger system

The high flow machine really is for larger people who need 60 liter treatments and dont want to go 5 hours

What is the weight cutoff for "larger"?

There is no exact cut off. They use a calculator (it is on line for medical people to use) that takes into account weight, height, sex, age, hematocrit , and UFF needs. I ran a generic for you base only on weight and I beleive it came out to about 50 liters but again that is very generic without your particulars and also without your blood speed and other info. You could easily run 50 liters on the slower system at 12 liters per hour for 4 hours, 10 minutes.

[Simon Dog]

You could easily run 50 liters on the slower system at 12 liters per hour for 4 hours, 10 minutes.

Great info - thanks again.

This would put my treatments on par with what I do now with the BabyK, though I only do 4 days a week with that systems (Tues/Thurs/Sun 4 hours and Friday for 3 hours),  so it appears that for me the option would be "daily" rather than "short daily".    Given that, I wonder if there would be a benefit to NxStage 5 or 6 days a week as opposed to increasing the BabyK frequency.  They don't make figuring this out easy.

But, the real issue is getting onto nocturnal with a slower blood flow.