NxStage and high bp

Hello I’m being trained to use the NxStage machine. After 5 straight days of dialysis, 4 hours per treatment and having reached my dry weight ( I could hear my voice was hoarse from dehydration) my blood pressure is still high. 160/90 sometimes 170/100. This is the 4th week of training.

I was on PD for 6 years. In center hemo for 1 year, then home nocturnal on the Fresenius 2008k2 for 8 years, now being trained on NxStage. In the past by bp was mostly 120/80 to 130/90.

The high bp gives me headaches and sometimes dizziness. What should I do? What’s the cause?

Thank you!


I am very sorry to hear of your problems. I used to have high blood pressure but since I receive such frequent dialysis, I no longer have an issue. In fact, my blood pressure is frequently low after dialysis.

I am not a doctor, but you may have an issue not directly caused by dialysis. I would seek the advice of a cardiologist. Sorry that I cant diagnose your issue. It seems that the longer were on dialysis, the sicker we get.

Dear Realistor:

The answer I will give is far more complex than you might have thought, but I will try to keep it as simple as I can.

You say you have ‘reached your dry weight’ and though I note your reasoning for that is ‘a hoarse voice from dehydration’, and that your ‘blood pressure is still high.’ Although these are both clearly troubling for you, I am not sure that they necessarily mean what you think they do - or at least, are not the whole story. Can I suggest you also consider some of the following points - all of which have been proffered without any knowledge of other key variables like: age, gender, body weight and habitus, medication, co-existing disease (diabetes, cardiac disease etc.), and other past history - as all or any of these may temper/change the responses I give below. That said, here goes:

Firstly, and importantly, you do not say whether you are on any anti-hypertensive medication … for if you are, then by definition – dry mouth or otherwise – you re not at dry weight. There are other reasons why your mouth may be dry … specifically, the rate of volume removal during dialysis.

We have all learned much from Bernard Charra and Charles Chazot in Tassin (near Lyon in France) whose experience in volume management in HD since the 1970’s has shown that one can only be at dry weight if all anti-HT medications have been ceased and the blood pressure has normalised (pre and post dialysis) with pre-BPs in the 135-140/- range and post BPs in the 120/- range. To achieve this also requires long, slow volume removal – in their program: 8 hours x 3-4 x week.

If you are on (or require) BP medication(s), then you are not at dry weight – even if you might think you are. Further, if you are on BP meds (hopefully not), then are you withholding them prior to dialysis? If you are not, then this is something to discuss with you team … though also if you are, I would argue this is also something to discuss with your team.

You do not give your body weight, nor your inter-dialytic weight gains … but these measurements matter, as a 4 hour treatment – even if you think this should be long enough – may still be removing fluid at a (xxx) ml/kg/hr rate sufficient to dry out your mucous membranes (your dry mouth and your sensation of an altered voice) yet fail to control your BP – or even cause your BP to rise (yes, rise) through dialysis such that your exit BP is greater than your entry BP. This latter phenomenon is often called ‘paradoxical’ intra-dialytic hypertension. This phenomenon is symptomatic of chronic fluid overload (yes, overload) … and is present in +/- 15% or so of all dialysis patients, despite that they (and their professionals) believe them to be at ‘dry’ weight. Can I suggest that you copy and enter the following URL into your browser: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4854275/ … then read the first 18 words of the ‘Summary’ paragraph. The rest gets a bit hairy, but that will give you a sense of where the rest leads to.

Can you also read my ‘primer’ on dialysis weight at the KidneyViews site … see: http://www.homedialysis.org/news-and-research/blog/201-A-Primer-on-Haemodialysis-"Weight"
= one of my 75 or so blogs about better dialysis at KidneyViews … it will help you (I hope) to better understand weight on dialysis.

Importantly, it seems that you have switched from a system (the Fresenius 2008K) that permits the dialysate sodium to be easily varied, to one that does not. You do not say what the Fresenius sodium setting was set at, back in your better (if I might say so) period of 8 years of (I presume BP-stable) nocturnal home HD on the Fresenius 2008K, but I wonder if it was in the 137-138 range = a common setting range and a range we often use. A key difference is that the dialysate sodium in the Pure Flow created dialysate is set (and unalterably so) at 140, as best as I know … see https://www.nxstage.com/wp-content/uploads/2017/08/NxStage-Therapy-Handbook-APM907.pdf (scroll to page 39 for dialysate fluid compositions). The Pure flow sodium concentration is fixed and cannot be individualised or adjusted - again to the best of my understanding.

The dialysate sodium is (or can be) a critical component in BP, volume and dry weight management … and I would venture to say that the 140 delivered by the Pure Flow might be a tad high for you. Another uncertainty is whether the Pure Flow sodium is actually 140 … as dialysate sodium concentrations can sometimes be more then we bargain for! We often run sodium concentrations of 137 or 138 – we vary them from patient to patient as it seems fit – in order to encourage sodium efflux and fine-tune volume management. Unfortunately, the NxStage system does not permit individually variable dialysate constructs – at least for sodium – one of its several Achilles heels. It might be interesting for your team to sample the dialysate your Pure Flow is creating for you and determine if the actual sodium concentration is the 140 that it is said to be.

As one who has spent a long professional lifetime arguing for the benefits of longer, slower, gentler, more physiological haemodialysis, it is something of a mystery to me why you would chose (or have had ‘chosen’ for you) to switch from a single pass system in the ‘longer, slower, gentler, more physiological’ setting (with, perhaps, a lower sodium setting on the machine), to a short hour, un-adjustable sodium system. But … I won’t go there.

It would be of passing interest to see what your ml/kg/hr calculations were (doing several serials) using the UFR calculator I devised with the help of our team, here, in Geelong for the Home Dialysis Central site and that has been available (and widely used) since early 2017. You can find this at https://www.homedialysis.org/ufr-calculator … You may find this useful and, if your clinic is not using it, I hope I might be forgiven for asking why not?

If (1) you do plug your numbers in and (2) if you do find you are in excess of 8ml/kg/hr = our current recommended maximum, then there are several steps you can take to ‘get there’.

… wean from all anti-HT drugs, preferably following the Tassin Guidelines

… to achieve a target UFR <8ml/kg/hr, these are the three key imperatives:
 Drink less fluid in the inter-dialytic period (easier said than done)
 Control and strictly diminish your inter-dialytic sodium intake
 Lengthen your dialysis sessions such that the UFR is reduced to <8ml/kg/hr (max.)

There are many more nuances that I could pack this answer with, but these key points do give you a starting point.

But … discuss all these points with your team.

Remember: any advice over the Internet is given (despite with all good intention) without ‘knowing’ you, as an individual … and your team does

Internet advice is given without knowledge of your individual history’
… what is your age, weight, height, gender (none have been given)
… are you diabetic – that changes stuff
… do you have cardiac disease – that changes stuff, too
… etc.

Hopefully, though, this will give you some threads to follow up with your team.

Good luck


The NxStage cycler is FDA-approved for nocturnal dialysis. Would you consider doing nocturnal HD again? The longer, slower treatment might improve your fluid and toxin removal as well as your BP.

Thank you so much for the detailed responses. So to answer some of your questions:

I’m a 47 year old male, my dry weight is 63.5kg lifestyle is mostly sedentary. Medication I’m on is 40mg of Propanalol and 5mg of Amlodipine per day. These are the antihypertensives. I’m also on 60mg of Sensipar and 6mcg of Hectorol 2 times a week and 4mcg once per week for the parathyroid. 20mg of Pravastatin once a day for cholesterol. I don’t have diabetes nor cardiac disease.

Edit: I forgot to list 25mcg Aranesp and 100mg of Venofer once per week.

Right now during training, we are doing 4 hour treatments 4 to 5 times per week but Saturdays and Sundays off so 2 days in a row with no treatment. I gain about 2.5 liters of fluid those 2 days off. The days in a row of treatment I gain much less, 1 to 1.5 liters of fluid.

Last week, Thursday and Friday my BP was a lot better, so that leads me to think I just needed a few days in a row of dialysis treatment to remove more fluid and toxins. Although I still need the antihypertensives. Though they are a low dose maybe I will be able to be weened off of them when I do home hemo as the plan is not to ever take 2 days off in a row, unlike during training.

I will be doing nocturnal HD when I do it at home, and that will be next week. Though the plan, at least for now, is 4 hour treatments because with the NxStage machine Heparin must be given as a bolus at the beginning of each treatment and cannot be administered during treatment. At least that’s what I was told. I wish it had a Heparin pump like the Fresenius machines.

They switched from Fresenius to NxStage for home treatments at the unit so I wasn’t given a choice. I would have prefered to stay on the Fresenius machine. On the Fresenius machine the sodium was set at 138.

I don’t use the PureFlow system on the NxStage, I use the premixed bags. Though I do have a choice if I want to use PureFlow I can, but there is a bit more training involved and more set up time per treatment. The pre-mixed bags are also set to 140 sodium and as far as I know are not alterable, as in they don’t offer bags with lower sodium.

I plugged in the numbers into the UFR calculator link you gave (Thank you for that also, great link!) and got this result:

Your Ultrafiltration Rate (UFR):

5.8 ml/Kg/hour

Great! You are in the green. Your HD treatment is removing water at a safe rate for you.

Thank you all so much and Happy Holidays to you!

Hi Realistor,
You might want to join the Home Dialysis Central Facebook Group at https://www.facebook.com/groups/HomeDialysisCentral. It’s a closed group of over 5,000 members (patients, care partners, and professionals). What you post there stays there and non-members can’t see members’ posts. Several members use the NxStage cycler to do nocturnal dialysis. Patients and care partners are always willing to answer questions and support each other. You could ask members of the FB group how they dose heparin when doing nocturnal dialysis.

A couple of things:

It looks like you are settling down (BP-wise) = good. And yes, your should be able to stop your anti-HT meds (propanolol and amlodipine) once you start on more regular (no-long-break) therapy at home. I would probably drop the amlodipine first and the propanolol second - but that is a decision for your team. As you drop each of them off, you BP may edge a little higher - but not alarmingly so - and this should allow a compensatory but small downward adjustment in your target weight.

We have long been using enoxaparin (here in Australia, marketed as ‘Clexane’). Enoxaparin has a half life of 4.5 hours c/w heparin with a half life of 60-90 minutes … this allows many/most of our many home nocturnal patients to potter happily through a full 8 hour treatment on a single up-front dose. Perhaps your team might consider this option. Of course, here, drugs are all covered by our universal health care system, so cost is not an patient issue. I am not sure of the comparative costs of enoxaparin to heparin in the US … nor whether you would have to pay for it or whether your program covers it, as it does here.

I am very comfortable with your calculated UFR though your weekend (long-break) value would likely be a bit higher. Still, 5.8 ml/kg/hr is a nice number!

It is a weakness of the NxStage system - Pure Flow or the System 1 bags - that they do not allow/permit sodium adjustment … but, enough said there! All our patients use Fresenius machines though here we use the 4008S and not the 2008K … Fresenius do not market the Baby K in Australia as the Asia-Pacific use the European (German) models and not the US ones = quite different machines.

We do not use the NxStage here, for a variety of reasons.

Finally, Beth’s suggestion re the FB site is a good one - but there ARE some odd ideas and, sometimes, some incorrect information often based on an incorrect understanding or ideas transposed from centre-based care into home care without a full realisation that home dialysis is a very different beast and it is not simply an equivalent therapy with centre-based care transposed into the home.

So, if you do join/use the site, learn to get a sense of those that are experienced and uniformly helpful vs. those who may be ‘a little less so’. There are many awesome, experienced, savvy, and ever-helpful fellow dialyzors on the HDC FaceBook site, but, sit back and watch a while before you leap in. Learn to pick (as I think you easily can and will) those contributors - like Henning Sondergaard, for instance - who know their stuff and separate them from those who don’t. Just be aware that not all that is said - often with deep conviction - is necessarily correct.

Hi John,

I would be interested to know the reasons why you don’t use Nxstage?

I choose to use it mainly because I will occasionally stay with my parents and can dialyse there.
It is very difficult to find dialysis places where my parents live but I’m interested in my long term health.

Thank you,

Dear Suzi

I feel I have answered this so many times, I simply cant go over it yet again.

I have discussed this in many forums.

It is NOT that I don’t admire/salute the NxStage for the freedoms and home concepts it (almost single handedly) introduced to the US - long after the rest of the world understood that home HD was not only a viable option, but the best option. For that, NxStage stands alone - in the US at least.

The trouble is that for a raft of reasons, we find the NxStage offers less than other systems, especially in the quality of dialysis - notwithstanding the advantages in size and transportability. Others may disagree, but, well, thats been my view.

To understand this better, you might like to pick up and follow an old thread @ Concerns with the NxStage System One?

This thread DOES reference long past discussions with other HCD users but maybe Dori or others may like to fill in these gaps.

Maybe this will help.