Hi Prof. Agar,
I am honored to ask the first question. When it comes to nocturnal dialysis, what do nocturnal docs look at to determine that the scrip has been optimized as much as possible so that the patient is getting the most efficient nocturnal tx possible ?
Dear Jane
Though this may sound contradictory to what follows, the first thing to say about optimising the dialysis prescription is that there is no one optimal prescription. This is one of the whole problems with the way most nephrologists currently think of dialysis and of our dialysis patients - as one single conglomerate, and not as a whole bunch of individuals.
Dialysis can only be optimal if it is individualised. This means that every person is different – different sex, different age, different body mass, different co-morbidities, different everything. To think that we can write a prescription that covers all people is naive and just plain wrong. Yet that is exactly what we do. Most patients have the same dialysis duration, frequency, dialyser, blood flow rates, dialysate flow rates, dialyser, dialysate compositions … the whole kit and caboodle.
This said, I do have a few personal rules of thumb and strong views about what constitutes good dialysis. Above all else, the most crucial component of ‘optimal’ dialysis is the number of weekly hours of dialysis that are completed. Clearly, this implies a mix of time and frequency and, no matter how you cut the deck, I keep coming back – and will keep coming back – to this simple formula and concept.
This will clearly indicate to you that I am not a particular fan of short daily haemodialysis. We do not have equipment in Australia that encourages the uptake of short daily regimes … and I must say that personally, this does not bother me a jot. Though short daily treatments offer frequency, they do not offer time. Removal rates of fluid in particular thus remain high.
Nocturnal dialysis implies long treatment time as well as the opportunity for more frequent treatments. One must presume that most people who do nocturnal dialysis actually do sleep through the night on their machines. In Australia, this is commonly between eight and nine hours of treatment. By lengthening time, one can slow the dialysis process down. Dialysis becomes more subliminal. The ultrafiltration rate (UFR) can be reduced such that the rate at which fluid is removed from circulation gets down to the low the rate at which the plasma can be refilled from the body. This simple act diminishes or abolishes any effect on the circulation and blood pressure and therefore minimises the risk of’ flats’ and dialysis related symptoms.
Just as important, however, is dialysis frequency. Scribner and Oreopoulos once rather naïvely coined a concept in 2001 that they called ‘the haemodialysis product’ … a compilation of time and frequency (txf2). They advanced this concept as a possible measure of dialysis adequacy. As much as I admire Scribner and Oreopoulus, their concept was , I think, too simplistic. Nevertheless, I think they were on the right track in identifying the two most important things in good dialysis … time and frequency.
In the United States, much of the nocturnal dialysis is delivered in centres where, as I believe, overnight treatments are still only delivered three times a week, even if for a longer treatment time per session. Unfortunately, this does not overcome one of the great disasters ‘we’ - the treaters - have visited on dialysis patients … the’ long break’. Carl Kjellstrand, a wise yet outspoken dialysis guru whom I much admire, describes the long break as’ the killer break’ … and he is right.
In Australia, nocturnal dialysis is delivered almost exclusively at home. There is only one very small centre experimenting with overnight dialysis in a facility. Our patients on nocturnal dialysis are home patients. In addition, our funding mechanisms permit patients at home to dialyse when and how they wish, making it easy for them to embrace longer (nocturnal) treatments and more frequent treatments … abolishing the long break. In addition, the total dialysis hours/week are maximized.
In my view … though you may think I am biased … all optimal outcomes stem from the capacity to do longer and more frequent treatment. Not only can the UFR be lowered, but so, too, can blood flow rate (we run between 225 and 250 ml/min pump speeds) and the dialysate flow rate can be lowered (we run 300 ml/min). In my own view, a lower blood flow rate is kinder to the fistula and a lower dialysate rate is kinder to the environment and to water use (another of my hobby horses and now dealt with in a special new chapter at my website on dialysis and the environment. And, if dialyzing longer and more frequently, who needs ‘bazooka’ blood flow rates and high dialysate flow rates.
More frequent and longer treatments remove solutes better too. I think you were one of the attendees at webinar I gave on this subject at HDC. You may wish to replay that webinar to refresh your memory on this issue. You will also find these issues discussed at my website … http://www.nocturnaldialysis.org.
With nocturnal dialysis, potassium control is easier … indeed, most of our patients (not all) run 3K baths and have a free dietary potassium intake.
Phosphate control is so efficient with frequent nocturnal dialysis that phosphate replacement may be necessary – particularly with five or six night/week nocturnal dialysis. We use fleet enema pack added to Part A. We decide how much to add by performing a few estimates of the pre- and post- dialysis phosphate levels over the first week or two after a patient converts to nocturnal therapy. We aim for the post dialysis phosphate to skim the lower limits of normal and we ‘titrate’ … adjust … the amount added to achieve this. This may vary over time (as diets change) … so we keep an eye on the post-dialysis phosphate each couple of months, adjusting the added phosphate as need be. If the nocturnal treatment is only every alternate night, phosphate removal seems to be just about right and binders can be avoided yet additional phosphate replacement also being unnecessary. In frequent nocturnal programs, most (though not all) patients will need some phosphate given back. This has to be tailored to each patient.
In the US, where the NxStage machine is popular, there is a problem with administering phosphate (if it is needed). We use single pass systems in Australia – in my unit, Fresenius B machines – for our home nocturnal patients and phosphate replacement is not difficult.
There seems to me to be a preoccupation among US patients with ‘labs’ … or as we say,’ bloods’. Don’t get me wrong – they are important to know – but a well patient, broadly, will have normal ‘labs’!
Firstly, Kt/V is irrelevant in high-frequency long hour treatment regimes. We don’t measure it. Why would you? It means nothing.
We measure pre- and post-biochemistry every 2 to 3 months. We teach our patients to use a centrifuge and spin their own bloods at home. They do this every 2 to 3 months. They drop the bloods and the centrifuge back to the unit and see us in clinic either the same day or shortly afterwards. We see our stable home patients at clinic every 2 to 3 months. There is no need to see them more frequently if they are well. Indeed, most Australian patients, by and large, prefer us to be ‘out ‘of their lives when they are well, not ‘in’ them. Clearly, if they are unwell, we are prepared to see them as often as necessary but why interfere and call a patient in when things at home are good. Although I am very proud of our strong and robust home support systems and they are there if the patient needs them, we do not intrude if there is no need to do so.
Back to your question ‘what is optimal nocturnal dialysis’? In a nutshell, long and slow, gentle treatment, abolition of the long break (at the least), higher frequency therapy, gentle and low blood flow rates, a free diet and free fluid intake (without guzzling), minimal intrusion into the life of a well patient but strong, robust, flexible and rapid response support systems when they are required, infrequent laboratory measurements in well patients although those measurements should be both pre-and post-dialysis.
Above all, each patient is an individual. Each patient is different. Each patient must have a regime tailored specifically for them and no one ‘prescription’ can fit all.
John Agar
Very instructive, thank you! I have a number of questions not necessarily in order, but as they come to mind:
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Since nocturnal is done in Australia to fit in with one’s natural sleep and supposing one is doing txs at least 6x, does it matter significantly if one is doing 6 or 7 hr txs as opposed to 8 or 9? Or put another way, is there a minimum number of hrs/days per week one must treat to have gentle txs plus optimal results?
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What does all the individual factors of a patient’s wgt, body mass, age, sex, co-morbidities etc. have to do with one’s scrip?
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Do some patients in your country dialyze 7x due to not feeling well on the off day due to sensitivity to fluid and toxin build-up?
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How important is dialysate volume as compared with time/frequency?
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Patients run at 225-250 BFR. Is there any reason why one could not run at a 200 BFR?
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Are all labs run pre and post or just certain ones like PO4, K and bun? How soon post tx are the post labs taken?
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If some lab values are going to change and need adjustment in 2-3 months which ones would it be most likely?
I very much like the Australian philosophy of providing optimal txs which enables patients to live with less problems and more freedom.
Very instructive, thank you! I have a number of questions not necessarily in order, but as they come to mind:
First – as I said in my previous post, I am actually away on my annual leave this week – so though I will answer these, briefly, perhaps you could wait with more till I return.
1) Since nocturnal is done in Australia to fit in with one’s natural sleep and supposing one is doing txs at least 6x, does it matter significantly if one is doing 6 or 7 hr txs as opposed to 8 or 9? Or put another way, is there a minimum number of hrs/days per week one must treat to have gentle txs plus optimal results?
[B]I tried to answer this in my 1st post: (1) Longer is better (2) more often is better (3) a combination of both is best. This clearly must dovetail with living and life – for isn’t that what a person dialyses to achieve? Better living and lifestyle? I will try to explain it in a different way: we all must make compromises as we live – whether in day to day living … or in dialysis. As regards dialysis: we should try to find the very best dialysis outcomes that we can, but within the compromise of lifestyle that we are prepared to allow.
With dialysis: longer and more often is better. That is my view. But, we are all different, Jane. We all have different ‘tipping points’. So … within that framework that each of us have - and each person will have different aspirations, different needs, different expectations of and from their treatment and their life … we should, for that individual, seek the best possible dialysis we can, given that from a dialysis aspect, more and more often is better.
So, please let’s move on from ‘minimum’ and ‘maximum’ to simply say that more is good. I have already made that point. How MUCH more, is for the individual to set within his/her levels of lifestyle tolerance. I cannot put a ‘set’ number of hours, a ‘set’ number of times a week. It is fruitless to enter into that debate. Clearly, no one will agree (until the day of wearable dialysis becomes reality) to dialyse 24 hours a day, 7 days a week. So, if more is good – it comes down to how much ‘more’ an individual feels comfortable with, yet can achieve what dialysis is supposed to achieve: keep him/her well … and allow as open and as unrestricted access to ‘life’ as is possible.
End of the debate.[/B]
2) What does all the individual factors of a patient’s wgt, body mass, age, sex, co-morbidities etc. have to do with one’s scrip?
[B]Clearly, big people are different to small people. Their muscle mass is different. Their blood volume is different. Their solute load is different. Older people tend to be frailer. Co-morbidity means the co-existence of all sorts of things which might need modification of the dialysis process: bad hearts which need medication which might complicate their dialysis, or cause a greater intolerance of excess fluid loads … or intolerance of rapid fluid removal on dialysis (this was explained in detail in my Webinar on fluids: see the HDC home site) …, bad eyesight or arthritic hands that might preclude self needling.
All these impact on the way we prescribe and conduct and run a dialysis treatment. And, as I tried to make the point in my first answer to you, each patient is an individual and … in the best of all dialysis worlds … each treatment is, to some extent, individual too. Clearly, there are limitations (life abounds in limitations and compromises) to the degree we can vary each dialysis variable for every patient, let alone vary within each patient for each treatment. We’d all go ‘potty’.
Commonsense must play a part.
But … commonsense also says that the same surface area dialyse, the same dialysis time, the same dialysis frequency, the same UFR the same flow rates etc. etc. … for a 38 kilogram 82 year old woman and for a 145 kilogram 26 year old man would be nonsensical. So, yes, weight, body mass, sex, age, co-morbidity … all matter! All (and others, too) impact on how dialysis should be constructed for that individual patient.[/B]
3) Do some patients in your country dialyze 7x due to not feeling well on the off day due to sensitivity to fluid and toxin build-up?
Indeed, I only know of a handful of patients who actually DO undertake 7 x week dialysis in Australia. I doubt I would if I were on dialysis. I know I’d want a day or two off a week … but not (for me) more than that. I don’t think a day off a week – or even 2 (but not in a row) – is particularly damaging. I would need to weigh up – for me – which is more damaging … dialysis EVERY night (sigh) or feeling badly and doing badly by having less (and inadequate) dialysis. For each person, that answer is likely to be subtly different.
But, try to get away from the minutia of toxins and build-ups and prescriptions to the big picture … and yes, I again come back to it … the big picture is: how much dialysis does an individual wish to do within the limits of his/her lifestyle.
4) How important is dialysate volume as compared with time/frequency?
Not very.
5) Patients run at 225-250 BFR. Is there any reason why one could not run at a 200 BFR?
[B]BFR does matter … a bit. For people accessing over (say) ~40hrs/week or more … and PLEASE don’t take that 40 hrs as literal (I use it ONLY as a figure plucked for the air to split ‘very long’ from ‘less long’ dialysis … 40 hours holds no magic connotation of ’goodness) … then a lower blood flow rate is OK.
If I might make a comment here on ‘numbers’ … think in terms of lower or higher, longer or shorter, faster or slower, more or less frequent. The application of ‘a number’ to the various parameters or ‘prescriptions’ of dialysis is part of the problem! We are individuals. We do not all work to the same rules. The fun of physiology is that is changes, day to day and from person to person. Please, don’t think numbers all the time. A ‘number’ that applies to you will NOT to another.[/B]
6) Are all labs run pre and post or just certain ones like PO4, K and bun? How soon post tx are the post labs taken?
[B]Most blood tests are done pre-dialysis except that, post-dialysis, we also do electrolytes, urea, creatinine, FBE, Ca++ PO4 and CaPO4 product and a few other less frequently done post-dialysis tests.
Our patients have a home centrifuge (this is discussed at my website http://www.nocturnaldialysis.org ) and take their bloods – just like the nurses take blood, post dialysis, in a unit – within a minute of pump cessation. They then spin and store and then return (or post in) to the laboratory after they come off dialysis.[/B]
7) If some lab values are going to change and need adjustment in 2-3 months which ones would it be most likely?
[B]In long and more frequent dialysis, perhaps phosphate replacement is the main ‘adjustment’, time by time. As well, maybe a bit more potassium may be needed in the diet or the calcium concentration in the dialysate may sometimes need to be tweeked.
Not a lot, really. We have got things pretty sorted out , so not too much needs fiddling with, visit to visit, in the long hour, high frequency/week patients.
Dry weight and pre and post BP assessment with changes in post dialysis weight range is the commonest – as people do gain and lose weight over time … but our patients are taught to make these adjustments themselves and most get this pretty right without us having to interfere.[/B]
I very much like the Australian philosophy of providing optimal txs which enables patients to live with less problems and more freedom.
If I can underline one last comment, Jane, it is to repeat this … … … try to think in terms of lower or higher, longer or shorter, faster or slower, more or less frequent.
Dori said:
"Hi Jane,
Those forums are open! Dr. Agar will be taking several vacation days starting next week, I think, but ask away."
Sorry to post again too soon. I took Dori to mean you would be away, but to go ahead and post and you would answer when you returned. I respect your time and wish you a good annual leave.
Jane
I don’t know where the post that was on here a moment ago went to, but below is my response when asked what HDC does and my part in bringing about the Ask Our Experts feature:
Hi and welcome!
I view HDC as a gateway site to home dialysis therapies. I have long encouraged the moderator, Dori, to bring in every form of dialysis education possible as “knowledge is power” when it comes to successfully dealing with kidney disease. I will let Dori give you an overview of the educational opportunities available here. This latest endeavor to bring dialysis professionals in to simply answer patients’ and others’ questions, is a project I am particularly proud of inspiring. First came the webcasts where dialysis professionals speak to a specific topic for about an hour or so followed by a brief time of patients’ and others’ questions. And next has come this new, Ask Our Experts feature wherein patients/caregivers/ dialysis professionals can ask whatever questions they desire, and experienced dialysis professionals/experts who specialize in one, or more, disciplines of dialysis care provide intensive, one-on-one responses in a timely manner, at the teachable moment. I am very gratified that HDC, with Dori at the helm and social worker Beth’s frequent input, has stepped up to the plate to make HDC a site of growing value to the dialysis community to provide educational services that truly make a difference.
Hi Jane,
I’m afraid that was a spam post, so I deleted it and permanently banned the user. 
Yes I got those vibes, too, but saw it as an opportunity to sing the praises of HDC one more time : )
Oh, feel free to do that any time you like! 