Frequently Asked Questions
The following are some of the questions that have been received. The answers are those that were returned by email. For ease, they are grouped under topic headings.
To protect contributor privacy, some questions have been edited. Although I can not acknowledge them by name, I am grateful to all who have sent questions and comments. Their efforts have helped to strengthen this web site.
Would you say NHHD approaches the long-term outcomes of a transplant? Is NHHD the best option for those who can’t be transplanted and/or for keeping patients on the transplant waiting list healthier while they wait?
In Australia, about 25% of all dialysis patients are on peritoneal dialysis (PD) and 75% on haemodialysis (HD). My own unit has some 30 PD and 110 HD patients and closely approximates the average national 'split' quite closely. About ½ of our PD patients are on automated peritoneal dialysis (APD) using Baxter Home Choice 2 machines while the other ½ use continuous ambulatory peritoneal dialysis (CAPD), doing manual through-the-day 'bag exchanges'.
Do not, however, confuse the two techniques. HD and PD are quite separate and use quite different principles.
HD effectively 'washes (or filters) the blood'. Blood is removed from an ‘access’ device placed in a large blood vessel. ‘Access’ to the blood is (1) most often via a surgically created 'fistula' in the forearm or upper arm or (2) especially in the US, through a surgically inserted artificial blood vessel (graft) in the forearm or (3) from a jugular vein catheter at the base of the neck. The blood is then passed the blood through a filter (dialyser) inside which the wastes and excess fluid removal occurs. The cleansed blood is then returned back through the same ‘access’ device.
PD is where a soft pliable tube called a Tenckhoff catheter is surgically placed into the tummy cavity through the front wall of the belly. Some get the wrong idea that this catheter goes into the stomach ... no - it goes into the cavity in which the abdominal organs lie, not into the organs themselves. Through this tube (or catheter), fluid is 'cycled' either during the day by the patient manually running 2-3 L of fluid in, leaving it to ‘dwell’ inside for a few hours before then draining it out and replacing it with fresh fluid. This usually requires ~4 cycles per day with each 'exchange' process taking 30-40 minutes. Alternatively, the same process can be done but in an automated fashion by a 'cycler' machine at night. This automated process is known as APD and though it is carried out through the night, it should not be confused with NHHD.
Though APD and NHHD both occur during sleep - and as I noted, we offer and encourage both - this is about the sum total of their similarities.
Both HD and PD are effective. Both have advantages and disadvantages. Some patients are more suited to one than the other.
Make no mistake: APD is an excellent treatment. It doesn't suit all patients - no single option in dialysis does. It’s a matter of sizing up all available choices (and there are many) and choosing the one that appears to be optimal for any one individual patient. This may depend on a range of factors - age, sex, geography, dexterity, vision and underlying disease - diabetics for example often do very well on peritoneal dialysis - etc etc.
Don’t confuse NHHD (a very specific and new form of HD) with APD (a very specific and long-available form of PD). The only real similarity is that they both are done during sleep and leave the daytime free. In that, I am personally a very strong believer in and advocate for both NHHD and APD.
There are no absolute contraindications to NHHD in country areas though if the patient’s home doesn’t have ‘town water’ (a reticulated municipal water delivery system), some difficulties can result in both water quality and in adequate supply (volume). On the face of it, however, it is possible and practical in Australia in most circumstances. I am not able to comment with any certainty for countries other than Australia but here, we have used both tank water (collected roof-runoff rain water) and bore water with success.
There are two basic 'models of care' in NHHD - 6 nights/week and 3.5 nights/week (i.e. 'rolling' alternate night dialysis). Both offer better-documented outcomes when compared to conventional HD. Both give extended hour dialysis (6 x 8 = 48 hrs and 3.5 x 8 = 28 hrs respectively) compared with conventional HD (3 x 4 = 12 hrs). The 6/week option is more expensive than 3.5/week - the consumables double - but 6/week still works out to be cheaper than conventional HD (no nurses, buildings or infrastructure supports are needed).
On the outcome side, my personal belief is that 6/week is superior to 3.5/week … for several reasons. Primarily, though, in the 6/week NHHD option there are no dietary or fluid restrictions needed. In 3.5/week NHHD option, there is a 2-day gap as distinct from a 1-day gap for 6/week NHHD. This does make a big difference in fluid and potassium balance. The dietary importance and freedoms of 6/week NHHD cannot be emphasised enough. The 'concertina-like’ expansion and contraction of the blood volume and of the heart remains an issue in 3.5/week NHHD but isn’t in the 6/week option. This gives 6/week NHHD a major cardiovascular health advantage. Though there are other differences, these predominate.
Put simply, it means using all modalities in a flexible, match-to-patient-expectation-or-aspiration, lifestyle-conscious way. By using the budget savings from our NHHD program to maximum effect, we have been able to also establish the more costly short daily HD modality for those who either want or might benefit from it. The core idea of this ‘flexible’ or ‘lifestyle’ program is introduced in my website in Part 2 of the 'Three Contentious Issues' segment.
Why is 6 nights/week better than alternate night NHHD and alternate night NHHD better than 3 nights/week NHHD?
First, let’s deal with why the 3 night/week NHHD option is not as good as the alternate night (7 nights/fortnight or 3.5 nights/week) option – and I feel very, very strongly about this …
There is no question in my view that a rolling 2nd nightly program is better than the weekly routine of Mon/Wed/Fri or Tue/Thu/Sat HD (in any format). I believe (and there is good evidence to back up this belief) that the 'long break' of 3/week HD really stresses and stretches the circulation and the heart. This is really deleterious in the long term! If is can be avoided by switching to every 2nd night at least - then I believe it is wrong not to make the switch.
As for 6/week NHHD option, again I believe (and again there is evidence to back this belief) that 6/week is better than every second night ... in essence, the more the better.
I believe (as do others) that 6/week NHHD is the 'Rolls Royce" of available dialysis modalities and anything less is lesser ... though I think it is fair to say that the potential benefits of 3.5/week (alternate) NHHD over CHD are much greater than the advantage of 6/week over 3.5/week NHHD.
The HMO's in the US (the health management organisations which are the funding bodies for much of the dialysis done in the US) are, understandably, anxious about cost blowouts from more frequent dialysis techniques - whether in the home or in a centre. One can’t blame them. The 'upfront costs' are higher as NHHD uses more machines and more dialysers, lines and fluids. Later on though, the savings accrued from reduced staffing and infrastructure more than make up for the added consumable and equipment expenditure.
But, the math is irresistible! Higher upfront costs actually do translate into lower long-term expenditure and cheaper programs yet with far, far better patient outcomes.
However, and here's the nub of the problem, the benefits really don’t begin to outweigh the early costs until a program has gained a 'critical patient mass'. In our experience, this amounts to a program of ~10-12 patients in an enhanced frequency NHHD program. This makes it hard for programs to start because they will inevitably cost more to begin with and only gain a cost advantage once reasonable patient numbers have been sustained >12 months in the enhanced frequency program.
NHHD is clearly a cost winner as it is performed without a nurse and at home. More importantly but in addition, it results in a better health outcome for the patients by far. However, centre-based short daily HD will always be more expensive than conventional HD until it is possible to routinely perform short daily at home – as will eventually be the case once faster on-off technology allows easier, faster on-off times at home. Though NHHD clearly wins in health outcomes for the reasons given, it is seen by many ‘funding bodies as too expensive to consider. For any individual patient, though, this may seem harsh and unfair.
Enhanced frequency dialysis is far better – in my view, there is no doubt about it - but will the local health authority bear the early costs to reap the later outcome/health and cost reduction benefits? That’s the sticking point. We were successful in lobbying a forward thinking Health Department in Victoria along these lines and our predictions to them have proven correct, beyond our and their hopes, in both health outcomes and cost reductions.
Each area must, for the moment, fight its own fight but will do so with a growing body of evidence (including our experience and that of Pierratos, Lockridge, Ting, Kjellstrand and so many more) to support their argument for support for any new NHHD initiative.
What is the best dialysis possible (b) How is ‘good’ dialysis assessed (c) Are there web links to help decide what’s best (c) What you would do in my position?
3.5 x week (alternate day) and 5 hrs/treatment is about the best you can reasonably do on a daytime regime - but it is pretty restrictive and you are spending a lot of your waking time on dialysis. Nevertheless, the data is now overwhelming that more dialysis time and more dialysis frequency = better clinical outcomes.
It is dangerous to start me on the topic of dialysis adequacy – current methods (like Kt/V) make me see red – but Dimitri Oreopoulos, a ‘doyen of PD’ from Canada and the late Belding Scribner, the widely accepted and universally revered 'Father of HD’ from Seattle recently wrote a beautiful little paper together in Dialysis and Transplantation about ‘adequacy’. Oh, and by the by, adequate is, by definition inadequate – in my view only optimum is good enough! Scribner and Oreopoulos proposed that dialysis adequacy should be measured not by mathematics but simply by what they dubbed "the Haemodialysis Product” (HDP). Their HPD was simply Time x Frequency2.
It is an easy article to read, is beautiful in its simplicity and makes the concepts of adequacy far easier to understand and more succinct. You can find the article at:
There is also a good 'comment' by Scribner at:
There is little to say other than - the more and the gentler the dialysis, the better the outcome and the symptom relief. Obviously, dialysis during the day is limited in time – after all, what is dialysis for but to allow you to continue to enjoy life. Living, simply for dialysis, is not living! But, the only practical way to increase dialysis time (a la Scribner) is to dialyse while asleep.
That said, how often?
In my view - and applying Scribner’s principles of Time x Frequency2 - there is an advantage to 5, 6 or (best) 7 nights/week over and above alternate nights (3.5/week) though this has to be offset against logistics and cost.
We undertook a pilot project for 6 nights/week - and feel there is greater benefit from this than from 3.5 nights/week - but it more also does cost more – though any home-based therapy is less expensive than any centre-based care. Our cost modeling shows 6nights/week NHHD is significantly cheaper than satellite and/or incentre once the initial number on the program exceeds ~10-12 patients.
Why do we believe 3.5/week is less ‘optimal’ than 6/week??
Well, alternate night patients must ‘last’ 40 hrs between treatments where 6 night/week patients only need last 16 hrs. Alternate night patients thus have > twice the time to accumulate fluid (volume) and solutes (wastes) – or twice as much to remove in the same time. This increases the need for a 3.5 patient to exercise both dietary control and fluid restriction. Potassium and phosphate accumulation looms too while, because of the greater fluid retention in alternate night patients, BP fluctuations and cardiac expansion and contraction are more pronounced (see my website http://www.nocturnaldialysis.org for details)
Alternate night NHHD is, in my view, heaps better than conventional HD but, again in my view 6 night/week NHHD is best.
How much better? And at what cost? And is the greater 'betterness' and the greater cost worth the trade? I dont know. Time will tell. What is not in doubt is that you will benefit from longer and more frequent dialysis – either/or or best, both.
Interestingly, this is an often
unspoken but chief concern of many patients.
Anxiety and fear:
In short, the answer to your question is 'yes'. One man, now successfully transplanted after 9 months at home on NHHD has 3 school-aged children. Another, an older single parent male with an intellectually handicapped child (indeed she was the reason he wanted to do NHHD so he could be ‘there for her’ when she needed him during her waking hours) continues to enjoy good health on NHHD and manage his child where, before NHHD, he had significant management and absenteeism issues with her. A third, also now transplanted after 4 months of successful home NNHD, managed well with the 4 pre-teen kids of his partner prior to successful transplantation.
Water availability is one of the big issues for rural patients, especially if your home is not on ‘town water’. This might be an issue for you where you live, 2 hours out from Canberra. This said, we have two patients on NHHD in country Victoria; one on bore water and the other on tank water. With the right filter systems, dubious water quality can usually (but not always) be overcome.
The bigger issue is often an adequate water supply (volume) in our drought-prone country and can be a limiting factor. Remember, NHHD needs 300ml/min for ~8hrs a time. Alternate night NHHD has good outcomes and may be the more water-economical alternative but even this can severely stretch an individual home supply if it is not connected to a town supply.
Other than that, there is no obvious impediment to NHHD though I am not sure of your individual circumstance and your local team would be better placed to advise you.
Another significant problem can be for your dialyzing unit. Nighttime advice and/or help (though rarely needed) must be available and providing this back-up can be an issue where distance is a factor. Again, this is up to your unit to decide whether it is possible.
In most Australian states, many country and outback patients are supported at home from distant metropolitan centres and the mechanisms are in place to do this. You may also need to spend a month or so away from home to be trained and this may be a factor too. My advice is to discuss the problem with your team. They will not mind.
Would you say NHHD approaches the long-term outcomes of a transplant? Is NHHD the best option for those who can’t be transplanted and/or for keeping patients on the transplant waiting list healthier while they wait?
I would certainly say ‘yes’ to the latter two ... in my opinion there is absolutely no question that NHHD is the best option for those that cannot have a transplant and for keep those patients on the transplant list ‘healthier' while they wait. NHHD fulfills both of these.
As for the first part of the question - 'that NHHD might, for ‘healthy’ patients, approach the long-term outcomes expected from a transplant?' - its too early to say that … and I doubt we ever could. We would need many more NHHD patients for far, far longer yet before comparable survival rates are possible between transplantation and NHHD. I cannot in my heart of hearts think, though, that NHHD will ever be as good as a good new human kidney!
Nevertheless, having said that, we have patients on NHHD who have had transplants ... three were ~10 year grafts.... and they say they feel as well as they did when they had good graft function and, they add, they don’t have to take all those immunosuppressant drugs. Certainly, their biochemistry on NHHD is generally as good as that of a transplant but, NHHD has its drawbacks - and, like the rest of dialysis, they are significant ones. There is the ‘drudge’ of dialysis (conventional/short daily/PD/NHHD ... ‘drudge’ is a fact with all dialysis modalities). We think (and the patients affirm) that NHHD is significantly better in this regard, but its still a drudge! And there are the usual dialysis risks (eliminated as best as we can) of infection (guarded against as best as we can) etc ... that add to the dialysis 'negatives'.
I believe implicitly that NHHD is head and shoulders above the other dialysis options. A wealth of data now confirms that ... but to rank it with a good transplant? ... no, in all conscience I cannot do that. As a nephrologist who is as much transplant-friendly as dialysis-friendly, I could never say that good dialysis was equal to a good transplant ... it just isn’t – and may never be. But, that doesn’t and shouldn’t prevent me striving to provide the best dialysis I can for as many of our patients that I can.
As for 'criteria' for satellite dialysis ... that is a complex question as there are no hard and fast criteria.
Incentre patients are usually heavy workload, very nurse-dependent patients who are unable to do much for themselves. They commonly cannot assist the dialysis procedure in any way and are usually dependent on some measure of assisted transport and daily living care.
Satellite patients, in theory at least, are independent, able to self-care or assist in their care (eg. take blood pressures, clean machines, set up and clean down
- or at least some of these), drive to and from the centre or else 'find their own way' there. In other words, they should be moderately or wholly self-sufficient. In practice, though, many satellite centres now look more like incentre units than satellites – particularly in recent years... One additional satellite 'function' has to been to provide dialysis care for ‘un-partnered’ patients who might otherwise be considered home candidates but who, at least until the advent of NHHD, have not been considered ‘ok’ for home management where ‘partnered’ dialysis has been the accepted norm. Long, slow, overnight dialysis is, however, changing this dynamic.
Home patients clearly self-care.
Don’t forget home-based PD as an option – it suits many, is done at home and negates the issues of travel too.
Yes, no more calcium carbonate or aluminium hydroxide – or whatever phosphate binder(s) you currently take. These stop completely the day you convert to NHHD. It is also important to use a high calcium dialysate concentrate of 1.75mmol/L – though this is a dialysis prescription change your dialysis team will make. These prescription changes, once made, stay.
Blood pressure medications (if you take any) usually reduce or are stopped too - but that is for your doctor to decide.
The amazing thing is the confidence you will develop - and the certainty - and the awesomely better way you will feel ... you will revel in the things you will be able to eat and drink and the hours in the day you will suddenly have and that you don’t have now.
The beauty of NHHD, particularly 6/week NHHD, is that diet and fluid intake is free!
Under normal circumstances and in an otherwise normal day-to-day existence, one simply cannot eat so much potassium or drink so much fluid in a single day that cannot be removed with ease in an 8-9 hour dialysis on the same night.
Let’s think about fluid first. Most humans drink (comfortably) between 1.75 and 2.5 litres of fluid each day. We sweat, breath and excrete in our motions about 500 mls of fluid each day at average environmental temperatures in a temperate climate. This means the net gain in fluid each day (balanced in normal circumstances by urine losses) is, give or take, 1.25 to 1.75 litres. For this discussion, let’s assume an average of 1.5 litres as the required daily urinary loss to balance intake and after other losses have been counted.
Of course, most dialysis patients pass little or no urine - though there are some lucky ones who still pass reasonable volumes. The less urine a dialysis patient can pass, the more stringent their daily fluid 'restrictions'.
Why restrict? As the control of normal fluid 'losses' are denied through kidney failure, the only way any fluid taken in can later be removed is by dialysis. Most dialysis patients (those on conventional HD) are only on dialysis for 4 hrs out of every 48 hrs or, at weekends, 4 hrs out of 72 hrs. If a 'normal' fluid intake were allowed (remember we have assumed an average urine loss/day of 1.5L and, because of renal failure, this is denied the patient), there would be a gain between each dialysis of 3 litres (2 days x 1.5L/day) or, over a weekend, 4.5 litres (3 days x 1.5L/day)!
With conventional dialysis, there is commonly only ~4 hrs to remove any excess fluid and return the patient to 'dry weight'. That means removing between 3 and 4.5L in 4 hrs!
The blood volume can be and is replenished from tissue fluids at a maximum rate of ~400ml/hr. That means a maximum replenishment rate of 1.6L over 4hrs ... but we have just shown that between 3 and 4.5L needs removal.
The difference is the amount the blood volume must fall over a 4 hr dialysis
3L - 1.6L = 1.4L or, over a ‘3 day break’ weekend, a whopping 2.9L.
Many patients, especially older ones, just can’t tolerate that! The eyes roll back, the blood pressure falls … = a dialysis ‘flat’. So, what is the response? The dialysis nurse has to run in fluid fast to restore the BP. But, hang on; aren’t we trying to remove fluid?
NHHD allows 8 to 9 hrs/treatment. That is twice as long. NHHD (our way at least) is also twice as often (pretty much every night). Twice as long and twice as often = ¼ the rate of fluid removal needed each dialysis. Drink 2 litres today and gain 1.5L after other losses are accounted for? … Easy peasy! That means 1.5L to take off in 8 hrs – or about 200ml/hr. This is well within the capacity of the tissue fluids to replenish without the blood volume falling.
That’s why fluid intake can be free.
In addition, the stretch-stress on the heart is far less - which is why we see the measurements of heart function improve so much on NHHD.
Regarding potassium, the main problem we have found is to persuade patients who have been taught for so long about the mortal dangers of excess dietary potassium to turn around and have a high potassium diet. Potassium control is so easy and complete that we actually encourage a high potassium diet - bananas, kiwi fruits, stoned fruits, citrus, roast potato or baked potato in their jackets ... all are back on an unrestricted menu. In fact, we have had to give a few patients some potassium supplemental pills until they can adjust to the freedoms of the unrestricted dietary intake.
And what of protein? ... it’s the same. No restrictions. Meat, fish, cereals and grains ... all are free and encouraged.
Obviously, NHD doesn't fix diabetes or a raised cholesterol ... so patients with diabetes still must do the carbohydrate thing and patients with a raised cholesterol must still take their statin drugs etc.
From a patient's perspective, the diet and fluid joys of NHHD are among the most cogent benefits of all.
Much has been written on the advantages to the heart and to the blood vessels of both:
(1) 'enhanced frequency' HD (usually known as short daily HD and commonly performed for 2 - 2.5 hrs every day in a dialysis centre)
(2) 'enhanced frequency and time' HD (nocturnal home-based HD either 6 nights/ week or alternate nights/week)
George Ting (San Francisco) has the best experience and data I know of regarding short daily HD and there is no doubt that this HD method offers superior outcomes compared to conventional HD, especially for patients with poorly contacting hearts where there is a low ejection fraction (the volume of blood ejected by each beat of the heart). The reasons for this are explained in the Dialysis Issues section of my website. Simply put, there is less expansion and contraction of the blood volume (there is less fluid taken in by mouth) if dialysis is done every day and less strain put onto an already over stressed/stretched heart. Though at first it would seem that six 2hr sessions a week offers no more advantage than three 4 hr sessions (both give 12hrs a week) but this isn’t so at all.
Firstly, the fluid and weight gain (and the over-filling or ‘expansionary’ force this puts onto the heart) that occurs when a patient is on daily HD is only ½ that which occurs in HD performed only every 2nd or 3rd day. In addition, most of the waste removed by dialysis is removed in the first 1 to 2 hours of dialysis with the least removal occurring in the last 2 hours. This makes six 2 hr sessions far more efficient at waste removal and 'toxin reduction' than three 4 hr sessions. On two counts then, short daily (6 x 2 hrs) is way out ahead of conventional HD (3 x 4 hrs).
NHHD, as I explain in depth in my website, adds the advantage of extra time to increased frequency and is even better than short daily – in my view, substantially so. I think even George Ting would acknowledge this. At present, however, NHHD is only available in most centres as a home-based therapy and patients have to be well enough to cope at home. In our view, many more patients and their families - though having a partner isn’t necessary in our experience - are capable of home HD than are given credit for it. Only a few sites (notably France) offer in-centre sleepover care and even then usually only on an alternate night basis. There is also no doubt that NHHD offers the very best available chance for a floppy heart.
This is a complex problem and, without knowing specific details of you case, your duration of renal failure and/or any previous dialysis history, the details of the NHHD program you are on (frequency and hours etc), your prior treatment and a whole lot more about your biochemistry, I cannot give you a 'you-specific' answer but, in broad terms, the problem may be as follows ................
NHHD will control your blood phosphate. There is no question of this. We know that a raised phosphate is an independent risk factor to progressive bone and cardiovascular disease and that its control by NHHD is a major advance and advantage for you. You should by now be off phosphate binders - these are usually withdrawn at the start of NHHD and your phosphate level should now be well within the normal range.
If you have had long periods of poorly controlled phosphate level (high levels) prior to NHHD, this will have induced hypocalcaemia (a lowering of the calcium level) and a resulting stimulation of parathyroid gland activity (a low ionized calcium does this). This results in over-activity of the parathyroid gland function and production of excess PTH. Though this can initially be reversed by controlling the blood phosphate level (binders or, nowadays, NHHD), if the problem has been persistent and uncontrolled for a significant time, the PTH glands can become 'autonomous'. This means that they kind of ‘get a mind of their own’ and continue to make excess PTH even if, later on, phosphate and calcium are controlled. We see this sometimes even after successful renal transplantation where, despite normalisation of the phosphate and calcium levels, excessive PTH gland activity just keeps on keeping on – and a parathyroidectomy is needed. This, of course, is also often the case in dialysis patients where a parathyroidectomy may ultimately also be needed.
NHHD will control phosphate and will also thus allow for aggressive calcium replacement and high normal or even modestly elevated calcium levels to be achieved in order to maximally 'suppress' PTH production (either by using a high dialysate calcium of 1.75mmol/L – our 1st choice - or by calcitriol ... your version is Zemplar … or by both). NHHD will not, however, reverse autonomously active PTH glands once autonomous activity has been established. This may be the problem you face.
It may also be that your renal team is simply trying to now suppress PTH production through Vitamin D (as we would all do) now that the risk of a high calcium/phosphate product has been removed by controlling your phosphate level with NHHD. If this is successful, you may find that the PTH levels do begin to respond (given time) and fall.
Our PTH levels have fallen in almost all patients on NHHD by (1) controlling phosphate (2) then driving up calcium with a high dialysate calcium though, as the phosphate level has already been lowered, not risking a high product in the process (3) in some also using calcitriol (our Zemplar equivalent). I believe that a high calcium dialysate is the prime factor here rather than any administered Vitamin D. You must recognize though that (4) sometimes autonomous PTH production is inevitable (depending on the length of prior dialysis dependence etc) and that in some patients these high calcium and Vitamin D 'ploys' will still fail and gland removal become the final option.
This 'area' of calcium, phosphate and PTH 'balance' - or perhaps better put, imbalance - is one of the greatest problem areas we face in dialysis medicine. NHHD has, however, given us one additional and hugely powerful tool we have not had before – the utter control of phosphate. Though this added tool is a huge advance, we still have to try and clean up the mess left by its previous rampant misbehavior - and that can still be a very difficult thing to do.
We routinely supplement B and C group vitamins in all patients – conventional HD, short daily HD and NHHD alike.
We use Multi B forte 1 daily, a formulary providing both B and C (the 'forte' component) combined in one tablet. We have not found the need to increase the supplementation rate in our NHHD patients.
We also routinely supplement with folic acid 5 mgm taken daily in our NHHD and short daily HD patients while we give folic acid 5 mgm 3 x week post dialysis in our conventional HD patients as a replacement for dialysis losses of folate. Why did we increase the folate supplementation rate to daily in NHHD? ... it was a 'feeling in my water' that we should, though I am not sure that it is either necessary nor borne out in fact that it makes any difference.
We routinely measure B12 and folate
blood levels every 6 months - and have always done so. We have not found any
change in levels of B12 (always normal) or folate (always normal or high)
following switching to NHHD or to short daily HD from conventional HD.
I have described the alarm mouse we use under the machine and around the fistula in a previous question. As we use native AV fistulae … a radiocephalic [choice (A)], a brachiocephalic [choice(B)] or a superficialised (lifted) brachiobasilic [choice (C)], we have had little call for catheter lock-boxes though these can be either made by your local health system instrument maker or, alternatively, can be accessed from some of the catheter companies .... your local renal unit would be able to source these. For fistulae, however, no such device is needed. I have detailed the fixing process previously as well.
We considered light-weight, removable forearm backslabs for AVF support but in the end, did not use them - though I remain intrigued by the possibility that they might help in some cases. They would be easily fashioned by any standard orthopaedic service (the same as for a fractured wrist).
Bedside phones? They are essential. All phones can be programmed now a days with your 10, 25, 50 or 100 most-used numbers. Simply make 1 and 2 your 'help team'.
As for modem monitoring, this remains debated. NHHD units here in Australia do not use modem or internet monitor. Many of the US unit I am aware of do not either. At the beginning, when the Canadians first sailed into the uncharted seas of NHHD and devised modem monitoring, they wanted to have as much certainty as possible. Interestingly, they have not shown benefit but note considerable complexity and cost. A decision re monitoring also depends upon state and national indemnity attitudes. Here in Australia and New Zealand where home-based HD has always been an accepted and common HD modality (~12-15% of patients in Australia and New Zealand dialyse at home), monitoring has not been a part of the home HD landscape. I can only suggest this be discussed with your local team - as all these issues should be - as local, state and national regulations all interplay and your local team is always best placed to advise you.
You mention an electrode-impregnated tape to protect the access during sleep. Can you tell me more about this?
Some use enuresis detectors under the machine to detect dialysate leakage. Though we used to do this, we no longer do. We sourced our Zircon(TM) water detectors from JAT Trading, St Ives, NSW, Australia (http://jat1.customer.netspace.net.au/jat.htm) but I imagine any similar device is just fine and they are widely available if you wish to use them. They cost ~A$60.
We use an electrode impregnated tape and alarm device sourced from DRI-Sleeper(TM) [flexible], Alpha Consultants, Nelson, New Zealand (web address = http://www.dri-sleeper.com/) which is a natty, simple, cheap and effective alarm device. Its only disadvantage is that it is too sensitive and can be set off easily by normal skin sweat - especially in summer months here in sunny Australia. To avoid this problem, we loose-fold a strip of simple gauze under the tape to act as a low-level moisture guard between it and the skin.
The tape monitors are cheap ... about A$ 20-30 or, in US money, about US$15-18. They are reusable, we purchase just one per patient and they last for about 6 months before they need replacing. I imagine similar detectors are available in the US but as we found these closer to home in NZ, we didn’t need to look further.
As for the specifics of needle fixation ... this is a very individualised thing. Every access and fistula is different - in anatomical size/shape and location - and as such, fixation can vary a little from patient to patient.
For fistula needling, we favour the buttonhole technique first developed by Twardowski. We also use specially designed blunt tipped buttonhole-specific steel needles. Although the earlier NHHD work done by Pierratos used plastic cannulae, we found them harder to insert and feel the blunted steel needles are the better way to go.
We use rotating buttonholes (2 for each of the venous and arterial sites) and use simple tape fixation. In Toronto, they use Morborg adhesive Velcro tapes. Although I personally liked these, my nursing staff has preferred simple tape. In any event, the Morborgs aren’t available in Australia, the cost of importing them was high and simple tape fixation has turned out to be very successful. One does need to be careful to tape the needles correctly and to do it the way the staff have trained you in order that you avoid inadvertent needle dislodgement. We have now trained 28 patients for NHHD with a total of nearly 3000 patient weeks experience @ 6 treatments/week and 2 needles/treatment ... or 36,000 overnight needle placements … and we are yet to have a significant leak or needle dislodgement issue.
Yes ... we do emphasise secure taping – perhaps a little more so than the looser taping most patients use during daytime dialysis - but there's nothing to it. It is more important to use the right taping technique to achieve needle stability rather than layering on masses of tape ... but no, we use nothing special. We prefer dull steel buttonhole needles and the buttonhole technique – but it really is horses for courses and sharp needles are not taboo.
It is important to realise that you don't have to sleep stiff and immobile ... rolling and turning is fine, normal and safe and rarely causes any problems. Some nights are just ‘bad nights’ (not often, but sometimes – eg: maybe the needle is inadvertently against a vein valve) … so, ok, no drama – just come off if the alarms keep going off and tries again the next night. Most nights are alarm-free (or, at worst, one to two) and this is almost exclusively because you have rolled - and kinked the arterial line. That’s ok - no panic or harm - push 'mute', shake your arm and free the line then go back to sleep. It might take a little while to get used to it - but it’s ‘so cool’ once you are. Hang a tea towel over the dials to shut the lights out – though the newer version home machines (not ours!) now have dials that are alarm-linked and self-dim unless an alarm is triggered and they light up again until the cause for the alarm is corrected.
The main thing is - trust yourself and trust your equipment ... its good stuff now!
Don’t stiffen up - relax, breathe deep and go to sleep. Don’t wait, breathless, for disasters that don’t come.
Above all, it’s not complicated. It’s what you have been used to during the day - but at night. No more. No less.
Most of our patients (though not all) use the buttonhole technique. It really does depend on the individual AVF and its unique characteristics ... each AVF is different. Only those who can see, touch and assess the AVF 'in the flesh' can really know which technique might be best for needling a specific AVF and your team is best placed to determine whether your AVF is suitable for buttonholing. We have a preference for the buttonhole technique where it’s possible and/or feasible but NHHD doesn’t sink or swim on the technique - so don't worry either way.
Here are a couple of papers that describe the buttonhole technique (technically) - but which may be of interest to you:
Twardowski, Z. (1995) Constant Site (Buttonhole) Method of Needle Insertion for Haemodialysis. Dialysis & Transplantation Vol 24, no. 10.
Peterson, P.(2002) Fistula Cannulation: The Buttonhole Technique. Nephrology Nurses Journal. Vol 29, no.2.
Will there be damage to my fistula? This is the chief fear and anxiety of every patient (and nurse and doctor), whether dialysis is in a unit with a nurse doing the needling, at home during the day with self needling or, perhaps the most scary of all, at night and through the night, at home, alone.
We use several techniques, both as reassurance and as real security, to ensure the fistula is protected.
Is the frequent use of the fistula a concern? (b) What is the access method have you found best? (c) Is that access method sustainable over the long term? (d) Are any new access developments coming?
Access has ever been the Achilles heel of all dialysis (especially HD - but PD too). Sadly (for us) the human body isn’t designed - or at least the immune defense mechanisms aren’t - for permanent or recurrent breaches of the 'integrity' of skin or blood.
For a period, we became worried re the infection rate in our AV fistulae (mostly mild but infection all the same) about half way through our second year of NHHD but identified this as a problem with ‘corner-cutting’ in needling technique. With due diligence and with regular reinforcement of strict protocols for sterility and access care, our recent experience has been much more reassuring and we have had no further infections for >18 months now. Patients do tend to develop 'familiarity’ with a procedure and we identified this as the problem. We now emphasise - and emphasise again, and then again - that the fistula MUST NOT BE put at risk by ‘corner-cutting’ at home. Though we briefly considered using mupirocin ointment (Bactroban) on the puncture sites, we decided not to do so and preferred to emphasise the protocols for sterility and skin care as the mainstays of good access outcomes. Our results – no further infections – attest to the importance of access care.
We use AV fistulae (native only) and have only used catheters minimally on a couple of occasions where an AVF has been briefly unusable. Either is ok though I strongly believe native AVF remains the optimum access available. We have not used grafts – we have no grafts in our unit – and nothing will persuade me that an artificial vessel should be inserted.
No, there are no new access methods in the pipeline (the Hemaport, a Swedish ‘button’ device is not, in my view, a forward step). Even from outside the box (a place I like to be) there seems nothing (to me) that will even possibly replace or ‘better’ the native AVF.
Care of the AVF is vital and an absolute devotion to its protection and to the care of the adjacent skin is paramount. As per the website, we prefer rotating buttonholes in some but not all our patients but though they are great for some, they are not for others. Working this out is part of the training process.
I am aware of catheter research such as impregnating the catheter wall with antibacterials or with bubble trap methods for lumen protection (Twardowski) but none of these (in my view) replace or ‘better’ the native AVF.
In the end, each access in each patient is unique. Working out strategies that are individual to each patient but which also fall within the broad guidelines of protecting and sustaining skin integrity seems the best answer. Some skin cannot manage alcohol cleansing without irritation ... ok then, change the skin prep. Be prepared to seek the best answer for each individual patient - but never breach the protocol that is set up for that patient. Then always reinforce, re-educate and review. But always also keep an open mind on new thinking and new ideas – for example, there are new skin-oil preps that the ID teams are talking about ... not yet available but in development ... maybe...!
There are different dialysis membranes – ‘low flux’ and ‘high flux’. Does flux make a difference, and why?
The body wastes removed by dialysis are almost countless in type. We talk most of urea, creatinine and phosphate but the list is far, far larger. Some are listed here:
Some of these chemicals wastes (molecules) are small in size. Some are large. Some lie in a middle range in size (‘middle molecules’) and include an important ‘nasty’ called beta2 microglobulin (B2M.)
Flux refers to the ‘leakiness’ of the dialysis membrane. The leakier the membrane is, the bigger the molecules that can pass across it and be easily removed. A low flux membrane isn’t very leaky and will only remove small molecules like urea, phosphate and creatinine. A high flux membrane is much leakier and, to remove B2M, a high flux membrane is essential. High flux NHHD removes about 4 times as much B2M as does high flux CHD - in essence, twice as often and for twice as long. In addition, B2M losses are also more time than concentration dependant ... so longer and more frequent treatments magnify the benefit.
On the other hand, phosphate removal is concentration dependant early in the dialysis treatment ... its blood level zings down fast in the first 1-2 hours but after that fades to a slower more linear loss ... meaning more frequent short hour treatments (like short daily HD) remove it well - though longer frequent treatments (like 6/week NHHD) add even more removal.
Each substance that dialysis removes behaves and is ‘dialysed off’ in a slightly different way – yes, membranes are weird things.
First, NHHD is much longer, gentler and slower. Everything can be slowed down - almost subliminalized (is there such a word?). The blood flow rate is dropped to an average of 225ml/min. The dialysate flow rate is also reduced to 300 ml/min (an adjustment easily made on Fresenius machines by the dialysis technicians). Doing this allows standard concentrate volumes and Bibags to ‘last the full distance’ (and more) with ease. So, yes, you can sleep soundly through the night for your full 8hrs without worrying you will run out of concentrate or bicarbonate.
You use lower NHHD flow rates than we do – why is this and aren’t high flow rates beneficial and necessary?
Your question says you use a blood flow rate (Qb) of 300 ml/min and dialysate flow rate (Qd) of 500 ml/min. We use an average Qb of 225-250 and a Qd of 300. The following reasons underpin our decision …
Initially in 1993-4, when Uldall and Pierratos began the first NHHD program in Toronto, they used a program of 8 hr dialysis/treatment, 6 x week and a Qd of 100 and Qb of +/- 250.
When I visited in 1999 and decided to ‘import’ his program to Australia, he only recently had increased the Qd from 100 to 200 and finally to 300. We chose to use 300 based on his experience at that time.
Since then, others have used even higher rates - see below - but remember, our two programs (Toronto and Geelong) are based, in the main, on 6 treatments/week whereas many of the more recent ones are alternate nights (7/fortnight or ‘3.5’/week). The less frequent the dialysis, the greater the need to up-regulate flows to compensate for the loss of time and to ensure adequate dialysis.
So, what are the positives and negatives of all this?
Clearly the greater the Qd and the Qb, the more efficient the dialysis … but we already were achieving super-efficient and effective dialysis. Our patients’ Kt/V's (the current 'measure' of dialysis efficiency which, incidentally, I do not believe in for a moment nor agree with at all) were far in excess of those achieved by CHD. Our patients were reaching a glomerular filtration rate (GFR) equivalent of 50 ml/min. 2 normal kidneys produce a GFR equivalent of 100 while CHD produces an equivalent of 13 and chronic kidney disease (CKD) just before entry into a dialysis program is usually equivalent to ~8-10. Compare 8-10, 13, 50 and 100 and you will see that NHD is achieving about ½ of normal two-kidney function whereas CHD achieves about 1/8th .
As such we felt no need to ‘push' the fistula but to simply 'cruise' with gentle blood flows and a Qd which didn’t risk either the concentrate or the Bi-bag running out before the planned end of the treatment. The initial rationale for a low Qd was to extend the life of the treatment time and thus ensure bi-bag and concentrate continuity. Remember, our NHHD program is primarily six treatments/week.
As we have introduced patients to alternate night NHHD (7 nights/fortnight or ‘3.5’ nights/week) as well as 6/week NHHD.... and here I stress my very strong belief in 3.5/week not 3/week regimes, we have kept our initial Qb and Qd regime for no better reason than it was in our protocol! OK, I know this is not a good scientific reason, but it is truthful! Despite this, we are very happy with our phosphate control, dialysis efficiency and other parameters under both options so I suppose there has been no driving cause to review or change.
As for why higher flow rates are beneficial? ... simply, the more 'passes' that occur between blood and dialysate, the more efficient is the solute removal. There is therefore some theoretical benefit from both a higher Qd and Qb but if one only - which?
Well, a Qd of 500 compared with a Qd of 300 significantly raises solute removal whereas increasing Qb from, say, 250 to 300 has only a small effect on efficiency - certainly a correspondingly smaller effect than changing Qd. In addition, I have a personal belief (founded more in my experience and ‘gut feelings’ than in my scientific head) that higher AVF flows don’t do the fistula much good. So … if a Qb of 225-250 gives good numbers and outcomes, I think I am justified to be happy with it. In my view then, if one flow rate is to be increased, make it the Qd.
What needs ‘converting’ for the machine to be at home? Can I use my en-suite sink? How long are the lines?
Certainly, there is a bit of plumbing required.
Though each machine (we use Fresenius 400B's) needs a portable (and quiet) reverse osmosis (R/O) water treatment machine piggybacked to the back of the dialysis machine (the R/O is about the size of a big overnight case), the water must first be multi-filtered through sand and charcoal filters to remove particles and chlorine residues (chloramines). Where possible, this is fitted outside the building. The water is then piped through to the machine and R/O in the bedroom. Though this is not a huge 'plant', it serves no other purpose than for pre-treating water for dialysis and, in rental accommodation, some landlords have resisted having their building modified and this can present problems.
An effluent trap is also needed to conduct waste water to the drain. The en-suite basin isn’t an ideal option, I am afraid, as a more robust and stable system is likely required.
The length of lines has not been an issue.
We have extensive cost data on our program and are in the process of finalizing a detailed costing document for the dialysis literature and for our state government. In Victoria, Australia, the set up costs for home HD are borne by the renal unit and not by the patient. This includes the installation costs at home. All dialysis is funded by direct government reimbursement of costs to the treating renal unit and the consumables, machines and other equipment are also provided free of charge.
The major 'out-of-pocket' expense for our patients is:
(1) the government surcharge on drugs up to the Commonwealth Government’s patient contribution limit (the ‘safety-net' @ A$600/year)
(2) the 'excess' expenses of water and power. In Victoria, there is a reimbursement scheme for water bills specifically negotiated with the state government (~$250/yr) but I do not know if similar arrangements exist elsewhere. You should check this with your managing renal unit. We also considered installing a 'winner meter', a day-to-night rate power converter to minimise power bills, but found the cost/benefit to be marginal, if at all. At the end of the day, there still is a small increase in water/power rates over and above the savings generated through the water reimbursement/winner meter initiatives - but this is not great and amounts, in Victoria, to A$150-250 per year.
All other costs are borne by the program though ultimately, by you, the taxpayer. However, as NHHD is cheaper than centre or satellite dialysis, the taxpayer (you) gets off more cheaply with NHHD than with centre/satellite dialysis. This is due to the major savings in NHHD on wages and infrastructure.
Only your local renal unit can advise about arrangements in place in your specific area and you should discuss all financial issues with them in the 1st instance.
Have you considered including the cost benefits of (1) fewer patient bed days/year and (2) the $ value of patients who no longer receive disability benefits and now pay tax?
I admit we are ‘in evolution’ with our ‘costing’ sophistication though we are getting better at it as we go. The cost data I supply in my website is really a 'for-the-lay-person’ overview but we certainly have far more detailed data available. A detailed paper is in final preparation for the peer-review Australian literature.
The bed-day issue is available – but it’s hard to be sure one is comparing ‘apples with apples’. Nevertheless, this will also be published in the Australian literature in 2005.
The tax dollars saved by re-engagement in the workforce is a difficult outcome to show. The best (but highly unethical) way would be to access the NHHD patient tax returns! Hardly fair or appropriate - but the only foolproof way of showing this. The only other validated way would be to have the tax office 'quantitate' the sickness and/or ‘carer’ benefits on a $/week value then assess the mean likely benefit paid per patient in the NHHD program prior to and subsequent to NHHD. As you can understand, we have pursued neither of these options.
Authored by Prof John Agar. Copyright © 2012