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Daily
Haemodialysis - (full conference transcript)
(Click here to go back to the summary page for this speech).
Professor Terry Feest
Director of the Richard Bright Renal Unit in Bristol, Chairman
of the UK Renal Registry, Member of the External Reference Group for
the renal National Service Framework, Member of the Appraisals Board
of NICE, Clinical advisor to the NKF.
I’m going to introduce the subject of daily haemodialysis. I suspect that many dialysis patients might rather think you’d be mad to want to do dialysis every day, instead of three times a week or twice a week as some people do. The prospect of the needling, the travelling to the unit six or seven times a week, the sheer boredom of sitting on lots of dialysis and all the symptoms you get during the dialysis, I suspect that many people would think doing this every day would be madness. It’s a pity really because many people see dialysis like being strapped in an electric chair with the technician trying desperately to make it work and the doctor and nurse rather piously looking on. I think we get dialysis wrong because really dialysis should be your friend. If you’ve got renal failure, you need dialysis, and if we get it right and if you get it right with us it should make you feel better. I hope you’ll see from some of this that possibly having dialysis every day would not be madness but could be the best thing you could possibly do.
You might think this is something dreamed up by doctors and nurses to irritate patients even more, and if you’re an American doctor, to make more money, because you get paid for every dialysis you do, or is it an idea that might make patients better?
One or two introductory things. it isn’t actually daily. You will also see it called quotidian dialysis sometimes in the fancy journals, but if you speak English it should be five or six times a week dialysis. I don’t think anybody does seven days a week. It’s usually six days, sometimes five.
The Theory
’I’ll do a little bit of theory first. The proposal is. and I’ll talk about another one later. is that you still do 12 hours a week dialysis, but instead of doing three four-hour sessions you do six two-hour sessions. Now why should that be better, that’s the question.
And there are good reasons, apart from the fact that kidneys work every day, so you might think that dialysis would be better every day, there are good theoretical reasons which I’ll try and explain.
It’s the concept of body pools. You are an informed audience, you know that inside your body everything doesn’t just slosh around in one great big pool of water and blood and waste products and everything else. If you take the skin off the body it’s very complex inside (by the way, this is from the Body World exhibition. It’s absolutely brilliant). If you look at a kidney, and this is just the blood supply to your kidney, it’s incredibly complex. It has big blood vessels breaking down to smaller and smaller and smaller blood vessels. Now when we dialyse we only dialyse the blood, we’re not dialysing in one sense the whole body. We clean out the blood of waste products and excess water and that blood is in the blood vessels, even down in the organs to the tiniest level. If you look inside the kidney magnified thousands of times, you can see the tiny blood vessels coming into the kidney, there is the glomerulus and all the little capillaries that filter the blood and produce urine. But what is important to see is that outside the blood vessels there is a space with other fluid in and lots of cells and all these cells inside them have fluid. Now as waste products and poisons build up in the body, they build up in these spaces and these cells. Most of the waste products are not in the blood - they’re in the cells and in all these other spaces. So when we dialyse we only dialyse waste products and excess fluid out of the blood vessels but most of it isn’t in the blood vessels, it’s then got to get into the blood vessels before we can remove it. So we’re only cleaning out with dialysis this tiny fraction of the body. If you think of it in diagrammatic form and you think of all the body’s fluid, this is the small amount of the body fluid that is in the blood and most of it is in the cells and in these tissues round the blood vessels. So when we do dialysis, we sort of turn on a tap, and we start taking out waste products and excess fluid from the blood compartment. You can turn the tap on fast and get big drops coming out. But of course you are then limited by how fast more waste products can get into the blood compartment from the cellular compartment, which is the great big compartment of the body. And so the blood compartment empties, because you’re draining it quickly, but you’ve only got a small refilling of the blood compartment. So the main part of the body is only having waste products removed quite slowly. And then there comes a point where you can only remove things from the blood as fast as they are getting into it, because you have virtually emptied the blood of waste products and things, and so really the effectiveness of dialysis is going to be limited by how quickly things get into the blood.
So in the first hour or so of dialysis you get this very rapid cleaning of the blood, and for the rest of the time the removal of waste products and anything else is going to be limited by how fast they can get into the blood and a lot of the toxins that we want to get rid of get into the bloodstream very slowly. So the first hour of dialysis you remove lots of things, but the subsequent time you’re getting much less removal of waste products and extending the length of dialysis too far won’t really get rid of much more waste. And then of course over the next three or four hours the blood fills up again with poisons from the cellular fluid until the blood is full, and three or four hours after dialysis there are just as many toxins in the blood as there were before you started. And what you’ve done is just remove a tiny bit from the big body pool. So that’s what we call rebound, if you hear the doctors talk about rebound. So after dialysis the levels of waste products rebound over a few hours to what they were before.
Now this is the serum concentration of phosphate. we’re all giving you phosphate binders, Calcichew, Renagel, Alicaps, whatever, to try to bind phosphate and we’re telling you not to eat too much. This is the blood level, quite high, of phosphate. you start dialysing someone and in the first hour the blood levels rapidly fall, and then they stay level and this is the point where you’re only removing phosphate from the blood as fast as it can get into it, which isn’t very fast. And then you stop dialysis here and over the next four hours the phosphate level goes back to where it was before.
So if you think about this there is a limited effect in clearing all these toxins from just lengthening dialysis and what we really need is the first hour of dialysis more often. And that’s the principle of daily or more frequent dialysis. you dialyse for an hour or two, you get the rapid removal of waste products, large quantities in the first hour. You then stop, the blood levels build up again, and the next day you have that first hour and drop the levels very quickly with large quantities removed, so you’re getting that first hour when a large part of the activity happens, you’re getting that every time.
So that’s why you may only do 12 hours dialysis a week, but six times of two hours ought to be better than three times of four hours.
The Practice - and the Benefits
So the big test is. does it work in practice?’ There isn’t a lot of information. There have been a few studies. When I was a senior registrar there was an American study that showed that people felt really well on daily dialysis, and some of us have believed in it for 30 years, but we have not been able to put it into practice, particularly in the UK. So the published information is actually only on a few hundred patients. From all around the world, in California, the East Coast of America, France and Holland in particular, and these studies are only for a short time. They mostly have only studied patients for a few months, although there are reports of patients who have been on this treatment for a few years, and obviously in the long term we want to know how they do over ten or 20 years, so just bear that in mind when you look at the things I show you.
A survey was done on patients’ top six symptoms. I think you might call them the bottom six, the ones they complained about most. This was about ten years ago, things might have changed a bit, but I think that most of you who have been on dialysis will recognise these are particularly related to being on dialysis. you’re short of breath, and in the longer term the joint pains and problems, and as we look through the possible benefits of daily dialysis, you might like to tick in your mind which of these symptoms might get better.
The first study I’ll show you is a study which was actually done on patients who are doing badly on dialysis. Now that’s unusual. most studies select very fit people to try something new. These were patients who were started on short daily haemodialysis, and first of all they did lots of well-validated studies on the quality of life of the patients. And the quality of life over months of the patients, reported in terms of their activity, their enjoyment of life, anxiety, a whole range of things, the quality of life improves, so the patients felt better. They particularly reported that they felt a lot better during the dialysis session, and although that immediate period after dialysis they weren’t getting the tiredness and didn’t have to go home to go to sleep and go to bed. You can see some reasons for that. During the dialysis session the dialysis session is short, you do it more frequently, and so the weight you remove each session, instead of averaging two and a half kilograms, these patients were taking off just one kilogram of fluid in each session. So by dialysing more frequently you’ve also put on less fluid between dialysis and you have to take less fluid off, you have less drop in your blood pressure. And so the patients didn’t report low blood pressure, they weren’t getting headaches on dialysis and they very rarely got cramps on dialysis, so that one of the things is that they were reporting that the dialysis experience was much better. And also this weakness and tiredness after dialysis. they weren’t experiencing it. And this is people who are finding the same benefit even two to three years after starting. I think that is partly the frequency and the need not to remove so much fluid. We don’t shorten your three times a week dialysis because you have a lot of fluid to lose and you can’t lose a lot of fluid quickly without feeling ill. But if you are dialysing six times a week, with less fluid to lose, you don’t need to dialyse so long and you can still remove it quite gently. And as a result of this you tend to be able to drink more which most people enjoy.
Probably related to the fluid and the sodium is the fact that blood pressure improves, and collected data on lots of patients who had this treatment shows that one year after they started daily dialysis, 80 per cent of the people were not taking drugs to lower their blood pressure. Now I don’t know how many of the dialysis patients here are taking drugs, but in most units 70 or 80 per cent of people are taking something, particularly on haemodialysis, to lower their blood pressure. And I suspect that maybe this is why people feel better. There’s hardly a patient who says they don’t feel something from taking blood pressure drugs. They don’t like taking beta blockers, they don’t like taking most of the drugs, you swell up with nifedipine or whatever it is. So that’s a high benefit, and as a result the heart muscle begins to look more healthy after a year, and the patients when measured are carrying less fluid around, so the fluid becomes less of a problem.
As well as this appetite improves and nutrition improves, so people eat more and they put on weight. And they put on, not fluid weight, but proper weight, muscle and things like that. And this is just in a group of 12 patients. Every single patient actually gained body weight when they started this treatment, some of them gained huge quantities of body weight. In one or two cases this was excessive, but this was a group of six patients who were doing badly on dialysis, who were malnourished and weak, and they got a lot stronger and a lot better. You can eat more because you want to eat more and also if you are dialysing every day we get rid of a few more of the waste products more quickly, so you can be given a more liberal diet.
The anaemia also improves, and the reduction in the use of Epos, 30 or 40 per cent in most studies. This might be important when you start negotiating to get a treatment like this, because it will be said to cost money, but here is a cost saving that you can argue with your health authority.
Serum phosphate doesn’t change very much in most of the studies of short daily dialysis, so you may still have to carry on taking Calcichew or some form of phosphate binder, but this is probably good in the sense the patients are eating more, you would have expected the phosphate to rise. So phosphate is being cleared better, and in some of the studies it falls. And certainly if you look at the bones, the bones show more activity and look more normal after a year of this treatment than they do at the beginning, so calcium phosphate does improve.
And the benefit for the patient is the reduction from when they go to daily haemodialysis from standard haemodialysis, so in phosphate binders there is a 50 per cent reduction in calcium carbonate, everybody stopped aluminium hydroxide, vitamin D was reduced by 60 per cent, beta blockers for blood pressure - at the end of the year no-one was taking beta blockers in this study. And other drugs for blood pressure almost eliminated. So you may rattle with a few fewer pills if you have this treatment.
And it happens quite quickly so the problem with big weight gain disappears immediately, the blood pressure drops within two to three weeks of starting the treatment, the heart looks better after a few months and all the dietary things improve, certainly by three months, the anaemia is getting better by two months, so the benefits are really quite quick.
The other thing that people would like to do is live a bit longer, so do we improve survival by doing this?’ That we can’t answer because nobody has done studies for long enough to find out. We’ve got to be doing studies for five and or ten years to really know the answer, but we do know that huge numbers of dialysis and renal failure patients die of some sort of cardiovascular disease and the big risk factors of the anaemia, the high blood pressure, and the high phosphate are all lowered and improved by daily dialysis. So you would anticipate, unless it does something harmful to you, it is probably going to improve survival.
I should mention there is another variety of daily nocturnal dialysis, particularly practised in Canada, where patients go on for six or eight hours every night, on a very slow form of dialysis. They do it alone whilst asleep, and in those patients they actually need to take phosphate supplements because they get rid of so much phosphate. It works very well, it has all the other benefits, but you have to do it by a neckline rather by a catheter, and although some people seem very successful with these, a lot of you will have experienced problems with clotting and infection of catheters, so I think that would have very limited application. It sounds marvellous, so there has to be a problem.
Possible Drawbacks/Costs
The first problem we all think about is your fistula, your access. If you’re going to needle your fistula six times a week, is it going to damage it?’ In the studies that have been done, survival of fistulae is no worse than in normal patients, but you have to acknowledge that it’s only been done in patients who had good fistulae in the first place, so they are a selected group. If you are going to hospital for this, you have to travel six times a week, you’ve got to deal with the hospital transport, or non transport, six times a week, and the travel time could become a big problem. It obviously therefore in many ways makes it an ideal treatment for the home, particularly because even if you get to the renal unit, the chances of your renal unit organising itself so well that it could be running six shifts a day and put you on dialysis as soon as you get there I suspect are not very high. So unit-based daily dialysis is going to be difficult. It is not impossible and I don’t think you should think it is only a treatment for the home but it is going to need some fairly radical rethinking of how things are organised to provide this kind of thing daily in an acceptable way without you hanging around forever.
If you are at home, the problem is the preparation and cleaning up. You have got to prepare dialysis six times a week and clean up. Obviously doing it six times involves a bit more cleaning and preparation time. Now there are developments of new equipment that will make that much easier. And at the end, of course, it costs more because you use more dialysers, you use more lines, and if you’re in hospital you use a lot more transport and staff. But there are offsets on that. It will depend how much it costs whether you are at home or hospital but we think probably at home it may cost only.2,500 to.3000 more. Now that still makes it cheaper than hospital dialysis and there are real savings. Patients on this treatment are admitted to hospital less often, you need to be admitted about eight per cent less to save that money and the estimates are that there are 30 per cent fewer admissions. The usage of erythropoeitin drops by 30 per cent and the blood pressure drugs, and in fact most of the cost analyses suggest that if this is done well it could be cheaper. The dialysis costs more but the patients feel better and spend less money in other ways. It is going to need an act of faith, I think, to get people to take this up. We’re going to have to persuade the commissioners that they’ll pay for us to do this treatment because we’re telling them people will be better and will cost less money down the line.’ You can imagine that negotiations with health authorities like that are not very easy. They never want to spend money today to make you better tomorrow. They only want to spend today for today. But I think if we can produce enough evidence and if it is as good as it looks, the cost may not be a problem.
Conclusions
So if you look at your top six symptoms, the cramps are better, the tiredness is better, the anaemia is better, the itching is certainly better on dialysis, (I’m not so sure about between dialysis, although there is some evidence it is), the headaches are certainly better, you’re less breathless. What it doesn’t address is the joint pains. It doesn’t make them worse but as far as we know it may not make them better. But that’s not a bad hit list of your top six symptoms.
It provides better dialysis theoretically, and it provides better dialysis, as far as we can see, in practice, the quality of life is better, and so many things get better for the patients. We think it might increase survival but we can’t prove it yet. It will probably have a limited application. You will have to have good access so that you can needle five or six times a week, and I think in the first phase it will be limited to people who are able to manage their own treatment at home, which isn’t everybody, although we can look beyond that later on. So it will be introduced I’m sure in a phased and limited way so that we can get more experience.
Is it cost effective?’ I think it is effective. It makes people better. But it’s more effort. The big question for the patient is - is it worth it? Well, the thing that’s most impressive is is that at the end of all these studies when patients were offered the choice of going back to three times or staying on six times a week just about 100 per cent said.I’m staying on six times a week.’ What’s more they said when they went on holiday and could only dialyse three times a week, they felt less well two weeks later. They noticed a difference in one or two weeks. So the patients are telling us they feel better and that has to be in the end what makes it a good treatment.
And it is slowly being introduced in the UK for suitable patients. At the moment it is limited to home patients with good access, but it is beginning in the UK. there are a lot of patients in France and Holland in particular on this treatment and in the USA. So I hope that some of you may get daily dialysis offered to you soon.
At the end of the day if it makes you feel better and you can drink more I shall have to stop being a camel doctor and give you other advice other than simply advising you to lay off the water..
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