The mean dialysis treatment time for facility-based care in Australia is a tad over 4.5 hrs (4 hrs 35 minutes) with centre-based dialysis ranging from 3.5 hrs (a very few), to 4 hrs (a lessening number), to 4.5 hrs (the majority), and to 5 hrs (an increasingly common duration) x 3 treatments a week (still) … though there are many who would like to toss the ‘killer weekend’ break.
It is at home where the 18+ hours occurs (see below)
Despite that we only dialyse 4.5+ hrs in our centres, volume control seems much better ‘over here’ in OZ than it is ‘over there’ in the US.
I think this is likely due to the following scenario:
The extra average hour or so of dialysis that we give each treatment (when compared to the US mean of 211 minutes) makes a HUGE difference … and perhaps (read ‘for certain’) because of the slower rate of fluid removal we have to impose, the intravascular volume therefore contracts less severely and thus the thirst centre is stimulated less.
It is this contraction of intravascular volume during dialysis (= a massive contraction in most US programs where shorter time ‘bazooka’ dialysis seems to reign supreme) that turns on the primal survival instinct of thirst.
In turn, this ‘switching on’ of thirst … and thirst (or the response to 'dehydration) is a primal and visceral response made by any living organism in defence of self-preservation … then triggers the poor bazooka’d US dialysis patients to rush home and drink - they can’t help themselves - and so the cycle is set for the next high volume (weight) gain … and so it goes on.
It is not the poor patients who are at fault - it is we who dialyse them too fast, too hard, and/or too infrequently, who are at fault. Then, we have the gall to yell at our poor patients for gaining excess weight via the obligatory thirst and the resulting excess fluid intake that is the direct result of our poor dialysis practices! … that our all-too-short a dialysis treatment triggered!
In OZ, the longer centre-based dialysis times (see DOPPS for some excellent multi-country comparisons) result in a lesser drinking ‘demand’ for our patients post dialysis. So, the volume (weight) they then gain before the next dialysis is less and the amount of fluid (weight) that we need to remove during the next (longer) dialysis tends to be less.
OZ patients seem to manage to control their interdialytic weight gains better … we rarely hear the word ‘compliance’ in our services … and as the time we have to remove the lesser gain is a longer 4.5 hrs, and the stimulation of thirst is far less, it clearly also makes it easier for the OZ dialysis patient to maintain his/her fluid restriction.
So … 18 hours? … not in facility-delivered dialysis … no.
But … at home? … absolutely!
Almost all our home patients in OZ would do a minimum of 18 hours a week … most do far more - if not all. This is achieved through nocturnal dialysis - in the main - where 8-9 hour runs are the most common. Or, some (not a lot but some) do shorter hour treatments of 5-6 hours but dialyse at least every other day (alternate day without a ‘killer 3 day break’) … and most of ours do 4-5 nights of 8-9 hours with a mean of over 40 hours of dialysis (done during sleep) per week.
Short daily dialysis is rare here - except in my own centre where we have about 8-10 on short daily in-centre (for bad hearts, not for good dialysis, though it IS good dialysis for them as it is preferrable to long 2 day (or worse, 3 day) interdialytic breaks.
As for the GDI … the centre-based patients in OZ would all fail to gain that hours/week point … and so they should. The GDI is set up to have them fail that point (its only 1 of 20) but, to fail that point at least then opens up the discussion on how they might achieve it … ha! surprise, surprise … the answer is - ‘Go Home’!
Thanks for your reply, short answer: GO HOME -if you can. I also seem to recall the U.S. ‘bazooka-style’ dialysis (going to have to remember that description) causes heart failure, would you care to comment on that?
Clearly, the less frequent the dialysis sessions, the greater the time-lapse between them.
The longer the time between treatments, the more will be the fluid (read weight) gain.
This pattern is exacerbated by the long break at the weekend where, almost as ‘punishment’ for daring to require dialysis and interrupt ‘our’ weekend, a 3 day break is visited upon dialysis patients world-wide (here too) and an even longer inter-dialytic gap encourages even greater fluid (read weight) gain. The ‘fix’ for this = 1 x extra dialysis session every two weeks so that 7 treatments are given every 14 days, not the current 6, and dialysis is truly delivered every second day. This means an added consumable cost to the payer and, if your system is like ours where penalty rates are paid for work done on Sundays, an extra wages cost to the system. Add this to the easy-life dislike of working weekends … and you have a significant disincentive to the dialysis ‘deliverers’ - both funders and givers - to go that extra mile for our patients and do what we should do - deliver alternate day dialysis.
To be truthful, too, there is (would be) likely resistance from (most) patients, too … who like their ‘day off’ … even if it is a major threat to their life and health.
If the dialysis sessions are short (as they especially are in the US), there is less time in a bazooka dialysis session to remove the greater accumulated volume of fluid (read weight).
Fast, hard dialysis to remove large accumulated fluid (weight) volumes means that fluid must be drawn by the dialysis process, fast and hard, out of the blood stream.
Remember, there are 3 main fluid ‘spaces’ in the body.
(1) … the fluid that forms, along with red and white cells, platelets and proteins, the blood volume:
(2) the fluid contained within the cells that make up the organs, tissues and structural supports of the body = the intracellular fluid:
(3) the fluid that fills the spaces and gaps that lie in between cells but is outside the pipes (arteries, veins and capillaries) that make up our blood vessels and that carry the blood volume = the extra-cellular (outside the cells), extravascular (outside blood vessels) fluid … the so-called extracellular or ‘interstitial’ fluid space.
Drawing fluid out of the blood stream creates a waterfall effect. dropping the blood volume then causes fluid to leeching from the interstitial fluid into the blood stream to replace the blood volume. Then, in turn, fluid leeches from the cells into the interstitail fluid to replace its volume.
In due course, the fluid volume of all 3 spaces is slowly reduced, as the reduction of one causes a leeching from the next …
But, dialysis ONLY plunders the blood volume. The other two steps follow - but slowly - as the 3 fluid spaces gradually equalize’ or ‘equilibrate’.
Short, fast, hard ‘bazooka’ dialysis will drop the blood volume fast and hard … but there is not enough time to allow the equilibrating process.
Ergo … the blood volume MUST contract … hard, and fast! The replacement waterfall is rate-limited and can’t keep up, can’t replace the blood volume fast enough to prevent an aggressive drop in the circulating blood volume.
FINALLY TO YOUR QUESTION … but all that had to be explained (especially to newcomers to this site) first!
If the blood volume (and blood pressure) falls rapidly, the perfusion pressure (ie: blood flow) to the organs and tissues of the body falls rapidly.
The blood perfusion of an organ perfusion is vital for the function of that organ. Blood perfusion (blood flow, if you like) is what brings life and function-preserving oxygen to the cells of that organ.
Crash the blood volume with fast, hard, and cruel (bazooka) dialysis … US dialysis … and the oxygen perfusing flow (and pressure) crashes too.
Organ perfusion drops fast, and hard. Oxygen delivery falls fast, and hard.
The heart needs oxygen to work.
Drop the blood volume and pressure and the perfusing volume and pressure (and oxygen delivery) to the coronary arteries drops, fast and hard.
This is called ‘myocardial stun’!
Every fast, hard (bazooka) dialysis stuns the heart. Every one. The harder, the faster, the more volume-removing the dialysis, the worse, the more sustained, the more damaging the degree of myocardial stun will be.
The same happens to the kidneys - or what is left of them - as each fast, hard dialysis induces (effectively) an acute reduction in perfusion to what is felt of ‘residual’ renal function. Each hard, fast dialysis stuns whatever remains of renal function … this is the reason why conventional hemodialysis causes such a rapid loss of whatever residual renal function remains after starting dialysis whereas the gentler peritoneal dialysis does not … and there is emerging evidence that long, slow, frequent hemodialysis (like nocturnal dialysis) preserves residual renal function too (like PD does).
Myocardial stun buggers hearts!
Myocardial stun, in effect, causes a mini-heart attack - every fast, hard, conventional dialysis … and the more fluid that has to be removed, the faster and harder the treatment will be … and the more the amount of heart damage that will result.
(1) Longer dialysis allows the rate at which the same required amount of fluid that needs to be removed … is removed.
(2) More frequent dialysis reduces the interval between dialysis treatments … thus reducing the time available to accumulate fluid.
(3) Combine the two … both more frequent and longer dialysis treatments … and the benefit becomes a multiplier … less fluid to remove AND a longer time to remove the smaller amount of accumulated fluid.
The result? … the blood volume CAN be replaced from the interstitial fluid AS it is reduced by dialysis.
The outcome? … the blood volume does not contract.
The benefit? … tissue perfusion and oxygen delivery is sustained and ‘organ stun’ is averted … and, remember, it is NOT just the heart that gets damaged, but all out ‘bits’ … the residual kidneys, the gut … and the brain too!
Myocardial stun is one of the hidden threats of fast, hard, short dialysis … sadly, a ‘brand’ too often prescribed and followed in your country … and too little appreciated too.
Oh … and back for a moment to the original answer to your first question … about ‘18 hours of dialysis’ … implicit in all this is that the rapid volume contraction of fast, hard dialysis ALSO drives the thirst mechanism, a powerful primal instinct that then feeds and multiplies the gain in weight (read fluid) that the next dialysis has to remove.
This rapid weight (fluid gain) over-stretches the heart … then, damn it all if the next dialysis doesn’t then add a ‘myocardial stun’ to ‘cardiac muscle fibre overstretch’ … and the stage is set for a perfect storm for both cardiac function and longevity!
Finally, it has to be said again … as good dialysis - in my view - equates to long, slow, frequent dialysis, and this is only possible at home … the solution is, where ever possible … the answer is - ‘Go Home’!
[B][I]NB: you might be
(1) interested in having a look at …
(2) letting others know about my new website:
While it is a bit clunky and primitive-looking (I neither have the web-skills to do it better nor funding to access IT help), I think it does put forward some useful messages and concepts about a range of more environmentally sustainable dialysis practices - practices that we have already tested and installed here in Geelong.
Let me know what you think … and, if you think the concepts it contains are worth promulgating, let others know about it too.[/I][/B]
The definitive paper is probably that of Chris McIntyre’s group, from the School of Medicine, University of Nottingham, Derby, UK.
The data is well described and has been the subject of many HD forums though, sadly, it seems many nephrologists are still unaware of the impact of repetitive ischemia on cardiac function – both short and long term.
I have a nice couple of PPT slides on the real-time echocardiographic effects on ventricular wall motion and function during and post dialysis (courtesy of James Heaf, a leading dialysis nephrologist from Denmark) but unfortunately I do not know how/if PPT slides can be loaded at this site.
Suffice to say, the ischaemic impact of dialysis when associated with rapid volume contraction and intra-dialytic hypotension (a fall in BP during dialysis) is profound … and it lasts well after the dialysis treatment has ended.
Left ventricular wall motion and function are not similarly affected in nocturnal dialysis. There is good data available to show this … I can’t show the slides but the reference is Jefferies CJASN 2011. 6:1326. I can send the appropriate powerpoint summary slides separately if these would help.
The seminal paper on myocardial stun is from Chris McIntyre’s team in Nottingham. The paper is:
James O. Burton, Helen J. Jefferies, Nicholas M. Selby, Christopher W. McIntyre: Hemodialysis-Induced Repetitive Myocardial Injury Results in Global and Segmental Reduction in Systolic Cardiac Function : CJASN 4(12) 2009, pp 1925-1941.
This paper should be required reading for all who dabble in haemodialysis, particularly if they use short, hard, facility-based dialysis regimens.
The topic has been allocated a sessions at the last 2 (perhaps 3) ADC conferences at least and is now a topic that is widely discussed at most HD meetings world-wide.
Wow! I looked over your site: http://www.greendialysis.org/, looks like you are well on your way to dialysis Shambala! Love your holistic approach with concerns not only for patients, but also the environment. I don’t know of anybody starting anything like that here in the US? You’ve got me thinking of asking for political asylum (afraid the health care here is going to get me someday).
I should mention the people I’m trying to get interested in this are legislative types. If I were asked for experts who had an opinion on our dialysis here, I of course would mention you. And I recall Dr. Carl Kjellstrand (lifetime award winner for his work in hemodialysis), Dr. Christopher Blagg (former Executive Director of Northwest Kidney Centers), Dr. Peter Laird (patient/doctor who writes a blog at http://www.hemodoc.com/), and Dr. Belding Scribner (unfortunately deceased, but a pioneer in dialysis and inventor of the Scribner shunt who left a fantastic body of work). Do you know of anybody else who might want to offer an opinion of US dialysis? I’m wondering about the people you mentioned above?
Thanks for your appreciation of our green progress.
Perhaps, if you liked the direction we have taken, you might let others know about it.
As for others who wish to improve dialysis - wherever it is delivered - there are many. I hesitate to dob others in, but the last 5 years faculty list of the home hemodialysis symposium that precedes the ADC is a great place to start.