Don’t Flog the Fistulas: Slow Hemodialysis Blood Flow!
The use of excessively high blood flow rates (read "pump speed") during dialysis—flow rates of upwards of 350 ml/minute—appears to be a US-only phenomenon (read "tragedy"). They are symptomatic of the short-hour dialysis epidemic that is also a US-only phenomenon.
When will US nephrologists learn?
The mean blood flow rate in the US (DOPPS 2011) is ~450 ml/min. The mean blood flow rate in Australia and New Zealand is ~300 ml/min (~36% less). Blood flow rates in Australia and New Zealand are similar to those used throughout Europe, and both are still greater than flow rates used in Japan. Patient session times in the US are also markedly shorter than in any other country. And, patient survival in the US is dramatically less than in any other country—yet patient age, incidence/prevalence of diabetes, and cardiovascular morbidity is no different.
The flawed logic of US dialysis, driven as it is by the twin forces of profit and through-put, is that short, and commonly also infrequent dialysis is somehow "OK." Well, it is not OK. The misguided view that shorter treatment times—only possible if blood flow rates are screwed way up in an attempt to achieve the CMS-approved Kt/V (also a flawed and discredited measure of dialysis) are somehow 'acceptable', is a fallacy that has benighted US dialysis for more than two decades.
Speaker after speaker at the recent Annual Dialysis Conference in Atlanta (February 8th - 11th 2013)—myself included, in all of my four separate addresses to the conference, including the conference-opening Keynote speech—pleaded for longer, more frequent and gentler dialysis regimens.
Speaker after speaker emphasised the benefits of slower blood flow rates and longer dialysis time on patient symptomatology (nausea and vomiting, cramp induction, in-treatment hypotension, post-treatment recovery time), on middle molecular clearance from deep compartmental tissues (Eloot)1, on prevention of myocardial and other organ 'stunning' that accompanies rapid volume contraction (McIntyre), and on quality of life and survival.
Nephrologists who do not understand the simple principles and widely documented advantages of slower volume removal and better solute clearance that accompany longer time on dialysis simply do not understand the first principles of dialysis.
They might do well to read the literature that confirms these unassailable dialysis facts. They might do well to hear the message—a message given and shared by every dialysis expert—that the only...repeat ONLY...determinant of good dialysis, of a well patient, and of a long-surviving patient, is the time spent each week on dialysis: the weekly membrane contact time.2
They are the poorer if they have not read and understood the potent message about 'time and frequency' left to us by Belding Scribner and Dimitri Oreopoulos3 – the two regarded widely as the 'fathers of modern maintenance dialysis' ('Scrib' for HD and Dimitri for PD). This meaasge was contained in their lightning-rod 2002 paper: The Hemodialysis Product (HDP): A Better Index of Dialysis Adequacy than Kt/V.3
They might even do well to attend the next ADC.
It is self-evident and has been long understood that the NCDS study, the study that spawned the iniquitous concept of Kt/V, got it badly (and sadly) wrong. It was not 'K' that mattered...it was 't'. Boosting K, by employing an ever faster and more furious pump speed to allow the contraction of 't', is incorrect. It kills people! Increasing 't' and, in the process, allowing the speed and ferocity of the dialysis process to be dialled back, saves people. It saves well-being as well as lives.
On a different but parallel plane, the December 2013 issue of CJASN featured a special section on fistula flow and flow dynamics. It emphasised the many causes of turbulence that accompany venous limb endothelial damage and in-fistula stenosis. One of these is the interruption and/or disruption of normal vascular laminar flow that occurs when the venous needle return jets into and against the venous endothelium at the site of venous return, creating physical turbulence and biochemical excitation of nitric oxide production...factors intimately associated with up-stream in-vessel stenosis.
At a symptom level, short dialysis treatments are symptom-rich; long treatments are symptom-free. Shorter treatments induce ever more cramp, hypotension, and misery. The shorter the treatment, the more comes the complaint: "I can't take this anymore" ...and the louder the pleas to "take me off".
Just think about it ...
- The shorter the treatment, the faster the removal of fluid must be to attain "dry weight".
- The faster the fluid removal, the more there is a risk of hypotension.
- The greater the risk of hypotension, the more likely is the need for saline resuscitation.
- The more saline that is given, the greater the counterproductive re-infusion of salt and water—and isn't this exactly what the dialysis process has been intent on removing?
- The greater the rate of contraction of the circulating blood volume, the greater the dimension of organ "stun"...and this affects more than just the heart!
- Residual renal function plummets as repeated acute kidney injury results from renal ischaemia.
- Cerebral function suffers from repeated hypo-perfusive cerebral injury.
The list is endless, yet somehow, the ignorance goes on. Yet, the cure is so simple that is beggars description that it has been so long ignored. Gentleness...respect for our patients and their physiology, and, above all, time.
Speaker after speaker at the ADC said it. Speaker after speaker pleaded.
Slow it down, America.
References:
- Eloot S, Vanholder R, Van Biesen W. Dialysis duration: the longer the better, but why? [corrected]. Nephrol Dial Transplant. 2012 Nov;27(11):3975-8
- Agar JWM, MacGregor MS, Blagg CR. Chronic Maintenance Hemodialysis: Making sense of hemodialysis terminology. Hemodialysis Int. 11(2): 252-262, April 2007
- Scribner BH, Oreopoulos DG, The Hemodialysis Product (HDP): A Better Index of Dialysis Adequacy than Kt/V, Dialysis & Transplantation, 2002 Jan;31(1):13-15
Comments
John Paul
Sep 14, 2018 1:37 AM
Whereas initially my blood results were very promising, instantly there was a huge drop off and my creatine rose to 700. Worse still I began to experience severe crushing heart pain and problems. I began to absolutely dread and fear dialysis. At each session the alarms would sound six or seven times and i felt i just would not survive another minute unless i came off the machine. Then i would spend the following 24 hrs totally exhausted and wiped out. . The arterial line stopped working so it was just swapped on the machine with the venous line. The staff said it made no difference at all but as there’s was only a once a month visit from the consultant and no trained doctor on the ward at any time i had to make the decision to lower the pump speed myself. I feel very strongly that there is a lack of training with most dialysis staff in the UK and all patients are treated with the same need to dialyze as quickly as possible but in doing so, It doesn’t always work for the good of the individual.
John Agar
Sep 14, 2018 1:43 PM
I am not sure whether I discern a question here, or take it as a comment. I suspect part of your problem may be limited hour dialysis. You say that the symptoms induced BY dialysis lead you to not want a minute, a second,longer ... i get that - I really do - and this is the key, the crucial, the absolute discussion we have - or have had - with OUR patients, too..
It is SUCH a hard conversation to have ... so hard ... to make patients (and staff, and colleagues) UNDERSTAND that longer time means lesser symptoms, better dialysis, happier patients!
There are SO many blog posts at this site that explain why this is so ... so many.
Go to the search function and search ‘ultrafiltration rate’ ... read, and learn.
JA
John Paul
Sep 14, 2018 7:47 PM
I think you may have misunderstood;
It was not that i was ‘tired’ of dialysing or that just wanted to come off of the machine for the sake of it, but the fact that the higher pump speeds which the staff were pushing me to have were causing angina and heart problems every time i went onto the machine.
Looking at my blood results, I discovered that at the lower pump speeds for the same period of time, i was dialysing far more successfully and efficiently and without pain, than when the pump speeds were raised in line with the hospital recommendations.
The heart pain which i experienced was because of the turbulence being caused in the central line itself, which as i have already explained, was already switched because of a blockage in the arterial line.
Part of the problem which i feel we have here with our NHS dialysis units is that dialysis sessions are not necessarily based on how the patient feels or progresses but more of what is written in the guidelines. A ‘one size fits all’ approach. Four hours each time with as high a pump speed as possible, and at the same time everyone needs to aim to take off 2.5ltr of fluid at each session etc etc.
Rarely is it ever taken into consideration that a patient who weighs a little heavier may have had breakfast that morning or not even been to the lavatory. Is it any wonder so many patients are now reported to be passing out hypo on the machines or going home with dehydration and headaches?
It seems to be cast in stone, that regardless of how the patient feels, it is essential to have a KT/v of 1.2. That is ok for those that can tolerate four hours at at pump speed of 400 or higher, but where does patient safety come into the equation? There has to be reasonably quality of life as well and not just a blind attempt to aim for an unnatainable figure at the expense of a blown fistula and heart attacks.
What would be far more sensible is, for those people that cannot tolerate the higher pump speeds and restricted time limits, arrangements are made by the unit so that they CAN dialysis for longer but at a much slower and gentler pump speed.
Personally i think we would see far fewer deaths for renal patients if this could be managed.
Sadly the NHS isn’t capable of thinking outside of the box.
JW
Dec 05, 2017 5:49 PM
My pump speed was reduced to 330, after consultation with my renal cardiologist (yep we had one).
And yet I read of a lot of other UK patients almost 'boasting' of higher pump speeds they can reach.
I also read a LOT about failed fistulas, wether first surgery isn't as good, or immediate aftercare isn't given. There are too many factors to make a decision there.
Certainly for home heamo over here nocturnal and short daily are encouraged where possible. (Although I note your not a fan of short daily:))
Angie
Aug 18, 2018 4:34 AM
John Agar
Dec 06, 2017 4:31 AM
Angie
Aug 18, 2018 4:38 AM
John Agar
Aug 21, 2018 3:51 AM
jerry howell
Feb 26, 2017 8:45 AM
They told me I need to try nocturnal dialysis. However, they do not have it in the area. I would stay on for 5 or 6 hours to attain 300 blood flow rate. I guess I will have to be happy with what I have. I also realize that they have a bottom line to contend with and the machines there at clinic are different than the home units and are designed to operate at high blood flow rates for the bottom line.
Thank you for all help and suggestions;
God bless;
Jerry
chris walton
Dec 06, 2017 8:02 AM
Now I run pump speed of 350 with diaysate flow factor of 2.0 (700)
I am hoping some of the associated problems I have will improve with these settings. Always done 4 hours 3 times a week.
jerry howell
Feb 04, 2017 3:44 AM
John Agar
Feb 05, 2017 1:36 AM
Response: It is common for many fistulas to eventually run into difficulty – whether with stenosis (narrowings or constrictions in either the feed ‘arterial’ or run-off ‘venous’ vessel), or aneurysmal dilatation (a ballooning of the wall of the vessel from wall weakening – often due to repeated area puncturing for cannulation, or, hopefully now only in the days of yore, from antegrade insertion of the arterial needle). Most fistula problems can be fixed by either radiological angioplasty (stretching-up of the narrowed segment with a balloon – though these commonly are temporary fixes and the stenosis returns), or by a good and careful fistula-friendly vascular surgeon.
I self cannulate with sharps as blunts did not go in well.
Response: That’s fine, not all patients can (or should) use Twardowski’s button-hole technique. While it is good for some, either it isn’t appropriate, or it doesn't work well, for others. But avoid area puncture. But, when using the ladder technique, ensure your home team sets a good ladder plan for you so that the needle sites are spread over a good length of vein and are rotated carefully at both the arterial and venous sites – thus maximizing the available insertion area.
My dialysis machine at clinic just started running yellow for whole treatment. I had it checked and everything was put in correct. I run on profile one.
Response: We do NOT use the NxStage system and while I understand what you are telling me, I am not skilled in this machine by repetitive use and thus it would be wrong for me to pass comment.
My blood flow rate is set at 450 I had it dropped from 500 and feel better . I think if I stay on longer than 4 hours and drop flow from 450 to 350 or 400 I may run green again.
Response: Those are blood flow rates that are – in my view – stratospheric! The blog explains why longer, slower dialysis is better, but doesn't fully explain why I believe that high rates are ‘bad’ for the fistula.
see … http://homedialysis.org/life-at-home/articles/blood-pump-speed-and-your-dialysis-fistula a
and … http://forums.homedialysis.org/threads/1668-Blood-Flow-dialysate-flow-amp-fistula-life
or … http://forums.homedialysis.org/archive/index.php/t-3362.html
I do not want to mess with my site as I think it is still good? What do you think? I have done this at home but my wife did not like to help with it as a needle came out and soaked her with blood. Plus machine broke and we couldn't get a part for it right away. I am 75 years of age and will probably not get a transplant as I think younger people should get them first as they are more productive. I have time to set in my chair and read.
Response: You have rather neatly answered your own question with your last sentence! My view? … slow it all down … take a bit (or a lot) longer for your sessions. Clearly, though, this MUST be after due consultation with and with the advice and approval of your team. Never just ‘do it’ because some wraith from the Internet has said you should. That said, you have my views … !
Thank you for your help and God bless all those that help us, and each other.
Angie
Aug 18, 2018 4:47 AM
John Agar
Aug 21, 2018 3:54 AM
Angie
Aug 24, 2018 9:30 AM
Greg francis
Jan 05, 2016 10:47 PM
John Agar
Jan 06, 2016 12:25 AM
Jean Lynch
Jan 05, 2016 6:39 PM
Angie
Aug 18, 2018 4:41 AM
Dori
Jan 05, 2016 11:43 PM
John Agar
Jan 05, 2016 11:14 PM
The gentler, the slower, the longer and the more frequent your dialysis treatment is ... the better you will feel, the less symptomatic will be the treatment itself, the more healthy you will feel, the longer you will live, and the more at peace with your (sadly essential) treatment you will become.
No-one wants to be on dialysis. No-one would choose it as a career path or job. No-one. But, the sad fact is, that if you are on dialysis, you are there for one single reason - your kidneys no longer work. There are then only three choices: transplantation (the best option), dialysis (the next best), or death.
Transplantation comes - sooner or later - for some. But ... and this is something the general public and the media often don't get ... transplantation is NOT an option for many dialysis patients where age, co-morbidity (other illnesses or health factors), or immune system issues prevent listing. In Australia, for example, only about 1 in 4 dialysis patients are suitable for consideration for a transplantation. And the same is true, whatever the country of origin. It is a sad fact that more than 75% of dialysis patients are dialysis-bound ... into their future.
Dialysis can be made to work for you, if you work with it, not against it. Accepting that dialysis IS your lot, is hard ... there is no doubt of that ... but once you do, then understanding dialysis and how to make it work for you becomes the essential next step. And, dialysis is NOT a fast, wham-bam therapy. The slower (and, yes, longer) your treatments, the more gently your biochemistry can be modified and the less symptomatic that recurrent modification becomes. The slower fluid is removed, the less unstable the blood pressure is, and the more stable is the circulation. There is a saying "Rome wasn't built in a day" ... and it applies to dialysis.
You will find a number of articles at the KidneyViews site, written by myself and by others, that explain WHY slow dialysis is best.
And ... yes ... I really DO get it that chair-time sucks. That is why I (and others) encourage as many as possible to embrace overnight sleep-time dialysis so that (1) longer time can be easily accessed while at the same time (2) daytime hours are freed up for 'life' and 'living' and at the least, alternate day (or better, alternate night) treatment can be accessed to exclude the dreaded and lethal 'long break'.
So, to answer your question ... how long? The real answer is, as long as is humanly and logistically possible.
3 hours? Well, if you were doing that every day (and who would or could) maybe 3 hours might do it. But I suspect your 3 hours isn't daily. I prefer 8 hours x a minimum of alternate night ... or even better ... a 2 nights on, one off regimen.
I am NOT a fan of short daily dialysis ... and I have written much on this already and can only suggest you access either the old message boards or previous blogs to find out why.
As for feeling cold … there has been a log discussion about this at the HDC Facebook page just in the last week and Dori asked me to make some comments there regarding dialysate temperature and the sensation of cold. Another unpalatable truth about dialysis is that lower dialysate temperatures are beneficial – even though so-doing increases the sensation of coldness in a small but significant number of patients. An excellent review of this was recently published by Gihad Nesrallah and his Canadian group (AJKD Dec 2015) that confirmed the advantages to both circulatory and blood pressure stability but also noted that feeling ‘cold’ was reported nearly 3 times as often by the low temperature groups. The FaceBook discussion listed a number of user ways to counter this feeling of coldness.
At the end of the day … while longer treatment lengths and lower dialysate temperature clearly have their ‘negatives’ – undeniably these are (1) chair time and (2) a feeling of coldness or chill – both will also undeniably improve your clinical, health and survival outcomes.
The ultimate choice remains between you and your team but, I know that if I were to be on dialysis, I would be dialysing for as long as I possibly could and would be wearing a beanie and covering up with a snuggly rug to counter my choice for a lower dialysate temperature.
I hope you won't mind but I have taken the liberty of sending a copy of your question and this answer to Dori Schatell at HDC. She may wish (or be able) to put you in touch with Henry or some of the other experienced dialysis patients who understand this well and have a wealth of self-experience. It might be useful for you to have access to their views and thoughts, as these may be helpful in aiding your appreciation of this one single and over-riding principle of dialysis ... the longer, the slower, the more frequent and the more gentle your dialysis treatment, the better.
Zoi
Dec 19, 2015 4:22 AM
liz
Feb 11, 2015 4:06 AM
A patient continuously coughs during tx..rn thinks its do to high bfr ...
John Agar
Feb 12, 2015 5:32 AM
There are a number of reasons why hemodialysis patients might cough, but I am really struggling to come up with a cogent reason why your husband might cough just during dialysis.
Thinking about cough and hemodialysis (NB: PD and cough have been linked), first and foremost, cough may be a feature of chronic fluid (volume) overload. However, in the situation you describe, if the cough is fluid-related I would have expected the cough to improve as fluid is removed and dialysis progresses. So, that seems at odds with your husband’s situation where the cough is seems to be promoted by dialysis.
Many dialysis patients are on ACE inhibitors (medications ending in ‘pril’). These agents quite commonly cause cough. However, I would not have thought that a ‘pril’-related cough would occur only during dialysis … but, if he is on a ‘pril’ it might be worth discussing with your dialysis team whether this medication could be discontinued for a week or so, just on the off-chance it might help. That said, I have some difficulty matching a mechanism to the suggestion I have just made!
Neither of these would seem to be in any way directly or indirectly related to access flow.
Cough, is a potential symptom of pulmonary hypertension (PHT), and PHT is a common problem in hemodialysis patients – especially where chronic fluid overload contributes to congestive cardiac failure. But, in this circumstance, it might be expected to improve with fluid reduction. However, high flow AVF’s have also been shown to promote or contribute to a high output left ventricular failure state by acting as a circulatory-based left to right short-circuiting shunt. In this case, one could potentially visualize an AVF playing a role … but it is, at best, a tenuous argument. Indeed, I am struggling to come up with a cogent mechanism.
Many, many years ago, in the old days of bio-incompatible cuprophane membranes, complement activation and the subsequent sequestration (accumulation) of macrophages (white blood cells) in the pulmonary circulation often led to acute shortness of breath and cough about 10 minutes into the dialysis treatment, but since we now use bio-compatible membranes, this early-days complication of dialysis has, to my knowledge, not been reported for decades.
Though a high return flow through an AVF might (even will) create local turbulence and be a contributing factor to local vein damage upstream from the venous return needle, I would not expect this to affect pulmonary flow and/or promote symptomatic cough.
Chronic pulmonary disease may also, clearly, cause cough, but not specifically promoted by dialysis, unless the removal of fluid leads to alveolar re-expansion and, secondarily, an irritant cough.
So … I am sorry, but I don’t think I have been much help.
Barbara Claussen
Apr 22, 2014 5:06 PM
John Agar
Apr 21, 2014 1:42 PM
While it is a simple matter of mechanics, the distortion and vibration set up by the return flow from the venous needle - and the greater the flow rate, the greater the effect - also cause the formation and release of chemicals that induce oxidative stress and tissue injury. However, this is best explained and determined by your physician as not all stenosis are related to these mechanisms. However, high venous flows are well described to contribute to many upstream issues in AVF.
Slowing the flow rate simply lessens the contribution of flow rate to fistula failure.
Barbara Claussen
Apr 21, 2014 12:09 AM
Angie
Aug 18, 2018 4:44 AM
John Agar
Aug 21, 2018 4:04 AM
There has been a good discussion about this at the FaceBook page just this last 48 hours ... you might find it helpful ... it appeared under a lead post from Ant de Villiers (20/8/18). I would suggest you join in there, or at a post further down the FB page from Deborah Harwood LePow under the heading 'Does anyone here dialyze at a rate higher than 450? (HHD/ not nocturnal)'?
Angie
Aug 24, 2018 9:31 AM
Dr. O .
Mar 15, 2014 2:01 PM
I hope every home dialyzer will slow down their blood speed. We have slowed ours down to 340 .
Our KT/V (which of course is flawed) still runs 3.24 so slowing down from 400 did not compromise dialysis for us on NxStage.
Lance Holt
Mar 14, 2014 10:30 PM
"You can hear the truth, but you've gotta choose it!"
Dylan