Incremental Dialysis

This blog post was made by Dr. John Agar on September 14th, 2017.
Incremental Dialysis

Incremental dialysis (iHD) is a term that is beginning to appear more frequently in the haemodialysis literature and, while I am not a particular fan of the practice—not for theoretical reasons, but for practical ones—it has been the subject of some recent papers from some recognised international dialysis heavyweights. These have included Andrew Davenport and Ken Farrington from the UK, and Tom Golper from the US, and whatever they say deserves due attention and consideration.

iHD has been promoted most aggressively by a Southern Californian team led by Kaymar Kalanter-Zadeh. While iHD does have some sound dialysis theory on its side, I still cannot bring myself to agree with it, or with those who proselytize it. Though I will come to the reasons why, first let me examine the underpinning theory behind iHD. As a key academic dialysis group from the UK including Andrew Davenport and Ken Farrington correctly note in their 2015 NDT paper “1”: “…the measurement of residual renal function is an accepted practice for peritoneal dialysis patients and the importance of residual renal function in determining technique success is well established …but few centres routinely assess residual renal function in haemodialysis patients”.

The UK team go on to correctly note that,“intra-dialytic hypotension and episodes of acute kidney injury (i.e., episodic renal “stun,” similar to the now well-described myocardial “stun,” “may lead to an earlier loss of residual renal function,” and they conclude that: “an incremental approach to the initiation of dialysis may potentially provide some haemodialysis patients with an improved quality of life and greater preservation of residual renal function, whilst fewer dialysis sessions may reduce health care costs.”

But…the devil is always in the details! The authors also warn—wisely—that… “an incremental approach requires careful monitoring of residual renal function,” and further, that: “once residual renal function has been lost, dialysis prescriptions should-must be re-examined to consider the use of longer or more frequent treatment sessions, and switching from low to high-flux dialysis or haemodiafiltration to offset the retention of middle sized molecules and protein-bound solutes.”

Another dialysis luminary for whom I have the utmost respect is Tom Golper. He published a paper “2” noting that: “incremental hemodialysis is not widely used nor is it well understood”. He also correctly observed that, “incremental hemodialysis is critically dependent on the amount of residual kidney function as well as the individualized goals of end-stage renal disease management.” But, importantly, he observed that, “residual kidney function must be assessed frequently and dialysis adjusted accordingly”. While I particularly liked his next statement that, “home HD lends itself to an incremental approach more so than in-center HD”, and think that this message is well worth serious thought, especially from those well-attuned to home therapies, Tom goes on to say, “I have had a long and successful experience in performing incremental dialysis (both peritoneal and hemodialysis),” and in the paper “shares practice strategies and approaches” to incremental therapies.”

Implicit in this last thought thread is that the application and implementation of iHD is for experienced and successful home therapies exponents. So, why do I hesitate when respected dialysis clinicians like Davenport, Farrington, Golper, and others support the concept? Well, while I understand and fully concur with the theoretical ideas behind iHD, I believe the wide adoption of iHD across an uncontrolled patient population in a wide cross-section of dialysis services/clinics would prove a dialysis disaster. There are several reasons why I say this:

  1. Central to the concept of iHD must be the regular, repetitive (and accurate) monitoring of residual renal function (RRF), and an accurate and reproducible measurement of RRF is NOT easy, especially in patients who are in a non-steady state, simply because of the intermittent dialytic component super-added by their treatment. Measurement of GFR at very low levels of renal function is inexact at the best of times, but add the near impossibility of careful measurement of native GFR in a patient also receiving concurrent dialysis and is thus in a permanent state of volume and biochemical flux, and a very complex assessment results! The summation of native GFR in dialysis-induced flux—and thus fluctuating—and dialysis-generated solute and volume clearance generates a nigh on impossible mathematical conundrum. Yet, this composite would need to be (a) assessed (and I can't see how), and (b) regularly re-measured to plot the inevitable background decline of native GFR and corresponding in-parallel rate at which to upscale weekly total membrane contact time as the native clearance component declined…While this may be an assessment within the capacity of some academic services, to think that this could be done widely across all services as each new patient entered his/her dialysis journey is, I am afraid, not likely to happen. Regarding RRF, current evidence suggests that the rate of fluid removal during dialysis is a key determinant (indeed, perhaps the key determinant) of the rate of RRF loss. Each episode of dialysis that imposes an excessive rate of volume removal…ergo drops circulating volume…ergo drops organ perfusion (myocardial stun is well understood but so, now, too, is there evidence for reduced renal perfusion with each episode of excessive UFR)…ergo inducing recurrent episodes of mini-AKI…contributes to an accelerated decline in residual GFR. This is the key reason for the more rapid loss of RRF seen in HD relative to the gentler decline seen in steady-state PD. For those on HD lucky enough to have a zero or near-zero sum volume status, then the HD regimen—whatever it may be—is unlikely to accelerate the loss of RRF at a rate greater than the rate of loss dictated by the ongoing, background native disease. A residual urine output does help—particularly regarding volume—and those with residual volume rarely need more than minimal amounts of volume removed by the dialytic process. But, the maintenance of a urine volume does not necessarily secure adequate solute clearance, and urine volume alone is not sufficient as a measure of RRF.
  2. Even more than the issues around residual renal function and its measurement, the natural reluctance embodied in human nature will make most—if not all patients—argue, resist, and down-right refuse to agree or accept the timely incremental increase in dialysis time and frequency that would need to accompany the inevitable decline of native GFR. This, to me, is the true Achilles heel of the iHD argument. Not only will most patients strongly resist any sequential increase in their dialysis frequency and time, but there maybe a parallel reticence on the part of services to lengthen and increase dialysis time, too. The complex logistics of varying sessional hours and frequencies would prove a nightmare for services to embrace and implement. Many simply would not do it…or would implement far too late, allowing patients to drift ever further into under-dialysis…as if this isn’t already a huge underbelly problem, especially in the US. Moreover, in the US, where funding streams are difficult enough to follow already, the complexity that iHD may add to billing and charging may be yet another disincentive—for patient and centres alike—though I dare not even peek into that Pandora’s Box! For all theses reasons and more, I think iHD, if applied widely, would be a recipe for worse dialysis, and not better. Let us say that someone starts dialysis twice a week, for 2-3 hours per session to augment a native GFR of 8 or 9. After 2 or 3 months, just when that patient has adjusted to a regimen she or he hates, but has finally (and grudgingly) come to accept, the nephrologist waltzes up and says, “hmmm, my fuzzy formula (and one that I cannot rely on) tells me that you now need 3 treatments a week, not 2, and oh—by the way—your sessional length will need to increase to 3.5 hours.” I know exactly what would come back from the patient. “Why? I don't feel any different! Sod off! I am not going to do a moment longer than I already am!” Try, then, also saying that she/he really needs 4.0, 4.5 or 5.0+ hours, and the retort will inevitably be “No!” It just won't work! Maybe the occasional very disciplined patient will understand and/or accept, but for most it will be a flat no! Human nature is hard (if not impossible) to change once a precedent of lesser sessions or hours has been set.
  3. Finally, I (we) already do introduce dialysis incrementally, though not quite for the same reasons, and I (we) always have. While I admit that I do always start patients on a 3 x week regimen, the first few weeks are commonly iso-volaemic, while dialysis time is truncated at the start to 2.0-2.5 hours, then in the second week = 3.0-3.5 hours, etc, until a full 3 weekly sessions of 4.5 to 5 hours is achieved. OK - that is clearly not what is meant by iHD, but it is a form of mini-incremental start! While I know of no data to support my next suggestion—though perhaps there should be. Rather than fight the patient again and again over sessional frequency and duration, if an incremental start is planned, perhaps it should be governed by incremental settings, rather than by incremental duration and frequency. The patient starts at full frequency and duration from the get-go, but the dialysis itself is made subliminal by using lower pump speeds (150-200), iso-volaemic or ultra-low ultrafiltration with minimal volume removal, smaller and perhaps even low flux-dialysers, with the adjustments over time being setting changes, not time and frequency changes.

The comment from Tom Golper that home haemodialysis lends itself best to incremental dialysis is true—save for the training period. To train for home HD, a relatively intense and “full-on” training period lasting (in our country, at least) 6-8 weeks, or even significantly longer, could significantly impede any intent to offer less, rather than more, dialysis. Intense, frequent, careful, and as-long-as-is-needed training—our current model for home training—would diametrically oppose an incremental, less is better approach.

Should our training model change? Possibly, but we have come to believe that good training is long, slow, and often training. Training in the home might help serve both masters, but training 1-2 times per week for short periods, the introductory iHD model, would, in my view, be poor and set-to-fail home training. So, even initiating iHD at home presents its conundrums.

Though I will not dwell on peritoneal dialysis, iPD is far, far easier. iPD has long and commonly been used—slowly ramping up PD exchanges from 1 or 2 exchanges per each 24 hour cycle to a full overnight APD regimen as the far-more-easily performed Adequest assessment (i.e. Peritoneal Equilibration Test) of native clearance dwindles. So … while iPD is easy, iHD is not.

I could say a lot more, but that is likely more than enough.

So…back to the start! While there is a theoretical argument—though not a particularly strong one—for some devotee and/or largely academic services to “play with” the iHD models, in my view the practical application would be a “dogs breakfast,” and would lead to comprehensively worse dialysis for all but the occasional, highly disciplined, well-informed patient who understood the residual RRF/dialysis interface as well (or likely far better) than I do.

  1. Nephrol Dial Transplant (2015) 30 (10): 1639-1648 https://academic.oup.com/ndt/article/30/10/1639/2337128/Incremental-haemodialysis ↩︎
  2. Seminars in Dialysis. 2016 Nov;29(6): 476-480. https://www.ncbi.nlm.nih.gov/pubmed/27561174 ↩︎

Comments

  • Dori

    Sep 21, 2:10 PM

    Nieltje, what really concerns me about your comment is that you are conflating two things that do NOT have to be related: 1). Ignoring residual kidney function and 2). Initiating HD.

    First, apologies for the all-caps--I really like italics or bold, but this format doesn't let me use them. Trust that I am not shouting. :-)

    Here's the thing: iincremental HD is by no means the only or best way to ensure that people receive thoughtful, gentle, appropriate HD treatments as they start. I do agree 100% that this does NOT happen now the way it should, and, like you, have seen far too many examples of folks who still have significant urine volume and yet receive too much ultrafiltration because this is discounted--causing blood pressure drops, organ stunning, and a horrifying rate of withdrawal from treatment in the 2nd month of HD.

    However, all that is needed in this case is, as Dr. Agar points out, a change in SETTINGS. GENTLER UF. LESS UF. We are only dealing with the WATER side of the dialysis equation here, but the TOXIN side is important as well, and there is no way around the need for TIME to remove the toxins that are most likely to cause long-term harm to nerves, joints, and bones. Advocating for incremental HD start means advocating for less toxin removal. I just don't think this makes any sense. We know that the urine that failed kidneys still make does not remove toxins with anything near the efficiency that would prevent harm.

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  • Amy Staples

    Sep 16, 7:06 AM

    Love this article. I learn something from you with everything you write and the dialysis community worldwide is indebted to you and your willingness to share. Thank you (btw Tom Golper is my nephrologist here at Vanderbilt in TN - and I'm very fortunate)

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  • Nieltje C Gedney

    Sep 15, 10:26 AM

    John, I am so glad you weighed in on this controversial subject. So forgive me if I take issue with your statement "I believe the wide adoption of iHD across an uncontrolled patient population in a wide cross-section of dialysis services/clinics would prove a dialysis disaster”, In fact, current research has recommended a very specific list of criteria to be considered before implementing the IHD approach. Wong, et al state “attention should also be paid to other parameters such as nutritional state, volume status, middle molecule removal, anaemia, bone mineral metabolism, control of metabolic acidosis and inflammation—all of which contribute to overall well-being in HD patients” (https://academic.oup.com/ndt/article/30/10/1639/2337128/Incremental-haemodialysis ) Second. IHD is not nor has it ever been recommended that it should be implemented for all dialysis patients, in an "uncontrolled patient population”. Dr. Kalantar-Zadeh also recommends the use of strict criteria in evaluating candidates for IHD: weekly dialysis dose, in particular HD treatment frequency, is based on a variety of clinical factors, such as RKF (including urine output > 0.5 L/d), volume status, cardiovascular symptoms, body size, potassium and phosphorus levels, nutritional status, hemoglobin level, comorbid conditions, hospitalizations, and health-related quality of life. These 10 clinical criteria may identify which patients might benefit from beginning maintenance HD therapy twice weekly.” (http://www.ajkd.org/article/S0272-6386(14)00803-8/abstract) It would be irresponsible to even suggest that IHD be “widely” implemented, and nowhere in my research, and in discussions with proponents of IHD, (including several of the nephrologists you mentioned) and other prolific researchers in the renal field, did I discern that it ought to. But it should be considered as an acceptable treatment modality for a specific patient population.

    The current practice in US dialysis of ignoring RRF is not only wrong, but defies all logic. Would you tell a diabetic to ignore their blood sugar levels? I was extremely lucky when I started dialysis 4 years ago that I had a home training nurse who understood the value of RRF, even if I didn't. When I didn't meet clearance, she initiated routine 24 hr urine tests, and after applying the results, clearance went from 1.4 to 2.8, on average. She could far more easily, and at less cost, simply increased treatment to achieve the desired outcome, no matter how it affected me. At the time, I understood none of this. I only knew that every time we tried to increase my dialysis regimen, either time or frequency, the results were horrific. The pain to my kidneys was excruciating, like being stabbed with hot daggers. My residual function dropped dramatically. My overall health, as established in routine labs, deteriorated. Inflammation increased, my thyroid function was totally skewed. Cutting back treatment time, from 4 to 3 hours, 3x per week, yielded a dramatic improvement in my health, and more importantly to me, my quality of life.

    I totally concur with Peter Laird’s statement that he “refused the unit to allow aggressive UF since I still peed more than 2 liters a day. This article's findings were exactly my reasoning.” I have spoken out often about the barbaric practice of “challenging” fluid removal in patients. In fact, I have been guilty of it myself, in my home treatments, with disastrous results. But UF is only part of the total picture used in evaluating a candidate for incremental dialysis, as Wong and Kalantar-Zadeh previously stated, for transitioning to dialytic therapy. I believe that the one reason IHD will never be “universally” implemented is that it is a time-consuming practice that requires the complete engagement of the entire medical team, and an educated patient.

    I have tried increasing tx time during my 4 year journey, mostly based on what I have read here on this site, and from patients who have benefitted from this approach. Frankly, I felt that I was made to feel guilty that I was not doing nocturnal dialysis. But every effort I made to increase tx time and/or frequency was met with resistance from my body. It rebelled. My labs suffered, my quality of life disappeared, and I spent more than half my time in bed. I felt like a failure!

    As I learned about incremental dialysis from reading the studies, I moved from being a patient who started dialysis with my head in the sand, to one who is knowledgeable and informed, and takes an active role in my treatment plan. I can only thank God for inadvertently stumbling into IHD, even before even knowing what it was. I truly believe that IHD saved my life. And it certainly is responsible for improving my quality of life.

    My current treatment plan, 4 years into dialysis, is almost half of what I started on. My last set of labs were the best I have seen in almost 15 years, across all functions. My thyroid function has stabilized, inflammation has disappeared, all anemia indicators are normal for a healthy person, not to mention a dialyzor, iron function (which has been my Achilles heel) was perfect, pth is stable and normal. Not being an irresponsible patient, I even insisted that the beta-microglobulins be tested (no small feat here in the US - requiring use of the hospital lab). Results were perfect. Recent cardiology studies (for someone with 20+ years of CKD and chronic illness) at age 65 were also excellent, with an ejection fraction of 65. I am actually clinically healthier today, on dialysis, than I was at any point during the previous 20 years. My goal with IHD is not to cease dialysis, but to provide “optimum” dialysis for my body’s specific needs.

    While I can agree with most of what you said, I find one thing glaringly missing. At no time did you ever mention how the patient felt or ask about what quality of life was important to them! And your statement "the natural reluctance embodied in human nature will make most—if not all patients—argue, resist, and down-right refuse to agree or accept the timely incremental increase in dialysis time and frequency that would need to accompany the inevitable decline of native GFR." truly offends me. As we, the researchers, patients, and trend setting nephrologists who have implemented IHD in their treatment plans, say repeatedly, IHD is not for everyone, but when implemented correctly, using exacting criteria, and increased monitoring, the results can be astounding. I think it is insulting to the average patient to think that we would not increase our treatment as needed, to achieve optimum health. In my case, however, I tried that on numerous occasions, with disastrous results. Simply put, my body is not yet ready for it. I live under no delusions that I will be miraculously cured, nor that I won't need more dialysis in the future. But for now, I will treat according to what my labs, my body, and my quality of life, dictate.

    So when a disgruntled patient who has recently started dialysis asks when they will feel better, please don’t tell them “this is it”. Listen to them, and encourage them to work with you to achieve an optimum treatment program, whether that treatment is 2 hours or 8 hours, 2x per week or 6, or any combination thereof. Knowing that treatment can, will, and must change over time, I think that most patients here will agree that dialysis, done right, is actually a soothing, effective treatment that provides us with an excellent quality of life, despite the fact that we are literally living at death’s door. But if a patient is complaining of any of the standard side-effects, you have a duty to examine their treatment plan. Think about it. If you prescribe any other medication, and it produces side effects such as vomiting, passing out, pain, etc… would you insist that the patient continue on that medication? I would hope that any competent physician would seek alternative dosing or treatment.

    Yes there will always be the patients (primarily incenter, but not exclusively) who will be satisfied with checking their independence at the door, blindly accepting their fate in life, being told that the pain and suffering they endure is the price they must pay for dialysis keeping them alive, and that we don't count your residual because you will lose it anyway. I chose not to be one of those patients.

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    • John Agar

      Sep 15, 9:24 PM

      All your points are taken, Nieltje. I am sorry you took offence at my blog. I did try to make it clear that incremental dialysis, in any of its potential forms, may well suit some committed, well-dialysis-educated, and aware patients - and you are clearly one - but equally, if applied widely to a less aware dialysis population by less careful providers, then the potential risk is that under-dialysis would increase. Again, my apologies for having apparently insulted you - that was not my intention. I do believe I have tried, in all the years I have made efforts to explain and reason the complexities of dialysis for patients, to be sensitive to the patient perspective. That you are angry and upset that I did not mention the patient's perspective suggests that I have failed, again, to capture the right balance in my blog. I may need to reflect on whether to write them at all.

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      • Nieltje C Gedney

        Sep 16, 11:21 AM

        John, Please don't ever stop writing. I absolutely appreciate all that you say and do for the ESRD community. Your blog did not offend me personally (only the statement about patients not accepting increased tx), nor did I mean my comment to indicate that. I only wanted to convey, however clumsily, that the patient voice did not come through here. Since I know that is paramount in all that you do and say, I felt compelled to point that out. And I think, because one of my first neph's made that exact same statement, and he was insensitve and gave me no more than a 5 minute nod during "clinic visits", is why I reacted so strongly to that statement. I know you are better than that. Patients here revere you, as do I. As I noted, I agree with almost all that you say, I just ask that you not promote the one size fits all approach for more dialysis, any more than we would for the standardized tx. IMHO there should be no one size fits all dialysis tx. PERIOD. Shorter, longer, or anything in between.

        As has been discussed to death, incremental is not suited, nor was ever meant to suit, the entire dialysis population. Since people revere your viewpoint, I just hope that, while I agree that more dialysis will always be best, there is sometimes a better way to get there with patients who have excellent residual, etc...Second, in response to Eric's comment, (whose viewpoints I also respect, like yours) PD is an excellent intro to IHD and dialysis, but sadly there are many, like myself for whom it is not suited. So yes, IHD could be a PD First initiative, as long as it is not discounted for those initiating HD who meet the criteria, etc...

        But please, don't ever stop writing, and I apologize if I sounded angry. I am just passionate about "optimal dialysis" as I know you are! If our views sometimes clash, that is OK, it is a point from which we can both learn!

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  • Eric Weinhandl

    Sep 15, 12:40 AM

    I have a question for you. Incremental hemodialysis is indeed an approach that dovetails with monitoring of residual function. However, it seems to me that many incident patients who are good candidates for incremental hemodialysis are, at least clinically, also good candidates for peritoneal dialysis. And as you point out, PD training is relatively straightforward. So from my admittedly non-clinical view, I wonder why one would choose twice-weekly HD over PD, as the latter would permit the patient to remain in his/her home. Nothwithstanding patient preference for HD over PD (or vice versa), what clinical reasons would lead you prescribe twice-weekly HD over PD? Maybe I am being overly simplistic.

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    • John Agar

      Sep 15, 9:22 AM

      Absolutely ... good question, Eric! Away for w/e ... will respond. Beaut conundrum!

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      • John Agar

        Sep 15, 8:58 PM

        Eric, you raise a very important point ... if an incremental start IS to be considered, then why not iPD in preference to iHD? Absolutely spot on. IPD does not destabilise the circulating volume, does not trigger (or risk) mini-AKI, is easy to learn as a home therapy, and can be ramped up as RRF falls with much less potential patient resistance to or argument with the change.

        Indeed, the capacity to seamlessly implement iPD is a core positive that supports the choice of, and benefit from the PD-First approach that has long been promoted by dialysis luminaries in ANZ - like David Johnson from Brisbane and Fiona Brown from Melbourne - and which is widely embraced here, such that 22% of ANZ patients start on PD first. One could argue - and many here do - that this number should be much higher still. So, if incremental IS to be favoured, then - very sensibly - better iPD than IHD. I agree that I gave this conclusion far too little emphasis, although my main thrust was to caution against an untrammelled uptake of iHD.

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        • Eric Weinhandl

          Sep 18, 4:47 PM

          I think that both of the threads on this page collectively summarize my thought about this topic. The idea of incrementally increasing dialysis intensity has clinical merit, particularly if the person on dialysis understands that the definition of incremental is "relating to or denoting an increase or addition, especially one of a series on a fixed scale." That said, I think that I would aim to initiate with PD, unless the person has a clear contra-indication, thus necessitating hemodialysis. So in my fictional practice, applications of incremental HD would be limited (but not absent).

          That said, the US also has some significant problems with transitioning patients from PD to hemodialysis. So a broader application of incremental PD remains an operational challenge.

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