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Incremental and Once- to Twice-Weekly Hemodialysis: From Experience to Evidence

2017; Elsevier BV; Volume: 2; Issue: 5 Linguagem: Inglês

10.1016/j.ekir.2017.07.006

2468-0249

Yoshitsugu Obi, Kamyar Kalantar‐Zadeh,

Acute Kidney Injury Research

In most dialysis centers in North America and Europe, it has been the prevailing dogma to ensure adequate solute clearance by thrice-weekly hemodialysis treatment in the management of dialysis-dependent patients. However, an outright transition from non–dialysis-dependent chronic kidney disease to a thrice-weekly hemodialysis schedule may underappreciate the importance of individualized care among patients with end-stage renal disease. Given that nearly half of incident dialysis patients in the United States may initiate maintenance dialysis therapy at an estimated glomerular filtration rate >10 ml per minute per 1.73 m2, the clinical effectiveness of an incremental hemodialysis approach has been re-evaluated in recent studies (Figure 1).1Obi Y. Streja E. Rhee C.M. et al.Incremental hemodialysis, residual kidney function, and mortality risk in incident dialysis patients: a cohort study.Am J Kidney Dis. 2016; 68: 256-265Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar Salient benefits of starting with less frequent hemodialysis schedule, for example, once- or twice-weekly hemodialysis and gradually transitioning to a thrice-weekly schedule over time and as needed, includes better quality of life, preservation of residual kidney function (RKF), and longer time of arterio-venous fistula patency. Nevertheless, until very recently, an incremental hemodialysis approach was rarely implemented in the United States, notwithstanding the swiftly heightened interest and enthusiasm since 2014.2Kalantar-Zadeh K. Unruh M. Zager P.G. et al.Twice-weekly and incremental hemodialysis treatment for initiation of kidney replacement therapy.Am J Kidney Dis. 2014; 64: 181-186Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar In this issue of KI Reports, Chin et al.3Chin A.I. Appasamy S. Carey R.J. et al.Feasibility of incremental 2-times weekly hemodialysis in incident patients with residual kidney function.Kidney Int Rep. 2017; 2: 933-942Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar reported the feasibility of twice-weekly hemodialysis among incident end-stage renal disease patients in the United States. They assumed twice-weekly hemodialysis with 4-hour treatment time per session as the initial modality, and examined what proportion of their patients could have started maintenance hemodialysis with a twice-weekly schedule (i.e., examining this question as to what if patients had been treated with twice-weekly hemodialysis) based on the following 4 criteria: weekly urea clearance (i.e., standard Kt/Vurea) delivered by dialysis and RKF; ultrafiltration rate; intradialytic blood pressure; and intradialytic symptoms such as nausea and vomiting. Their 14-year historical cohort holds a highly unique position because the periodical measurement of RKF has been a part of their standard care for hemodialysis patients. Among 784 incident hemodialysis patients who survived the first 6 months of dialysis, 646 patients (82%) had baseline RKF data including patient-reported "no significant urine output." Based on the findings in this simulation study, incremental hemodialysis regimen appeared feasible in many patients. Chin et al.3Chin A.I. Appasamy S. Carey R.J. et al.Feasibility of incremental 2-times weekly hemodialysis in incident patients with residual kidney function.Kidney Int Rep. 2017; 2: 933-942Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar selected 410 patients who actually collected 24-hour urine during the first 3 months of dialysis, and reported that 112 patients fulfilled their proposed conditions and were considered "optimal" for twice-weekly hemodialysis. An additional 107 patients had adequate urea clearance, but their interdialytic weight gain was not acceptable to achieve an ultrafiltration rate 3 ml per minute, whereas >50% of patients had a urine output of >500 ml per day, which have been proposed in a recent consensus article2Kalantar-Zadeh K. Unruh M. Zager P.G. et al.Twice-weekly and incremental hemodialysis treatment for initiation of kidney replacement therapy.Am J Kidney Dis. 2014; 64: 181-186Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar as one of the criteria for initiating and maintaining twice-weekly hemodialysis. The heterogeneity of kidney diseases may cause a variation in the decreased solute clearance and impaired concentrating capacity, depending on the severity of tubular injury in the kidney. Given that the majority of patients who were considered "appropriate" or "ideal" for incremental hemodialysis had urine output >500 ml per day with a low prevalence of diuretic use, this criterion may be used as a minimum requirement for twice-weekly hemodialysis that warrants further evaluation by 24-hour urine collection. The study by Chin et al.3Chin A.I. Appasamy S. Carey R.J. et al.Feasibility of incremental 2-times weekly hemodialysis in incident patients with residual kidney function.Kidney Int Rep. 2017; 2: 933-942Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar has the strength of low missing frequency in data on RKF, thus reducing selection bias that might otherwise have overestimated the prevalence of good candidates for incremental hemodialysis as done in some other reports. However, several potential limitations of this study are worth noting. First of all, the authors did not have data on patients who actually received incremental hemodialysis. Their judgement on "optimal" or "appropriate" for twice-weekly hemodialysis was made solely by hypothetical simulation based on several assumptions. For example, the authors established hemodynamic criteria using pre- and post-hemodialysis blood pressure among patients on thrice-weekly hemodialysis, but no data on blood pressure were available from patients who actually decreased treatment frequency from thrice to twice weekly. Therefore, it remains unclear as to how many successful cases there would have been among patients in the "optimal" and "appropriate" groups. Second, there was no information as to how long patients remained "optimal" or "appropriate" for twice-weekly hemodialysis. RKF declines over time as a whole, but there are large variations in change in RKF. Factors associated with faster decline in RKF include female sex, nonwhite race, diabetes, and history of congestive heart failure,7Obi Y. Rhee C.M. Mathew A.T. et al.Residual kidney function decline and mortality in incident hemodialysis patients.J Am Soc Nephrol. 2016; 27: 3758-3768Crossref PubMed Scopus (107) Google Scholar and patients in the "optimal" and "appropriate" groups might have met the criteria for twice-weekly hemodialysis only for a limited time if they had those risk factors. Longitudinal assessment of patient characteristics including RKF and standard Kt/Vurea would provide additional insight into this study topic. Third, it is not possible to conclude from these findings whether the authors' criteria could appropriately guide an incremental hemodialysis approach. When considering twice-weekly hemodialysis, standard Kt/Vurea has been suggested as an indicator in the Kidney Disease Outcome Quality Initiative (KDOQI) Clinical Practice Guidelines,6National Kidney FoundationKDOQI clinical practice guideline for hemodialysis adequacy: 2015 update.Am J Kidney Dis. 2015; 66: 884-930Abstract Full Text Full Text PDF PubMed Scopus (622) Google Scholar and the international consensus paper by Kalantar-Zadeh et al. also proposed criteria comprising several conditions including urine volume and interdialytic weight gain.2Kalantar-Zadeh K. Unruh M. Zager P.G. et al.Twice-weekly and incremental hemodialysis treatment for initiation of kidney replacement therapy.Am J Kidney Dis. 2014; 64: 181-186Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar Although a previous study demonstrated equivalent survival between incremental and conventional hemodialysis if patients retained substantial renal urea clearance (i.e., ≥3.0 ml/min/1.73 m2),1Obi Y. Streja E. Rhee C.M. et al.Incremental hemodialysis, residual kidney function, and mortality risk in incident dialysis patients: a cohort study.Am J Kidney Dis. 2016; 68: 256-265Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar there are still scarce data on how to identify patients who would benefit the most from incremental dialysis without compromising their long-term survival and health-related quality of life. Finally, these findings may not be extrapolated to facilities where incident end-stage renal disease patients have different characteristics from those in this study. Indeed, there is large variability in mean estimated glomerular filtration rate at dialysis initiation across geographic regions in the United States,8Scialla J.J. Liu J. Crews D.C. et al.An instrumental variable approach finds no associated harm or benefit with early dialysis initiation in the United States.Kidney Int. 2014; 86: 798-809Abstract Full Text Full Text PDF PubMed Scopus (25) Google Scholar and some countries initiate dialysis at lower estimated glomerular filtration rate levels. In addition to patients with substantial RKF, patients with severe comorbid conditions may be treated with twice-weekly hemodialysis as a palliative measure. Mortality is exceptionally high during the first 6 months of dialysis among incident hemodialysis patients, and 283 of 1067 patients were excluded from this study because of not being treated on hemodialysis for >6 months. A reliable risk prediction tool, if it were to become available in the future, would help identify patients with a very short life expectancy and aid to implement once to twice-weekly hemodialysis as a palliative measure. A decremental hemodialysis approach, that is, reducing the frequency from thrice- to twice-weekly, could also be considered as an end-of-life adjustment approach for terminally ill dialysis patients.9Rhee C.M. Ghahremani-Ghajar M. Obi Y. et al.Incremental and infrequent hemodialysis: a new paradigm for both dialysis initiation and conservative management.Panminerva Med. 2017; 59: 188-196PubMed Google Scholar The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Hemodialysis: 2015 Update does not have a specific statement for how to adjust dialysis frequency according to RKF levels, mainly due to a lack of concrete evidence,6National Kidney FoundationKDOQI clinical practice guideline for hemodialysis adequacy: 2015 update.Am J Kidney Dis. 2015; 66: 884-930Abstract Full Text Full Text PDF PubMed Scopus (622) Google Scholar which suggests that the 2007 KDOQI guidelines10National Kidney FoundationKDOQI clinical practice guidelines for hemodialysis adequacy, update 2006.Am J Kidney Dis. 2006; 48: S2-S90PubMed Google Scholar are still valid in recommending less-than-thrice-weekly dialysis when KRU is >3 ml per minute per 1.73 m2 and a switch to thrice-weekly dialysis when KRU falls to 10 ml/min per 1.73 m2, may not have a better survival with incremental dialysis versus waiting to initiate standard dialysis at lower eGFR levels.3 Increasing urea clearance with 3 times per week dialysis, although used for assessing dialysis adequacy, has not been shown to have a survival benefit. 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