Ultrafiltration Profiling Research Articles

Impact of Ultrafiltration Profiling Compared to Conventional Methods on Blood Pressure Regulation Among Hemodialysis Patients

Background: Standard hemodialysis sessions pose challenges for patients due to fluctuations in blood pressure. Alternative strategies, such as ultrafiltration profiling, have been proposed as potentially more effective treatments. Objectives: This study aimed to evaluate the effects of ultrafiltration profiling compared to the conventional method on blood pressure regulation among hemodialysis patients. Methods: This study employed a pre-test and post-test design, involving a single group of 30 hemodialysis patients undergoing treatment at Shahid Beheshti Hospital in Hamadan in 2022. The sampling method used was simple random sampling. The intervention consisted of three sessions using the routine method, followed by three sessions utilizing the ultrafiltration profile method, which employed an interval with a negative slope. Demographic and clinical information about the patients was recorded on a checklist. Systolic and diastolic blood pressure measurements were taken before the commencement of hemodialysis, at 1-, 2-, and 3-hour intervals post-treatment initiation, and again 15 minutes after completing hemodialysis. Results: The mean blood pressure changes observed during dialysis stages increased with both methods; however, there was a significant difference between the methods (P < 0.001). Specifically, patients receiving the ultrafiltration profile method experienced significantly lower increases in blood pressure compared to those receiving the routine method. Conclusions: Based on the research results, integrating ultrafiltration profiling into hemodialysis can be regarded as an effective and viable strategy for enhancing blood pressure regulation in patients undergoing hemodialysis treatment. Therefore, it is recommended that this approach be considered in hemodialysis programs as well.

Patient Safety with Fluid Removal with In-Center Hemodialysis.

Fluid management, which is discussed in the article “Ultrafiltration Rate Levels in Hemodialysis Patients Associated with Weight-Specific Mortality Risks,”1 published in this issue of CJASN, has been an aspect of dialysis care that I believe should be the top priority for doctors to manage and has been getting much more attention this past decade. Failure to establish and maintain an appropriate dry weight can lead to serious complications. I would add that if the patient crashes because of dialysis fluid removal and they believe that the treatment itself is causing them pain, it can lead them to miss or shorten treatment or even discontinue vital care. The authors concluded that “ultrafiltration rates associated with various levels of higher mortality risk depend on body weight, but not in a 1:1 ratio, and are different in men versus women, in high–body weight older patients, and in high-vintage patients.”1 As a youth, I had both my kidneys removed as the doctors believed this could help my high BP. After my double nephrectomy, my BP remained very high, and I was hospitalized frequently for it. I was switched to peritoneal dialysis, and within weeks, my BP normalized to 100/70, and I no longer required BP medication. I found myself having to increase my fluid and sodium intake to help maintain my BP. Thankfully, because of either a working kidney transplant or effective fluid management on dialysis, I have not had high BP in decades. Ultrafiltration and fluid removal is a delicate balance, and the goal of hourly fluid ultrafiltration removal is dependent on changes in the intravascular volume. Using volume monitoring, I witnessed my body reacting differently every time I had a hemodialysis treatment, despite the fact that my ultrafiltration goal for my dry weight guestimate was consistent. I could see the difference in my tolerance level if I consumed more sodium in between treatments. It is not surprising to me that weight is a factor in ultrafiltration efficacy. People who maintain higher body weight most likely have a better appetite and may consume more salt, leading them to consume more fluids. Albumin levels would be good to study in comparison and to see if people who have normalized albumin levels tolerate ultrafiltration better. If diabetes is not properly managed, the patient's thirst affects fluid removal goals. In addition, the arbitrary dry weight number the physician sets as a guestimate for dialysis ultrafiltration could change because of hospitalization, changes in eating habits, or other health events. The use of ultrafiltration profiling, in which a predetermined rate of fluid is programmed to be removed per hour, lacks a timely feedback function showing how the patient is tolerating the volume shifts. The feedback is only apparent when the patient has symptoms either of fluid overload or crashing. The kidney community lacks education about crashing on dialysis. When you crash, it does not mean you are at a correct dry weight. The opposite is also true: If you do not have any crashing and have a smooth treatment, this does not mean you are at a correct dry weight. I have heard numerous stories of my peers losing 10–20 pounds of fluid with a functioning kidney transplant within days of surgery. I have experienced great anxiety when my ultrafiltration rate was increased, and I know my peers do as well. Again, the opposite is true: If we think it is too low, we worry about how it will limit our ability to drink fluid in between treatments. It is well documented that people on peritoneal dialysis keep their existing kidney function longer. Preserving existing kidney function plays a big role in our overall health. I was able to keep my existing kidney transplant function for a year during hemodialysis because of the fact that blood volume depletion was monitored and minimized to not dry out my kidney. Ultrafiltration rates can have serious consequences in our overall health. You cannot take too little, and you cannot take too much—you have to take the right amount. Fluid removal is a dynamic process. A sex-, weight-, and vintage patient–indexed ultrafiltration rate measure demonstrates the health disparities of patients on dialysis. However, without an understanding of albumin levels with blood volume changes, along with a patient's overall assessment, it is unclear how this measure will improve patient care or reduce mortality.

Using the Intelligent System to Improve the Delivered Adequacy of Dialysis by Preventing Intradialytic Complications

Acute kidney failure patients while detoxificated by hemodialysis (HD) mostly or continuously faced regular problems such as low blood pressure (hypotension), muscle cramps, nausea, or vomiting. Higher intradialytic symptom leads to low-quality HD treatment. Although more known therapeutic interventions are used to relieve the HD side effects, this study was designed to investigate how intelligent systems can make highly beneficial alterations in dialysis facilities and equipment to ease intradialytic complications and help the staff deliver high-quality treatment. A search was performed among relevant research articles based on nonpharmacological intervention methods considered to prevent adverse effects of renal replacement therapy until 2020 in the PubMed databases using the terms “intradialytic complications,” “intradialytic complication interventions,” “nonpharmacological interventions,” “intradialytic exercises,” and “adequacy calculation methods.” Studies included the prevalence of intradialytic complications, different strategies with the aim of preventing complications, the outcome of intradialytic exercises on dialysis symptoms, and dialysis dose calculation methods. The results showed the incidence of hypotension varying between 5% and 30%, fatigue, muscular cramps, and vomiting as the most common complications during dialysis, which greatly affect the outcome of HD sessions. To prevent hypotension, ultrafiltration profiling, sodium modeling, low dialysate temperature, and changing the position to Trendelenburg are some strategies. Urea reduction ratio (URR), formal urea kinetic modeling (FUKM), formal single-pool urea kinetics, and online clearance monitoring (OCM) are methods for calculating the delivered dose of dialysis in which OCM is a low-cost and accessible way to monitor regularly the quality of dialysis delivered. Integration of the chair and HD machine which is in direct contact with the patient provides an intelligent system that improves the management of the dialysis session to enhance the quality of healthcare service.

Sodium and ultrafiltration profiling in hemodialysis: A long-forgotten issue revisited.

Sodium and ultrafiltration profiling are method of dialysis in which dialysate sodium concentration and ultrafiltration rate are altered during the course of the dialysis session. Sodium and ultrafiltration profiling have been used, commonly simultaneously, to improve hemodynamic stability during hemodialysis. Sodium profiling is particularly effective in decreasing the incidence of intradialytic hypotension, while ultrafiltration profiling is suggested to decrease subclinical repeated end organ ischemia during dialysis. However, complications such as increased interdialytic weight gain and thirst due to sodium excess have prevented widespread use of sodium profiling. Evidence suggest that different sodium profiling techniques may lead to different clinical results, and preferring sodium balance neutral sodium profiling may mitigate adverse effects related to sodium overload. However, evidence is lacking on the long-term clinical outcomes of different sodium profiling methods. Optimal method of sodium profiling as well as the utility of sodium/ultrafiltration profiling in routine practice await further clinical investigation.

Effect of ultrafiltration profiling on outcomes among maintenance hemodialysis patients: a pilot randomized crossover trial.

More rapid fluid removal during hemodialysis is associated with adverse cardiovascular outcomes and longer dialysis recovery times. The effect of ultrafiltration (UF) profiling, independent of concomitant sodium profiling, on markers of intradialytic hemodynamics and other outcomes has been inadequately studied. Four-phase, blinded crossover trial. Participants (UF rates > 10mL/h/kg) were assigned in random order to receive hemodialysis with UF profiling (constantly declining UF rate, intervention) vs. hemodialysis with conventional UF (control). Each 3-week 9-treatment period was followed by a 1-week 3-treatment washout period. Participants crossed into each study arm twice (2 phases/arm); 18 treatments per treatment type. The primary outcomes were intradialytic hypotension, pre- to post-dialysis troponin T change, and change from baseline in left ventricular global longitudinal strain. Other outcomes included intradialytic symptoms and blood volume measured-plasma refill (post-dialysis volume status measure), among others. Each participant served as their own control. On average, the 34 randomized patients (mean age 56years, 24% female, mean dialysis vintage 6.3years) had UF rates > 10mL/h/kg in 56% of treatments during the screening period. All but 2 patients completed the 15-week study (prolonged hospitalization, kidney transplant). There was no significant difference in intradialytic hypotension, troponin T change, or left ventricular strain between hemodialysis with UF profiling and conventional UF. With UF profiling, participants had significantly lower odds of light-headedness and plasma refill compared to hemodialysis with conventional UF. Ultrafiltration (UF) profiling did not reduce the odds of treatment-related cardiac stress but did reduce the odds of light-headedness and post-dialysis hypervolemia. Clinicaltrials.gov identifier: NCT03301740 (registered October 4, 2017).

Integrated strategies to prevent intradialytic hypotension: research protocol of the DialHypot study, a prospective randomised clinical trial in hypotension-prone haemodialysis patients

IntroductionIn patients on maintenance haemodialysis (HD), intradialytic hypotension (IDH) is a clinical problem that nephrologists and dialysis nurses face daily in their clinical routine. Despite the technological advances in the...

Ultrafiltration-profiled hemodialysis to reduce dialysis-related cardiovascular stress: Study protocol for a randomized controlled trial

Rapid fluid removal (ultrafiltration, UF) is associated with higher cardiovascular morbidity and mortality among individuals receiving maintenance hemodialysis (HD). Fluid removal rates that exceed vascular refill rates can result in hemodynamic instability, end-organ damage to the heart, kidneys, gut and brain, among other organs, and patient symptoms. There are no known evidence-based HD treatment strategies to reduce harm from higher UF rates. Ultrafiltration profiling, the practice of varying UF rates to maximize fluid removal during periods of greatest hydration and plasma oncotic pressure, has been proposed as an HD treatment intervention that may reduce UF rate-related complications. This study is a randomized 4-phase cross-over trial in which participants are successively alternated between study arms with intervening washout periods, and treatment order is randomized. After 4-week screening and 6-week baseline periods, participants are randomized to HD with conventional UF or HD with UF profiling for a period of 3 weeks followed by a 1-week washout period before crossing over. Participants cross into conventional UF and UF profiling phases twice (2 phases per arm). The primary outcomes of interest are intradialytic hypotension (nadir intradialytic systolic blood pressure <90 mmHg), pre-to post-HD change in troponin T (expressed as a percentage), change in left ventricular global longitudinal strain (an echocardiographic measure of left ventricular systolic function), and development of intradialytic left ventricular stunning (worsening of contractile function in ≥2 segments). This study will determine the impact of UF profiling on UF rate-related cardiovascular complications in prevalent, maintenance HD patients.

Cumulative Exposure to Frequent Intradialytic Hypotension Associates With New-Onset Dementia Among Elderly Hemodialysis Patients

Cumulative Exposure to Frequent Intradialytic Hypotension Associates With New-Onset Dementia Among Elderly Hemodialysis Patients

Interventions to prevent hemodynamic instability during renal replacement therapy in critically ill patients: a systematic review

BackgroundHemodynamic instability related to renal replacement therapy (HIRRT) may increase the risk of death and limit renal recovery. Studies in end-stage renal disease populations on maintenance hemodialysis suggest that some renal replacement therapy (RRT)-related interventions (e.g., cool dialysate) may reduce the occurrence of HIRRT, but less is known about interventions to prevent HIRRT in critically ill patients receiving RRT for acute kidney injury (AKI). We sought to evaluate the effectiveness of RRT-related interventions for reducing HIRRT in such patients across RRT modalities.MethodsA systematic review of publications was undertaken using MEDLINE, MEDLINE in Process, EMBASE, and Cochrane’s Central Registry for Randomized Controlled Trials (RCTs). Studies that assessed any intervention’s effect on HIRRT (the primary outcome) in critically ill patients with AKI were included. HIRRT was variably defined according to each study’s definition. Two reviewers independently screened abstracts, identified articles for inclusion, extracted data, and evaluated study quality using validated assessment tools.ResultsFive RCTs and four observational studies were included (n = 9; 623 patients in total). Studies were small, and the quality was mostly low. Interventions included dialysate sodium modeling (n = 3), ultrafiltration profiling (n = 2), blood volume (n = 2) and temperature control (n = 3), duration of RRT (n = 1), and slow blood flow rate at initiation (n = 1). Some studies applied more than one strategy simultaneously (n = 5). Interventions shown to reduce HIRRT from three studies (two RCTs and one observational study) included higher dialysate sodium concentration, lower dialysate temperature, variable ultrafiltration rates, or a combination of strategies. Interventions not found to have an effect included blood volume and temperature control, extended duration of intermittent RRT, and slower blood flow rates during continuous RRT initiation. How HIRRT was defined and its frequency of occurrence varied widely across studies, including those involving the same RRT modality. Pooled analysis was not possible due to study heterogeneity.ConclusionsSmall clinical studies suggest that higher dialysate sodium, lower temperature, individualized ultrafiltration rates, or a combination of these strategies may reduce the risk of HIRRT. Overall, for all RRT modalities, there is a paucity of high-quality data regarding interventions to reduce the occurrence of HIRRT in critically ill patients.

Prevention of Intradialytic Hypotension in Patients with Acute Kidney Injury Submitted to Sustained Low-Efficiency Dialysis

Objectives: This study evaluated the effects of a protocol aiming to reduce hypotension in acute kidney injury (AKI) patients submitted to sustained low-efficiency dialysis (SLED). Methods: Patients were randomly assigned to two SLED prescriptions—control group, dialysate temperature was 37.0°C with a fixed sodium concentration [138 mEq/L] and ultrafiltration (UF) rate; and profiling group, dialysate temperature was 35.5°C with a variable sodium concentration [150–138 mEq/L] and UF rate. Results: Sixty-two SLED sessions were evaluated (34 in profiling and 28 in control). Patients (n = 31) were similar in terms of gender, age, and Sequential Organ Failure Assessment (SOFA) score. Dialysis time, dialysis dose, and post-dialysis serum sodium were similar in both groups. The profiling group had significantly less hypotension episodes (23% vs. 57% in control, p = 0.009) and achieved higher UF volume (2.23 ± 1.25 L vs. 1.59 ± 1.03 L in control, p = 0.04) when compared with control group. Conclusions: SLED protocol with modulation of dialysate temperature, sodium, and UF profiling showed similar efficacy but less intradialytic hypotension when compared with a standard SLED prescription.

Ultrafiltration control during haemodialysis

Haemodialysis (HD)-induced hypotension is still a severe complication in spite of all the progress in HD treatment. Because of its multifactor causes, HD-induced hypotension cannot be reliably prevented by conventional Ultrafiltration (UF) and sodium profiling in open-loop systems, as they are unable to adapt themselves to actual decreases in Blood Pressure (BP). Therefore, the ultimate goal of this paper is to build a biofeedback system dynamics software to provide automatic control of UF during HD. Furthermore, the treatment should improve patient comfort and be carried out without use of additional body sensors and without additional medication.

Blood Volume- and Blood Temperature-Controlled Hemodialysis in Critically Ill Patients: A 6-Month, Case-Matched, Open-Label Study

Background/Aims: Online monitoring devices for intermittent hemodialysis have been developed to improve intradialytic cardiovascular stability in chronic dialysis patients. We propose to test blood volume and blood temperature biofeedback control systems in critically ill patients with acute kidney injury (AKI). Methods: Twenty patients were prospectively dialyzed with machines equipped with online monitoring new devices and compared with 42 historical controls. In addition to feasibility and safety appraisals, efficacy was assessed by the intradialytic hypotension rate. Results: During the study period, controlled temperature was assessed by a mean Δ_max body temperature of –0.3 ± 0.2°C, and all but 7% of dialysis sessions achieved relative blood volume-guided ultrafiltration profiling without increased dialysis-related complications. This was associated with decreased intradialytic hypotension rate. Conclusion: The combination of active controlled body temperature and profiled ultrafiltration by online monitoring systems is feasible and safe in critically ill AKI patients, and suggests possibilities for improvement in intradialytic hemodynamic stability.

Impact of sodium and ultrafiltration profiling on haemodialysis-related hypotension

Symptomatic hypotension is the most frequent complication in patients receiving haemodialysis (HD). Previous studies have reported that the use of modulating dialysate sodium concentration or ultrafiltration (UF) rates, or the combination use of sodium profile and UF profile may better preserve blood volume and reduce the incidence of hypotensive episodes. The aim of this study was to evaluate the effects of sodium balance-neutral sodium profile and UF profile and their combination on preservation of blood volume, cardiac function and occurrence of hypotensive episodes. Using Fresenius MC 4008S, eight stable HD patients underwent four treatments: (1) control, constant dialysate sodium concentration of 138 mmol/l with constant UF; (2) sodium profile, a linearly decreasing dialysate sodium concentration (148-131 mmol/l) with constant UF; (3) UF profile, a linearly decreasing UF rate with dialysate sodium concentration of 138 mmol/l; (4) sodium+UF profile, combination of sodium and UF profile. Each treatment was applied in 10 dialysis sessions. Relative blood volume (RBV), mean blood pressure (MBP), heart rate (HR), interior vena cava diameter (IVCD), stroke volume (SV), cardiac output (CO), plasma sodium concentration and the frequency of symptomatic hypotension were monitored. There were no significant differences in the IVCD, MBP, SV, CO and body weight before dialysis between the three profiles and the control. The total plasma protein, haemoglobin, and intradialytic sodium mass removal showed similar results. Compared with the control, better preservation of RBV and MBP at 4 and 5 h and a higher stability in SV variation, but larger UF volume were achieved during sodium+UF profile (P<0.05, respectively), the incidence of intradialytic hypotension was significantly reduced (P<0.05). With the similar intradialytic sodium removal, during sodium balance-neutral linearly decreasing sodium profile combined with linearly decreasing UF profile, greater intradialytic stability of the blood volume, blood pressure and cardiac function could be obtained, and hypotensive episodes were significantly reduced.

Effects of combining sodium profiling with ultrafiltration profiling as strategies to reduce intradialytic hypotension

目的 观察联合应用可变钠和超滤曲线透析对透析中低血压(intradialytic hypotension,IDH)及相关症状发生率的影响.方法选择既往常规血液透析有IDH倾向的患者40例,采用可变钠和超滤曲线透析6周,监测血压、体重、超滤量,分别于2、4、6周完成透析相关症状问卷.结果联合方法透析2、4、6周后IDH、头晕、肌肉抽搐和头痛发生率均显著低于常规方法症状发生率(P＜0.05).结论联合采用可变钠和超滤曲线有助于减少IDH发生,增加患者的耐受力,该方法不以增加患者钠负荷为代价,不造成透析间期体重增重过多。

Profiled hemodialysis reduces intradialytic symptoms

A prospective study on the effect of profiled hemodialysis on intradialytic symptoms was undertaken among patients recruited between September 2002 and December 2002. Evaluated intradialytic symptoms included hypotension, muscle cramps, dizziness, headache, nausea, discomfort, thirst, and shortness of breath. Symptomatic patients were allocated to one mode of combined sodium and ultrafiltration profile during hemodialysis. The programs were readily available on Fresenius MC 4008 H&E hemodialysis machines. Evaluation was performed before profiling and at 2, 4, and 6 weeks into the profiled hemodialysis. On standard hemodialysis 40 (36.4%) patients were symptomatic. Hypotension was reported in 29 (72.5%) of patients receiving standard treatment. Dizziness, headache, and muscle cramps were reported in 22 (55%), 15 (37.5%), and 9 (22.5%) patients, respectively. These symptoms were significantly ( P < .05) improved at 2, 4, and 6weeks of profiling. Other symptoms, such as discomfort, nausea, vomiting, and thirst, were infrequently reported among patients without or with profiling. There was no significant difference between the applied profiles when compared with each other. In conclusion, sodium and ultrafiltration profiling are effective techniques to reduce acute adverse side effects of hemodialysis. They improve patient well-being and dialysis tolerance, minimize interventions during dialysis.

THE EFFECT OF PROFILING DIALYSATE SODIUM AND ULTRAFILTRATION ON PATIENT COMFORT AND CARDIOVASCULAR STABILITY DURING HAEMODIALYSIS

The aim of this study was to investigate what affect profiling dialysate sodium and ultrafiltration rate had on cardiovascular stability during haemodialysis, and if there was any effect on patients' fluid balance, thirst, serum sodium levels, blood pressure, or comfort and tolerance. The past decade has seen major advances in haemodialysis machine technology. Parallel developments have included profiling dialysate sodium levels and fluid removal during dialysis. However, some dialysis centres do not use profiling due to fears of long-term detrimental effects, especially with regard to hypertension and fluid control. Within my own workplace, approximately 30% of haemodialysis treatments utilise either sodium or ultrafiltration profiling, or a combination of both. Anecdotally, we have seen an increase in cardiovascular stability and haemodialysis tolerance. The aim of this study was to identify the effects of profiling haemodialysis, to ensure that the treatment we offer patients is safe and effective.

The final word

The content of this Supplement issue reflects our personal experiences during 40 years of dialysis treatment in a remarkable way. We have witnessed tremendous progress in the treatment of end-stage renal disease (ESRD). However, uremia remains a constellation of signs and symptoms that, in large part, await definitive elucidation. There is growing awareness that it is the entire spectrum of accumulated products that play a pathophysiological role, rather than an as yet unknown "uremic toxin." It is not surprising that the question of what actually constitutes adequate dialysis for ESRD patients is still a controversial and debated issue within the dialysis community. The term "adequate" may, in fact, refer not only to the "dose," but also to the "systems' biocompatibility," the reduction of cardiovascular and atherosclerotic risk factors, and the minimization of chronic inflammation. The previously mentioned attributes of dialysis adequacy have developed during the last decade as fast-evolving areas of pathophysiological research in dialysis, and this issue contains contributions from different individuals who have actively participated in their development. We, as Guest Editors, avoided giving practical guidelines, but felt we should highlight whatever consensus could be found in the dialysis community. When this was not possible, we felt that both sides of the ongoing controversies should be presented, with the aim of leaving the reader to make a final conclusion. We were motivated by the fact that at the turn of the new millennium, we all are facing a new era of clinical medicine that whenever new, more sophisticated investigations become available, less and less space will remain for simplistic empiricism. The clinical practice of hemodialysis is no exception to this trend. The still unacceptably high mortality/morbidity rates in ESRD patients and the high cost of ESRD management are imperatives for the dialysis community to direct all efforts toward a more comprehensive understanding of the underlying mechanisms and for possible corrective measures.

Ultrafiltration profiling and measurement of relative blood volume as strategies to reduce hemodialysis-related side effects

Hemodialysis (HD) side effects, such as hypotension and muscle cramps, may be related to excessive ultrafiltration (UF) in relation to refilling of fluids from the extravascular space, resulting in hemoconcentration and reduction of relative blood volume (RBV). This study examines the suitability of RBV measurements and UF modeling to reduce the incidence of dialysis side effects. We followed up 188 dialysis sessions in 53 patients. RBV and incidence of side effects were evaluated. Six treatment regimens were examined: UF profile 0, with a constant UF rate; UF profile 1, with a linear decreasing UF rate; UF profile 2, with a stepwise decreasing UF rate; and UF profiles 3 through 5, with intermittent high UF rates interrupted by UF pauses. During dialyses with a constant UF rate (UF profile 0), 10.6% of the treatments were associated with symptomatic hypotension. UF profiles 2 through 5, intermittently using high UF rates, caused a marked increase in hypotensive episodes (18.4%). In contrast, UF profile 1, providing a continuously decreasing UF rate, showed a reduced incidence of hypotension at only 5.7%. Symptomatic hypotension occurred in 13 of 53 patients during one or more dialysis sessions. With the help of RBV measurements, a subgroup of 8 patients with hypovolemia-induced hypotension could be identified. In these patients, an individual threshold of RBV could be defined, below which 92.3% of all hypotensive episodes occurred. In the remaining 5 hypotension-prone patients, there was no correlation between the occurrence of symptomatic hypotension and low RBV during HD treatments. In conclusion, UF profiles intermittently using high UF pulses cannot be recommended. RBV measurements help define a subgroup of patients at risk for hypovolemia-induced hypotension. Only these patients may benefit from blood volume–controlled UF. The incidence of symptomatic hypotension can likely be reduced if an individual threshold of RBV is avoided during HD treatments, eg, using lower UF rates in these patients.