The use of newly developed mixed-dilution hemodiafiltration (HDF) can supplement the weaknesses of pre- and postdilution HDF. However, it is unclear whether mixed-HDF performs well compared to predilution HDF.
We conducted a prospective, open-labeled, randomized controlled trial from two hemodialysis centers in Korea. Between January 2017 and September 2019, 60 patients who underwent chronic hemodialysis were randomly assigned at a 1:1 ratio to receive either predilution HDF (n = 30) or mixed-HDF (n = 30) for 6 months. We compared convection volume, changes in small- and medium-sized molecule clearance, high-sensitive C-reactive protein (hs-CRP) level, and dialysis-related parameters between the two dialysis modalities.
A mean effective convection volume of 41.0 ± 10.3 L/session in the predilution HDF group and 51.5 ± 9.0 L/session in the mixed-HDF group was obtained by averaging values of three time-points. The difference in effective convection volume between the groups was 10.5 ± 1.3 L/session. This met the preset noninferiority criteria, suggesting that mixed-HDF was noninferior to predilution HDF. Moreover, the β2-microglobulin reduction rate was greater in the mixed-HDF group than in the predilution HDF group, while mixed-HDF provided greater transmembrane pressure. There were no significant between-group differences in Kt/V urea levels, changes in predialysis hs-CRP levels, proportions of overhydration, or blood pressure values. Symptomatic intradialytic hypotension episodes and other adverse events occurred similarly in the two groups.
Use of mixed-HDF was comparable to predilution HDF in terms of delivered convection volume and clinical parameters. Moreover, mixed-HDF provided better β2-microglobulin clearance than predilution HDF.
Remarkable technical advances have been made with regard to dialysis membranes and hemodialysis (HD) machines in recent decades. In spite of such improvements, mortality rates remain high, and the overall 5-year survival rate in patients of kidney failure with replacement therapy (KFRT) is 30% in the United States [
There are two representative HDF modes: pre- and postdilution. Each has strengths and limitations. Postdilution HDF is the most effective way to maximize molecule clearance. However, blood concentrations can be elevated using HDF, which can cause thrombosis. On the other hand, predilution HDF can resolve this problem [
This study was a prospective, randomized, open-label trial conducted at two hospitals in Korea (Severance Hospital, Seoul; National Health Insurance Service [NHIS] Ilsan Hospital, Goyang). Individuals aged 20 to 75 years who had received HD 3 times weekly for ≥3 months were allowed to participate in the study. Exclusion criteria were as follows: (1) life expectancy < 12 months, (2) dialysis treatment received for less than 3 months or initiated due to acute kidney injury, (3) current history of malignancy, (4) pregnancy, (5) contraindication to anticoagulants, (6) systemic blood pressure < 90 mmHg, and (7) previously received HDF before enrollment. The study was conducted in accordance with the principles of the Declaration of Helsinki, and the study protocol was approved by the Institutional Review Board at each center (No. 4-2016-0702 for Severance Hospital; No. 2018-11-002 for NHIS Ilsan Hospital). All participants provided informed consent when enrolled in the study.
Between January 2017 and December 2019, a total of 66 patients was screened. After a 1-month screening period, 60 patients were randomly assigned at a 1:1 ratio to receive either mixed-HDF or predilution HDF for 6 months. The random assignment was performed using a web-based, random allocation table that considered institution, sex, and causative disease of KFRT (
All participants received thrice-weekly dialysis for at least 3 hours. Both groups were treated with the 5008 or 5008S dialysis system using CorDiax dialyzer (Fresenius Medical Care, Bad Homburg, Germany) and maintained a blood flow rate of 250 mL/min and dialysate flow rate of 700 mL/min. TMP was not expected to exceed 400 mmHg in either predilution HDF or mixed-HDF patients. Prescribed ultrafiltration rate and substitution fluid in both predilution and mixed-HDF groups were calculated using previously reported equations [
The demographic and medical history of participants was collected at enrollment. We recorded dialysis-related information at baseline and every 3 months thereafter. Information collected included dialyzer characteristics, dialysis time, dialysis machine, blood and dialysate flows, substitution volume, TMP, height, dry body weight, pre- and postdialysis body weight, delivered convective volume, net ultrafiltration volume, and predialysis systolic and diastolic blood pressure. Further, the following laboratory data were measured at 0, 3, and 6 months after initiation of this research: hemoglobin, hematocrit, white blood cell differential count, platelet count, predialysis urea concentration, creatinine, sodium, potassium, concentration of bicarbonate using total carbon dioxide, calcium, phosphate, intact parathyroid hormone, high-sensitivity C-reactive protein (hs-CRP), albumin, and fasting glucose. To determine the reduction ratio (RR) of β2-microglobulin at pre- and postdialysis, serum β2-microglobulin level was measured at 0 and 6 months. All laboratory tests were performed locally using standard procedures in certified laboratories. The RR of β2-microglobulin was calculated using pre- and postdialysis serum β2-microglobulin levels and the following formula: RR (%) = [1 − (concentration of serum β2-microglobulin obtained after dialysis/concentration of serum β2-microglobulin obtained before dialysis)] × 100. Extracellular fluid and total body water volumes were measured via multiple frequency bioelectrical impedance analysis (BCM; Fresenius Medical Care). Measured extracellular fluid volume is presented as overhydrated (L). Measured relative extracellular fluid volume considering total body water fluid volume is presented as overhydrated-extracellular fluid (%).
The primary outcome assessed was the delivered convection volume difference between mixed-HDF and predilution HDF treatment methods [
The total substitution fluid volume is always greater when using predilution HDF versus mixed-HDF. Because mixed-HDF uses both pre- and postdilution modes during the dialysis session, we hypothesized that the effective convective volume in mixed-HDF would be 120% of that of predilution HDF, and the difference in convective fluid would be approximately 7.5 L, which was used as a noninferiority limit. Thus, it was determined that 25 patients within each group were needed to detect a 10-L delivered convective volume difference between the two groups assessed with a power of 90% and an α-value of 0.05. Considering a dropout percentage of 20%, the number needed per group was 30 patients.
All data were analyzed according to the per-protocol principle. Data are expressed as mean ± standard deviation or as median (range) for skewed data. Baseline clinical data and laboratory findings, measured at the time of random group assignment, were compared using the t-test and chi-square test. In addition, changes in primary and secondary outcome parameters were analyzed using repeated measures analysis of variance (ANOVA). Continuous variables were assessed using a mixed model approach for repeated measurements, after adjustment for age, sex, serum albumin and hemoglobin levels, systolic blood pressure (SBP), predialysis serum β2 microglobulin concentration, and dialysis blood flow. A two-sided significance test was used throughout the analysis, and values of p < 0.05 were considered significant. All statistical analyses were performed using the STATA version 16 statistical package (StataCorp, College Station, TX, USA).
The baseline characteristics of patients and treatment parameters are summarized in
In secondary outcome analyses, we first compared middle- and small-molecule clearance rates of mixed-HDF and predilution HDF groups. The predialysis serum β2-microglobulin level was significantly higher in the mixed-HDF group than the predilution HDF group during the study period. However, serum β2-microglobulin level of the mixed-HDF group significantly decreased from the baseline value (25.4 ± 5.6 mg/L to 22.2 ± 4.4 mg/L), while they remained relatively constant in the predilution HDF group at the same time period (p for intergroup difference = 0.02) (
During the study period, there were no significant between-group differences in terms of serum hs-CRP, albumin, phosphate, sodium, potassium, and bicarbonate concentrations (
At baseline, SBP for the predilution HDF and mixed-HDF groups were 147 ± 25.7 and 148.1 ± 22.6 mmHg, respectively. SBP increased at 3 months relative to baseline but then decreased at 6 months relative to the increase observed at 3 months in both groups. The difference observed between the two groups did not reach statistical significance. DBP of both groups remained similar throughout the 6-month study period (
In this randomized controlled study, we demonstrated that mixed-HDF therapy produces outcomes similar to predilution HDF. Convective volume was delivered well in the mixed-HDF group, and the difference in effective convection volume met noninferiority criteria. We also showed that mixed-HDF more efficiently decreased β2-microglobulin circulating level compared with predilution HDF. There were no differences in removal rates of small molecules, nor were other clinical or biochemical parameter differences observed during the study period. All adverse events were minor and occurred similarly in the two groups. These findings suggest that mixed-HDF is comparable to predilution HDF with regard to convection volume delivery, and that it removes middle molecules more efficiently.
HDF has been established as effective dialysis therapy, and its use has many advantages over conventional HD. These include higher clearance of middle molecular weight uremic toxins, better maintenance of hemodynamic stability, greater removal of inflammatory cytokines, and better responsiveness to erythropoietin [
Both pre- and postdilution HDF modes have pros and cons. Although the postdilution HDF mode, which is being recommended to most patients in Western countries, is associated with a highly efficient clearance of uremic toxins with a relatively small substitution volume, the limitation of the method is that blood flow should be maintained at a certain speed to reduce risk of blood clot formation. Patients in East Asian countries, who have relatively low blood flow of arteriovenous access, prefer predilution HDF mode to postdilution HDF, due to lower risk of clotting events in the former mode [
Delivered convective volume is considered a crucial factor that influences HDF therapy. Mixed-HDF is a new concept of high-efficiency HDF in which predilution and postdilution modes are mixed, and it is difficult to compare quantitatively absolute substitution fluid with those of the predilution mode. Given that a greater volume of substitution fluid is required in predilution mode versus postdilution HDF mode, we developed the concept of using effective convection volume for quantitative comparison between the two groups. Since the predilution mode of HDF uses twice as much replacement fluid as does postdilution mode, we hypothesized that the effective convection volume via mixed-HDF mode consisted of a sum of the substitution volume in postdilution mode times two, substitution volume in predilution mode, and ultrafiltration volume. Although the absolute convection volume was higher in predilution HDF, we showed that the effective convection volume delivered by mixed-HDF was greater than that of predilution HDF. The effective convection volume from mixed-HDF was approximately 20% higher than that of predilution HDF. The optimal convection volume delivered by mixed-HDF remains unknown because no studies have yet examined mixed-HDF outcomes such as mortality or cardiovascular events based on convection volume. In this regard, the concept of effective convection volume might be an alternative tool for the comparison of convection volumes for predilution and mixed-HDF. Notably, differences in effective convection volume might result in improved β2-microglobulin clearance by mixed-HDF. This is important because the accumulation of middle molecules, such as β2-microglobulin, is an independent predictor of mortality [
This study has limitations. First, the sample size was small, and only two centers participated. Therefore, selection bias could not be excluded. Second, we could not determine optimal convection volume. It should be noted that many previous trials with postdilution HDF consistently showed improved patient survival rate compared with conventional HD in patients with adequately delivered convection volume. To date, there has been no randomized controlled trial that has assessed the delivered convection volume in patients given predilution HDF or mixed-HDF therapy. Future studies with larger sample sizes will be needed to address this. Third, we measured β2-microglobulin and hs-CRP levels as representative middle molecule and inflammatory markers, although other uremic toxins with deleterious effects exist. Because the predilution mode has an intrinsic limitation in the degree of clearance compared with postdilution HDF, the performance of mixed-HDF should be further tested using other molecules. Fourth, we used a simple equation of RR of β2-microglobulin, which was not calibrated for body fluid reduction during dialysis. However, as there was no significant difference in ultrafiltration volume between the predilution and mixed-HDF groups, ultrafiltration volume is unlikely to alter the outcomes. Finally, we did not evaluate albumin loss via dialyzer during the study. Albumin loss via HDF can differ depending on the dialyzer, dialysis modalities, and convection volumes. Previous studies have reported a wide range of albumin loss between 0.5 and 4.5 g per session in postdilution HDF [
In conclusion, we demonstrated that mixed-HDF performed well with regard to convective volume delivery and provided better middle molecule clearance than predilution HDF. For the implementation of mixed-HDF in clinical practice, further studies should explore whether the use of mixed-HDF is advantageous over other dialysis modes with regard to its cost-effectiveness and long-term outcomes.
Tae-Hyun Yoo is the Editor-in-Chief of
This study was supported by Fresenius Medical Care Korea.
Conceptualization: SHH
Data collection and curation: All authors
Formal analysis: KSP
Funding acquisition: SHH
Investigation: KSP, WJ
Writing - original draft: KSP
Writing - review & editing: SHH
All authors read and approved the final manuscript.
HDF, hemodiafiltration.
(A) Effective convection volume over 6 months (p for intergroup difference < 0.001). (B) Noninferiority of mixed-HDF compared with predilution HDF. The gray line indicates predilution HDF, and the black line indicates mixed-HDF.
HDF, hemodiafiltration.
The yellow line indicates predilution HDF, and the red line indicates mixed-HDF. HDF, hemodiafiltration; B2MG, β2-microglobulin.
Baseline characteristics
Variable | Predilution HDF (n = 27) | Mixed-HDF (n = 26) | p-value |
---|---|---|---|
Age (yr) | 59.0 ± 1.3 | 60.5 ± 1.1 | 0.63 |
Male sex | 16 (59.3) | 11 (42.3) | 0.22 |
Body mass index (kg/m2) | 23.7 ± 3.4 | 22.6 ± 3.9 | 0.25 |
Diabetes mellitus | 16 (59.3) | 14 (53.8) | 0.69 |
Cerebrovascular disease | 10 (37.0) | 4 (15.4) | 0.07 |
Cardiovascular disease | 12 (44.4) | 10 (38.5) | 0.66 |
CCI | 2 (2–3) | 3 (2–3) | 0.14 |
Cause of KFRT | |||
Diabetes mellitus | 16 (59.3) | 12 (46.2) | 0.46 |
Hypertension | 9 (33.3) | 10 (38.5) | |
Glomerulonephritis | 1 (3.7) | 3 (11.5) | |
Others | 1 (3.7) | 1 (3.8) | |
BP-lowering drug | 23 (85.2) | 21 (80.8) | 0.67 |
ARB | 17 (63.0) | 17 (65.4) | 0.85 |
CCB | 11 (40.7) | 14 (53.8) | 0.34 |
β-Blocker | 12 (44.4) | 15 (57.7) | 0.34 |
α-Blocker | 3 (11.1) | 6 (23.1) | 0.25 |
SBP (mmHg) | 147.0 ± 25.7 | 148.1 ± 22.6 | 0.87 |
DBP (mmHg) | 73.5 ± 17.4 | 72.8 ± 13.9 | 0.86 |
Hemoglobin (g/dL) | 10.6 ± 1.1 | 10.2 ± 1.3 | 0.32 |
Albumin (g/dL) | 3.9 ± 0.3 | 3.9 ± 0.3 | 0.57 |
hs-CRP (mg/dL) | 0.7 (0.11–1.4) | 0.8 (0.23–1.5) | 0.87 |
Sodium (mmol/L) | 137.7 ± 2.8 | 134.0 ± 17.7 | 0.29 |
Potassium (mmol/L) | 5.1 ± 0.7 | 4.9 ± 0.7 | 0.35 |
Bicarbonate (mmol/L) | 23.6 ± 4.6 | 23.8 ± 2.6 | 0.89 |
PTH (pg/mL) | 255.5 (188.7–395.6) | 265.8 (169.6–451.9) | 0.75 |
Calcium (mg/dL) | 8.6 ± 1.3 | 8.9 ± 0.6 | 0.26 |
Phosphate (mg/dL) | 5.4 ± 1.8 | 5.2 ± 1.3 | 0.73 |
BUN (mg/dL) | 62.1 ± 15.8 | 58.8 ± 16.8 | 0.47 |
Creatinine (mg/dL) | 10.1 ± 2.4 | 10.0 ± 4.4 | 0.88 |
B2MG (mg/L) | 21.7 (19.7–23.4) | 25.6 (21.4–28.0) | 0.006 |
Glucose (mg/dL) | 138.6 ± 58.9 | 132.2 ± 73.2 | 0.73 |
Dialysis parameter | |||
Vintage (yr) | 1.5 (1.0–4.25) | 3 (1–4) | 0.89 |
Dialysis time (min) | 241.0 ± 0.9 | 241.6± 2.5 | 0.52 |
TMP (mmHg) | 150.2 ± 47.6 | 162.5 ± 51.2 | 0.37 |
Blood flow (mL/min) | 272.8 ± 39.7 | 256.2 ± 31.8 | 0.005 |
Heparin dose (IU/session) | 2,205.6 (1,201.7–2,213.9) | 1,899.4 (1,603.3–2,209.5) | 0.48 |
Dialysate flow (mL/min) | 607.0 ± 90.5 | 589.5 ± 113.3 | 0.54 |
Net ultrafilation (L/sesseion) | 2.3 ± 1.0 | 2.3 ± 1.1 | 0.91 |
Data are expressed as mean ± standard deviation, number (%), or median (interquartile range).
ARB, angiotensin receptor blocker; B2MG, β2-microglobulin; BP, blood pressure; BUN, blood urea nitrogen; CCB, calcium channel blocker; CCI, Charlson comorbidity index; DBP, diastolic blood pressure; HDF, hemodiafiltration; hs-CRP, high-sensitivity C-reactive protein; KFRT, kidney failure with replacement therapy; PTH, parathyroid hormone; SBP, systolic blood pressure; TMP, transmembrane pressure.
Primary outcome analysis: the differences in convection volume between predilution HDF and mixed-HDF
Variable | Treatment | Observed data | p-value | ||||
---|---|---|---|---|---|---|---|
Mean value during 6 mo | Baseline | Month 3 | Month 6 | Between-group | Within-group | ||
Convection volume (L/session) | |||||||
Absolute | Predilution | 41.0 ± 10.3 | 40.4 ± 8.0 | 39.1 ± 8.7 | 44.0 ± 13.1 | 0.17 | |
Mixed | 35.0 ± 5.7 | 32.6 ± 7.8 | 36.3 ± 4.2 | 36.1 ± 3.7 | <0.001 | 0.01 | |
Effective | Predilution | 41.0 ± 10.3 | 40.4 ± 8.0 | 39.1 ± 8.7 | 44.0 ± 13.1 | 0.17 | |
Mixed | 51.5 ± 9.0 | 47.9 ± 10.4 | 53.3 ± 7.6 | 53.2 ± 7.4 | <0.001 | 0.003 | |
Substitution volume (L/session) | |||||||
Via predilution mode | Predilution | 38.8 ± 10.5 | 37.7 ± 8.0 | 36.8 ± 8.9 | 41.8 ± 13.4 | 0.16 | |
Mixed | 16.6 ± 4.2 | 15.6 ± 6.8 | 17.1 ± 2.3 | 17.1 ± 2.1 | 0.44 | ||
Via postdilution mode | Predilution | NA | NA | NA | NA | ||
Mixed | 16.3 ± 2.5 | 14.8 ± 2.6 | 16.9 ± 2.2 | 17.1 ± 2.1 | <0.001 | ||
Net ultrafiltration (L/session) | Predilution | 2.3 ± 1.1 | 2.3 ± 1.0 | 2.3 ± 1.1 | 2.2 ± 1.1 | 0.72 | |
Mixed | 2.2 ± 1.1 | 2.3 ± 1.1 | 2.3 ± 1.0 | 1.9 ± 1.1 | 0.73 | 0.06 | |
Convection volumes adjusted for body surface area (L/m2 per session) | |||||||
Absolute | Predilution | 24.5 ± 3.8 | 24.4 ± 5.1 | 23.1 ± 5.5 | 25.8 ± 7.8 | 0.27 | |
Mixed | 20.6 ± 5.5 | 18.0 ± 5.1 | 20.0 ± 4.1 | 23.8 ± 10.5 | 0.004 | 0.004 | |
Effective | Predilution | 24.5 ± 3.8 | 24.4 ± 5.1 | 23.1 ± 5.5 | 25.8 ± 7.8 | 0.60 | |
Mixed | 31.5 ± 5.3 | 27.5 ± 5.4 | 32.6 ± 4.6 | 34.4 ± 11.2 | <0.001 | 0.003 |
Data are presented as mean ± standard deviation.
All analyses were conducted using repeated measures analysis of variance.
HDF, hemodiafiltration; NA, not applicable.
Secondary outcome analysis
Variable | Treatment | Observed data | p-value | ||||
---|---|---|---|---|---|---|---|
Mean value of three time points | Baseline | Month 3 | Month 6 | Between-group | Within-group | ||
Predialysis B2MG (mg/L) | Predilution | 21.2 ± 4.8 | 21.5 ± 3.5 | 21.2 ± 6.3 | 20.9 ± 4.5 | 0.88 | |
Mixed | 23.6 ± 4.7 | 25.4 ± 5.6 | 23.3 ± 3.6 | 22.2 ± 4.4 | 0.02 | 0.004 | |
Reduction ratio of B2MG (%) | Predilution | 73.9 ± 6.6 | 75.2 ± 4.9 | NA | 72.8±7.9 | 0.36 | |
Mixed | 76.5 ± 5.9 | 76.0 ± 4.8 | NA | 78.7±5.1 | 0.01 | 0.02 | |
Kt/V urea | Predilution | 1.53 ± 0.2 | 1.53 ± 0.3 | 1.49 ± 0.2 | 1.57 ± 0.2 | 0.37 | |
Mixed | 1.56 ± 0.3 | 1.51 ± 0.3 | 1.59 ± 0.25 | 1.57 ± 0.3 | 0.33 | 0.19 | |
TMP (mmHg) | Predilution | 139.6 ± 42.0 | 150.2 ± 47.6 | 135.7 ± 36.9 | 132.9 ± 40.3 | 0.09 | |
Mixed | 176.2 ± 51.9 | 162.5 ± 51.2 | 192.7 ± 42.4 | 173.1 ± 59.1 | 0.001 | 0.06 | |
hs-CRP (mg/dL) | Predilution | 0.6 (0.1–1.7) | 0.7 (0.1–1.4) | 0.6 (0.2–2.2) | 0.6 (0.1–3.3) | 0.14 | |
Mixed | 0.9 (0.3–2.0) | 0.8 (0.2–1.5) | 1.1 (0.3–2.0) | 0.9 (0.3–3.5) | 0.82 | 0.82 | |
Albumin (g/dL) | Predilution | 3.9 ± 0.3 | 3.9 ± 0.3 | 4.0 ± 0.4 | 3.9 ± 0.3 | 0.14 | |
Mixed | 3.8 ± 0.4 | 3.9 ± 0.3 | 3.8 ± 0.4 | 3.8 ± 0.4 | 0.16 | 0.14 | |
Phosphate (mg/dL) | Predilution | 5.1 ± 1.7 | 5.4 ± 1.8 | 5.0 ± 1.4 | 4.8 ± 1.7 | 0.30 | |
Mixed | 5.0 ± 1.4 | 5.2 ± 1.3 | 4.9 ± 1.5 | 4.8 ± 1.3 | 0.79 | 0.29 | |
Sodium (mmol/L) | Predilution | 137.7 ± 4.2 | 137.7 ± 2.9 | 138.3 ± 3.1 | 137.2 ± 6.0 | 0.51 | |
Mixed | 137.3 ± 3.5 | 137.9 ± 4.3 | 136.7 ± 3.3 | 137.3 ± 2.7 | 0.59 | 0.19 | |
Potassium (mmol/L) | Predilution | 5.0 ± 0.8 | 5.1 ± 0.7 | 5.0 ± 0.8 | 4.9 ± 0.8 | 0.49 | |
Mixed | 5.0 ± 0.7 | 4.9 ± 0.7 | 4.9 ± 0.8 | 5.2 ± 0.6 | 0.91 | 0.13 | |
Bicarbonate (mmol/L) | Predilution | 23.4 ± 4.0 | 23.6 ± 4.6 | 23.4 ± 3.5 | 23.3 ± 3.9 | 0.81 | |
Mixed | 23.4 ± 3.0 | 23.8 ± 2.6 | 23.4 ± 3.7 | 22.9 ± 2.8 | 0.89 | 0.13 | |
Bioimpedance parameter | |||||||
OH (L) | Predilution | 0.8 (–0.9 to 1.2) | NA | 1.0 (–0.3 to 2.7) | >0.99 | ||
Mixed | 0.3 (–0.2 to 1.23) | NA | 0.7 (–0.6 to 2.9) | 0.32 | 0.16 | ||
OH-ECW (%) | Predilution | 4.5 (–5.6 to 9.1) | NA | 7.1 (–1.9 to 14.6) | 0.98 | ||
Mixed | 2.7 (–1.2 to 8.0) | NA | 4.1 (–4.5 to 18.2) | 0.33 | 0.16 | ||
Predialysis blood pressure (mmHg) | |||||||
SBP | Predilution | 147.0 ± 25.7 | 155.8 ± 25.5 | 149.2 ± 26.0 | 0.14 | ||
Mixed | 148.1 ± 22.6 | 156.1 ± 24.7 | 153.9 ± 28.8 | 0.74 | 0.22 | ||
DBP | Predilution | 73.5 ± 17.2 | 74.0 ± 14.6 | 73.9 ± 18.6 | >0.99 | ||
Mixed | 72.8 ± 13.9 | 74.9 ± 15.9 | 74.1 ± 13.4 | 0.97 | 0.68 |
Data are presented as mean ± standard deviation or median (interquartile range).
B2MG, β2-microglobulin; DBP, diastolic blood pressure; hs-CRP, high-sensitive C-reactive protein; NA, not available; OH-ECW, overhydration/extracellular water; OH, overhydration; SBP, systolic blood pressure; TMP, transmembrane pressure.
All analyses were conducted using repeated measures analysis of variance.
Adverse event rates
Variable | Predilution HDF (n = 81) | Mixed-HDF (n = 78) | p-value |
---|---|---|---|
No. of adverse events | 42 (51.9) | 40 (51.3) | 0.94 |
At least one event | |||
A decrease in SBP >10 mmHg without symptoms | 36 (44.4) | 34 (43.6) | 0.73 |
Symptomatic intradialytic hypotension | 3 (3.7) | 1 (1.3) | |
Headache | 1 (1.2) | 2 (2.6) | |
Muscle cramps | 2 (2.5) | 1 (1.3) | |
Nausea, vomiting | 0 | 1 (1.3) | |
Fever | 0 | 1 (1.3) | |
Chest pain | 0 | 0 | |
Arrhythmia | 0 | 0 |
Data are presented as number (%). The percentages were calculated with number of adverse events per dialysis sessions during study period.
HDF, hemodiafiltration; SBP, systolic blood pressure.
Symptomatic intradialytic hypotension is defined as a decrease in SBP by ≥20 mmHg associated with symptoms that include abdominal discomfort, yawning, sighing, nausea, vomiting, muscle cramps, restlessness, dizziness or fainting, and anxiety.