Dialyzer Surface Area Research Articles

Residual Red Blood Cell Volume in Extracorporeal Blood Circuit after Hemodialysis: A Single-Center Study

Introduction: The factors contributing to blood loss during hemodialysis (HD) procedures remain underexplored. This study aimed to quantify blood loss during HD and identify the potential factors associated with it. Methods: The study included 70 ESRD patients undergoing HD. After dialysis, the extracorporeal blood circuits were rinsed with 1,000 mL of 0.05% NH3 solution in distilled water, and hemoglobin levels were measured. Univariate regression was used to assess the linear relationship between residual red blood cell (RBC) volume and various parameters, including HD mode, dialyzer surface area, ultrafiltration goal, hypotension during HD, blood flow rate, activated partial thromboplastin time, and C-reactive protein. Multivariate regression was also conducted to explore the relationships among these parameters. Results: The mean RBC volume remaining in the extracorporeal blood circuit after HD was 1.6 ± 0.9 mL (mode: 1.0, range: 0.3–6.5 mL). When converted to whole blood volume per patient, the mean blood volume was 5.3 ± 3.0 mL (median: 4.1 mL, mode: 4.0 mL, range: 1.0–19.0 mL). Multivariate analysis identified the dialyzer surface area as the only significant determinant of residual RBC volume. Conclusion: After HD, the remaining RBC volume in the extracorporeal blood circuit varies from 1.6 to 6.5 mL. When the RBC volume was converted to whole blood volume for each case, the blood loss ranged from 1.0 to 19.0 mL. Dialyzer surface area was the only significant determinant of residual RBC volume.

Assessment of Neutrophil Activation in Children with Chronic Kidney Disease Stage 5 on Hemodialysis: Effect of a Single Procedure

Abstract Background Hemodialysis (HD) process can trigger inflammation and induce cytokines activation. Neutrophils extrude neutrophil extracellular traps (NETs) which are extracellular chromatin containing a variety of granular proteins that have been implicated in infection, as well as vascular inflammation and occlusion. Objective To assess the effect of a single HD session on the level of circulating NETs in children with chronic kidney disease stage 5 (CKD-5) on regular HD treatment. Methods This is a cross sectional study done at Pediatric Dialysis Unit (PDU), Children’s Hospital, Ain Shams University during the period from April 2023 to July 2023. It included 26 CKD-5 cases receiving 3 hours HD session 3 times per week using low flux polysulfone dialyzer and 26 age and sex matched children as controls. Patients with the following medical conditions were excluded: failed renal graft, active infection, autoimmune disease, active thrombosis, diabetes mellitus, malignancy, cardiovascular disease like (infective endocarditis, vegetation and intracardiac mass) and patients on immunosuppressants. Complete blood cell (CBC), C-reactive protein (CRP) and serum NETs measured by enzyme-linked immunosorbent assay were done for all cases pre- and post-dialysis as well as the control group. Results The mean±SD age of the patient was 12.2±2.8 years. They were 16 males (61.5%) and 10 females (38.5%). The mean age of the controls was 10.9±2.7 years. They were 13 males (50%) and 13 females (50%). There was significantly elevated pre-HD (Median= 535.95ng/L, IQR= 519.6ng/L) and post-HD (Median=1310.5ng/L, IQR=916.4ng/L) serum NETs compared to its level (Median=149.1ng/L, IQR=69.7ng/L) in controls (p < 0.001 for both). There was also significantly higher post-HD level of serum NETs than its pre-HD one (p < 0.001). Gender did not have significant effect on serum NETs levels (p = 0.089). The age of patients, dialyzer surface area, pump blood flow rate, and duration of HD didnot correlate significantly with serum NETS levels (p = 0.95, 0.68, 0.23 and 0.83, respectively). In addition, there was no significant correlation between serum NETs and total leukocyte count, absolute neutrophil count and lymphocyte count (p = 0.29, 0.17 and 0.6, respectively). Conclusion Children with CKD-5 on regular HD had higher basal levels of circulating NETs than normal controls. These levels were further increased after HD session using low flux polysulfone membrane implying the associated subclinical inflammation.

Factors influencing circuit lifetime in paediatric continuous kidney replacement therapies – results from the EurAKId registry

BackgroundContinuous kidney replacement therapy (CKRT) has recently become the preferred kidney replacement modality for children with acute kidney injury (AKI). We hypothesise that CKRT technical parameters and treatment settings in addition to the clinical characteristics of patients may influence the circuit lifetime in children.MethodsThe study involved children included in the EurAKId registry (NCT 02960867), who underwent CKRT treatment. We analysed patient characteristics and CKRT parameters. The primary end point was mean circuit lifetime (MCL). Secondary end points were number of elective circuit changes and occurrence of dialysis-related complications.ResultsThe analysis was composed of 247 children who underwent 37,562 h of CKRT (median 78, IQR 37–165 h per patient). A total of 1357 circuits were utilised (3, IQR 2–6 per patient). MCL was longer in regional citrate anticoagulation (RCA), compared to heparin (HA) and no anticoagulation (NA) (42, IQR 32-58 h; 24, IQR 14-34 h; 18, IQR 12-24 h, respectively, p < 0.001). RCA was associated with longer MCL regardless of the patient’s age or dialyser surface. In multivariate analysis, MCL correlated with dialyser surface area (beta = 0.14, p = 0.016), left internal jugular vein vascular access site (beta = -0.37, p = 0.027), and the use of HA (beta = -0.14, p = 0.038) or NA (beta = -0.37, p < 0.001) vs. RCA. RCA was associated with the highest ratio of elective circuit changes and the lowest incidence of complications.ConclusionAnticoagulation modality, dialyser surface, and vascular access site influence MCL. RCA should be considered when choosing first-line anticoagulation for CKRT in children. Further efforts should focus on developing guidelines and clinical practice recommendations for paediatric CKRT.Graphical abstractA higher resolution version of the Graphical abstract is available as Supplementary information

Anti-inflammatory effect of high flux dialyzer surface area 2.6m2 in high flux hemodialysis and hemodiafiltration

Dialysis therapy has remarkably evolved through the innovation in dialyzers and hemodialysis modalities, enhancing patients’ quality of life. The efficacy of dialysis can be determined by measuring the reduction ratio (RR) of middle molecules such as Interleukin-6 (IL-6) and Procalcitonin. In our study, we tested a high-flux dialyzer, BIOPURE (Biorema) 260 HF, with a surface area (SA) of 2.6 m2, in terms of IL-6 and Procalcitonin removal while performing high-flux hemodialysis (HF-HD) and post-dilution online hemodiafiltration (OL-HDF). This crossover study comprised 25 patients who received a session of HF-HD using the BIOPURE (Biorema) 260 H, followed by a session of post-dilution OL-HDF. A washout period of 2 weeks was instilled between the two sessions, during which the patients received HF-HD using high-flux dialyzers (maximum SA 2.0 m2). All patients’ pre/post dialysis concentrations of IL-6 and procalcitonin were measured. The dialyzer used in this study resulted in a significant IL-6 RR of 44.92±5.11% (p&lt;0.001) with HDF and 32.48±5.72% (p&lt;0.001) with HF-HD; and a procalcitonin RR of 50.32±3.94% (p&lt;0.001) with HDF and 41.80±4.32% (p&lt;0.001) with HF-HD. In conclusion, the dialyzer BIOPURE (Biorema) 260 HF (SA 2.6 m2) is efficient in eliminating IL-6 and procalcitonin, especially with OL-HDF compared to HF-HD, with acceptable albumin loss in the dialysate.

#3062 ROLE OF ONLINE HEMODIAFILTRATION (OL-HDF) IN THE CONTINUOUS MEASUREMENT OF THE DIALYSIS DOSE

Abstract Background and Aims OL-HDF provides multiple advantages and benefits to patients compared to conventional high-flow hemodialysis (HFHD). Current monitors have a wide variety of biosensors and devices that provide continuous information on the patient's biological parameter and the efficiency of the dialysis session. Monofrequency bioimpedance (BIVA) provides information regarding the state of hydration (HE) and nutrition (EN) of our patients. Method Observational study in 493 patients, distributed in 8 dialysis centers and with a three different model of dialysis monitor. Demographic data, dialysis techniques and regimens, mean values for one month of ultrafiltration rate readings and KT are analyzed. The continuous measurement of DD is estimated by the ion dialysance biosensor. The OL-HDF technique is post-dilutional. The BIVA measurement is performed between 10 and 30 minutes after the end of the session. The Kt/V is estimated from the total TBW (V) by BIVA, using the Watson and Hume-Wiers formulas. Statistical analysis: descriptive, t-Student for statistics of groups and independent samples, Chi square for the association in cross tables. Results See Table 1. Conclusion Obtaining lower dialysis dose values in OL-HDF than in HFHD in some monitor models, despite longer dialysis times and greater dialyzer surface area, is probably due to dilution due to post- re-infusion and/or to the positioning of the dialysance sensors within the hydraulic circuit. This makes us think about the advisability of maintaining urea Kt/V measurements, by laboratory, to ensure adequate dialysis quality.

MO889: High Flux Dialyzer 2.6 M2 is Promising for Free Light Chains Removal in High Flux Hemodialysis and Hemodiafiltration

Abstract BACKGROUND AND AIMS Immunoglobulin light chains are classified as middle molecule uremic toxins and its removal through effective dialyzer is needed with less albumin loss. This study assessed the free light chains removal using dialyzer surface area (SA) 2.6m2 in high flux dialysis (HD) versus hemodiafiltration (HDF) and its relation to cumulative albumin loss. METHOD A cross-over study included 25 patients who underwent hemodialysis using dialyzer surface area 2.6 m2 in high flux HD followed by online post-dilution hemodiafiltration with washout period 2 weeks using high flux dialyzers (max 2.0 m2 SA). All patients were subjected to single session measurement of dialysate albumin every hour and pre-post dialysis Free light chains (FLC) kappa and Lambda by ELISA. RESULTS Dialyzer (SA) 2.6m2 showed significant reduction in post-dialysis kappa and lambda in comparison to pre-dialysis level in high flux hemodialysis and hemodiafiltration (P &amp;lt; 0.001). HDF showed higher kappa and lambda FLC reduction ratio (45.16 ± 6.53 ng/mL), (28.68 ± 4.36 ng/mL), respectively compared with high flux HD (29.52 ± 6.38 ng/mL), (19.48 ± 1.96 ng/mL), respectively (P &amp;lt; 0.001). HDF/HD fold change of kappa and lamda were (1.56 ± 0.23) and (1.48 ± 0.26), respectively. Patients on HDF dialysis had significant total albumin loss in dialysate [median (IQR) 2.47 (1.16) gm/dL] compared with high flux dialysis [median (IQR) 0.65 (0.64) gm/dL] with (P &amp;lt; 0.001). Maximum albumin loss in patients on HDF was in the first hour [median (IQR) 1.22 (0.59)] gm/dL with lower albumin loss in the next hours reaching median {0.17 (0.15) gm/dL} in the fourth hour. Trans-membrane pressure was positively correlated with total albumin loss in high flux hemodialysis and hemodiafiltration (r 0.443, p 0.027, r 0.745, P = 0.001), respectively. CONCLUSION High flux dialyzer 2.6 m2 (SA) is effective for free light chains removal especially with online post-dilution hemodiafiltration with acceptable albumin loss.

The Effect of Increasing Surface Area of Dialyzer Membrane on Adequacy of Hemodialysis

Introduction: The patients with end stage renal disease requires 12 hours of hemodialysis per week divided in three equal sessions (4 hours/day for 3 days/week). Some studies show that adequacy of hemodialysis can be maintained by increasing the surface area of the dialyzer membrane and decreasing the frequency of treatment which can help the poor socioeconomic status patients in getting effective hemodialysis at a low cost.&#x0D; Objectives: To observe whether by increasing the surface area of dialyzer the dose of dialysis can be reduced against the standard hemodialysis prescription.&#x0D; Study design: Randomized Control Trial.&#x0D; Study Duration: Six months from March 2017 to August 2017.&#x0D; Settings: Department of Nephrology, The Indus Hospital Karachi.&#x0D; Subjects: ESRD patients undergoing Hemodialysis for at least 6 months at The Indus Hospital Karachi.&#x0D; Methods: In this prospective randomized control study, a total of 60 patients of end stage renal disease receiving hemodialysis for more than six months were included and divided into 2 groups randomly (Arm-A: twice weekly dialysis using a larger surface area dialyzer and Arm-:B thrice weekly dialysis using regular surface area dialyzer).&#x0D; Results: A total of 59 (30 in Arm A and 29 in Arm B) patients were enrolled in the study out of which majority of the patients were male (59.3%). On average significantly higher URR and eKt/V were reported in Arm A whereas, higher mean standard (weekly) stdKt/V was reported in Arm-B.&#x0D; Conclusion: Standard protocols should be followed to maintain the adequacy of Hemodialysis.

Dialyzer surface area is a significant predictor of mortality in patients on hemodialysis: a 3-year nationwide cohort study

A target Kt/V of > 1.4 and use of a high-flux dialyzer are recommended for patients on hemodialysis. However, there is little information on the relationship between the dialyzer surface area and mortality in these patients. In this nationwide cohort study, we aimed to clarify this relationship by analyzing data from the Japanese Society for Dialysis Therapy for 2010–2013. We enrolled 234,638 patients on hemodialysis who were divided according to quartile for dialyzer surface area into the S group (small, < 1.5 m2), M group (medium, 1.5 m2), L group (large, 1.6 to < 2.0 m2), or XL group (extra-large, ≥ 2.0 m2). We assessed the association of each group with 3-year mortality using Cox proportional hazards models and performed propensity score matching analysis. By the end of 2013, a total of 53,836 patients on dialysis (22.9%) had died. There was a significant decrease in mortality with larger dialyzer surface areas. The hazard ratio (95% confidence interval) was significantly higher in the S group (1.15 [1.12–1.19], P < 0.0001) and significantly lower in the L group (0.89 [0.87–0.92] P < 0.0001) and XL group (0.75 [0.72–0.78], P < 0.0001) than in the M group as a reference after adjustment for all confounders. Findings were robust in several sensitivity analyses. Furthermore, the findings remained significant after propensity score matching. Hemodialysis using dialyzers, especially super high-flux dialyzers with a larger surface area might reduce mortality rates, and a surface area of ≥ 2.0 m2 is superior, even with the same Kt/V.

Stepwise achievement of high convection volume in post‐dilution hemodiafiltration: A prospective observational study

High-volume online hemodiafiltration (HDF) has been reported to reduce the patient's mortality. However, achieving a high convection volume is challenging. In this prospective study, we investigated the feasibility of achieving high-volume HDF with ≥21L substitution volume via modification of blood flow rate (BFR), needle size, and dialysis membrane. In 30 patients undergoing hemodialysis, we followed a stepwise protocol and gradually increased the BFR (280→300→330ml/min; steps 1, 2, and 3) and needle size (16→15G; step 4). After changing dialyzer surface area (1.8m2 →2.5m2 ), the BFR and needle size were similarly increased stepwise (steps 5, 6, 7, and 8). The mean substitution volume was 18.7±2.2L at step 1 and it significantly increased to 25.1±2.6L by step 8. A substitution volume of 21L was achieved by 13.3% of patients in step 1 and by 96.7% after step 8. The substitution volume was higher for the dialyzer with a large surface area and for the larger needle (15G). Between steps 1 and 8, the Kt/V and β2 microglobulin reduction ratios also improved significantly. High-volume HDF is feasible through a stepwise increase in the BFR, needle size, and surface area of the dialysis membrane.

Modification and Validation of the Phosphate Removal Model: A Multicenter Study

Background: Our research group has previously reported a noninvasive model that estimates phosphate removal within a 4-h hemodialysis (HD) treatment. The aim of this study was to modify the original model and validate the accuracy of the new model of phosphate removal for HD and hemodiafiltration (HDF) treatment. Methods: A total of 109 HD patients from 3 HD centers were enrolled. The actual phosphate removal amount was calculated using the area under the dialysate phosphate concentration time curve. Model modification was executed using second-order multivariable polynomial regression analysis to obtain a new parameter for dialyzer phosphate clearance. Bias, precision, and accuracy were measured in the internal and external validation to determine the performance of the modified model. Results: Mean age of the enrolled patients was 63 ± 12 years, and 67 (61.5%) were male. Phosphate removal was 19.06 ± 8.12 mmol and 17.38 ± 6.75 mmol in 4-h HD and HDF treatments, respectively, with no significant difference. The modified phosphate removal model was expressed as Tpo4 = 80.3 × C45 − 0.024 × age + 0.07 × weight + β × clearance − 8.14 (β = 6.231 × 10−3 × clearance − 1.886 × 10−5 × clearance2 – 0.467), where C45 was the phosphate concentration in the spent dialysate measured at the 45th minute of HD and clearance was the phosphate clearance of the dialyzer. Internal validation indicated that the new model was superior to the original model with a significantly smaller bias and higher accuracy. External validation showed that R2, bias, and accuracy were not significantly different than those of internal validation. Conclusions: A new model was generated to quantify phosphate removal by 4-h HD and HDF with a dialyzer surface area of 1.3–1.8 m2. This modified model would contribute to the evaluation of phosphate balance and individualized therapy of hyperphosphatemia.

Does Dialyzer Surface Area Alone Adjusted to Body Surface Area Have Any Clinical Impact on Adequacy: A Single-Center Observation Study in Saudi Arabia

Does Dialyzer Surface Area Alone Adjusted to Body Surface Area Have Any Clinical Impact on Adequacy: A Single-Center Observation Study in Saudi Arabia

Adequacy of Hemodialysis and Its Associated Factors among Patients Undergoing Chronic Hemodialysis in Dar es Salaam, Tanzania.

The worldwide prevalence of maintenance hemodialysis continues to rise. An adequate delivery of hemodialysis dose as measured by Kt/V or urea reduction ratio is a crucial determinant of clinical outcome for chronic hemodialysis patients. The aim of this study was to assess the adequacy of hemodialysis and its associated factors among patients undergoing chronic hemodialysis in Dar es Salaam. This was a cross-sectional study done on patients undergoing chronic hemodialysis in four dialysis centers in Dar es Salaam. Sociodemographic information and treatment characteristics were collected. Urea reduction rate and single-pool Kt/V were calculated to determine the adequacy of hemodialysis. The data were analyzed and any associated factors for inadequate hemodialysis were determined using a chi-square test and a logistic regression analysis. A total of 143 patients participated in the study. Males represented 65.7% of the study population. The mean age (±SD) was 51.7 ± 1.2 years. Only 34.3% (based on urea reduction ratio (URR)) and 40.6% (based on Kt/V) of patients received adequate hemodialysis. The univariate analysis showed that males were more likely to have inadequate dialysis (65.6% versus 48.0%, p=0.048 based on Kt/V). Patients using hemodialyzers with dialyzer surface area less than 1.4 m2 received significantly less hemodialysis dose than those with more than 1.4 m2 (69.0% versus 41.2%, p=0.02, by URR) (62.7% versus 35.3%, p=0.03, by Kt/V criteria). Patients who had hemoglobin <10 g/dl received significantly inadequate hemodialysis dose as compared to patients with hemoglobin ≥10 g/dl by Kt/V criteria (69.8% versus 51.3%, p=0.03). None of the factors acquired significance in the multivariate analysis. The proportion of patients receiving an adequate hemodialysis dose is low (34.3% based on URR and 40.6% based on Kt/V). Male gender, dialyzer surface area of <1.4 m2, and hemoglobin level of <10 g/dl were associated with an inadequate delivered dose of hemodialysis in the univariate analysis but not in the multivariate analysis. This study can increase awareness about the importance of measuring hemodialysis adequacy and giving the correct hemodialysis dose to achieve the intended benefit.

The relationship between hypoalbuminemia and intradialytic hypotention in hemodialysis patients

Objective The aim of this study was to evaluate the relationship between serum albumin and intradialytic hypotension (IDH). Background Hypoalbuminemia and IDH are common complications during hemodialysis (HD) session. Hypotension is a risk factor for mortality and morbidity in HD patients. Patients and methods We conducted a cross-sectional study on 50 patients with end-stage renal disease who received regular HD session three times weekly for more than 3 months (from April to July 2017) at Ashmoun General Hospital. They were divided into two groups: group 1 included patients who developed recurrent attacks of IDH (24 patients) and group 2 included patients who did not develop IDH (26 patients). Data collected from each patient included the following: (i) demographic features and clinical features (blood pressure (BP) changes during session, ultrafiltration rate, intradialytic weight gain, duration of dialysis, cause of end-stage renal disease, surface area of dialyzer, and blood flow of the machine); (ii) blood chemistry (creatinine level, urea, hemoglobin, hematocrit value, albumin, triglycerides, cholesterol, aspartate aminotransferase, alanine aminotransferase, Na*, K*, and KT/V); (iii) echocardiographic assessment of left ventricular geometry; and (iv) inferior vena cava-guided ultrasonography. Results Serum albumin level among group I ranged between 2.4 and 4.7 mg/dl, with mean ± SD of 3.1 + 0.53 mg/dl, whereas in group II, serum albumin level ranged between 2.6 and 4.6 mg/dl with mean ± SD of 3.6 ± 0.48 mg/dl, with P value of 0.002, indicating there was a high significant difference between both groups. There was a highly significant positive correlation between delta systolic BP and IVC collapsibility index (IVCC). There was a highly significant negative correlation between serum albumin and IVCC, and there was a highly significant negative correlation between delta systolic BP and IVC diameter. Conclusion We concluded that serum albumin is a parameter that is associated with IDH and found that bedside measurements of IVCC and IVC diameter are easy and good markers for prediction of IDH.

The Relationship between Hypoalbuminemia and Intradialytic Hypotension in Haemodialysis Patients

Objective: To evaluate the relationship between Serum albumin and Intradialytic Hypotension (IDH). Background: Hypoalbuminemia and Intradialytic Hypotension (IDH) is a common complication during HD session. Hypotension is a risk factor for mortality and morbidity in HD patients. Patients and methods: We conducted a cross-sectional study on 50 patients with ESRD who received regular hemodialysis session 3 times weekly for more than 3 months (from April to July 2017) at Ashmoun General Hospital. They have been divided into two groups; Group 1: Patients of this group developed recurrent attacks of IDH and Group 2: Patients of this group did not develop IDH. Data collected from each patient included: (I) Demographic features, clinical features (blood pressure changes during session, ultrafiltration rate, intradialytic weight gain (IDWG), duration of dialysis, cause of ESRD, surface area of dialyzer and blood flow of the machine), (II) Blood chemistry (creatinine, urea, hemoglobin, hematocrit value, albumin, triglycerides, cholesterol, AST, ALT, Na*, K*and KT/V), (III) Echocardiographic assessment of left ventricular geometry and (IV) IVC guided ultrasonography. Result: Serum albumin level among group I ranged between 2.4-4.7 mg/dl with mean ± SD 3.1 ± 0.53 mg/dl, while in group II serum albumin level ranged between 2.6-4.6 mg/dl with mean ± SD 3.6 ± 0.48 mg/dl with p-value 0.002 and there were a high significant difference between both groups. Conclusion: We concluded that serum albumin is a parameter which is associated with intradialytic hypotension and found that beside measurement of IVCC and IVCD are easy and good markers for prediction of intradialytic hypotension.

Assessment of dialyzer surface in online hemodiafiltration; objective choice of dialyzer surface area

IntroductionOnline haemodiafiltration (OL-HDF) is most effective technique; several randomised studies and meta-analyses have shown a reduction in mortality, with a directly related association with convective volume. At present, it is not properly established whether the increasing in dialyser surface area may suppose better outcomes in terms of convective and clearance efficacy. The purpose of the study was to assess the effect of increase in dialyser surface area on the convective volume and clearance capacity. Materials and methodsA total of 37 patients were included, 31 male and 6 female subjects who were participating in an OL-HDF programme with a 5008 Cordiax monitor with autosubstitution. Each patient was analysed in three sessions, and only the dialyser surface area (1.0, 1.4 or 1.8m2) varied. In each session, urea (60Da), creatinine (113Da), β2-microglobulin (11,800Da), myoglobin (17,200Da) and α1-microglobulin (33,000Da) serum concentration at baseline and at the end of each session were determined, so the reduction of thes solutes could be calculated. ResultsConvective volume achieved was 29.8±3.0 with 1.0m2, 32.7±3.1 (6% increase) with 1.4m2 and 34.7±3.3L (16% increase) with 1.8m2 (p<0.001). The increase in dialyser surface area showed an increase in urea and Creatinine clearance and urea and creatinine clearance. The reduction percentage of β2-m increased from 80.0±5.6 with 1.0m2, to 83.2±4.2 with 1.4m2 and to 84.3±4.0% with 1.8m2. Regarding myoglobin and α1-microglobulin, significant differences were observed between the smallest surface area (1.0m2), 65.6±11 and 20.1±9.3 and the other two surface areas, 70.0±8.1 and 24.1±7.1 (1.4m2) and 72.3±8.7 and 28.6±12 (1.8m2). ConclusionThe increase in 40% and 80% of dialyzer surface area entails an increase in convective volume of 6 and 16% respectively, showing minimal differences both in convective volume and clearance capacity when UFC was greater than 45mL/h/mmHg. It is advisable to optimise dialyser efficiency to the smallest surface area possible, adjusting treatment prescription.

Valoración de la superficie del dializador en la hemodiafiltración on-line. Elección objetiva de la superficie del dializador

IntroductionOnline hemodiafiltration (OL-HDF) is currently the most effective technique. Several randomized studies and meta-analyses have observed a reduction in mortality as well as a direct association with convective volume. Currently, it has not been well established whether a larger dialyzer surface area could provide better results in terms of convective and depurative effectiveness. The aim of this study was to assess the effect of larger dialyzer surface areas on convective volume and filtration capacity. Material and methodsA total of 37 patients were studied, including 31 men and 6 women, who were in the OL-HDF program using a 5008 Cordiax monitor with auto-substitution. Each patient was analyzed in 3 sessions in which only the dialyzer surface area varied (1.0, 1.4 or 1.8 m2). The concentrations of urea (60 Da), creatinine (113 Da), β2-microglobulin (11800 Da), myoglobin (17200 Da) and α1-microglobulin (33000 Da) were determined in serum at the beginning and end of each session in order to calculate the percent reduction of these solutes. ResultsThe convective volume reached was 29.8 ± 3.0 with 1.0 m2, 32.7 ± 3.1 (an increase of 6%) with 1.4 m2, and 34.7 ± 3.3 L (an increase of 16%) with 1.8 m2 (p<.001). The increased surface of the dialyzer showed an increase in the dialysis dose as well as urea and creatinine filtration. The percentage of β2m reduction increased from 80.0 ± 5.6 with 1.0 m2 to 83.2 ± 4.2 with 1.4 m2 and to 84.3 ± 4.0% with 1.8 m2. As for myoglobin and a1-microglobulin, significant differences were observed between smaller surface area (1.0 m2) 65.6 ± 11 and 20.1 ± 9.3 and the other two surface areas, which were 70.0 ± 8.1 and 24.1 ± 7.1 (1.4 m2) and 72.3 ± 8.7 and 28.6 ± 12 (1.8 m2). ConclusionThe 40% and 80% increases in surface area led to increased convective volumes of 6 and 16% respectively, while showing minimal differences in both the convective volume as well as the filtration capacity when the CUF was higher than 45 ml/h/mmHg. It is recommended to optimize the performance of dialyzers with the minimal surface area possible when adjusting the treatment prescription.

Modifiable factors associated with achievement of high-volume post-dilution hemodiafiltration: results from an international study.

The aim was to investigate factors associated with the successful achievement of ≥21 l/session of substitution fluid volume in patients on post-dilution hemodiafiltration. 3315 patients treated in 6 European countries with the Fresenius 5008 CorDiax machine including the AutoSub Plus feature were considered. Variables that showed a relationship with convection volume were entered in a multivariable logistic regression model. Mean blood flow was 379 ± 68 ml/min. Median substitution volume was 24.7 L (IQR 22.0-27.4 L). Mean filtration fraction was 28.3 ± 4.1%. 81.5% of sessions qualified as high-volume HDF (substitution volumes ≥21 L). Higher age, dialyzer surface area, blood flow and treatment time were positively associated with the achievement of ≥21 L substitution volume; higher body mass index, male gender, higher hematocrit, graft or catheter vs. fistula, and start of week vs. mid-week were negatively associated. Dialysis center policy in terms of blood flow, treatment time, filter size, and perhaps even hemoglobin targets plays a key role in achieving high-volume HDF. All of these are modifiable factors that can help in prescribing an optimal combination of dialyzer size, achievable blood flows, and treatment times.

Successful delivery of chemotherapy to treat small-cell prostate cancer in a patient undergoing haemodialysis.

We report on the successful treatment of small-cell prostate cancer in a patient undergoing haemodialysis. The therapeutic regimen included 300 mg/m2 of carboplatin and 50 mg/m2 of etoposide coupled with radical radiotherapy. Adjustments to the patient's haemodialysis prescription included the use of high flux, a larger dialyser surface area and an increased dialysis time. The parameters used aided tolerance to the drug, allowing the delivery of safe, effective treatment. At an interval of over 12 months post-treatment the patient shows no clinical evidence of recurrent disease. This case provides evidence to encourage the use of chemotherapy in otherwise potentially undertreated haemodialysed patients.

Hemodialysis: Core Curriculum 2014

From the Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN. Received May 1, 2013. Accepted in revised form July 1, 2013. Originally published online November 21, 2013. Address correspondence to Thomas A. Golper, MD, S3303 Medical Center North, Vanderbilt University Medical Center, 21st Ave S, Nashville, TN 37232. E-mail: thomas.golper@vanderbilt. edu 2013 by the National Kidney Foundation, Inc. 0272-6386/$36.00 http://dx.doi.org/10.1053/j.ajkd.2013.07.028 PRINCIPLES OF DIALYSIS AND HOW MODALITIES DIFFER

The ultrafiltration coefficient of a dialyser (KUF) is not a fixed value, and it follows a parabolic function: the new concept of KUF max

Hydraulic permeability (KUF) is an intrinsic characteristic of dialysers, reported by the manufacturer as a single value, which drives and limits fluid removal. High-flux dialysers have been introduced with the appearance of convective techniques, aiming to increase fluid and solute removal. High convective volumes are being employed, although their advantages have not been fully demonstrated. We assessed KUF over a pre-selected range of ultrafiltration rates (QUF) in post-dilutional haemodiafiltration and high-flux haemodialysis. KUF vs QUF was neither a fixed value nor a linear function but followed a parabolic function with a vertex der (y)=0, which we have called KUF max. This also held true in high-flux routine dialysis. These findings are completely new and have clear applications in clinics. The vertex point might be used to define the optimal QUF of a dialysis system, which would be that obtained at KUF max and corresponds to the best QUF/transmembrane pressure ratio, as opposed to the maximum QUF (which corresponds to the highest possible QUF), frequently associated with haemoconcentration, clotting, loss in dialyser surface area, and treatment problems. Determining KUF max in vivo could be of help in dialysis prescription and control with automatic systems.