Effect of residual kidney function and dialysis adequacy on chronic pruritus in dialysis patients.

BACKGROUND: Chronic kidney disease-associated pruritus (CKD-aP) is common in dialysis patients, and is associated with lower quality of life and increased risk of death. We investigated the association between residual estimated glomerular filtration rate (eGFR), dialysis adequacy or serum phosphate level and CKD-aP in incident dialysis patients. METHODS: A total of 1256 incident hemodialysis (HD) and 670 peritoneal dialysis (PD) patients (>18 years) from the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) study were included (1997-2007) and followed until death, transplantation or a maximum of 10 years. CKD-aP was measured using a single item of the Kidney Disease Quality of Life Instrument-36. The associations were studied by logistic and linear regression analyses, adjusted for potential baseline confounders. RESULTS: At baseline mean (standard deviation) age was 60 (16) years, 62% were men and median (interquartile range) residual eGFR was 3.4 (1.7; 5.3) mL/min/1.73 m2. The prevalence of CKD-aP (∼70%) was similar in HD and PD. It was observed that 12 months after starting dialysis (after multivariable adjustment) each 1 mL/min/1.73 m2 higher residual eGFR, one unit higher total weekly Kt/V, or 1 mmol/L lower serum phosphate level was associated with lower burden of CKD-aP in HD and PD patients of -0.05 (95% CI -0.09; -0.02) and -0.09 (95% CI -0.13; -0.05), -0.15 (95% CI -0.26; -0.05) and -0.35 (95% CI -0.54; -0.16), and of -0.34 (95%CI: -0.51; -0.17) and -0.45 (95%CI: -0.71; -0.19), respectively. We found no association between dialysis Kt/V and CKD-aP. CONCLUSIONS: Higher residual eGFR and lower serum phosphate level, but not the dialysis dose, were related with lower burden of CKD-aP in dialysis patients.

Dialysis in Pregnancy: An Update Review.

Chronic kidney disease and end-stage kidney disease (ESKD) are important public health problems with increased rates of morbidity, mortality, and social costs. Pregnancy is rare in patients with ESKD, with reduced fertility rates in women undergoing dialysis. Although current advances have led to an increase in live births in pregnant dialysis patients, this modality still has an increased risk of multiple adverse events in pregnant women. Despite these existing risks, large-scale studies investigating the management of pregnant women on dialysis are lacking, resulting in the absence of consensus guidelines for this patient group. In this review, we aimed to present the effects of dialysis during pregnancy. We first discuss pregnancy outcomes in dialysis patients and the development of acute kidney injury during pregnancy. Then, we discuss our recommendations for the management of pregnant dialysis patients, including the maintenance of pre-dialysis blood urea nitrogen levels, the ideal frequency and duration of hemodialysis sessions, as well as the modality of renal replacement therapies, the difficulty of maintaining peritoneal dialysis in the third trimester of pregnancy, and optimization of prepregnancy modifiable risk factors. Finally, we present our recommendations for future studies investigating dialysis among pregnant patients.

Clinical Benefits of Laparoscopic Adhesiolysis during Peritoneal Dialysis Catheter Insertion: A Single-Center Experience.

Background and Objectives: In peritoneal dialysis (PD) therapy, intra-abdominal adhesions (IAAs) can cause catheter insertion failure, poor dialysis function, and decreased PD adequacy. Unfortunately, IAAs are not readily visible to currently available imaging methods. The laparoscopic approach for inserting PD catheters enables direct visualization of IAAs and simultaneously performs adhesiolysis. However, a limited number of studies have investigated the benefit/risk profile of laparoscopic adhesiolysis in patients receiving PD catheter placement. This retrospective study aimed to address this issue. Materials and Methods: This study enrolled 440 patients who received laparoscopic PD catheter insertion at our hospital between January 2013 and May 2020. Adhesiolysis was performed in all cases with IAA identified via laparoscopy. We retrospectively reviewed data, including clinical characteristics, operative details, and PD-related clinical outcomes. Results: These patients were classified into the adhesiolysis group (n = 47) and the non-IAA group (n = 393). The clinical characteristics and operative details had no remarkable between-group differences, except the percentage of prior abdominal operation history was higher and the median operative time was longer in the adhesiolysis group. PD-related clinical outcomes, including incidence rate of mechanical obstruction, PD adequacy (Kt/V urea and weekly creatinine clearance), and overall catheter survival, were all comparable between the adhesiolysis and non-IAA groups. None of the patients in the adhesiolysis group suffered adhesiolysis-related complications. Conclusions: Laparoscopic adhesiolysis in patients with IAA confers clinical benefits in achieving PD-related outcomes comparable to those without IAA. It is a safe and reasonable approach. Our findings provide new evidence to support the benefits of this laparoscopic approach, especially in patients with a risk of IAAs.

Effects of Exercise on Physiologic and Psychologic Outcomes in Patients with End Stage Kidney Disease on Hemodialysis: A Quasi-Experimental Study.

End stage kidney disease (ESKD), a public health concern, has overwhelming effects on individuals' holistic wellbeing. Hemodialysis, albeit a life-saving treatment for patients with ESKD, can lead to muscle atrophy, weakness, and decreased quality of life mostly due to an inactive lifestyle. This quasi-experimental, pre-post design was used to study the effects of exercise on physiologic and psychologic outcomes of patients with ESKD at a hemodialysis unit in Lebanon. Patients acted as their own controls and were assessed before and after introducing the exercise program. Data were collected on quality of life of patients as well as their dialysis adequacy. Results showed that while there was a significant improvement in the dialysis adequacy post-exercise intervention, quality of life was not affected.

Individualized hemodialysis: Is similar hemodialysis adequacy possible using less water?

Background and aim: There are over 60,000 hemodialysis (HD) patients in Türkiye, and the number of patients is increasing yearly. Dialysate flow rate (Qd) is a factor in HD adequacy. Approximately 150 L of water are consumed per session to prepare the dialysate. We aimed to investigate whether HD effectiveness can be achieved at a low Qd in different patient groups for the purpose of saving water. Materials and methods: This prospective study included 81 HD patients from 2 centers. The patients underwent an aggregate total of 486 HD sessions, including 3 sessions at a Qd of 500 mL/min and 3 sessions at a Qd of 300 mL/min for each patient. We used online Kt/V readings recorded at the end of each dialysis session to compare the effectiveness of these 2 types of HD session performed at a different Qd. Results: The online Kt/V readings were similar between the standard (500) and low (300) Qd HD (1.51 ± 0.41 and 1.49 ± 0.44, respectively, p = 0.069). In the subgroup analyses, men had higher online Kt/V values at the standard Qd compared to the low Qd (1.35 ± 0.30 and 1.30 ± 0.32, respectively, p = 0.019), but the Kt/V values were not different for women. While the low Qd did not reduce online Kt/V in patients using small surface area dialysis membranes (1.75 ± 0.35 for 300 Qd and 1.75 ± 0.32 for 500 Qd, p = 0.931), it was associated with reduced online Kt/V in patients using large surface area dialysis membranes (1.12 ± 0.25 for 300 Qd and 1.17 ± 0.24 for 500 Qd, p = 0.006). The low Qd did not result in differences in online Kt/V among low-weight patients. However, online Kt/V values were better with the standard Qd in patients weighing 65 kg and above. Conclusion: In our study, dialysis adequacy at a reduced dialysate flow was not inferior for women, patients with low body weight, or patients using small surface area membranes. Individualized HD at a reduced Qd of 300 mL/min in eligible patients can save 48 L of water per HD session and an average of 7500 L of water per year.

Dialyzer Performance During Hemodialysis Without Systemic Anticoagulation Using a Heparin-Grafted Dialyzer Combined With a Citrate-Enriched Dialysate: Results of the Randomized Crossover Noninferiority EvoCit Study.

RATIONALE & OBJECTIVE: The EvoCit study was designed to evaluate performance of a heparin-grafted dialyzer during hemodialysis with and without systemic anticoagulation. STUDY DESIGN: Randomized, crossover, noninferiority trial. Noninferiority was defined as a difference of≤10% for the primary outcome. SETTING & PARTICIPANTS: Single hemodialysis center; 26 prevalent patients treated with 617 hemodialysis sessions. INTERVENTIONS: Hemodialysis using a heparin-grafted dialyzer combined with a 1.0mmol/L citrate-enriched dialysate ("EvoCit") without systemic anticoagulation compared with hemodialysis performed with a heparin-grafted dialyzer with systemic heparin ("EvoHep"). Patients were randomly allocated to a first period of 4 weeks and crossed over to the alternative strategy for a second period of 4 weeks. OUTCOMES: The primary end point was the difference in Kt/Vurea between EvoCit and EvoHep. Secondary end points were urea reduction ratio, middle molecule removal, treatment time, thrombin generation, and reduction in dialyzer blood compartment volume. RESULTS: The estimated difference in Kt/Vurea between EvoCit and EvoHep was-0.03 (95% CI, -0.06 to-0.007), establishing noninferiority with mean Kt/Vurea of 1.47±0.05 (SE) for EvoCit and 1.50±0.05 for EvoHep. Noninferiority was also established for reduction ratios of urea and ß2-microglobulin. Premature discontinuation of dialysis was required for 4.2% of sessions among 6 patients during EvoCit and no sessions during EvoHep. Effective treatment time was 236±5 minutes for EvoCit and 238±1 minutes for EvoHep. Thrombin generation was increased and there was greater reduction in dialyzer blood compartment volume after treatments with EvoCit compared with EvoHep. LIMITATIONS: The effects of avoiding systemic anticoagulation on clinical outcomes were not evaluated. CONCLUSIONS: EvoCit is noninferior to EvoHep with respect to solute clearance but results in a greater number of shortened treatments, more membrane clotting, and greater thrombin generation TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT03887468.

Comparison of measured vs kinetic-model predicted phosphate removal during hemodialysis and hemodiafiltration.

BACKGROUND: To what extent hemodiafiltration (HDF) improves management of hyperphosphatemia over hemodialysis (HD) is a subject of ongoing investigation. METHODS: We modified a previously described phosphate kinetic model to include incorporation of EUDIAL recommended equations for hemodiafiltration (HDF) clearance. We used the model to predict the recovery of phosphate from spent dialysate/hemofiltrate and compared this with averaged data from five published studies. Mean study average predialysis serum phosphate was 1.81 ± 0.20 mmol/L. Session length was close to 240 min per treatment. All HDF was done postdilution, at an average rate of 65 ± 24 mL/min. RESULTS: Measured mean phosphate removal was 1039 ± 136 mg (33.5 ± 4.41 mmol, slightly lower than the model-predicted mean value of 1092 ± 127 mg (35.3 ± 4.09 mmol). The measured ratio of phosphate removal with HDF compared with HD averaged 1.15 ± 0.22, ranging from 1.01 to 1.44. Using mean study input parameters for patient size and treatment characteristics, the predicted ratio of phosphate removal with HDF compared with HD averaged 1.095 ± 0.029, ranging from 1.05 to 1.13. CONCLUSIONS: Addition of EUDIAL-recommended convective clearance equations to a phosphate kinetic model predicts a 10% or greater benefit in terms of phosphate removal for HDF compared with HD at typical dialysis and hemodiafiltration treatment settings. These predictions are similar to the HDF advantage reported in the literature in studies where phosphate removal has been measured in spent dialysate.

Identifying key predictors of mortality in young patients on chronic haemodialysis-a machine learning approach.

BACKGROUND: The mortality risk remains significant in paediatric and adult patients on chronic haemodialysis (HD) treatment. We aimed to identify factors associated with mortality in patients who started HD as children and continued HD as adults. METHODS: The data originated from a cohort of patients <30 years of age who started HD in childhood (≤19 years) on thrice-weekly HD in outpatient DaVita dialysis centres between 2004 and 2016. Patients with at least 5 years of follow-up since the initiation of HD or death within 5 years were included; 105 variables relating to demographics, HD treatment and laboratory measurements were evaluated as predictors of 5-year mortality utilizing a machine learning approach (random forest). RESULTS: A total of 363 patients were included in the analysis, with 84 patients having started HD at <12 years of age. Low albumin and elevated lactate dehydrogenase (LDH) were the two most important predictors of 5-year mortality. Other predictors included elevated red blood cell distribution width or blood pressure and decreased red blood cell count, haemoglobin, albumin:globulin ratio, ultrafiltration rate, z-score weight for age or single-pool Kt/V (below target). Mortality was predicted with an accuracy of 81%. CONCLUSIONS: Mortality in paediatric and young adult patients on chronic HD is associated with multifactorial markers of nutrition, inflammation, anaemia and dialysis dose. This highlights the importance of multimodal intervention strategies besides adequate HD treatment as determined by Kt/V alone. The association with elevated LDH was not previously reported and may indicate the relevance of blood-membrane interactions, organ malperfusion or haematologic and metabolic changes during maintenance HD in this population.

Predialytic versus Intradialytic Nutrition: A Study to Assess Effects on Intradialytic Blood Pressure, Dialysis Adequacy, and Urea Removal.

BACKGROUND: Provision of oral protein in hemodialysis (HD) is desirable due to improved compliance to protein requirements and better nutritional status, but the risks of hypotension and underdialysis need to be considered. This study compared 2 different timings for administering oral nutritional supplements (ONS), predialysis and mid-dialysis, with respect to hemodynamics, dialysis adequacy, urea removal, and tolerability. METHODS: This single-center, prospective crossover study analyzed 72 stable patients with ESRD on twice a week maintenance HD with a mean age of 38.7 (±11.2) years and a dialysis vintage of 28.2 (±13.1) months. In the first week, all the patients received ONS (450 kcal energy, 20 g protein) 1 h prior to start of dialysis (group 1) and in the next week, the supplement was administered after 2 h of start of dialysis (group 2), with a predialysis fasting period of at least 3 h in both groups. Blood pressures, serum, and spent dialysate samples were collected and nausea occurrence was noted by severity. RESULTS: Predialytic intake (group 1) was associated with higher predialysis and 1st hour blood urea, dialysis adequacy, and urea removal than group 2. Both groups achieved mean Kt/V > 1.2, and the occurrence of symptomatic hypotensive episodes and nausea was not significantly different between the groups. On repeated measures ANOVA, changes in blood urea over time showed significant group effect. CONCLUSIONS: Predialytic supplementation was associated with better dialysis adequacy and urea removal than intradialytic supplementation. However, both timings were equally tolerated and not associated with underdialysis.

Is health-related quality of life associated with adequacy of hemodialysis in chronic kidney disease patients?

INTRODUCTION: Monitoring Health Related Quality of Life (HRQoL) in different stages of chronic kidney disease is advised by all nephrology societies. We aimed to study the relation between quality of life and dialysis adequacy. METHODS: One hundred patients (51% males), on regular hemodialysis 3/week for > 6 months in two hospitals were included. Single pool Kt/V was used to assess dialysis adequacy. Patients were grouped into 3 divisions according to Kt/v: Group A > 1.5 (n = 24), group B 1.2-1.5 (n = 54) and group C < 1.2 (n = 22). KDQOL-SF™ questionnaire was used to study quality of life in our groups. Group C was reassessed after 3 months of improving Kt/v. RESULTS: Mean values were: Kt/V (1.48 ± 0.41), Cognitive Function (84.27 ± 9.96), Work status (30.00 ± 33.33), Energy (45.70 ± 13.89), Physical Function and Role limitations due to physical function (45.30 ± 12.39 and 31.25 ± 19.26, respectively). Group A had significantly higher scores of KDQOL-SF except Role limitations due to Physical Function. All subscales improved in group C after Kt/v improvement except 3 subscales, namely, work status, patient satisfaction and role limitation due to physical and emotional functions. CONCLUSION: Inadequate HD badly affects quality of life and improving adequacy refines many components of quality of life.

Changes in practice patterns in Japan from before to after JSDT 2013 guidelines on hemodialysis prescriptions: results from the JDOPPS.

BACKGROUND: The Japanese Society for Dialysis Therapy (JSDT) published in 2013 inaugural hemodialysis (HD) guidelines. Specific targets include 1.4 for single-pool Kt/V (spKt/V) with a minimum dose of 1.2, minimum dialysis session length of 4 hours, minimum blood flow rate (BFR) of 200 mL/min, fluid removal rate no more than 15 mL/kg/hr, and hemodiafiltration (HDF) therapy for certain identified symptoms. We evaluated the effect of these guidelines on actual practice in the years spanning 2005 - 2018. METHODS: Analyses were carried out to describe trends in the above HD prescription practices from December 2005 to April 2013 (before guideline publication) to August 2018 based on prevalent patient cross-sections from approximately 60 randomly selected HD facilities participating in the Japan Dialysis Outcomes and Practice Patterns Study. RESULTS: From April 2006 to August 2017 continual rises occurred in mean spKt/V (from 1.35 to 1.49), and percent of patients having spKt/V>1.2 (71% to 85%). Mean BFR increased with time from 198.3 mL/min (April 2006) to 218.4 mL/min (August 2017) , along with percent of patients with BFR >200 ml/min (65% to 85%). HDF use increased slightly from 6% (April 2006 and August 2009) to 8% by April 2013, but increased greatly thereafter to 23% by August 2017. In contrast, mean HD treatment time showed little change from 2006-2017, whereas mean UFR declined from 11.3 in 2006 to 8.4 mL/Kg/hour in 2017. CONCLUSIONS: From 2006 - 2018 Japanese HD patients experienced marked improvement in reaching the spKt/V target specified by the 2013 JSDT guidelines. This may have been due to moderate increase in mean BFR even though mean HD session length did not change much. In addition, HDF use increased dramatically in this time period. Other HD delivery changes during this time, such as increased use of super high flux dialyzers, also merit study. While we cannot definitively conclude a causal relationship between the publication of the guidelines and the subsequent practice changes in Japan, those changes moved practice closer to the recommendations of the guidelines.

B-type natriuretic peptide levels and volume status in twice-weekly hemodialysis patients.

BACKGROUND: Twice-weekly hemodialysis (HD) could be regarded as an important part of incremental hemodialysis, volume status of this treatment model remains to be elucidated. METHODS: Patients undergoing regular twice-weekly or thrice-weekly hemodialysis in our unit on June 2015 were enrolled into the cohort study with an average of 2.02 years follow-up. Volume status of the subjects was evaluated by clinical characteristics, plasma B-type natriuretic peptide (BNP) levels and bioimpedance assessments with body composition monitor (BCM). Cox proportional hazards models and Kaplan-Meier analysis were used to compare patient survival between the two groups. RESULTS: Compared with patients on thrice-weekly HD, twice-weekly HD patients had significantly higher log-transformed BNP levels (2.54 ± 0.41 vs. 2.33 ± 0.49 pg/ml, p = 0.010). Overhydration (OH) and the ratio of overhydration to extracellular water (OH/ECW) in twice-weekly HD group were significantly higher than that of thrice-weekly HD (OH, 2.54 ± 1.42 vs. 1.88 ± 1.46, p = 0.033; OH/ECW, 0.17 ± 0.07 vs. 0.12 ± 0.08, p = 0.015). However, subgroup analysis of patients within 6 years HD vintage indicated that the two groups had similar hydration status. Multivariate Cox regression analysis showed that log-transformed BNP levels, serum albumin and diabetes status were predictors of mortality in hemodialysis patients. Kaplan-Meier survival analysis indicated that patients with BNP levels higher than 500 pg/ml had significantly worse survival compared with those with lower BNP levels (p = 0.014). CONCLUSIONS: Twice-weekly hemodialysis patients had worse volume status than that of thrice-weekly HD patients especially for those with long-term dialysis vintage, BNP level was a powerful predictor of mortality in HD patients.

Unilateral nephrectomy versus renal arterial embolization and technique survival in peritoneal dialysis patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder associated with progressive enlargement of the kidneys and liver. ADPKD patients may require renal volume reduction, especially before renal transplantation. The standard treatment is unilateral nephrectomy. However, surgery incurs a risk of blood transfusion and alloimmunization. Furthermore, when patients are treated with peritoneal dialysis (PD), surgery is associated with an increased risk of temporary or definitive switch to haemodialysis (HD). Unilateral renal arterial embolization can be used as an alternative approach to nephrectomy. METHODS: We performed a multicentre retrospective study to compare the technique of survival of PD after transcatheter renal artery embolization with that of nephrectomy in an ADPKD population. We included ADPKD patients treated with PD submitted to renal volume reduction by either surgery or arterial embolization. Secondary objectives were to compare the frequency and duration of a temporary switch to HD in both groups and the impact of the procedure on PD adequacy parameters. RESULTS: More than 700 patient files from 12 centres were screened. Only 37 patients met the inclusion criteria (i.e. treated with PD at the time of renal volume reduction) and were included in the study (21 embolized and 16 nephrectomized). Permanent switch to HD was observed in 6 embolized patients (28.6%) versus 11 nephrectomized patients (68.8%) (P = 0.0001). Renal artery embolization was associated with better technique survival: subdistribution hazard ratio (SHR) 0.29 [95% confidence interval (CI) 0.12-0.75; P = 0.01]. By multivariate analysis, renal volume reduction by embolization and male gender were associated with a decreased risk of switching to HD. After embolization, a decrease in PD adequacy parameters was observed but no embolized patients required temporary HD; the duration of hospitalization was significantly lower [5 days [interquartile range (IQR) 4.0-6.0] in the embolization group versus 8.5 days (IQR 6.0-11.0) in the surgery group. CONCLUSIONS: Transcatheter renal artery embolization yields better technique survival of PD in ADPKD patients requiring renal volume reduction.

Hemodialysis Experience of a Large Group of Syrian Refugees in Turkey: All Patients Deserve Effective Treatment.

BACKGROUND/AIMS: Refugee dialysis is a worldwide growing dilemma with limited experience. This report presents the largest hemodialysis (HD) patient registry data of Syrian refugees in Turkey. METHODS: Demographic, clinical, laboratory, and dialysis practice data of 345 Syrian HD patients during one year were collected and analyzed. RESULTS: There were 345 prevalent Syrian HD patients at the end of 2016. Majority of the patients were placed in the Southeast Anatolian Region. The majority of the patients (74.8%) are in the age range of 20-64 years. Dialysis vintage in Turkey is less than 12 months in 20.8% and less than one month in 29.3% of patients. The vascular access was arteriovenous fistula in the majority of patients (72.5%). Kt/V is over 1.7 in 57%, serum albumin is above 35 g/L in 65.8% and hemoglobin level is more than 100 g/L in %65.2 of the patients. The ratio of patients with serum phosphorus level of 1.13-1.77 mmol/L was 56.2%. Twenty Syrian HD patients (14 male, 6 female) died within the year 2016 and annual mortality rate was 5.7%. CONCLUSION: This study with the largest number of Syrian refugees undergoing maintenance hemodialysis showed good dialysis practices, acceptable values for dialysis adequacy and biochemical parameters along with lower mortality compared to native HD population of Turkey. Longer follow up will enrich the knowledge related to care of refugee population in all over the world.

The association of dialysis adequacy, body mass index, and mortality among hemodialysis patients.

BACKGROUND: Although hemodialysis (HD) adequacy, single-pool Kt/Vurea (spKt/V), is inversely correlated with body size, each is known to affect patient survival in the same direction. Therefore, we sought to examine the relationship between HD adequacy and mortality according to body mass index (BMI) in HD patients and explore a combination effect of BMI and HD adequacy on mortality risk. METHODS: We retrospectively reviewed patient data from the Korean Society of Nephrology registry, a nationwide database of medical records of HD patients, from January 2001 to June 2017. We included patients ≥18 years old who were receiving maintenance HD. Patients were categorized into three groups according to baseline BMI (< 20 (low), 20 to < 23 (normal), and ≥ 23 (high) kg/m2). Baseline spKt/V was divided into six categories. RESULTS: Among 18,242 patients on HD, the median follow-up duration was 5.2 (IQR, 1.9-8.9) years. Cox regression analysis showed that, compared to the reference (spKt/V 1.2-1.4), lower and higher baseline spKt/V were associated with greater and lower risks for all-cause mortality, respectively. However, among patients with high BMI (n = 5588), the association between higher spKt/V and lower all-cause mortality was attenuated in all adjusted models (Pinteraction < 0.001). Compared to patients with normal BMI and spKt/V within the target range (1.2-1.4), those with low BMI had a higher risk for all-cause mortality at all spKt/V levels. However, the gap in mortality risk became narrower for higher values of spKt/V. Compared to patients with normal BMI and spKt/V in the target range, those with high BMI and spKt/V < 1.2 were not at increased risk for mortality despite low dialysis adequacy. CONCLUSIONS: The association between spKt/V and mortality in HD patients may be modified by BMI.

A two-pool kinetic model predicts phosphate concentrations during and shortly following a conventional (three times weekly) hemodialysis session.

Background: Previous studies have suggested that a conventional two-pool model cannot be used to predict intradialysis and early postdialysis phosphorus concentrations. Methods: A conventional two-pool urea model was modified by increasing the distal compartment volume from two-thirds to three times the total body water and by the use of a dynamically variable intercompartmental phosphorus clearance during dialysis. The phosphate solver model parameters were derived from an examination of the results in the literature, and fine-tuned using a training set (F4) of 415 Hemodialysis (HEMO) Study patients studied during a dialysis session where phosphorus was measured at 4 months of follow-up. Validation was done in a group of 380 different HEMO Study patients plus 9 from the original F4 group, who were evaluated at 36 months of follow-up. Results: The model predicted measured median early (1 h) intradialysis, end-dialysis and 30-min postdialysis serum phosphorus levels in the test and validation datasets with little apparent bias, including the highest and lowest deciles of predialysis serum phosphorus. The model tended to underestimate slightly intradialysis serum phosphorus when predialysis serum phosphorus was <3.0 mg/dL (0.97 mmol/L). There was a large scatter and standard deviation among patients, and whether aberrant values represent a patient-specific phenomenon is unclear. Conclusions: A modified two-pool model using a slightly expanded distal compartment and a dynamically varying intercompartmental clearance, depending on the intradialysis phosphorus concentration, can be used to predict serum phosphorus level during and shortly after dialysis, in patients following a conventional three times per week dialysis prescription.

Is Peritoneal Dialysis a Suitable Renal Replacement Therapy Option for Polycystic Kidney Disease Patients?

BACKGROUND/AIMS: Mounting clinical experience and evidence from scale observational studies have suggested that polycystic kidney disease (PKD) was not a contraindication for peritoneal dialysis (PD). Recent studies have reported that PD may be associated with a better prognosis in PKD than that of non-PKD patients. To solve the problem, we performed a systematic review and comprehensive meta-analysis to compare the outcomes between PKD and non-PKD patients on PD and the all-cause mortality between patients with PKD on PD and hemodialysis (HD). METHODS: We conducted a systematic literature using electronic databases (PubMed, Ovid, Embase and Web of Science) to identify the studies reporting the endpoint events of PKD/non-PKD patients with PD and the all-cause mortality between patients with PKD on PD and HD, such as dialysis adequacy, technique failure, PD-related complications, the mode of RRT change, and all-cause mortality. We searched the literature published February 2018 or earlier. We used both fix-effects and random-effects models to calculate the overall effect estimate. A sensitivity analysis and subgroup analysis were performed to find the origin of heterogeneity. RESULTS: 12 studies with a total of 17,040 patients reported the endpoint events of PKD/non-PKD patients with PD. No significant difference was observed on dialysis adequacy (Kt/V, SMD: -0.02, 95%CI: -0.12-0.08; D: Pcr (4h), SMD: -0.10, 95% CI: -0.26-0.06), technique failure (RR: 0.97, 95%CI: 0.78-1.20), RRT change (RR: 0.96, 95%CI: 0.77-1.19), total PD-associated complications (RR: 1.0, 95%CI: 0.91-1.09) and all-cause mortality (RR: 0.40, 95%CI: 0.33-0.47) in PKD patients, compared with non-PKD subjects undergoing PD. However, the proportion of renal transplantation in PKD patients was higher than that of non-PKD patients (RR: 2.04, 95%CI: 1.88-2.20) with significant heterogeneity (I2 =82.7%, P=0.000). 4 studies with a total of 5,762 patients reported that the all-cause mortality did not differ between the PKD patients on PD and HD (RR: 0.87, 95%CI: 0.72-1.06). CONCLUSION: Our meta-analysis found that the outcomes of given population of PKD patients on PD were at least not inferior as compared to those with other primary kidney diseases, and suggested that PKD might be not absolutely a contraindication for PD. Given the limitations of the proposed, it needs further large-scale studies to assess whether PD is a suitable RRT option for end-stage renal disease (ESRD) patients with PKD.

Effectiveness of a New Single-Needle Single-Pump Dialysis System with Simultaneous Monitoring of Dialysis Dose.

To date, single-needle (SN) hemodialysis (HD) requires a dialysis machine equipped with two blood pumps-one controlling arterial blood flow (Qb) and one controlling venous Qb. B. Braun has developed an innovative single-pump SN HD system. Therefore, usability is improved by reducing complexity. The aim of this study was to compare dialysis parameters of the new single-pump SN HD system with a double-pump SN HD system available on the market (Fresenius Medical Care [FMC] 5008). In this two-armed crossover study, patients were randomized into two groups (B. Braun - FMC/FMC - B. Braun). Study period was 2 weeks (6 HD sessions) for each SN HD system. Both B. Braun and FMC dialysis machines were operated in the single-needle auto mode. With the FMC dialysis machines, Qb was optimized manually, whereas for B. Braun machines it was optimized automatically using the auto-mode functionality. A phase volume of 25 mL, treatment time, needle type and size, and dialyzer type and size were kept constant per patient throughout the study. Due to technical prerequisites in the SN mode, online dialysis adequacy (Kt/V: K - dialyzer clearance of urea; t - dialysis time; V - volume of distribution of urea) monitoring could only be performed in the B. Braun group. Twelve HD patients (5 male/7 female, mean age 75.5 ± 8.8 years, mean time on dialysis 4.97 ± 3.86 years, 3× weekly HD) were enrolled. Total number of treatments performed: n = 132 (65 B. Braun, 67 FMC) and the mean online Kt/V value in the B. Braun group was 1.26 ± 0.29 (n = 63). Mean dialysis time per session: B. Braun 253.4 ± 19.9 min, FMC 251.6 ± 18.8 min. Mean phase volume: B. Braun 25.1 ± 0.2 mL, FMC 25.4 ± 3.1 mL. Mean cumulated blood volume (CBV): B. Braun 55.0 ± 5.5 L, FMC 40.5 ± 5.9 L (P < 0.0001). Mean Qb: B. Braun 217.8 ± 12.9 mL/min, FMC 178.6 ± 14.9 mL/min (effective Qb) (P < 0.0001), which corresponds to a difference of 39.3 mL/min (22.0%). Higher Qb has an influence on the CBV. To evaluate this effect, CBV was corrected for the difference in Qb by calculating the CBV/Qb rate. The mean CBV/Qb rate was 252.2 ± 19.4 min (B. Braun) and 226.8 ± 27.6 min (FMC) (P < 0.0001) per session. This represents a highly significant difference of 11.4%. To support the in vivo data the dead time for opening/closure of the clamps of the FMC 5008 was measured, resulting in 364 milliseconds. Over a 240 min dialysis session, with a blood flow rate of 250 mL/min and a phase volume of 25 mL, it was estimated at about 14.56 min (6.1% of the session). Similarly, it was estimated that the dead time of the pumps of the FMC 5008 during 240 min dialysis session was 4.7 min (1.9% of the session). In case single needle therapy is the only practical option for a patient, the advantages of the new single-pump single needle system-namely the proven higher cumulative blood volume, the alarm-free auto-regulation of the blood flow and the easier handling for the nursing staff-ensure higher treatment efficiency than conventional double-pump single needle systems.

Once-weekly hemodialysis combined with low-protein and low-salt dietary treatment as a favorable therapeutic modality for selected patients with end-stage renal failure: a prospective observational study in Japanese patients.

BACKGROUND: For patients with end-stage renal failure (ESFR), thrice-weekly hemodialysis is a standard care. Once-weekly hemodialysis combined with low-protein and low-salt dietary treatment (OWHD-DT) have been rarely studied. Therefore, here, we describe our experience on OWHD-DT, and assess its long-term effectiveness. METHODS: We instituted OWHD-DT therapy in 112 highly motivated patients with creatinine clearance below 5.0 mL/min. They received once-weekly hemodialysis on a diet of 0.6 g/kg/day of protein adjusted for sufficient energy intake, and less than 6 g/day of salt intake. Serial changes in their clinical, biochemical and nutritional parameters were prospectively observed, and the weekly time spent for hospital visits as well as their monthly medical expenses were compared with 30 age, sex- and disease-matched thrice-weekly hemodialysis patients. RESULTS: The duration of successfully continued OWHD-DT therapy was more than 4 years in 11.6% of patients, 3 years in 16.1%, 2 years in 24.1% and 1 year in 51.8%. Time required per week for hospital attendance was 66.7% shorter and monthly medical expenses were 50.5% lower in the OWHD-DT group than in the thrice-weekly hemodialysis group (both p < 0.001). Patient survival rates in the OWHD-DT group were better than those in the Japan Registry (p < 0.001). Serum urea nitrogen significantly decreased; hemoglobin significantly increased; and albumin and body mass index were not significantly different from baseline values. In the OWHD-DT patients, serum albumin at 1 and 2 years after initiation of therapy was significantly higher compared with prevalent thrice-weekly hemodialysis patients. Furthermore, residual urine output was significantly higher in the OWHD-DT patients than in those receiving thrice-weekly hemodialysis (p < 0.05). Interdialytic weight gain over the course of the entire week between treatments in patients on OWHD-DT were 0.9 ± 1.0, 2.0 ± 1.3, 1.9 ± 1.2, 1.9 ± 1.5 and 1.8 ± 1.0 kg at 1, 6, 12, 18 and 24 months, respectively, though the weekly weight gain for thrice-weekly hemodialysis group (summed over all 3 treatments) was 8.6 ± 0.63 kg, p < 0.001. CONCLUSIONS: OWHD-DT may be a favorable therapeutic modality for selected highly motivated patients with ESRF. However, this treatment cannot be seen as a general maintenance strategy. TRIAL REGISTRATION: UMIN000027555 , May 30, 2017 (retrospectively registered).

Scaling Hemodialysis Target Dose to Reflect Body Surface Area, Metabolic Activity, and Protein Catabolic Rate: A Prospective, Cross-sectional Study.

BACKGROUND: Women and small men treated by hemodialysis (HD) have reduced survival. This may be due to use of total-body water (V) as the normalizing factor for dialysis dosing. In this study, we explored the equivalent dialysis dose that would be delivered using alternative scaling parameters matching the current recommended minimum Kt/V target of 1.2. STUDY DESIGN: Prospective cross-sectional study. SETTING & PARTICIPANTS: 1,500 HD patients on a thrice-weekly schedule, recruited across 5 different centers. PREDICTORS: Age, sex, weight, race/ethnicity, comorbid condition level, and employment status. OUTCOMES: Kt was estimated by multiplying V by 1.2. Kt/body surface area (BSA), Kt/resting energy expenditure (REE), Kt/total energy expenditure (TEE) and Kt/normalized protein catabolic rate (nPCR) equivalent to a target Kt/V of 1.2 were then estimated by dividing Kt by the respective parameters. MEASUREMENTS: Anthropometry, HD adequacy details, and BSA were obtained by standard procedures. REE was estimated using a novel validated equation. TEE was calculated from physical activity data obtained using the Recent Physical Activity Questionnaire. nPCR was estimated using a standard formula. RESULTS: Mean BSA was 1.87m2; mean REE, 1,545kcal/d; mean TEE, 1,841kcal/d; and mean nPCR, 1.03g/kg/d. For Kt/V of 1.2, there was a wide range of equivalent doses expressed as Kt/BSA, Kt/REE, Kt/TEE, and Kt/nPCR. The mean equivalent dose was lower in women for all 4 parameters (P<0.001). Small men would also receive lower doses compared with larger men. Younger patients, those with low comorbidity, those employed, and those of South Asian race/ethnicity would receive significantly lower dialysis doses with current practice. LIMITATIONS: Cross-sectional study; physical activity data collected by an activity questionnaire. CONCLUSIONS: Current dosing practices may risk underdialysis in women, men of smaller body size, and specific subgroups of patients. Using BSA-, REE-, or TEE-based dialysis prescription would result in higher dose delivery in these patients.