Low-flux Dialysis Research Articles

MO799IS COMBINATION OF MAINTENANCE HEMODIALYSIS WITH HEMOPERFUSION AN EFFECTIVE METHOD IN MANAGEMENT OF RENAL OSTEODYSTROPHY AND INFLAMMATION IN HEMODIALYSIS PATIENTS?

Abstract Background and Aims Some of the conditions which occur in maintenance hemodialysis (MHD) patients with a high incidence resulting in a decline in their quality of life, include malnutrition, renal osteodystrophy, refractory hypertension and chronic systemic inflammation. In developing countries, due to the low level of economic development, low-flux dialysis is the main means of extracorporeal blood purification therapy. But it can hardly remove the middle and large molecule uremic toxins and protein-bound toxins; as a result, the patients suffer from long-term complications and poor quality of life. In this study, we attempted to investigate whether the combination of maintenance hemodialysis (MHD) with hemoperfusion (HP) could improve the clearance rate of middle and large molecule uremic toxins so as to improve their uremic complications. Method A total of 54 patients, who underwent routine hemodialysis, were assessed in this study. Those patients were randomly divided into two groups: Group 1 (27 patients) received combined treatment of HD with hemoperfusion (HP) in this regimen: HD 2 times a week with HD+HP once a week two times in a row, then after two weeks, and afterwards once a month as a maintenance treatment. Group 2 (27 patients) was only undergoing maintenance HD 3 times a week. The clinical and laboratory properties of both groups were followed up for 18 months, whereas the primary outcomes included normal clinical data, high sensitive C-reactive protein (hsCRP), immunoreactive parathyroid hormone (iPTH), phosphorus (P04), calcium (Ca), albumin, iron (Fe), total iron binding capacity (TIBC), hemoglobin, Epo doses and types of hypertensive drugs. Results At the end of the 18-month observation, the serum concentration of albumin, P04, hsCRP, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were lower with Group 1 than with Group 2 (p<0.05). Whereas, higher levels of iPTH were noticed in group 1, but when the laboratory and clinical data are analysed of the group 1 alone a statistically significant lower values after the observational period are noticed especially in the serum values of iPTH (p<0.05), P04 (p<0.001), CRP (p<0.011), SBP and DBP (p<0.05). Conclusion HD+HP was superior to HD in regularly eliminating middle and large molecule uremic toxins accumulated in the body which is mostly shown through reducing the values of iPTH and hsCRP. These findings suggest a potential role for HD+HP in the treatment of inflammation and renal osteodystrophy as well, because lowering these values of iPTH leads to a normalization of other minerals which is expected and therefore leads to a stabilization of this long-term uremic complications, which can improve the overall general condition of the MHD patient.

A simplified protocol for individualized regional citrate anticoagulation for hemodialysis: A single-center, randomized clinical study.

The lack of individualized treatment protocols and complicated procedures are important factors limiting the use of regional citrate anticoagulation (RCA) technology in hemodialysis. This study aims to validate the safety and efficacy of a simplified individualized RCA protocol for hemodialysis. From June 2019 to August 2019, 45 patients with active bleeding or bleeding tendency undergoing maintenance hemodialysis in the Nephrology Department of the First Affiliated Hospital of Nanchang University were randomly divided into a modified conventional RCA protocol group with a low-flux dialyzer, a simplified individualized RCA protocol group with a high-flux dialyzer, and a simplified individualized RCA protocol group with a low-flux dialyzer. A total of 45 patients were included in this study. The mean age of the patients was 57.38 ± 19.05 years, and 78% were men. Forty-three patients completed 4 hours of hemodialysis, and the median total clotting scores in the 3 groups were 11, 12, and 12. Compared with the modified conventional RCA protocol group with a low-flux dialyzer, the 2 simplified individualized RCA protocol groups had better clotting scores for the dialyzer, arterial bubble trap, and single-pool urea clearance index (spKt/VBUN) and lower costs. Moreover, these parameters did not differ between the 2 simplified individualized RCA protocol groups. No electrolyte or acid-base imbalances or citrate poisoning was observed in any of the 3 groups. Adverse events did not differ significantly among the 3 groups. The simplified individualized RCA protocol is safe, effective, and easy to implement. Therefore, this protocol can be promoted for clinical practice. This study was registered in the Chinese Clinical Study Registry under registration number ChiCTR1900023801.

Beta 2 microglobulin in kidney failure: A review and an algorithm for renal replacement therapy.

For decades, beta 2 microglobulin (B2M) has been a subject of great interest in nephrology and other fields such as multiple myeloma. B2M, a 99 amino acid protein, is associated with amyloid deposits in patients undergoing renal replacement therapy (RRT). The source of information is published articles on B2M in chronic renal failure since 1960. We have reviewed literature published since 1960 to date, highlighting the milestones of the role of B2M in chronic kidney disease (CKD) and B2M serum values in patients treated by various RRTs. B2M deposits associated with the disease include carpal tunnel syndrome, spondyloarthropathy, and arthritis of large joints such as the shoulders. The role of RRT in the removal of B2M in CKD is discussed. Recent reports include factors affecting the process of fibrillation and deposition of B2M in tissues. A comparative report of various modalities of treatment on the serum levels of B2M is provided. The presence of significant residual urine output in continuous ambulatory peritoneal dialysis patients may explain why peritoneal dialysis is a modality that is associated with the lowest level of serum B2M. Patients treated with hemodiafiltration or hemodialysis (HD) using high flux dialyzers have lower levels of B2M than those treated by HD with low flux dialyzers. Finally, based on the literature review, an algorithm for RRT using B2M level monitoring and other variables is proposed and needs evaluation in a controlled trial.

A comparative analysis of high-flux and low-flux dialysis in cervical cancer patients with obstructive renal failure showing no significantly improved renal function after catheterisation.

Objective:This study aims to compare the clinical application value of high-flux dialysis with low-flux dialysis in patients without significantly improved renal function after cervical cancer and obstructive renal failure catheterisation.Methods:This prospective randomised study was conducted from January 2018 to December 2019. Eighty cervical cancer patients with obstructive renal failure who showed no significant renal function improvement after catheterisation were randomised into two groups (n = 40 in each group) in the Second People’s Hospital of Yibin City. High-flux and low-flux dialysis were employed in the experimental group and the control group, respectively. Treatments in both groups were provided every other day, with the whole course lasting one week. Data were recorded before and after dialysis included inflammatory factors such as IL-6, CRP and TNF-a, large and moderate molecular toxins (e.g., β2 micro-globulin, parathyrin (PTH) and cysteine protease inhibitor). Renal function changes during the dialysis were also recorded. Afterwards, the two groups were compared regarding the overall efficacy.Results:Both the experimental group and the control group experienced a significant decrease in IL-6, CRP, TNF-a, β2 micro-globulin, PTH and cysteine protease inhibitor, with the decrease in the experimental group being more evident (p < 0.05). After dialysis was completed, the experimental group restored renal function indicators such as Cre, CysC and serum K+ levels more quickly than the control group (p < 0.05). The effective rate was 100% for the experimental group and 87.5% for the control group. The intragroup difference in the efficacy.was significant.Conclusions:High-flux dialysis appears to be more beneficial for cervical cancer patients with obstructive renal failure, showing no significant improvement in renal function after catheterisation. It restored renal function more quickly, had more radical draining of inflammatory factors and large and moderate molecular toxins, and had a higher overall effective rate.

Hemolysis as Cause of Hemodialysis Blood Leak Alarm: Case Study of a Patient with Freshwater Near-Drowning

Hemolysis may be an infrequent cause of hemodialysis blood leak alarms. We report the case of an unresponsive adult male who was placed on hemodialysis with a high-flux dialyzer. Within five minutes, the blood leak alarm sounded. The care team discontinued treatment and made two additional attempts to reinitiate hemodialysis with different machines, blood tubing lots, and brands of high-flux dialyzers, but continued to receive blood leak alarms. Laboratory studies were consistent with severe hemolysis. The attending nephrologist subsequently ordered continuous veno-venous hemofiltration, which was initiated and continued into the following day without incident or alarm. The patient later expired from complications of near-drowning. In the event of significant hemolysis, continuous kidney replacement therapy or hemodialysis with a low-flux dialyzer, and a lower ultrafiltration rate may be indicated.

Toward Respiratory Support of Critically Ill COVID-19 Patients Using Repurposed Kidney Hollow Fiber Membrane Dialysers to Oxygenate the Blood.

The COVID-19 pandemic has highlighted resource constraints in respiratory support. The oxygen transfer characteristics of a specific hollow fiber membrane dialyser was investigated with a view to repurposing the device as a low-cost, readily available blood oxygenator. Oxygen transfer in a low-flux hollow fiber dialyser with a polysulfone membrane was studied by passing first water and then blood through the dialyser in countercurrent to high-purity oxygen. Oxygen transfer rates of about 15% of the nominal 250 ml (STP)/min of a typical adult oxygen consumption rate were achieved for blood flow rates of 500 ml/min. Using two such dialysis devices in parallel could provide up to 30% of the nominal oxygen consumption. Specific hollow fiber dialysis devices operating with suitable pumps in a veno-venous access configuration could provide a cost-effective and readily available supplementation of respiratory support in the face of severe resource constraints.

Serum Lipoprotein(a) Level and Apolipoprotein B/A1 Ratio in Patients of Hemodialysis and Peritoneal Dialysis: A New Approach to Predict Cardiovascular Risks in Chronic Kidney Disease

Background: Serum lipoprotein(a) and Apolipoprotein B/A1 ratio are new, independent cardiovascular risk factors in patients on dialysis. Conversely, the choice of dialysis procedure influences the uremic dyslipidemia in chronic kidney disease (CKD) patients.&#x0D; Objective: To compare lipoprotein(a) levels and apolipoprotein B/A1 ratio in patients of chronic kidney disease (CKD) stage 5 undergoing hemodialysis or peritoneal dialysis.&#x0D; Methods: This cross-sectional study was conducted in Department of Nephrology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, from September 2016 to March 2018. A total of 55 CKD stage 5 patients were included in the study – 31 in hemodialysis (HD) (group A) and 24 in continuous ambulatory peritoneal dialysis (CAPD) (group B). Group A patients were on low flux dialysis with bicarbonate dialysate 4 hours twice weekly dialysis with unfractionated heparin as anti-coagulant with a dialysis adequacy (Kt/V) &gt;1.2. Group B patients were on 3 exchanges over 24 hours with 2 litres of 1.5% glucose fluid with a weekly measured Kt/V &gt;1.7. Serum levels of Lipoprotein(a), Apolipoprotein B/A1 ratio were measured in both groups by using the standard laboratory technique.&#x0D; Results: In group A, most of the patients were in 31-50 years age group (45.1%), while in group B, majority belonged to &gt;50 years age group (54.16%). Patients’ gender showed a male predominance in both groups, i.e. 54.83% and 70.83% respectively. Most of the patients were from urban areas, i.e. 87.1% and 70.8% group A and B respectively. Dialysis adequacy (Kt/V) was found 1.46 for HD patients (group A) and 1.81 for CAPD patients (group B). Dyslipidemia was evident more in CAPD patients than HD patients, as per raised serum Lipoprotein(a) level (83.3% vs 74.1%) and raised Apolipoprotein B/A1 ratio (100% vs. 77.4%). Moreover, comparing with HD patients, CAPD patients showed increased level of serum Lipoprotein(a) (41.4±23.5 mg/dl vs 37.4±25.3 mg/dl; p&gt;0.05) and Apolipoprotein B/A1 ratio (1.59±0.24 vs 1.04±0.22; p&lt;0.001).&#x0D; Conclusion: The maintenance CAPD treatment is associated with more pronounced alterations of the lipoproteins and lipid metabolism than those observed during HD treatment. Besides, serum lipoprotein(a) level and apolipoprotein B/A1 ratio were found simple, accessible and effective markers of dyslipidemia in both groups.&#x0D; Bangladesh Crit Care J September 2020; 8(2): 91-95

Effect of High Flux Hemodialysis versus Hemodiafiltration on Metabolic Status in Hemodialysis Patients

Background: Hemodiafiltration (HDF) is a newly developed renal replacement therapy blood purification technology with more advantageous effects on hemodynamic stability and better removal of B2 microglobulin and phosphorous Objective: The aim of this study is to compare effect of high flux (HF), low flux (LF) dialysis membranes and hemodiafiltration (HDF) on the metabolic status in hemodialysis patients and quality of life of those patients. Patients and Methods: This study included 60 patients more than18 years old, clinically stable with end stage renal disease on regular HD for at least three years (3 yrs), selected from HD unit in (Kobry El Kobba Military Nephrology Hospital) in the period from March 2018 to September 2018. The patients were divided into three groups equally. Group I: 20 patients on low flux dialyzer, Group II: 20 patients on high flux dialyzer, Group III: 20 patients on hemodiafiltration. Results: There was a highly significant decrease in iPTH, B2 microglobulin and Phosphorous in patients received HDF (363.80±149.04, 8.79±7.22 and 4.31±0.74 respectively in comparison with patients received HF hemodialysis (540.10±242.55, 20.47±3.97and 4.58±1.07 respectively) and patients received LF hemodialysis (725.95±270.01, 36.60±7.22 and 5.73±1.34 respectively).Also, there were a highly significant increase in urea reduction ratio in HDF group compared to HF and LF groups (80.43±7.46, 76.03±9.55 and 65.81±7.42 respectively. Conclusion: Hemodiafiltration is the most effective dialysis technique than high flux and low flux dialysis membrane in removal of medium sized molecule and improvement of quality of life.

P1112COMPARISON OF EFFICACY BETWEEN MAINTENANCE HEMODIALYSIS AND THEIR COMBINATION WITH HEMOPERFUSION IN PATIENTS UNDERGOING CHRONIC HEMODIALYSIS TREATMENT

Abstract Background and Aims The occurance of mid- and longterm uremic complications is related to the low clearance rate of middle and large molecule uremic toxins when hemodialysis (HD) alone is adopted. As the uremic toxins and their corresponding biological effects become increasingly clear, blood purification treatment that aims to remove these toxins, has developed from a stage of life-sustaining to improving the quality of life. The objective of this study was to evaluated demographic, clinical and laboratory data in patients who underwent the combination of maintenance hemodialysis with hemoperfusion (HP) and in those who recieved HD alone and to investigate whether this combination could improve the clearance rate of middle and large molecule uremic toxins. Method A total of 26 patients, who underwent routine hemodialysis, were assessed in this study. Those patients were randomly divided into three groups: Group 1 (7 patients) received combined treatment of HD with HP biweekly (HD 2 times a week with HD+HP once a week), whereas Group 2 (10 patients) was given HD with high flux dialyzer and Group 3 (9 patients) was given HD with low flux dialyzer 3 times a week. This study was followed for 4 months. Before and after the observational period demographic and clinical data were taken from the medical history and blood samples were taken for hemoglobin (Hb), iron (Fe), total iron binding capacity (TIBC), albumin (Alb), calcium (Ca), phosphorus (P04) and parathyroid hormone (PTH). Results This study included 13 female and 13 male patients with a mean age of 41, 62 + 11.12 and a mean dialysis duration of 62, 78+53, 33 months. When it comes to baseline characteristics, patients of the group 3 were significantly older than patients in other groups (p=0.001). At the end of the four months observation period, the same difference according to age was noticed (p=0.01). Also, HD+HP group had significantly higher values of TIBC (p=0.006) and significantly lower serum levels of P04 (p=0.001). EPO doses were very similar in group 1 and 2, but in group 3 there were noticeably lower than in those two groups but without a significant difference. The serum levels of albumin were higher in group 3 compared to the other two groups but also without statistical difference. No statistical difference between groups after the follow up period was observed in terms of Hb, Fe, PTH, Ca, BMI, duration of dialysis treatment and vascular access. When groups are viewed individually, in the HD+HP group serum P04 levels were significantly lower after the 4 months off the follow up period than it was at the beginning (p=0.031) and also TIBC was significantly higher (p=0.018). In group 2 the values of TIBC were significantly lower after the follow up period than it was at the beginning (p=0.025). No significant difference was noticed in group 3 but serum PTH levels tends to decrease after 4 months compared to baseline measurement. Conclusion This combination treatment of HD with HP was superior to HD in reducing levels of phosphorus. These findings suggests a potential role of reducing the risk of cardiovascular events in this population especially when it is known that hyperphosphatemia has been pointed out as the primary culprit in the process of cardiovascular calcification. Also, patients who underwent the combined treatment showed higher values of TIBC but unfortunately no difference was noticed between Hb levels and EPO doses. These results eventually demonstrates their role in the improvement of renal disease anemia, which opens up the possibility of further research on a larger sample and over a longer period of time.

P1116IS DIALYSIS ADEQUACY AMELIORATED AFTER INCREASING DIALYSATE FLOW RATE IN CHRONIC HEMODIALYSIS? - ONE YEAR FOLLOW-UP

Abstract Background and Aims Hemodialysis (HD) adequacy, as measured by single pool (sp) Kt/V and urea reduction rate (URR), has been reported to be ameliorated after increasing dialysate flow rate (DFR). However, this is a matter of controversy as no benefit has been observed with dialyzers incorporating features to enhance dialysate flow distribution. We investigated the effect of increasing DFR on dialysis adequacy and on various laboratory parameters. Method Twenty-three patients, M/F=20/3, aged 65(44-89) years, dialyzed thrice weekly for 50(6-274) months, using polysulfone low flux dialyzers, participated in an annual randomized cross-over study. Patients were dialyzed with DFR of 500 ml/min and 700 ml/min for 6 consecutive months respectively, according to their usual dialysis prescription and with ultrafiltration volumes according to clinical need. Blood was sampled before and at the end of midweek sessions at the beginning of the first, 7th and 13rd month for urea, creatinine, potassium, sodium, albumin, total Ca and phosphate (sP). URR, spKt/V, corrected for albumin Ca(sCa) and sCa x sP product (CaxP) values were calculated. Results Under both 500 and 700 ml/min DFRs used, the expected post-dialysis alterations were found: decreased values in serum urea (respectively 161,5±38,0 to 49,9±20.1-p&amp;lt;0,001 and 140,3±30 to 56,0±20.4 mg/dl-p&amp;lt;0,001), creatinine (respectively 10,2±2 to 3.9±1,2-p&amp;lt;0,001 and 10,2±3,3 to 4,1±1,6 mg/dl-p&amp;lt;0,001), potassium (respectively 5,2±0,7 to 3,7±0,3 mM-p&amp;lt;0,001 and 5,3±0,6 to 3,9±0,3mM-p&amp;lt;0,001) and phosphate (respectively 5,4±1,7 to 2,9±0,6-p&amp;lt;0,001 and 5,7±1,6 to 2,6±0,6 mg/dl-p&amp;lt;0,001); increased values in serum albumin (respectively 4,3±0,4 to 4,7±0,4 g/dl-p=0,001 and 4,2±0,3 to 4,7±0,4 g/dl-p&amp;lt;0,001) and sCa (9,1±0,7 to 11,3±0,9 mg/dl-p&amp;lt;0,001 and 8,7±0,6 to 9,9±0,7 mg/dl-p&amp;lt;0,001). After increasing DFR from 500 to 700 ml/min we observed no reductions in pre-dialysis serum urea and creatinine levels or URR (68,6±8,1% to 69,9±7,9%-p=NS) and Kt/V (1,41±0,4 to 1,42±0,3-p=NS) values. However, under DFR of 700ml/min post-dialysis sCa, sP and sCa x sP product values were always lower compared with those under DFR of 500 ml/min (respectively 9,9±0.7 vs 10,8±0.8 mg/dl-p&amp;lt;0,001, 2,6±0,6 vs 2,9±0,6 mg/dl-p=0,02 and 25,6±6,2 vs 30,9±6,7 mg2/dl2-p&amp;lt;0,001). Conclusion DFR increase from 500 to 700 ml/min did not lead to favorable effects on dialysis adequacy but resulted in post-dialysis amelioration of serum calcium and phosphate levels and may be useful in cases of hypercalcemia, hyperphosphatemia and calcifications. DFR increase utility needs further investigation in patients with disorders of calcium-phosphate metabolism.

Correction to: Interleukin 6 is a better predictor of 5-year cardiovascular mortality than high-sensitivity C-reactive protein in hemodialysis patients using reused low-flux dialyzers.

The article "Interleukin 6 isabetter predictor of5-year cardiovascular mortality thanhigh-sensitivity C-reactive protein inhemodialysis patients using reused low-fux dialyzers".

Doripenem Pharmacokinetics in Hemodialysis

Background Doripenem is a broad spectrum carbapenem with activity against gram-positive, gram-negative, and anaerobic bacteria. The drug concentration in target sites is an important determinant of carbapenem efficacy. Doripenem is primarily eliminated by kidneys and can be removed by hemodialysis. The purpose of this study was to determine the pharmacokinetics of doripenem in hemodialysis patients with moderate to severe infections. Methods This prospective, single-center study was conducted in end-stage renal disease patients undergoing hemodialysis and receiving doripenem. Low-flux hemodialysis was performed for 4 hours. Blood and dialysate samples were collected during hemodialysis and nonhemodialysis periods. The doripenem concentrations in plasma and dialysate were measured by reverse phase high performance liquid chromatography. The total amount of drug removed during hemodialysis was determined and the hemodialysis clearance of doripenem was calculated using PKSolver, the add-in program for Microsoft Excel. The appropriate dose of doripenem was estimated using Monte Carlo simulation. Results Six patients were eligible for the study. The fraction of doripenem eliminated via hemodialysis was 51.31%. The mean total amount of doripenem removed by 4 hours of hemodialysis was 1472.06 ± 861 mg at a removal rate of 6.13 ± 3.59 mg/min. Hemodialysis drug clearance volume was 26.06 ± 14.59 L/h. The recommended doripenem dose estimated from the simulation was 250 mg infused every 12 hours during hemodialysis and 250 mg infused every 48 hours for nonhemodialysis periods. Conclusions A low-flux dialyzer removes about half of the total amount of doripenem in blood circulation for 4 hours. Therefore, drug dosage adjustment is required for end-stage renal disease patients undergoing hemodialysis.

The Effect of High Flux versus Low Flux Dialyzers on Serum Fibroblast Growth Factor-23 (FGF-23) and Its Cardiovascular Implications in Prevalent Hemodialysis Patients

Background: Cardiovascular disease is the main cause of death in patients with end stage renal disease. Fibroblastic growth factor- 23 (FGF-23) is a novel phosphaturic hormone produced in the osteocyte. Patients with kidney disease complain of elevated levels of FGF-23 in response to hyperphosphatemia. Patients and Methods: This was a cross-over prospective study conducted on 30 patients on regular hemodialysis. The study period was 6 months, laboratory investigations for FGF-23, complete blood picture, s. urea (pre-dialysis and post-dialysis), serum albumin, serum electrolytes (Ca++ & PO4), alkaline phosphatase, PTH, serum ferritin, and lipid profile as well as echocardiography were obtained in the start of the study, after 3 months on maintained lowflux hemodialysis and 3 months after switching the patients to high-flux hemodialysis. Results: There was a highly significant reduction of FGF-23 level with high-flux dialyzers than with low-flux dialyzers. The adjusted difference in the absolute change in FGF-23 levels between the three months period of lowflux dialysis and the three months period of high-flux dialysis showed a highly significant reduction with high-flux than with low-flux (p= 0.000). There was a significant reduction of serum levels of PTH, calcium, phosphorus levels with high-flux dialyzers than with low-flux dialyzers, the adjusted difference was (p= 0.022), (p= 0.000), and (p= 0.006) respectively. Conclusion: FGF-23 levels were significantly higher in hemodialysis patients than in normal population. FGF-23 was better eliminated by high-flux dialyzers than low-flux dialyzers and high FGF-23 levels were associated with increased incidence of cardiac valve calcification. FGF-23 positively correlated with right ventricular systolic pressure.

Serum Levels and Removal by Haemodialysis and Haemodiafiltration of Tryptophan-Derived Uremic Toxins in ESKD Patients.

Tryptophan is an essential dietary amino acid that originates uremic toxins that contribute to end-stage kidney disease (ESKD) patient outcomes. We evaluated serum levels and removal during haemodialysis and haemodiafiltration of tryptophan and tryptophan-derived uremic toxins, indoxyl sulfate (IS) and indole acetic acid (IAA), in ESKD patients in different dialysis treatment settings. This prospective multicentre study in four European dialysis centres enrolled 78 patients with ESKD. Blood and spent dialysate samples obtained during dialysis were analysed with high-performance liquid chromatography to assess uremic solutes, their reduction ratio (RR) and total removed solute (TRS). Mean free serum tryptophan and IS concentrations increased, and concentration of IAA decreased over pre-dialysis levels (67%, 49%, −0.8%, respectively) during the first hour of dialysis. While mean serum total urea, IS and IAA concentrations decreased during dialysis (−72%, −39%, −43%, respectively), serum tryptophan levels increased, resulting in negative RR (−8%) towards the end of the dialysis session (p < 0.001), despite remarkable Trp losses in dialysate. RR and TRS values based on serum (total, free) and dialysate solute concentrations were lower for conventional low-flux dialysis (p < 0.001). High-efficiency haemodiafiltration resulted in 80% higher Trp losses than conventional low-flux dialysis, despite similar neutral Trp RR values. In conclusion, serum Trp concentrations and RR behave differently from uremic solutes IS, IAA and urea and Trp RR did not reflect dialysis Trp losses. Conventional low-flux dialysis may not adequately clear Trp-related uremic toxins while high efficiency haemodiafiltration increased Trp losses.

Obestatin levels in response to a meal and association with subsequent appetite sensations in maintenance hemodialysis patients.

Obestatin, a physiological opponent of acylated ghrelin, is linked to appetite suppression regulation in mice but its anorexigenic properties in humans are controversial. We aimed to investigate obestatin's potential role in dietary intake regulation by examining response to a meal in maintenance hemodialysis (MHD) patients. In this prospective observational case series study, we investigated the response of obestatin to a fixed calorie meal (500kcal) in 21 MHD patients (age 69.2±13.1 years, 10 women, with a body mass index 27.2±5.5kg/m2). Parallel changes in serum obestatin and insulin levels and subjective scores of appetite (visual analogue scales for hunger, satiety, fullness and prospective food consumption) were recorded on fasting and 30, 60 and 120min after the meal. In a linear mixed effects model controlling for baseline demographics and clinical parameters including serum insulin concentrations, postprandial levels of obestatin did not change significantly from baseline in response to the meal. The response was the same in MHD patients treated with high- or low-flux dialyzers. However, postprandial obestatin levels were associated with the rate of change in sensation of fullness (linear estimate: 11.60 (95% confidence interval 0.17 to 23.04, P<0.05)). The remaining sensations of appetite did not correlate with postprandial obestatin levels in time. Obestatin levels do not change acutely with food administration in MHD patients, but associate with the changes in sensation of fullness. This supports the possible role of obestatin in the long-term regulation of appetite in MHD patients.

Predicting 3-year mortality based on the tumor necrosis factor alpha concentration in low-flux hemodialysis patients.

Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine produced during acute inflammation. Few studies have evaluated the association between serum TNF-α and its receptors and their clinical outcomes in hemodialysis patients. However, a study assessing patients using a low-flux dialyzer reuse has not been conducted yet. The serum TNF-α concentrations of 319 prevalent hemodialysis patients (mean age, 45 ± 15 years; median duration of hemodialysis, 48 [interquartile range, 26-79] months; 185 males and 134 females) was examined to predict their 3-year mortality. The patients were divided into tertiles according to their serum TNF-α concentrations: T1 (n = 106; serum TNF-α concentration, <41.22 pg/mL), T2 (n = 106; serum TNF-α level, from 41.22 to 67.28 pg/mL), and T3 (n = 107; serum TNF-α concentration, ≥ 67.29 pg/mL). During the 36-month follow-up period, a total of 50 (15.7%) patients died from all causes. The Kaplan-Meier analysis revealed that the all-cause mortality in T3 was significantly higher compared to that in T1 and T2 (log-rank test, P < .001). The serum TNF-α level was a significant predictor for all-cause mortality (area under the curve = 0.887, P < .001, cutoff value, 89.812 pg/mL, sensitivity = 76%, specificity = 96.3%). The serum TNF-α level was a better predictor of mortality than the duration of hemodialysis and serum albumin, serum high-sensitivity C-reactive protein, and serum beta-2 microglobulin concentrations. The serum TNF-α concentration was a good predictor of the 3-year mortality in low-flux hemodialysis patients.

Metabolic acidosis in hemodialysis: a neglected problem in Brazil.

ABSTRACTIntroduction:Metabolic acidosis is associated with the high mortality seen in hemodialysis patients. The panorama of metabolic acidosis in hemodialysis in Brazil is unclear since 1996 when the analysis of bicarbonate levels was no longer a compulsory exam. We aimed to establish the prevalence of metabolic acidosis in a hemodialysis population and analyze the factors associated with low bicarbonate levels.Methods:A cross-sectional study was carried out to assess the prevalence of metabolic acidosis in adults undergoing regular hemodialysis from January to April 2017, in four dialysis centers from Niteroi, Rio de Janeiro, Brazil, and surroundings. For blood gas analysis, samples of 2 mL were collected in heparinized syringes before a midweek dialysis session.Results:384 patients with a mean age of 58.1 ± 15.8 years (54.5% men and 63.0%, non-white) were included. Approximately 30% had diabetes and 48%, hypertension. Nearly 88% used primary arteriovenous fistula as vascular access. The pre-dialysis mean serum tCO2 in the midweek session was 22.7 ± 3.0 mEq/L. The prevalence rate of serum bicarbonate below DOQI recommendation (22 mEq/L or higher) was 40.3%, and 6.5% had serum bicarbonate < 18 mEq/L. The dialyzer use count and the use of low-flux dialyzers were negatively associated whereas age and the standard Kt/V values were positively associated with the serum bicarbonate levels.Conclusion:The findings were in agreement with global data reported in previous studies. However, because the sample was relatively small and non-representative of the Brazilian population, a more comprehensive study, addressing national data is necessary to substantiate our findings.

Association between low serum prealbumin levels and carpal tunnel syndrome in maintenance hemodialysis patients

Aims Carpal tunnel syndrome (CTS) and low serum prealbumin concentration are common in maintenance hemodialysis patients. In this study, we focused on the association between low serum prealbumin levels and carpal tunnel syndrome in maintenance hemodialysis (MHD) patients using low-flux dialysis reuse. Materials and methods Serum prealbumin levels were assessed to determine the association between low serum prealbumin levels and CTS in 373 prevalent MHD patients (the mean age was 45 years old, hemodialysis duration was 46 months). The patients were divided into 2 groups: the CTS group with 44 patients and the non-CTS group with 329 patients. Results The prevalence of CTS was 11.8%. Serum prealbumin showed a good prognostic value to predict CTS in MHD patients using low-flux dialysis reuse (the Area Under the Curve = 0.841, p < .001; cutoff value: 26.5 mg/dL with sensitivity = 72.7% and specificity = 79.9%). Conclusions Serum prealbumin was a good prognostic biomarker of CTS in MHD patients using low-flux dialysis reuse.

Measuring serum beta2-microglobulin to predict long-term mortality in hemodialysis patients using low-flux dialyzer reuse.

PurposeBeta2-microglobulin (β2-M) is recognized as a surrogate marker relating to the mechanisms of dialysis-associated amyloidosis. Few studies have evaluated the association of serum β2-M with clinical outcome in hemodialysis patients using high-flux type. However, study on patients using low-flux dialyzer reuse has not been done yet.Patients and methodsUsing serum β2-M level on predicting long-term mortality of hemodialysis patients was examined in 326 prevalent hemodialysis patients (45.59±14.46 years, hemodialysis duration of 47.5 (26–79) months, 186 males and 140 females). The patients were divided into 3 groups with equal number of patients, according to their serum β2-M levels: group A (n=109, serum β2-M concentration ≤55.7 mg/L), group B (n=109, serum β2-M level from 55.8 mg/L to 75.4 mg/L) and group C (n=108, serum β2-M concentration >75.4 mg/L).ResultsDuring the follow-up period of 5 years, there were 75 all-cause deaths (23.0%). Kaplan–Meier analysis revealed that all-cause mortality in the higher β2-M group was significantly higher compared to that in the lower β2-M groups (p<0.001). Serum β2-M level was a significant predictor for all-cause mortality (AUC =0.898; p<0.001; Cut-off value: 74.9 mg/L, Se=93.3%, Sp=92.9%).ConclusionSerum β2-M levels were a significant predictor of long-term mortality in hemodialysis patients, who use only low-flux dialyzers and reuse 6 times.

Effect of High Flux Versus Low Flux Hemodialysis on Some Cardiovascular Risk Factors in Egyptian Children with End Stage Renal Disease.

Background Cardiovascular disease remains as the main cause of mortality in children with end stage renal disease (ESRD).Among the cardiovascular risk factors, dyslipidemia and inflammation are of great importance as they are both prevalent and modifiable risk factors. We aim to evaluate the effect of permeability of low-flux versus high-flux dialyzer on such 2 factors in children on regular hemodialysis (HD). Patients and Methods 48 children with ESRD were randomized into 2 groups. Group A used low-flux dialyzer, group B used high-flux dialyzer for 6 months. An initial and 6th month blood samples for lipid profile, serum albumin and serum high sensitivity CRP (hs CRP) were obtained. Statistical analysis was done. Results In the high flux group, there was a statistically significant difference in total cholesterol, HDL-cholesterol, triglyceride and hs CRP levels after 6 months when compared to baseline values of the same group, while LDL cholesterol and serum albumin showed no significant change. In the low flux group, results after 6 months didn’t show significant change in previously mentioned parameters when compared with its baseline values of the same group. Comparing these parameters between the 2 groups at 6 months, shows that high flux group has significantly lower total cholesterol, triglyceride, and hs CRP levels. Conclusion This study has demonstrated for the first time improvement of some markers of dyslipidemia and inflammation by using high-flux HD in children with ESRD. These results suggest that high-flux dialysis may benefit such young suffering population by reducing the atherogenic risk, cardiovascular morbidity and mortality.