Effect of a plasma sodium biofeedback system applied to HFR on the intradialytic cardiovascular stability. Results from a randomized controlled study.

BACKGROUND: Intradialytic hypotension (IDH) is still a major clinical problem for haemodialysis (HD) patients. Haemodiafiltration (HDF) has been shown to be able to reduce the incidence of IDH. METHODS: Fifty patients were enrolled in a prospective, randomized, crossover international study focussed on a variant of traditional HDF, haemofiltration with endogenous reinfusion (HFR). After a 1-month run-in period on HFR, the patients were randomized to two treatments of 2 months duration: HFR (Period A) or HFR-Aequilibrium (Period B), followed by a 1-month HFR wash-out period and then switched to the other treatment. HFR-Aequilibrium (HFR-Aeq) is an evolution of the haemofiltration with endogenous reinfusion (HFR) dialysis therapy, with dialysate sodium concentration and ultrafiltration rate profiles elaborated by an automated procedure. The primary end point was the frequency of IDH. RESULTS: Symptomatic hypotension episodes were significantly lower on HFR-Aeq versus HFR (23 ± 3 versus 31 ± 4% of sessions, respectively, P l= l0.03), as was the per cent of clinical interventions (17 ± 3% of sessions with almost one intervention on HFR-Aeq versus 22 ± 2% on HFR, P <0.01). In a post-hoc analysis, the effect of HFR-Aeq was greater on more unstable patients (35 ± 3% of sessions with hypotension on HFR-Aeq versus 71 ± 3% on HFR, P <0.001). No clinical or biochemical signs of Na/water overload were registered during the treatment with HFR-Aeq. CONCLUSIONS: HFR-Aeq, a profiled dialysis supported by the Natrium sensor for the pre-dialysis Na(+) measure, can significantly reduce the burden of IDH. This could have an important impact in every day dialysis practice.

Determination of dialysis dose: a clinical comparison of methods.

BACKGROUND: Guidelines recommend regular measurements of the delivered hemodialysis dose Kt/V. Nowadays, automatic non-invasive online measurements are available as alternatives to the conventional method with blood sampling, laboratory analysis, and calculation. METHODS: In a prospective clinical trial, three different methods determining dialysis dose were simultaneously applied: Kt/V(Dau) (conventional method with Daugirdas' formula), Kt/V(OCM) [online clearance measurement (OCM) with urea distribution volume V based on anthropometric estimate], and Kt/V(BCM) [OCM measurement with V measured by bioimpedance analysis (Body Composition Monitor)]. RESULTS: 1,076 hemodialysis patients were analyzed. The dialysis dose was measured as Kt/V(Dau) = 1.74 ± 0.45, Kt/V(OCM) = 1.47 ± 0.34, and Kt/V(BCM) = 1.65 ± 0.42. The difference between Kt/V(OCM) and Kt/V(BCM) was due to the difference between anthropometric estimated V(Watson) and measured V(BCM). Compared to Kt/V(Dau), Kt/V(OCM) was 15% lower and Kt/V(BCM) 5% lower. Kt/V(Dau) was incidentally prone to falsely high values due to operative errors, whereas in these cases OCM-based measurements Kt/V(OCM) and Kt/V(BCM) delivered realistic values. CONCLUSIONS: The automated OCM Kt/V(OCM) with anthropometric estimation of urea distribution volume was the easiest method to use, but Kt/V(BCM) with measured urea distribution volume was closer to the conventional method.

Simultaneous blood temperature control and blood volume control reduces intradialytic symptoms.

PURPOSE: Intra-dialytic morbid events (IME; e.g. hypotension, cramps, headaches) are frequent complications during hemodialysis (HD), known to be associated with ultrafiltration-induced hypovolemia and body temperature changes. Feedback control of blood volume adjusts the ultrafiltration rate in order to keep the blood volume above the patient's individual limit; feedback control of blood temperature maintains the mean arterial blood temperature at the individual pre-dialytic level. Each of these methods reduces the frequency of IME. METHODS: In a randomized clinical trial the simultaneous application of both feedback controls was investigated for the first time. In 15 weeks, each patient went through 3 study phases: an observational screening phase, a standard phase (STD), and a blood temperature- and blood volume-control phase (CTL). Patients with at least 5 sessions with IME out of 15 sessions in the screening phase were eligible for the study and randomized either into sequence STD-CTL or CTL-STD. RESULTS: 26 patients completed the study according to protocol, and 778 HD treatments were analyzed. The general treatment parameters were similar in both study phases: treatment duration (STD: 244 min, CTL: 243 min, NS), pre-dialytic weight (STD: 72.3 kg, CTL: 72.2 kg, NS), and weight loss due to ultrafiltration (STD: 3.26 kg, CTL: 3.15 kg, NS). The proportion of HD treatments with IME was 32.8% during STD and 18.0% during CTL (p=0.024). CONCLUSIONS: The frequency of HD sessions with IME was significantly reduced by 45% compared to standard HD in this randomized clinical trial by use of individualized HD treatments with simultaneous feedback control of blood volume and blood temperature.

Blood volume monitoring.

BACKGROUND: In CKD stage 5 diabetic patients (DM), only approximately half of the interdialytic weight gain was accounted for by sodium intake. The other half was due to pure water gain, probably caused by hyperglycemia. Dialysis treatment faces two major troubles: the removal of the extra amount of water and the therapy of the compromised compensatory mechanisms. The described situation is the reason why new technologies in hemodialysis were developed. Blood volume monitoring (BVM) with regulation of ultrafiltration and sodium (Hemocontrol, Hospal, Belgium; Hameomaster, Nikkiso Co. Ltd, Japan) was evaluated to describe the advantages for efficacy and compatibility in hemodialysis therapy. METHODS: 18 cardiovascular instable patients (DM) were included into the study (age 56.4 +/- 12.5, 7 female, 11 male). Begin of dialysis 39 +/- 9.3 months before the study, dialysis time/session 258.3 +/- 15.4 min, 3 sessions/week, blood flow 250 ml/min, dialysate flow 500 ml/min, prephase: standard bicarbonate dialysis (HD; HCO3 - 35 mmol/l) 2 weeks, BVM: 48 weeks. Clinical parameters evaluated before BVM and 48 weeks after BVM: number of muscle cramps (MC) and hypotensive episodes (HypoEp) during dialysis, optimal weight (OptW), single pool Kt/V (sp Kt/V), equilibrated Kt/V (db Kt/V), systolic blood pressure (BP), antihypertensive drugs (AntiDr), cardiac ejection fraction (EF) and left ventricular mass index (LVMI). RESULTS: In comparison with HD after 48 weeks with BVM, we can demonstrate a reduction of MC by 83.7%, HypoEp by 88.9%, OptW by 1.7%. The improved refilling and reduction of OptW led to an increase of sp Kt/V by 34.8% and db Kt/V by 33.3%. AntiDr were reduced to 56.6% compared to HD, BP lowered by 4.4%. Due to BVM, EF increases to 123.8% and LVMI decreases by 25.2%. CONCLUSION: BVM can improve clinical parameters for adequacy of hemodialysis. It offers a unique possibility to treat diabetic patients according to their special needs.

In vitro and in vivo evaluation of Adacolumn cytapheresis in healthy subjects.

Adacolumn is a medical device for adsorptive cytapheresis. It has been developed for selective adsorption of granulocytes and monocytes from peripheral blood of patients with immune disorders, such as autoimmune diseases and chronic inflammatory diseases. A double blind sham-controlled crossover study design was used in order to evaluate in vivo biological responses of leukocytes as well as biocompatibility during and after Adacolumn cytapheresis in healthy volunteers. In addition, experiments were undertaken to further evaluate leukocyte reactions to Adacolumn carrier (G-1: cellulose diacetate) beads in vitro. Six healthy volunteers, 4 males and 2 females, with a mean age of 26.7 years were randomly assigned to one of the two treatment arms in a crossover fashion. Three subjects received a single Adacolumn treatment, followed by a single sham treatment at an interval of 7 days. The other three subjects received the two treatments in reverse order. All subjects were followed up 7 days after the last treatment. Additionally, in vitro investigations were carried out using blood from the healthy donors to examine the effect of G-1 beads on granulocyte functions. In vitro exposure of human peripheral blood to G-1 beads caused downregulation of L-selectin expression and upregulation of Mac-1 expression on granulocytes, leading to a marked reduction of adhesive capacity of granulocytes to endothelial cells. The exposure also led to decreased granulocyte chemotactic activity to IL-8. The number of granulocytes and monocytes clearly decreased during Adacolumn cytapheresis. Granulocytes showed marked phenotypic changes of L-selectin(Low) and Mac-1(Hi) after passing through Adacolumn in vivo. Expression of TNF-alpha and chemokine receptors was downregulated. In addition, TNF-alpha and IL-1beta producing capacity of peripheral blood leukocytes was decreased after Adacolumn cytapheresis and these changes lasted even one week after the cytapheresis. The level of complement fragments, C3a and C5a, increased, while bradykinin concentration did not change during Adacolumn cytapheresis. Exposure of human peripheral blood to G-1 beads, both in vitro and in vivo, caused a significant reduction of adhesive capacity and proinflammatory cytokine producing capacity of peripheral blood leukocytes. Such changes were not observed after sham apheresis. Despite complement activation, tolerability of Adacolum cytapheresis was not influenced. These findings may at least partly explain the beneficial effect of Adacolumn cytapheresis in the treatment of autoimmune diseases.

Enhanced functional performance characteristics of a new polysulfone membrane for high-flux hemodialysis.

Elimination of uremic solutes with molecular weights up to 60 kD, without significant loss of albumin is an important therapeutic goal to optimize outcomes in chronic hemodialysis patients. To characterize a newly developed polysulfone dialyzer (APS-650) a comparative analysis was performed with a highly advanced polysulfone dialyzer (F-60S) including 22 stable chronic hemodialysis patients. Diffusive clearances were determined, and albumin loss was calculated. The elimination profile of uremic solutes up to 32.0 kD was assessed in vivo by sieving coefficients, clearances, and reduction ratios of beta(2)-microglobulin (11.8 kD), myoglobin (17.2 kD), prolactin (23.0 kD), and alpha(1)-microglobulin (32.0 kD). Hemocompatibility was tested in serial measurements of total white blood cell count, platelet count, C3a, and neutrophil elastase. No significant albumin loss was detected. Significantly higher sieving coefficients, clearances, and reduction ratios for proteins with molecular weight up to 32.0 kD were demonstrated with the newly developed polysulfone membrane. Both polysulfone membranes were equal concerning hemocompatibility parameters. The APS-650 dialyzer allowed optimized hemodialysis treatment with respect to clearance of medium-sized uraemic solutes by high-flux dialysis.

Online hemodiafiltration versus acetate-free biofiltration: a prospective crossover study.

Online hemodiafiltration (online HDF) and acetate-free biofiltration (AFB) are 2 innovative renal replacement therapies. Convincing evidence has shown that both techniques are superior to conventional hemodialysis in many aspects. The aim of the present investigation was to compare online HDF and AFB in 12 stable maintenance hemodialysis patients in a prospective, randomized crossover trial. Twelve stable dialysis patients, age 49.7 +/- 11.3 years and on dialysis for 83.5 +/- 76.7 months, were treated prospectively and randomly by either AFB, predilution HDF (pre-HDF), or postdilution HDF (post-HDF) for a total of 36 weeks using exclusively F60S high-flux dialyzers. Routine blood biochemical tests, bone metabolism parameters, and clearance for both small and larger molecular weight substances were measured at defined intervals. During the trial period inter- and intradialysis symptoms, e.g., hypotensive episodes and intradialysis arterial blood gas analyses, were recorded. Both online HDF and AFB were well accepted by the overwhelming majority of patients and also by the dialysis staff. Pretreatment sodium, total and ionized calcium, chloride, bicarbonate, and urea did not differ within or between the 3 treatment groups. Potassium increased slightly in HDF patients while phosphate and beta2-microglobulin (beta2-M) decreased in all groups. After dialysis, AFB patients exhibited a significantly higher bicarbonate concentration and lower potassium level when identical potassium concentrations in dialysate were used. Patients receiving AFB manifested less intradialysis partial pressure of oxygen drop and partial pressure of carbon dioxide rise than those on HDF treatments. HDF treatments could afford higher single-pool and double-pool Kt/V, higher effective urea and beta2M clearance, and lower total interdialysis symptom scores than the AFB treatment method. While bone metabolism parameters did not differ between the 3 dialysis modalities, some parameters such as deoxypyridinoline in HDF and osteocalcin, pyridinoline, and deoxypyridinoline in AFB deteriorated at the end of the crossover study. Aluminum concentration decreased progressively to about one-third of prestudy values at the end of the study with all 3 treatments. AFB was associated with a lower predialysis mean arterial pressure (MAP), a smaller drop in MAP during treatment, and similar hypotension episodes compared with the 2 HDF treatments. Albumin concentration showed a trend to decrease during the first 2 months of the trial period followed by a slight increase thereafter but still significantly lower than initial value at the end of crossover. Both online HDF and AFB share most of the features of optimal renal replacement therapy. Online HDF is superior to AFB in such aspects as increased delivered dialysis dose both for small and larger molecular weight toxins and less interdialysis symptoms. On the other hand, AFB is associated with a smaller effect on arterial blood gas values and improved intradialysis hemodynamic tolerance. Some dialysis-related symptoms and complications in the case of our AFB practice could be attributable, at least in part, to low dialysate calcium level.

Acetate-free biofiltration versus on-line hemodiafiltration: A prospective, cross-over study / 中华肾脏病杂志

Objective To compare the therapeutic efficacy between on-line hemodiafiltration (On-line HDF) and acetate-free biofiltration(AFB) in prospective, randomized cross-over way. Methods Twelve stable dialysis patients, aged (49. 7?11. 3) years old and on dialysis for (83. 5?6.7)months, were prospectively, randomizedly treated by AFB, pre-dilution HDF(Pre-HDF), and post-dilution HDF (Post-HDF) for total 36 weeks using F60S high-flux dialyzers. Routine blood biochemical tests, bone metabolism parameters and clearance for both small and larger molecular weight substances were measured at defined intervals. Meanwhile, inter-and intra-dialysis symptoms, hypotension episodes and intra-dialysis arterial blood gas were recorded during the research period. Results Both AFB and on-line HDF were well accepted by the overwhelming majority of patients and dialysis staff. Pre-treatment sodium, total and ionized calcium, chloride, bicarbonate, and urea did not differ within or between three treatment groups, while potassium increased slightly in HDF patients, and phosphate, ?z-microglobulin(?2-m) decreased in all groups. After dialysis, AFB patients exhibited significantly higher bicarbonate concentration and lower potassium level when identical potassium level in dialysate was used. Patients receiving AFB manifested less intra-dialysis PO2 drop and PCO2 rise than those on HDF treatments. HDF treatments could afford higher single-pool and double-pool Kt/V, higher effective urea and ?z-m clearance, and lower total inter-dialysis symptom scores than AFB method. While bone metabolism parameters did not differ between three dialysis modalities, some parameters, such as deoxypyridinoline in HDF and osteocalcin, pyridinoline, deoxypyridinoline in AFB, deteriorated at the end of cross-over. Aluminum concentration decreased progressively to about one-third of pre-study values at the end of study with all three treatments. AFB was associated with a lower pre-dialysis MAP, a smaller drop in MAP during treatment, and similar hypotension episodes compared with two HDF treatments. Albumin concentration showed a trend to decrease during the first 2 months of research period, followed by a slight increase thereafter, but still significantly lower than initial value at the end of cross-over. Conclusions Both on-line HDF and AFB share most of the features of optimal renal replacement therapy. On-line HDF is superior to AFB in such aspects as increased dialysis dose both for small and larger molecular weight toxins and less inter-dialysis symptoms. On the other hand, AFB is associated with smaller effect on arterial blood gas and improved intra-dialysis hemodynamic tolerance. Some dialysis-related symptoms and complications in the case of our AFB practice could be attributable, at least in part, to low dialysate calcium level.