Acute hypernatraemia during bicarbonate-buffered haemodialysis

Five patients on maintenance haemodialysis were exposed to varyingdegrees of hypernatric dialysate, leading to acute hypernatraemia(plasma sodium concentrations 158 mmol/l to 179 mmol/l). Withthe exception of one patient, who developed pulmonary oedema,symptoms were minimal and in each case hypernatraemia was correctedwithout residual complications. The hypernatric dialysate resultedfrom a granular and less soluble batch of sodium bicarbonatepowder. The extra effort required to dissolve the powder causedCO₂ to be shaken out of solution, producing sodium carbonateand raising the pH. Mixing calcium from the ‘acid’concentrate with excess carbonate in the ‘bicarbonate’concentrate led to rapid precipitation of calcium carbonateon the conductivity monitoring cells. Dialysate conductivitywas incorrectly sensed as low by the coated conductivity cells,so that an increasing amount of ‘acid’ concentrate,with its accompanying electrolytes, was delivered to the patient.When the granular powder was ground to a fine powder, passedthrough a 125 µm sieve and gently dissolved, the machineoperated normally. We recommend that sodium bicarbonate powderis supplied with a sieve size no greater than 125 µm,kept dry to prevent the formation of large crystals, and dissolvedgently.     

Characterization of insulin-like growth factors and their binding proteins in peritoneal dialysate

.Serum insulin-like growth factors (IGFs), which circulate bound to specific IGF binding proteins (IGFBPs), must exit the intravascular space before acting on target tissues. Little is known about the nature of IGF/IGFBPs in extravascular fluids of patients with chronic renal failure (CRF). Peritoneal dialysate (PD) was studied since, after a short incubation, PD contains proteins which have entered an extravascular space; thus, IGF/IGFBP forms in PD are more likely than serum forms to interact with target tissues. IGF-I and IGF-II, and IGFBPs 1 – 4, were readily identified by specific immunoassays and/or ¹²⁵iodine-IGF ligand blotting of simultaneously obtained PD and serum samples from seven CRF children; IGFBP-3 was a major IGFBP in PD as in serum. Where quantitated, IGF and IGFBP levels in PD were approximately 10% of serum concentrations. After separation of PD and serum by size-exclusion chromatography, serum had more IGFBP-3 in 150-kilodalton (kDa) than 35-kDa fractions, while PD had far less IGFBP-3 in 150-kDa than 35-kDa fractions. Immunoblot studies revealed a major 29-kDa IGFBP-3 fragment, in addition to intact 41- and 38-kDa IGFBP-3 forms, in PD and CRF serum; the 29-kDa form predominated in the 35-kDa PD fractions. These data suggest that the 29-kDa fragment is the IGFBP-3 form most likely to modulate IGF effects on target tissues of CRF individuals. Received: April 17, 1995; received in revised form September 19, 1995; accepted October 12, 1995     

Hernodiafiltration With Sodium Concentration-Controlled Dialysate

When hemofiltration and hernodialysis are compared, the former is more effective in removing larger substances, whereas the latter is superior in removing small substances. We consider hemodiafiltration, in which the advantages of the two treatment methods can be adopted, as the most effective and practical method. In the studies of hemodiafiltration, we demonstrated that disequilibrium syndrome associated with the treatment can be prevented by employing a high sodium concentration in the dialysate. The dialysate was successfully used for treating intracel-lular overhydration. However, it could not be used without causing adverse effects such as thirst in patients whose intracellular overhydration had already been treated and resulted in increase in their body weight. However, these patients were treated successfully by decreasing the high sodium concentration gradually or in a stepwise manner.     

Pyruvate anions neutralize peritoneal dialysate cytotoxicity

A new peritoneal dialysate containing pyruvate anions was developedin order to avoid cytotoxic effect of conventional lactate-baseddialysate. The dialysate has a final pH of 5.4 to 5.6 and iscomposed of 1.36–3.86% glucose-monohydrate; 132 mmol/lsodium; 1.75 mmol/l calcium; 0.75 mmol/l magnesium; 102 mmol/lchloride and 35 mmol/l pyruvate. For cytotoxicity testing peritonealmacrophages, and mesothelial cells (MC) were exposed to conventionallactate dialysate, and pyruvate dialysate. We investigated theO₂^– generation and cytokine synthesis after endotoxinstimulation in peritoneal macrophages and the proliferationof mesothelial cells of cultured human MC. After exposure tolactate dialysate O₂^– generation and cytokine synthesisin peritoneal macrophages and proliferation of mesothelial cellswere inhibited when compared to solution containing pyruvateand the control solution. After preincubation with 3.86% glucosecontaining solutions, all negative effects became even morepronounced in the lactate group whereas after pre-exposure topyruvate containing solution the toxic effects were absent.These results suggest that the acute toxic effects of commerciallyavailable peritoneal dialysates can be avoided by the use ofsodium pyruvate instead of sodium lactate.     

Pharmacokinetic studies of cefoxitin in continuous ambulatory peritoneal dialysis

Summary The pharmacokinetics of cefoxitin was examined in 9 patients undergoing peritoneal dialysis for chronic renal failure. Cefoxitin was administered intraperitoneally in the dialysate fluid every 6 h for 24 h, in two different concentrations, 50 µg/ml and 100 µg/ml.The plasma half-life of cefoxitin was 20.2 h. The major route of elimination was non-renal, with a clearance of 8.0 ml/min. Peritoneal clearance was 4.1 ml/min. As expected, renal clearance was negligible.The peak plasma concentrations of cefoxitin at the two dose levels used were 7 µg/ml and 15 µg/ml, respectively, when assayed by HPLC, and 12 µg/ml and 24 µg/ml when determined by a microbiological assay. The cefoxitin concentration in the dialysate decreased from 50 µg/ml to 14 µg/ml and from 100µg/ml to 37 µg/ml during the 6 h of its retention in the peritoneal cavity.     

氟伐他汀对高糖腹透液诱导人腹膜间皮细胞纤维连接蛋白表达的影响

目的:探讨氟伐他汀(fluvastatin,Flu)对高糖腹透液(high-glucose peritoneal dialysate,HGPDS)诱导人腹膜间皮细胞(human peritoneal mesothelial cells,HPMCs)纤维连接蛋白(fibronectin,FN)表达的影响?方法:体外培养HPMCs,同步化24 h后,分为正常对照组?HGPDS组?HGPDS+Flu组?单纯氟伐他汀组?DMSO对照组,各组分别刺激不同时间后,噻唑蓝(MTT)检测各组细胞的活力,RT-PCR检测FN的mRNA表达,ELISA法检测上清液FN蛋白表达的变化?结果:与正常对照组比较,HGPDS明显抑制细胞活力,HGPDS联合Flu共同培养24?36 h,细胞活力有所恢复,其中,1 × 10-6 mol/L Flu作用24 h,细胞活力改善差异有统计学意义(P < 0.05);与正常对照组比较,HGPDS明显增加人腹膜间皮细胞FN mRNA及蛋白表达(P < 0.05),并呈时间依赖性,其中FN mRNA于6 h达高峰,FN蛋白于24 h达高峰?Flu 可抑制HGPDS诱导的FN的高表达(P < 0.05),并呈浓度依赖性?结论:HGPDS诱导体外培养人腹膜间皮细胞FN表达增加,此作用可被Flu 抑制?     

Individualized Cool Dialysate as an Effective Therapy for Intradialytic Hypotension and Hemodialysis Patients’ Perception

Intradialytic hypotension (IDH) is the most common dialytic complication. Recurrent episodes of ischemia secondary to hemodynamic instability are associated with cardiomyopathy, increased risk of thrombosis of arteriovenous fistula, decreased quality of life, and increased mortality. Cool dialysate may be an effective approach to reducing intradialytic hypotension by promoting peripheral vasoconstriction. Most studies to date are small and do not employ individualized cool dialysates (ICD). The study consisted of standard and cool phases, with patients as their own controls. During the standard phase, participants underwent hemodialysis (HD) at their usual dialysate temperature at 37°C for six consecutive hemodialysis sessions. In the cool phase, the dialysate temperature was set at the core baseline temperature ?0.5°C for six more sessions. We compared hemodynamic parameters during the standard and cool phases. A total of 93 participants were included. The number of IDH episodes during the standard and cool phases were 3.3 ± 2.8 and 2.0 ± 2.2 per patient respectively (P < 0.001). Other hemodynamic parameters including lowest intradialytic mean arterial pressure were significantly increased with ICD. We found that there was a high baseline rate of feeling cold among all participants and it increased after the implementation of ICD; however, the dropout rate was approximately 5%. ICD is an effective tool to decrease the frequency of IDH in the HD population and we provide a pragmatic, real‐world approach to implement this technique.     

Review: Clinical usefulness of ultrapure dialysate--recent evidence and perspectives

It has generally been accepted that biological contamination of dialysate deteriorates the biocompatibility of dialysis therapy and accelerates dialysis-related complications such as dialysis-related amyloidosis (DRA) and malnutrition-inflammation-atherosclerosis (MIA) syndrome. During the past decade several studies have clarified that very slight amounts of contamination can lead to inflammatory response, and we could not confirm biological dialysate quality only by measuring endotoxin levels despite of measuring viable cell counts or biofilms. To achieve this, the European Renal Association/European Dialysis Transplantation Association and the American National Standardization Institute/Association for the Advancement of Medical Instrumentation published new standards for dialysate, in which very strict control levels were recommended with regard to viable bacterial cell counts. In 2004 JSDT raised the required standard of the levels of endotoxin, and began to develop a standard for bacterial cell counts. In Japan, many chronic kidney disease patients are treated with centralized dialysate supply systems which have weak spots in disinfecting the system. This causes some difficulties in making a standard for viable bacterial cell counts. In the present paper, we summarize evidences of clinical usefulness of ultrapure dialysate and perspectives of the standard for dialysate in Japan.     

Risk factors of the progression of abdominal aortic calcification in patients on chronic haemodialysis

Background. Vascular calcification is an independent determinantof cardiovascular events in maintenance haemodialysis (HD) patients.It is not known whether acute changes of the serum calcium concentrationbefore and after HD (Ca) are associated with the developmentof aortic calcification. Methods. We enrolled 71 patients dialysed with a dialysate with3.0 mEq/l calcium and determined their aortic calcificationindex (ACI) by abdominal computed tomography twice at an intervalof 3 years. To identify the factors contributing to the rateof progression of aortic calcification, we analysed the averagevalues for clinical and laboratory data obtained between thefirst and second evaluations of ACI. Results. The second ACI (mean ± SD: 80.2 ± 63.9)was significantly greater than the first ACI (61.0 ±61.0) after an interval of 35.8 ± 4.2 months. The annualizedchange of ACI (ACI/year) was significantly and directly associatedwith the Ca and C-reactive protein (CRP) (both P < 0.001,P for trend). Stepwise multivariate regression analysis revealedthat ACI/year was positively and independently associated withCRP, presence of diabetes mellitus and Ca, but negatively associatedwith a premenopausal status in women. Similarly, Ca was positivelyand independently associated with ACI/year and the ultrafiltrationrate, but was negatively associated with pre-HD Ca. Conclusion. The increase of serum calcium after HD was relatedto the rate of progression of aortic calcification. Excess calciumis transferred into patients on HD when using a dialysate of3.0 mEq/l calcium. This may be a risk factor for the developmentof vascular calcification.