Differences in Bio-incompatibility among Four Biocompatible Dialyzer Membranes Using in Maintenance Hemodialysis Patients

Abstract

Background: Following the introduction of modified cellulosic and then synthetic membrane dialyzers, it was realized that the dialyzer bio-incompatibility depends on the membrane composition. We designed a prospective, randomized, cohort study of 6 months to determine several parameters of biocompatibility in maintenance hemodialysis (MHD) patients treated with four different membrane dialyzers. Methods: There were 60 MHD patients enrolled in the study. In baseline, synthetic low-flux dialyzer, polysulfone (PS) membrane was used in all patients for at least 3 months. Then the patients were randomly divided into three groups according to different dialyzer membranes. Synthetic high-flux dialyzer group, ployethersulfone membrane, cellulose triacetate (CTA) high-flux membrane, and synthetic low-flux dialyzer, polymethylmethacrylate (PMMA) membrane were used in 6 months. A new dialyzer was used for each study treatment, and there was no dialyzer reuse. The biocompatibility markers and solutes removal markers were detected repeatedly at different time points. Results: The blood levels of highly sensitive C reactive protein, interleukin (IL)-1β, and interleukin (IL)-13 showed no difference among different groups at al time points. However, the blood complement levels and white blood cell counts were significantly different among three groups. When the dialyzers changed from PS to PMMA membrane, C3a levels and white blood cell counts changed significantly (p < 0.05). Moreover, the changes of C5a levels were significantly different between group CTA and group PMMA in month 3 (p < 0.05). Conclusion: There were much more differences on bio-incompatibility among different dialyzer membranes.     

Dialysis in Rats with Acute Renal Failure: Evaluation of Three Different Dialyzer Membranes

Abstract: Exposure to complement-activating cellulosic dialysis membranes has been claimed to adversely affect the course of acute renal failure (ARF). To test this hypothesis, male Sprague-Dawley rats were allocated to 2 groups: in Group t, ARF was induced by bilateral renal artery clamping whereas in Group 2, animals underwent a sham procedure. In each group, rats were further allocated to undergo hemodialysis with either a Cu-prophan, a Hemophan, or a polyacrylonitrile minidialyzer on Days 4 and 8 after surgery, or no dialysis. Renal function was measured by inulin clearance on the days after dialysis. Additionally, total complement activity (CH₅₀) was estimated on Days 1, 2, 4, and 8, and complement factor C3 was detected immunohistochemically. The degree of renal failure and the rate of recovery of renal function were similar in all the ARF groups irrespective of whether they had undergone dialysis or not, or of the type of the dialysis membrane. Furthermore, there were no significant differences in the course of CH₅₀ or in the amount and distribution of complement factor C3 in the kidney tissue between the rats of Groups 1 and 2. Our findings refute the hypothesis that in ischemic ARF exposure to complement-activating cellulosic dialysis membranes impairs the recovery of renal function in rats.     

Sorbent Membranes: Determination of Sorption Capacity and True Membrane Permeability

Sorbent membranes are designed to meet the requirements for extracorporeal treatment of body fluids. These membranes offer the possibility of combining hemodialysis and hemoperfusion in a single device. Transport of solutes with both sorption and dialysis occurs simultaneously in a sorbent membrane dialyzer. In an effort to determine the sorption capacity and true membrane permeability (by dialysis only) of sorbent membranes, in vitro data were obtained for creatinine. The individual effects of dialysis and sorption on the rate of removal of solutes and their dependence upon flow rate in a sorbent membrane dialyzer were determined from the data of solute vessel concentration vs time. Experiments were carried out with a continuous flow, flat-plate dialyzer and Enka AG sorbent membranes have been selected for evaluation. It was found that sorption plays an important role in the creatinine removal. However, as the time increases, sorption becomes relatively less important and the creatinine removal becomes dominated by dialysis.     

Comparison of Chemical Analyses of Hollow-Fiber Dialyzer Extracts

Hollow-fiber hemodialyzers containing cellulose-based membranes have been shown to produce positive results with the Limulus amebocyte lysate (LAL) test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel-plate and hollow-fiber dialyzers from eight different manufacturers were tested using three lysates and four LAL methods. In addition, four in vitro cellular methods--human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release--were used to evaluate endotoxin activity. The substance causing the reaction was identified using chromatographic methods. Results indicate that the LAL-reactive material is cellulose derived and is not pyrogenic.     

血液透析和腹膜透析患者生存比较

目的 比较血液透析和腹膜透析患者的生存情况,探讨影响透析患者生存的主要危险因素。 方法 研究对象为2005年1月1日至2008年12月31日期间新进入透析且年龄≥18岁患者,随访至2009年3月31日。应用Kaplan-Meier法、log-rank检验及Cox回归模型分析患者的生存资料。 结果 共460例透析患者入选,其中247例起始采用血透治疗,213例起始采用腹透治疗。两组患者的基线资料,包括开始透析年龄、体质量指数（BMI）、估算肾小球滤过率（eGFR）、平均动脉压、进入透析治疗前心脑血管事件、Charlson并发症指数（CCI）等的差异均无统计学意义。中位随访时间为17.9（0.25,51）个月。意向治疗分析结果中,Kaplan-Meier生存曲线显示血透总体生存率优于腹透（P ＜ 0.05,log-rank检验）;透析1年内两组生存率差异无统计学意义（P = 0.14）,而透析1年后腹透患者的生存率显著低于血透患者（P ＜ 0.05）。亚组分析结果显示,≥65岁的非糖尿病肾病血透组生存率显著高于腹透组（P ＜ 0.05）。Cox回归分析显示,经混杂因素调整后,两种透析方式本身对透析生存无明显影响（HR,HD：PD = 0.778,95%CI 0.483~1.254,P = 0.303）;而年龄（HR = 1.051,95%CI 1.030~1.073,P ＜ 0.01）、透前有脑血管意外史（HR = 2.032,95%CI 1.125~3.670,P ＜ 0.05）、透前CCI≥5（HR=2.592,95%CI 1.230~5.465,P ＜ 0.05）、前白蛋白（HR = 0.022,95%CI 0.001~0.768,P ＜ 0.05）为透析患者生存率的主要影响因素。 结论 透析龄≤1年的血透和腹透生存率无显著差异;透析龄>1年的血透患者生存率可能逐渐高于腹透患者。老年非糖尿病患者血透生存率可能高于腹透。年龄、透前脑血管意外史、透前CCI≥5为影响透析生存率的主要危险因素。     

In Vivo Evaluation of Platelet Activation by Different Cellulosic Membranes

Abstract: This study was undertaken to evaluate platelet activation in vivo induced by different cellulosic membranes by measuring the expression of P-selectin on the platelet surface during hemodialysis in 9 uremic patients. Hollow fiber dialyzers of similar surface with different cellulosic membranes (Cuprophan, cellulose acetate, cellulose triacetate, and Hemophan) were evaluated and compared to a synthetic membrane (polysulfone). Blood samples were obtained before hemodialysis and from the efferent and afferent limbs 5 min after the beginning of dialysis. P-select in exposure was evaluated by flow cytometry (FACScan) using a monoclonal antibody (RUU 2.17). The percentage of platelets expressing P-select in before hemodialysis and the percentage from the arterial line during hemodialysis were similar. All membranes evaluated induced platelet activation (estimated as the increase in percentage of platelets expressing P-selectin in samples obtained from the venous line with respect to the arterial line). Cuprophan induced more platelet activation than any other membrane (p < 0.05). The activation induced by cellulose acetate and cellulose triacetate membranes was also higher than that observed with Hemophan (p < 0.05). Hemophan-induced platelet activation was similar to that of polysulfone. These results indicate that all cellulosic membranes induce platelet activation during hemodialysis although there are quantitative differences among them. While Cuprophan induced the highest degree of platelet activation, Hemophan was the only cellulosic membrane that showed a degree of platelet activation similar to the biocompatible membrane polysulfone.     

Sorbent Membranes Used in a Conventional Dialyzer Format

The possibility of installing sorbent membranes into proven dialyzer configurations could result in certain advantages over dialyzers with conventional membranes. A sorbent membrane dialyzer might prove superior in that it allows a higher clearance in the middle molecule molecular weight range, thereby shortening dialysis time and possibly allowing a reduction in the amount of dialysate fluid required. Finally, this device could be used without dialysate if the technician's goal is to eliminate a single substance readily adsorbed by charcoal. For example, this would apply to the treatment of certain intoxications. In vitro data were established for six substances in the molecular weight range of 60 to 5200 daltons and compared to corresponding results for conventional Cuprophan dialyzers. Clinical evaluation of sorbent membrane dialyzers for patients with uremia and intoxication, both with and without use of dialysate, has proven effective with no adverse reactions.     

Prevention of Platelet Deposition and Thrombus Formationon Hemodialysis Membranes: A Double-Blind Randomized Trial of Aspirin and Dipyridamole

Abstract: A double-blind crossover study comparing low-dose aspirin (ASA) and dipyridamole (DPM) (100 mg ASA+75 mg DPM, t.d.s.), high-dose ASA and DPM (300 mg ASA+75 mg DPM, t.d.s.), and placebo on platelet deposition and thrombus formation on hemodialysis membranes was undertaken in 17 long-term dialysis patients. The high-dose combination significantly reduced the fall in platelet count during dialysis and also significantly increased postdialysis heparin concentrations. Scanning electron microscopy of the Cuprophan membranes showed a reduction in platelet desposition and fibrin formation during both treatment schedules, but this was most marked with the high-dose combination. The results of this study indicate that there is a graded response to combined ASA-DPM treatment and that this can significantly reduce platelet consumption and contact activation of fibrin during hemodialysis with Cuprophan membranes.     

Role of Dialyzer Contaminants in the Allergic Epiphenomena of Hemodialysis

Abstract: Cuprophan hollow-fiber dialyzers contain contaminants including 1,2,3-propanetriol, carbohydrates, Limulus amebocyte lysate-reactive material, and particulates. In a clinical study, the role of these substances in the allergic-type response seen in some hemodialysis patients was examined. Patients were dialyzed three times per week for 6-week intervals with each of four dialyzer preparations designed to vary the burden of contaminants presented to the patient. Predialysis eosinophil counts and serum immunoglobulin (Ig) E levels were obtained weekly. White cell and platelet counts and plasma C3a and C5a levels were measured during dialysis for each dialyzer preparation. Dialyzer preparation had no effect on predialysis eosinophil counts or IgE levels. All patients demonstrated transient leukopenia and complement activation during dialysis, the magnitudes of which were unaffected by the type of dialyzer preparation. At the levels found in the dialyzers studied, it was questioned whether water-soluble extractables or particulates play any role in the allergic epiphenomena of hemodialysis.     

腹膜透析生存率及其预后分析

目的 :调查腹膜透析病人的生存率及其独立的预后因素 ,识别病人死亡的高危人群 ,以指导临床治疗。方法 :随诊腹膜透析病人 2 6 8例 ,采用Kaplan -Meirie法分析生存率 ,采用COX模型多变量分析透析前各临床指标对预后的影响。结果 :2 6 8例病人中位数随访时间为 2 6个月 ;1年、2年、3年及 4年总体生存率分别为 85 .6 %、6 7.1%、5 6 .9%及 44 .4% ;经时序检验 ,透析前病人年龄、体重、经济状况、残余尿量、原发病、合并疾病、血红蛋白、血清白蛋白、血清尿素氮、肌酐及血磷浓度对生存率均有影响 (P值均 <0 .0 5 ) ;经COX回归分析 ,透析前病人年龄、血清白蛋白及合并疾病成为独立的预后因素。结论 :我国腹膜透析远期生存率稍低于西方发达国家。根据透析前年龄、血清白蛋白及有无合并疾病 ,可对腹透病人的预后进行初步判断     

Effectiveness of Hemodialysis in Chronic Schizophrenic Patients: A Double-Blind Study

Abstract: Twenty-four chronic schizophrenic patients were treated with active or sham hemodialysis in a double-blind, randomized-group design. Treatment outcomes, as measured by the Schedule for Affective Disorders and Schizophrenia (version PD), are presented. Patients in both active and sham conditions responded to the dialysis process. The research design may have prevented the separation of these groups of responders. Further research is needed to evaluate the effectiveness of hemodialysis on a selected group of schizophrenic patients.     

Effect of Reuse on Dialyzer Efficacy

The effect of reuse on dialyzer efficacy was examined by measuring blood compartment volume and dialyzer mass transfer coefficient (maximum dialyzer clearance) as a function of dialyzer use number. The 102 polysulfone dialyzers tested (F60 and HF80, Fresenius) were reprocessed on Renatron machines using peroxyacetic acid as the dual cleansing and sterilizing agent. Each dialyzer was used an average of 14.4 +/- 5.7SD times and was tested once (twice for 13/102 dialyzers) during a routine dialysis session at an arbitrary use number (7.6 +/- 5.3; range 1 to 24). The parameters tested were found to decrease only marginally with reuse, corresponding to a blood compartment volume loss of approximately 1% (R = 0.04) over a 5-week/15-use period and a decrease in dialyzer mass transfer coefficient of approximately 3% (R = 0.07 and 0.06) over the same period for urea and creatinine, respectively. It was concluded that the loss in dialyzer efficacy is negligible over the average use period of almost 5 weeks per dialyzer.     

Effect of Dialyzer Reprocessing Methods on Complement Activation and Hemodialyzer-Related Symptoms

The effects of different dialyzer processing methods and of reuse on complement activation and dialyzer-related symptoms were studied in 96 maintenance hemodialysis patients. New dialyzers were either unprocessed (Group 1) or machine-washed with bleach and stored in formaldehyde (Group 2). Reused dialyzers were manually cleansed using the combination of bleach and formaldehyde (Group 3), or machine-washed in formaldehyde (Group 4) or peracetic acid (Group 5). Prewashed new dialyzers (Group 2) were associated with greater complement activation during dialysis when compared with unprocessed, new dialyzers (Group 1) (p less than 0.05). Reused, unbleached but formaldehyde-treated or peracetic acid-treated dialyzers (Groups 4 and 5) were associated with reduced complement activation (p less than 0.05). Complement activation was not reduced when bleach was used for reprocessing (Group 3). The percentage of patients without symptoms during dialysis was significantly greater with reused dialyzers than with new dialyzers (Groups 3 through 5 versus Groups 1 and 2; 39 versus 25%; p = 0.035). The severity of total symptoms correlated significantly (p = 0.0004) with complement activation. Our results suggest that total symptoms during dialysis are correlated with the degree of complement activation. However, trends in the data pertaining to chest pain suggest that factors other than complement activation may be important in the pathogenesis of some dialyzer-related symptoms.     

Comparisons of hemodialysis and CAPD in patients over 65 years of age: A meta-analysis

International Urology and Nephrology - This meta-analysis had the aim of studyingthe available studies on comparison betweenHemodialysis and Peritoneal Dialysis in theelderly. The final objective...     

Errors in the Selection of Dialysate Concentrates Cause Severe Metabolic Acidosis During Bicarbonate Hemodialysis

Abstract: Severe metabolic acidosis occurred during bicarbonate hemodialysis as the result of an error made in the selection of the dialysate concentrate. We questioned whether or not it was possible for the dialysis equipment to regulate the proportions in the dialysate fluid using an incorrect dialysate concentrate and still obtain the proper conductivity. We simulated this situation in vitro and found that during bicarbonate dialysis an inappropriately acidic dialysate fluid could replace the normal dialysate with an adequate range of conductivity still being maintained and therefore no triggering of alarms. The investigation showed that the dialysis machines were not adequately adjusted for sensitivity to the concentrates being employed during dialysis. We concluded that dialysis equipment should be fitted with on-line pH meters with alarm systems.     

Growth of children following the initiation of dialysis: a comparison of three dialysis modalities

Maintenance dialysis usually serves as an interim treatment for children with end-stage renal disease (ESRD) until transplantation can take place. Some children, however, may require dialytic support for an extended period of time. Although dialysis improves some of the problems associated with growth failure in ESRD (acidosis, uremia, calcium, and phosphorus imbalance), many children continue to grow poorly. Therefore, three different dialysis modalities, continuous ambulatory peritoneal dialysis (CAPD), cycler/intermittent peritoneal dialysis (CPD), and hemodialysis (HD), were evaluated with regard to their effects on the growth of children initiating dialysis and remaining on that modality for 6–12 months. Growth was best for children undergoing CAPD when compared with the other two modalities with regard to the following growth parameters: incremental height standard deviation score for chronological age [–0.55±2.06 vs. –1.69±1.22 for CPD (P<0.05) and –1.80±1.13 for HD (P<0.05)]; incremental height standard deviation score for bone age [–1.68±1.71 vs. –2.45±1.43 for CPD (P=NS) and –2.03±1.28 for HD (P=NS)]; change in height standard deviation score during the dialysis period [0.00±0.67 vs. –0.15±.29 for CPD (P=NS) and –0.23±.23 for HD (P=NS)]. The reasons why growth appears to be best in children receiving CAPD may be related to its metabolic benefits: lower levels of uremia, as reflected by the blood urea nitrogen [50±12 vs. 69±16 mg/dl for CPD (P<0.5) and 89±17 for HD (P<0.05)], improved metabolic acidosis, as indicated by a higher serum bicarbonate concentration [24±2 mEq/l vs. 22±2 for CPD (P<0.05) and 21±2 for HD (P<0.05)]. In addition, children undergoing CAPD receive significant supplemental calories from the glucose absorbed during dialysis. CAPD, and possibly, other types of prolonged-dwell daily peritoneal dialysis appear to be most beneficial for growth, which may be of particular importance for the smaller child undergoing dialysis while awaiting transplantation.     

血液透析患者应用高通量透析的临床疗效观察

目的 比较高通量透析与低通量透析对透析患者的治疗效果.方法 40例维持性血液透析患者采用自身对照的方法,间断接受高通量透析及低通量透析治疗,总计48周.观察治疗过程中临床症状的改善情况,比较2种透析方式单次透析的效果,以及治疗过程中β2微球蛋白、C反应蛋白、白细胞、血清总补体水平的变化趋势.结果 高通量透析期间临床症状缓解明显,且对β2微球蛋白的清除能力明显优于低通量透析,而对于小分子物质的清除能力比较差异无统计学意义(P＞0.05).治疗过程中患者的C反应蛋白有下降趋势,但无统计学意义(P＞0.05),白细胞、血清总补体水平无明显变化.结论 高通量透析能有效地清除β2微球蛋白,从而改善维持性血液透析患者的临床症状及预后.     

慢性肾衰竭透析住院患者合并感染的临床分析

目的:了解慢性肾衰竭透析住院患者合并感染发生情况,以探讨其感染特点。方法:回顾性调查2004年～2005年间慢性肾衰竭透析患者住院病史,分别收集并统计血液透析和腹膜透析合并感染患者的临床资料。结果:调查透析患者病史400份,合并感染181例次。血透感染患者中肺部感染居首位,占54.9%,真菌、革兰阴性菌为主;其次是血流感染及尿路感染,分别占15%和13.5%,均以革兰阳性菌为主。肺部感染临床情况复杂,血流感染发生大多与临时深静脉插管或永久导管相关,尿路感染中无症状菌尿占多数。腹透患者肺部感染居首位占50.5%,革兰阴性菌居多;其次是腹膜炎占23.2%,以革兰阳性菌为主。且在腹透患者中发现了2例结核感染。两组中复数菌感染和多部位感染均超过20%,且病情严重,预后往往不佳。结论:透析患者合并感染发生率高,感染特点:感染种类及病原菌组成复杂,肺部感染最常见,其次分别为血流感染和腹膜炎。临床医生需高度重视预防并采取有效治疗措施。