葡萄糖多聚体新型腹膜透析液的研究进展

腹膜透析已广泛应用于临床,但近年来研究发现使用含葡萄糖的传统腹膜透析液存在许多不利因素,如血中葡萄糖浓度升高、渗透压升高、糖基化终产物的沉积和血管内皮生长因子的大量产生等,均与腹膜超滤衰竭有关.为解决葡萄糖透析液所带来的种种问题,一些新型的腹膜透析液有待研制.葡聚糖即葡萄糖多聚体可替代葡萄糖在透析液中充当渗透剂.它能通过胶体渗透作用产生超滤,甚至能在腹腔高渗的情况下防止透析液重吸收至体循环中.来自于外国一些动物实验和临床实践的数据资料证实使用葡聚糖腹膜透析液的利大于弊.本文就传统腹膜透析液和葡聚糖透析液的透析效应、特征、对腹膜结构和功能影响、代谢、糖负荷、葡聚糖相关腹膜炎、水合作用、超滤等做简要阐述.     

腹膜透析中超滤衰竭的治疗体会

目的:探讨腹膜透析中并发超滤衰竭的防治对策.方法:回顾性总结3例腹膜透析中超滤衰竭患者使用7.5%葡聚糖(Icodextrin)腹透液进行连续性不卧床腹膜透析(CAPD)治疗,并配合使用1.5%(或4.25%)葡萄糖腹透液,使病人恢复超滤,保持每天超滤1 000～1 500 ml.结果:病人水肿都消失,症状好转,观察1～15个月,病情稳定,复查各项生化参数稳定.结论:腹膜透析中超滤衰竭的防治对策:(1)腹膜透析中并发超滤衰竭的原因还不清楚,多于长期透析后出现,提示长时间是一个主要原因.(2)腹膜透析中并发超滤衰竭时,暂停腹膜透析,临时转为血液透析,多数病人腹膜功能能够恢复,是有效治疗方法之一.(3)使用生物相容性好、超滤效果佳的新类型7.5%葡聚糖腹透液进行CAPD治疗,葡聚糖分子量大(20 000 d),葡聚糖腹透液可保持有效渗透压达16 h,超滤效果好,可以改变超滤衰竭病人的治疗效果.(4)在传统的葡萄糖腹透液中添加药物,以期保护腹膜,增加净超滤量.(5)研制生物相容性更好的腹透液是预防腹膜超滤衰竭的关键因素.     

艾考糊精透析液对腹膜透析患者腹膜功能、容量负荷及代谢的影响

葡萄糖透析液是传统上广泛应用的腹膜透析液,在介导腹膜透析超滤、确保腹膜透析治疗成功中发挥重要作用.     

艾考糊精腹透液的临床优势及获益人群

腹膜透析（peritoneal dialysis,PD）是终末期肾病患者替代治疗的方式之一。以葡萄糖为渗透剂的传统腹膜透析液（腹透液）安全、有效的特性已被广泛接受,但由于葡萄糖相对分子质量较小,进入腹腔后易被吸收,难以维持较长时间的渗透梯度而致超滤下降,且生物相容性较差,长期使用可导致腹膜结构和功能的改变。艾考糊精是一...     

持续非卧床腹膜透析患者退出原因临床分析

目的 通过对腹膜透析病人退出原因的分析，探讨防治对策。方法 回顾11年来因慢性肾功能衰竭行腹膜透析的病人83例，统计其退出病例并分析原因。结果 共有31例病人退出腹膜透析。占37．3％。主要原因为腹膜炎(48．4％)。超滤衰竭(25．8％)，透析液引流不畅(19．4％)。结论腹膜炎和超滤衰竭是退出腹膜透析的重要原因。应注意严格无菌操作。尽早控制感染。限制水盐摄入，制定个体化透析处方。     

中医药防治腹膜透析相关性腹膜纤维化研究进展

腹膜透析患者由于长期使用葡萄糖透析液、腹膜炎等因素,可导致腹膜纤维化的发生,限制了该治疗方式在临床的使用。中医药防治腹膜纤维化具有广阔的应用前景,在实验及临床研究方面都取得了一定的成果。本文对近来中医药在防治腹膜透析相关性腹膜纤维化的研究进行综述,以期为更好的开展中医药防治腹膜透析相关性腹膜纤维化提供参考。     

腹膜超滤衰竭的危险因素及防治进展

正超滤衰竭(ultrafiltration failure,UFF)导致的液体超负荷及溶质清除率下降是腹膜透析(peritoneal dialysis,PD)技术失败的主要原因之一。UFF根据其病理生理机制可分为4型,Ⅰ型UFF其特点是腹膜对溶质呈高转运特性,腹腔中葡萄糖吸收增快,腹腔内有效渗透压梯度维持时间短,腹膜的超滤能力降低;     

腹膜透析患者腹膜转运功能的影响因素及其维护

腹膜透析是终末期肾脏病患者的重要替代治疗方式,尽管其短期技术存活率较好,但长期治疗后导致的超滤衰竭,仍然是退出治疗的主要原因。葡萄糖透析液所致的腹膜功能下降与其血管增生和腹膜纤维化密切相关,但是糖尿病、尿毒症毒素、药物、腹膜炎、残余肾功能等诸多因素也影响着腹膜的属性。现就相关的影响因素及其可能的干预方法进行综述。     

艾考糊精透析液治疗腹膜透析相关性腹膜炎3例及文献复习

腹膜透析(腹透)相关性腹膜炎是腹透的并发症之一, 严重影响腹透患者预后。腹膜炎期间, 由于腹膜毛细血管扩张等因素, 腹透患者可发生溶质转运增加及超滤下降等表现。艾考糊精透析液具有超滤功能持久、保护腹膜功能、不含葡萄糖及低葡萄糖降解产物等优势。我们在国内首次报告于艾考糊精透析液中加入经验性抗生素治疗腹透相关性腹膜炎3例, 以初步评估艾考糊精透析液在腹透相关性腹膜炎治疗中的作用, 为临床决策提供依据。     

尿毒症腹膜透析患者腹膜纤维化防治的新靶点：上皮间质转化

慢性肾脏病发病率呈逐年上升趋势，其中约有5％以上的病人将进入终末期肾衰竭，需接受肾脏替代治疗。全世界面临透析病人预计至2010年将增至200余万，而其中约20％左右的患者选择腹膜透析。2006年8月我国腹膜透析病人数约为9000人左右，虽然腹膜透析技术不断改进，但在1～4年内，仍有约3％～36％的病人出现腹膜超滤衰竭（ultrafiltration failure，UFF）。而腹膜纤维化是导致腹膜超滤衰竭的主要原因，与以下多种因素有关：（1）腹膜透析液的高糖及其降解产物和高渗透压、低PH值等生物不相容性因素；（2）反复腹腔感染导致腹膜损伤，使腹膜间皮细胞裸露，促进新生血管形成；     

Current concepts in peritoneal dialysis

Peritoneal dialysis has been increasingly employed to treat patients with end-stage renal failure. Solute transport can be enhanced by increasing ultrafiltration with hypertonic dialysate, infusing intraperitoneal vasodilators to increase the effective surface area for exchange, and by employing new methods of dialysate delivery which may improve dialysate mixing and decrease the effective membrane resistance to solute flux. While infection remains a major complication of peritoneal dialysis, techniques to prevent and treat infections have been effectively employed. Progress has also been made in the treatment of diabetic patients with peritoneal dialysis. Continuous ambulatory peritoneal dialysis, a relatively new technique with fast growing clinical application, may be the therapy of choice for many patients with end-stage renal failure.     

川芎嗪对慢性腹膜透析大鼠腹膜功能及间皮细胞形态的影响

目的 探讨不同剂量的川芎嗪对高糖透析液作用下慢性大鼠腹膜透析（腹透）模型腹膜间皮细胞的形态和功能的影响及它们之间的关系。方法 ４０只ＳＤ大鼠随机分为４．２５％腹透液（ＨＧ组）、４．２５％腹透液＋４０ｍｇ／Ｌ川芎嗪（ＨＧＬ组）、４．２５％腹透液＋１６０ｍｇ／Ｌ川芎嗪（ＨＧＨ组）、对照组。除对照组外,余３组每天分别腹腔内注入２０ｍｌ含不同剂量川芎嗪的４．２５％透析液［０（ＨＧ）、４０ｍｇ／Ｌ（ＨＧＬ）     

Peritoneal physiology--impact on solute and fluid clearance

A review is given on the physiology of peritoneal transport of solutes and fluid during peritoneal dialysis. Transport of low molecular weight solutes is dependent on the drained dialysate volume and the vascular peritoneal surface area. The transport of macromolecules is not only dependent on the surface area but progressively hindered the higher their molecular weight. Transport of solutes from the peritoneal cavity always exceeds transport in the other direction, caused by uptake in the lymphatics and the interstitium. Fluid transport is governed by transcapillary ultrafiltration and lymphatic absorption. The former is partly through aquaoporins when glucose-based dialysis solutions are used. The causes of ultrafiltration failure are reviewed, and the effects of the magnitude of the vascular peritoneal surface area on solute clearances and ultrafiltration, using various osmotic agents, are discussed.     

Histomorphological and functional changes of the peritoneal membrane during long-term peritoneal dialysis

In long-term peritoneal dialysis (PD) morphological and functional changes of the peritoneal membrane are common. Sub-mesothelial fibrosis, angiogenesis and vasculopathy are typical histomorphological alterations of the peritoneal membrane, which, to a certain degree, are induced by uremia and recurrent peritonitis. The most important causative factor, however, represents the chronic exposure to PD solutions. Glucose, glucose degradation products and advanced glycation end-products (AGEs) via different pathways induce inflammation, fibrosis and angiogenesis. As a functional consequence ultrafiltration failure due to peritoneal hyperpermeability and an increased effective peritoneal surface area represents a major clinical problem. An insufficient function of the water-selective aquaporin 1 (AQP-1) channel may also be causative for inadequate ultrafiltration. A rare but life-threatening complication of long-term PD is encapsulating peritoneal sclerosis (EPS). For both impaired AQP-1 function and EPS, the long-term effects of PD fluids are believed to be responsible, even though the mechanisms are not yet understood. The avoidance of glucose and modern PD fluids with fewer glucose degradation products, as well as first pharmacological attempts may help to preserve the peritoneal membrane in the long term.     

Effect of phosphatidylcholine on ultrafiltration in patients on continuous ambulatory peritoneal dialysis

Oral phosphatidylcholine at 900 mg/day was given to 4 patients with high lymph absorption for 8 weeks. Fluid and solute transfer before and after treatment were compared to 4 similar controls given placebo. None of the patients had overt ultrafiltration problems. After treatment, overnight peritoneal effluent phospholipid content did not change significantly. Ultrafiltration as well as solute and glucose transfer remained unchanged at the end of 8 weeks. A controlled trial on patients with overt ultrafiltration problems for a longer duration is required to further elucidate the role of phosphatidylcholine supplementation in patients on continuous ambulatory peritoneal dialysis.     

Effect of glucose on intercellular junctions of cultured human peritoneal mesothelial cells

During continuous ambulatory peritoneal dialysis, the peritoneum is directly and continuously exposed to unphysiologic peritoneal dialysis fluid; the resulting mesothelial damage has been suggested to cause loss of ultrafiltration and dialysis efficacy. The present study investigated the effect of a high glucose concentration on cultured human peritoneal mesothelial cells to clarify the cause of decreased dialysis efficacy during prolonged peritoneal dialysis. High glucose caused a concentration-dependent decrease in cell proliferation, damage to the intercellular junctions, and excess production of transforming growth factor-beta (TGF-beta). The levels of intercellular junctional proteins (ZO-1, E-cadherin, and beta-catenin) were decreased, and immuno-staining by anti-ZO-1 and anti- beta-catenin antibodies became weaker and often discontinuous along the cell contour. Mannitol had similar but weaker effects at the same osmolality, and an anti-TGF-beta neutralizing antibody reduced the effects of high glucose. Therefore, these effects were induced not only by glucose itself but also by hyperosmolality and by a glucose-induced increase of TGF-beta. These findings suggest that the peritoneal mesothelium is damaged by prolonged peritoneal dialysis using high glucose dialysate and that impairment of the intercellular junctions of peritoneal mesothelial cells by high glucose dialysate induces peritoneal hyperpermeability and a progressive reduction in dialysis efficacy.     

Peritoneal fluid and solute transport: influence of treatment time, peritoneal dialysis modality, and peritonitis incidence

The integrity of the peritoneal membrane in peritoneal dialysis (PD) is of major importance for adequate dialysis and fluid balance. However, alterations in peritoneal fluid transport, such as ultrafiltration failure, often develop during long-term PD. To investigate peritoneal solute and fluid transport and to analyze the influence of treatment time, peritonitis incidence, and PD modality (continuous ambulatory PD [CAPD] or automated PD [APD]), a cross-sectional study with an extended peritoneal transport test that used dextran 70 in 2 L of glucose was performed in 23 nonselected chronic PD patients. Compared were long-term (>40 mo) with short-term PD patients (<40 mo), CAPD with APD patients, and those with a peritonitis incidence of >0.25/yr to those with an incidence of <0.25/yr. Dialysate/plasma (D/P) ratio and mass transfer area coefficient of creatinine, lymphatic absorption rate (LAR), transcapillary ultrafiltration, and effective ultrafiltration were measured. Long-term PD patients had higher D/P ratio of creatinine (73.5 +/- 2.3% versus 65.9 +/- 2.2%; P < 0.01) and higher LAR (243 +/- 69 ml/4 h versus 96 +/- 31 ml/4 h; P < 0.03), both resulting in lower effective ultrafiltration (242 +/- 35 ml/4 h versus 324 +/- 30 ml/4 h; P < 0.05). D/P ratio (r = 0.66) and LAR (r = 0.67) were positively correlated to PD duration. Patients on APD compared with those on CAPD and patients with a history of peritonitis compared with those without did not differ in terms of D/P ratio, mass transfer area coefficient, LAR, transcapillary ultrafiltration, and effective ultrafiltration. Lower ultrafiltration after long-term PD is both the result of increased small solute transport and increased lymphatic absorption. APD or CAPD modality and peritonitis incidence do not have a significant influence on small solute transport or fluid kinetics.     

High peritoneal residual volume decreases the efficiency of peritoneal dialysis

BACKGROUND: Wide variation in peritoneal residual volume (PRV) is a common clinical observation. High PRV has been used in both continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis to minimize the time of a dry peritoneal cavity and to achieve better dialysis. However, the impact of PRV on peritoneal transport is not well established. In this study, we investigated the effect of PRV on peritoneal transport characteristics. METHODS: Peritoneal effluents were collected in 32 male Sprague-Dawley rats after a five-hour dwell with 1.36% glucose solution. Forty-eight hours later, a four hour dwell using 25 ml of 3.86% glucose solution and frequent dialysate and blood sampling was done in each rat with 125I-albumin as a volume marker. Before the infusion of the 3.86% glucose solution, 0 (control), 3, 6, or 12 ml (8 rats in each group) of autologous effluent (serving as PRV) was infused to the peritoneal cavity. RESULTS: After subtracting the PRV, the net ultrafiltration was significantly lower in the PRV groups as compared with the control group: 13.4 +/- 0.5, 12.0 +/- 1.0, 11.7 +/- 1.7, and 8.9 +/- 0.4 ml for 0, 3, 6, and 12 ml PRV groups, respectively (P < 0.001). The lower net ultrafiltration associated with higher PRV was due to (a) a significantly lower transcapillary ultrafiltration rate (Qu) caused by a lower osmotic gradient, and (b) a significantly higher peritoneal fluid absorption rate (KE) caused by an increased intraperitoneal hydrostatic pressure. No significant differences were found in the diffusive mass transport coefficient for small solutes (glucose, urea, sodium, and potassium) and total protein, although the dialysate over plasma concentration ratios values were higher in the high-PRV groups. The sodium removal was significantly lower in the PRV groups as compared with the control group (P < 0.01). CONCLUSION: Our results suggest that a high PRV may decrease net ultrafiltration through decreasing the Qu, which is caused by a decreased dialysate osmolality, and increasing the KE caused by an increased intraperitoneal hydrostatic pressure. The high volume of PRV also decreased the solute diffusion gradient and decreased peritoneal small solute clearances, particularly for sodium. Therefore, a high PRV may compromise the efficiency of dialysis with a glucose solution.     

Predictors of a favourable response to icodextrin in peritoneal dialysis patients with ultrafiltration failure

BACKGROUND AND AIMS: Icodextrin is a starch-derived glucose polymer that causes sustained ultrafiltration in long dwells in peritoneal dialysis. The aim of this study was to assess factors that were predictive of an increment in ultrafiltration following the introduction of icodextrin in patients with refractory fluid overload. METHODS: Thirty-nine patients (20 male/19 female, mean age 57.7 +/- 2.4 years) on peritoneal dialysis were enrolled in a prospective pretest/post-test, open-label study. All patients had symptomatic fluid overload refractory to fluid restriction (<800 mL/day), frusemide doses of 250 mg or more daily, optimization of dwell time and use of hypertonic dextrose. An icodextrin exchange was substituted for a 4.25% dextrose exchange for the long-dwell period. RESULTS: After 1 month, median (interquartile range) 24 h ultrafiltration volume increased by 500 mL (interquartile range: 50-1000). An increase in ultrafiltration volume correlated positively with the dialyate : plasma creatinine ratio at 4 h (r = 0.498, P = 0.001) and negatively with the ratio of dialysate glucose concentrations at 4 and 0 h (r = -0.464, P = 0.003). On multivariate regression analysis, high transporter status was predictive of a greater ultrafiltration response to icodextrin relative to dextrose peritoneal dialysis exchanges. Age, sex, race, peritoneal dialysis duration, peritoneal dialysis modality, diabetes mellitus, baseline albumin, and baseline ultrafiltration volume were not significantly correlated with the change in ultrafiltration volume. CONCLUSION: Icodextrin significantly augments ultrafiltration volumes in patients with refractory fluid overload. A high peritoneal membrane transporter status is the best predictor of a favourable ultrafiltration response to icodextrin.     

The peritoneal equilibration test in children

Eight children, aged 15 months to 17 years 9 months, maintained by continuous ambulatory peritoneal dialysis (CAPD)/continuous cycling peritoneal dialysis and nine adults, aged 20–59 years, managed by CAPD were compared using a standardized peritoneal dialysis protocol, the peritoneal equilibration test (PET). The peritoncal glucose concentration tended to equilibrate with the serum glucose more rapidly in children, but the percentage of the glucose load absorbed was not different between the two age groups. There was an inverse trend between the percentage of glucose absorbed and age in children. Peritoneal creatinine clearance scaled to surface area in children was significantly less than that of the adults; however, the clearances became similar when adjusted for body weight. Peritoneal creatinine clearace scaled to surface area bore a positive and significant relationship to age which, when expressed per kilogram body weight, disappeared. Children had a significantly higher dialysate/plasma (D.P) creatinine ratio after the first 2 h of the PET, but this ratio approached unity by 4 and was not different from adults. The fractional change in the creatinine D/P ratio during the PET was not different between the two age groups. Drain volume adjusted to surface area was significantly less in children than adults. This difference was reversed when drain volume was factored by weight. Similarly drain volume scaled to surface area demonstrated a significant and positive relationship to age, which disappeared when drain volume was expressed per kilogram body weight. Ultrafiltration, whether factored by weight or scaled to surface area, did not differ between the two groups. The post-PEt residual volume corrected for body weight was significantly larger in the children, but bore no relationship to age. It is possible that this larger residual volume in children functions as a tidal volume enhancing solute equilibration.