慢性肾功能衰竭患者细胞内外氨基酸水平的改变

目的观察游离氨基酸在正常人体细胞内外液中的浓度及其在慢性肾功能衰竭(CRF)时的代谢变化.方法对15例CRF患者和10例健康志愿者的血浆、红细胞内、骨骼肌细胞内的游离氨基酸浓度进行了比较.结果正常人体红细胞内天冬氨酸(Asp)、谷氨酸(Glu)和丝氨酸(Ser)浓度较血浆内高(P＜0.05),而胱氨酸(Cys)、精氨酸(Arg)和蛋氨酸(Met)浓度较血浆内低(P＜0.05),其余大多数游离氨基酸浓度与血浆基本一致;骨骼肌细胞内游离氨基酸浓度普遍较高.CRF时血浆中缬氨酸(Val)、亮氨酸(Leu)、异亮氨酸(Ile)、赖氨酸(Lys)、苏氨酸(Thr)、苯丙氨酸(Phe)、Ser、Cys、酪氨酸(Tyr)浓度和红细胞内Val、Tvr浓度明显降低(P＜0.05),而部分非必需氨基酸浓度升高;骨骼肌细胞内除Val、Thr、Lys浓度降低(P＜0.05)外余变化不显著.结论正常人体血浆、红细胞、骨骼肌细胞内游离氨基酸浓度不完全相同;CRF时这3种介质中的游离氨基酸代谢均发生改变,主要表现为一些必需氨基酸浓度明显降低,然而降低的幅度3者并不平行.     

钠与超滤模式对血液透析中低血压的作用

目的比较线性钠模式(SP)、线性超滤模式(UP)、线性钠和线性超滤结合模式(SP UP)与标准透析(SD)在透析过程中症状性低血压的发生情况。方法12例稳定血透患者,SD、SP、UP、SP UP各进行10次,监测透析过程中相对血容量(RBV)、平均动脉压(MAP)、心率(HR)、下腔静脉宽度(IVCD)、心排血量(CO)、每搏输出量(SV)、血钠、血浆渗透浓度的变化及发生症状性低血压的例次。结果(1)4种模式透前IVCD、MAP、HR、体重、透析过程中钠清除量、超滤量无明显差异。(2)SP UP发生症状性低血压的例次显著低于其他3种模式。(3)SP UP在透析4、5h时RBV值高于SD、SP、UP(P<0.01)。(4)SD、SP、UP透析4h时MAP明显低于SP UP(P<0.05);透析5h时HR明显高于SP UP(P<0.01)。(5)UP在透析3h时SV低于其他3种模式(P<0.05),CO较透前降低(P<0.05)。(6)透析1h时SP及SP UP的血钠、血浆渗透浓度明显高于SD、UP。结论在钠清除量大致相等情况下,SP UP比SD、SP、UP具有较好维持血容量作用,可显著减少症状性低血压的发生。     

调整透析流钠浓度和超滤方式对血液透析低血压的预防

目的 评价血容量监测结合可调钠曲线，可调超滤曲线对透析相关性低血压发生的预防作用。方法 维持性血透患者10例。治疗组采用容量监测结合可调钠曲线，可调超滤曲线治疗方案。对照组为血容量监测结合常规血透自身对照。观察治疗过程血容量变化（△BV），血压情况，透析前后血钠水平，透析间期体重增加及口渴感。结果 治疗组低血压发生率显著降低（P＜0．01）；超滤前后血容量变化与超滤量明显相关（r=0.4883)；两组透析前后血钠水平无显著性差异，治疗组透析间期口渴感无明显加重。结论 血容量监测结合可调钠曲线，可调超滤曲线治疗能有效预防透析相关性低血压的发生，并减少了传统单纯高钠透析所带来的副作用，血容量监测有助于确定干体重。     

不同超滤量对高通量血液透析尿毒症毒素清除的影响

目的 探讨高通量血液透析（HFHD）在不同超滤量时对尿毒症毒素清除的影响以及与低通量血液透析（LFHD）和血液透析滤过（HDF）清除效果比较.方法 从本院在透200多例维持性血液透析患者中选取符合入选标准75例,随机分成5组（HFHD2L组,HFHD4L组,HFHD6L组,LFHD组,HDF组）,每组15例.于透析上、下机前抽取静脉血送检小分子尿毒症毒素（简称小分子毒素,以下相同,包括UREA,Cr和P）、大分子尿毒症毒素（简称中大分子毒素,包括Hcy,β2-MG和iPTH）和血浆蛋白质（包括ALB和CRP）等,并计算各自的下降率.同时,留取透析液做细菌培养和内毒素检测,记录患者透析时出现的并发症.结果 五种透析方式对小中大分子尿毒素及血浆蛋白质的清除（下降率）比较：小分子毒素＞中大分子毒素,差异有非常显著性意义（P＜0.01）,对血浆蛋白质没有清除（下降率为负值）.组间比较：LFHD、HF-HD、HDF对小分子毒素的清除（下降率）达60％以上,三者之间差异无统计学意义（P＞0.05）;对中大分子毒素的清除（下降率）存在较大的区别,HDF＞ HFHD＞ LFHD.HFHD组三组内比较：中大分子毒素清除（下降率）随透析超滤量的增加呈下降趋势,但是这种差异无统计学意义（P＞0.05）.不良反应以LFHD发生病例数最多.HFHD和HDF病例数区别不大.结论 HFHD治疗优势主要在于对中大分子毒素的清除明显优于LFHD,稍逊于HDF.但其价格低廉,经济实惠,可长期使用.对中大分子毒素的清除也不必刻意的通过增加透析超滤量来提高透析器的清除率.注意超纯透析用水和透析液的应用.     

以葡萄糖测定细胞外液的研究

目的：对葡萄糖作为标记物测定细胞外液容量的方法进行临床可行性研究。方法：１７例择期病人分成两组：一组７例，于５１分钟内静脉持续输入葡萄糖０．８ｇ／ｋｇ；另一组为１０例，在１分钟内静脉注射５０％葡萄糖２０ｇ，两组分别在使用葡萄糖前、使用后第５、１０、１５、２０、２５、３０、４５、６０、９０、１２０分钟时取动血１ｍｌ，测定血糖浓度。结果：两组病人的血糖浓度，在停用葡萄糖后均似呈双指数曲一下降。经计算Ｂ     

超滤模式与透析液温度个体化在血液透析中的应用

透析中低血压严重影响患者脏器供血。使病死率大大增加，而严重高血压是导致脑血管病发生的危险因素．因此透析中血压的管理非常重要。本中心通过个体化调节超滤模式及透析液温度，使透析中严重高低血压发生率明显降低。     

血液透析过程中单个核细胞的激活及影响

维持性血液透析的患者合并的一些并发症与透析过程中单个核细胞激活产生细胞因子有关。其中透析膜的生物特性、特性膜激活补体的能力，以及透析液中内毒素进入血液循环是影响单个核细胞激活的主要因素。测定单个核细胞激活的方法较多，但目前尚无一种大家都认可的方法，有待进一步研究。     

The role of plasma volume and fluid overload in the tolerance to ultrafiltration and hypotension in hemodialysis patients

IntroductionUltrafiltration (UF) in hemodialysis (HD) patients is accompanied by irregular falls in plasma volume (PV) and blood pressure (BP).MethodsWe obtained in 321 patients (large cohort), body weight (BW), BP, samples of blood to determine hemoglobin (Hb) and hematocrit (Ht), Pre and Post HD. We estimated the % variation of the PV and its effect on the BP. In a small cohort of 38/321 patients, arterial blood was drawn Pre and Post HD and at 2, 48, and 72 h to determined Hb and Ht and % variation of the PV. Bio-impedance spectroscopy (BIS) was performed, in the same times, to estimate: dry weight (DW), total body water (TBW), extracellular water (ECW), Fluid overload (FO) and phase angle (PhA).ResultsWe divided our large cohort in two groups. The Hypotensive group with a fall equal or more than 20 mmHg (96/321,30%) and Normotensive group with a drop equal or less than 19 mmHg (225/321,70%). The UF was 2.73 ± 0.72 L in the Hypotensive group and 2.53 ± 0.85 L in the Normotensive group (p < 0.0001). The % PV was −11.7 ± 17.8 in the Hypotensive group and −8.53 ± 10.07 in the Normotensive group (p < 0.0001). The systolic blood pressure (SBP) correlated with the % change of the PV (r = -0.232; p < 0.0001). The FO was contrasted with the % of water removed by UF (r = -0.890; p < 0.0001).ConclusionThe SBP drop was secondary to the fall in the PV after UF. The FO was irregular and modulates in part the fall in the SBP.     

Fluid volumes determination by impedance spectroscopy and hematocrit monitoring: application to pediatric hemodialysis

A method for extracting fluid volumes from multifrequency bioimpedance, which takes into account the body geometry and the presence of nonconducting elements, was tested on 12 young dialyzed patients against correlations for total body water volumes (TBW) from Watson et al. and Humes et al. Our calculations of TBW from impedance were found to overestimate Humes' values by 0.25 L (0.8%) postdialysis and by 2.08 L (6.5%) predialysis. Extracellular water (ECW) was found to contribute an average of 93% of ultrafiltered volume. Intracellular water volume (ICW) determination from impedance was found to be too imprecise to predict its variation during dialysis; therefore, ICW variations were calculated as the difference between ultrafiltration and ECW changes. The continuous recording of hematocrit by an optical device monitored changes in plasma and interstitial volumes. In most cases, ultrafiltration was compensated mainly by a contribution from interstitial fluid, and the drop in plasma volume was generally moderate.     

Relationship between ultrafiltration rate and cardiovascular death in maintenance hemodialysis patients

Objective To investigate the relationship between ultrafiltration rate (UFR) and cardiovascular death in maintenance hemodialysis patients. Methods This retrospective study observed adult hemodialysis patients treated in Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University during January 2010 to December 2015 and the follow-up were finished at April 2017. Patients were averagely divided into 3 groups according to their UFR. Their clinic characteristics were collected, the survival rate and death related factors were analyzed by Kaplan-Meier (Log-rank test) method and Logistic regression. Results Totally 2184 patients (male 1370, 62.7%) were enrolled, the age was 53.39±16.47. The UFR was (8.88±3.05) ml?h-1?kg-1. During the 7 years' follow-up, 168 patients died, of whom 58 cases (34.5%) died due to the cardiovascular events. Chi-square test showed that there were significant differences in death causes among the high, middle and low UFR group (χ2=12.584, P＜0.01), and the mortality rate of cardiovascular events in high UFR group was significantly higher than that in low (χ2=10.861, P= 0.010) and middle UFR group ( χ2=4.671, P=0.031). Kaplan-Meier survival curve showed that the difference of the survival rates in the 3 groups was statistically significant (Log-rank test χ2=23.394, P＜0.001). Cox regression analysis showed that high UFR (UFR≥10.95 ml?h-1?kg-1), old age (＞60 years old), and low left ventricular ejection fraction (LVEF, ≤50%) were independent risk factors of cardiovascular death. Conclusions High UFR level, old age and low LVEF are independent risk factors of cardiovascular death in hemodialysis patients. Maintaining low UFR level is beneficial to reduce cardiovascular mortality in hemodialysis patients.     

生物电阻抗频谱法分析血液透析患者体液分布异常及其对血压的影响

目的了解血液透析(HD)患者透析前后体液的分布状况及其对血压的影响。方法106例健康志愿者作为正常对照,按性别分为组用生物电阻抗频谱法检测并计算细胞外2,液(ECV)、细胞内液(ICV)占体重的百分比(ECV%、ICV%)和ECV/ICV比值。选择我院透析龄月2以上的稳定HD患者67例,按照透析前后血压状况将患者分为低血压倾向组、正常血压组、普通高血压组和顽固性高血压组,分别于透析前和透析后测量体重、ECV、ICV,并计算ECV%、ICV%和ECV/ICV比值。ECV、ICV采用电生物阻抗分析仪测定。结果HD患者ECV%、ECV/ICV透后较透前下降,而ICV%上升;透前ECV%、ECV/ICV明显高于正常对照,透后接近正常人群水平。顽固性高血压患者(均为男性)透后ECV%仍明显高于正常对照水平[(31.6±1.0)%比(25.3±1.6)%,P<0.01],而低血压倾向患者均为女性在透析前()ECV%即与正常对照水平无明显差异[(21.6±1.5)%比(22.6±1.4)%,P>0.05],透后明显低于正常对照水平[(19.3±1.6)%比(22.6±1.4)%,P<0.01]。结论HD患者水分布与正常人相比存在着明显不同,表现为ECV%增加和ICV%减少,而血液透析通过脱水和水分向细胞内转移部分纠正了这种异常。ECV%反映了HD患者水负荷的情况,并与血压之间存在着密切的关系。     

Bacteria and endotoxin removal from bicarbonate dialysis fluids for use in conventional, high-efficiency, and high-flux hemodialysis

The use of bicarbonate-based dialysis fluids in hemodialysis centers in the United States has increased with the advent of high-efficiency and high-flux hemodialysis. However, bicarbonate dialysis fluids can support rapid bacterial growth and high endotoxin concentrations. This study determined the efficacy of an ultrafiltration device in reducing the bacterial and endotoxin concentrations in bicarbonate dialysis fluids. A polysulfone hollow fiber dialyzer was used to ultrafilter bicarbonate concentrate before entering the central proportioner and bicarbonate dialysate after exiting the proportioner in single patient dialysis machines. Pre- and post-ultrafilter samples were collected for bacterial and endotoxin assays over 10 months. Ultrafiltration of bicarbonate concentrate reduced bacterial and endotoxin concentrations from 288,330 colony forming units (CFU)/ml and 42,804 pg/ml to 0.47 CFU/ml and 109 pg/ml, respectively. Ultrafiltration of the dialysate in single patient systems decreased bacterial and endotoxin concentrations from 15,889 CFU/ml and 1,746 pg/ml to 0.003 CFU/ml and 0.109 pg/ml, respectively. These results demonstrate that ultrafiltration of bicarbonate dialysis fluids is effective in reducing bacterial and endotoxin contamination inherently associated with the use of bicarbonate-based dialysates.     

Pulse push/pull hemodialysis: in vitro study on new dialysis modality with higher convective efficiency

Abstract:  Midsize molecule retention is related with renal-failure-associated mortality. Here, the authors describe a new dialysis modality, pulse push/pull hemodialysis (PPPHD), which increases convective clearance. Blood and dialysate are circulated by a pulsatile pump, but with pulsatile flow patterns that are 180° out of phase. This causes blood-to-dialysate pressure gradients that oscillate between positive and negative, and which cause consecutive periods of ultrafiltration and backfiltration. The devised PPPHD was compared with conventional high-flux hemodialysis (CHFHD) in terms of solute clearances, albumin loss, and total protein levels. Human plasma containing dissolved uremic marker molecules was used as a blood substitute, and clearances were investigated for blood urea nitrogen, creatinine, vitamin B12, and inulin. Observed clearances were found to be significantly higher for PPPHD by approximately 3–14% for low-molecular-weight solutes, by 47–48% for vitamin B12, and by 38–49% for inulin than for CHFHD. No albumin loss was observed in either of these two study groups. The authors conclude that PPPHD offers a simple straightforward means of enhancing uremic molecule removal by increasing total ultrafiltration volume without the need to infuse replacement fluid.     

重症急性胰腺炎体液隔离病理生理特点的分析

目的 分析重症急性胰腺炎(SAP)体液隔离的病理生理特点.方法 回顾性分析新疆医科大学第一附属医院1995年1月至2000年1月53例SAP病人.按治疗结果分为早期死亡、晚期死亡、治愈3个组;统计3组入院后的前3d总人、出量和体液隔离量以及治疗48h前后3组红细胞压积(HCT)的变化.结果 ①早期死亡组和晚期死亡组体液隔离持续48h以上,早期死亡组、晚期死亡组和治愈组在48h体液隔离量分别为(10078.3±1616.2)ml、(6124.4±1081.1)ml和(4719.7±1397.7)ml,3组相比差异有显著性(P＜O.05);②治疗前HCT均高于正常值,治疗48h后3组HCT均下降,分别为(32.6±8.3)%、(37.5±4.1)%和(40.0±4.3)%,早期死亡组低于正常值范围,其中早期死亡组与治愈组相比差异有显著性(P＜O.05).结论 体液隔离并不是简单的体液丢失,其病理生理特点是细胞外液病理性再分布和细胞外液的液体量增加,尤其是组织间隙的液体量增加;而在量大时不仅有上述特点,血管内也存在体液隔离,导致容量负荷增加.