腹透原理1HowPDWorks1

1、Min Sun PARK, M.D., Ph. D., Medical Director Baxter Asia Renal,How PD works 1腹透原理 1,内 容,什么是腹膜？ 腹膜透析(peritoneal dialysis, PD)的生理学 尿毒症毒素的清除 液体的清除 钠的清除 PD的准备和实施 PD处方 PD的适应症和禁忌症 自动化腹膜透析（automatic peritoneal dialysis,APD) PD相关并发症 PD的临床预后 怎样建立PD中心?,What is the peritoneal membrane ?关于腹膜,腹膜是被覆于腹腔的光滑浆膜 脏层腹膜

2、壁层腹膜 腹膜凹陷 腹腔和腹膜腔,The mesothelium The interstitium Macrophages/Monocytes Peritoneal capillaries Plays important role water and solute exchange 间皮 间质 巨噬细胞/单核细胞 腹膜毛细血管 在水和溶质的转换中起重要作用,Components of the peritoneum 腹膜的结构,Role of the peritoneum腹膜的功能,Protect peritoneal organs Prevent friction of moving orga

3、ns Host defense mechanisms: Mesothelial cells, monocytesmacrophages, opsonins 支持、保护腹腔脏器 分泌滑液防止脏器移动时的摩擦 宿主的防御机制: 间皮细胞、单核巨噬细胞、调理素,Physiology of peritoneal dialysis 腹透生理学,Goal of Dialysis透析目标,Maintains symptom-free by replacing some of the functions performed by the healthy kidneys. To removes uremic t

4、oxins accumulated in the blood Water Electrolytes Urea, creatinine, phosphate, PTH, etc. H+ 通过部分替代正常肾脏功能减轻肾衰时机体相关症状 清除积聚在血液中的尿毒症毒素 水分 电解质 尿素、肌酐、磷、甲状旁腺素等等 氢离子,The transport of solutes and water across a “membrane” that separates two fluid containing compartments. The blood in the peritoneal capillari

5、es Dialysis solution in the peritoneal cavity 腹膜将下列两种液体分隔，水分和溶质进行跨膜转运 腹膜毛细血管中的血液 腹腔中的透析液,A Basic Concept of Peritoneal Dialysis 腹透基本概念,PERITONEAL TISSUE BLOOD 腹膜组织 血液,Membrane腹膜,PERITONEAL CAVITY DIALYSATE 腹腔 透析液,Membrane model 腹膜模型,Components of the peritoneum as a dialysis membrane腹膜（做为透析膜）的组成,The

6、 mesothelium The stagnant fluid film The interstitium Peritoneal capillaries Stagnant capillary fluid The capillary endothelium itself The endothelial basement membrane 间皮 滞留液体层（阻力） 间质 腹膜毛细血管 毛细血管滞留液体 毛细血管内皮 内皮基底膜,Removal of uremic toxins尿毒症毒素清除,Small solutes Diffusion: Convective transport Middle o

7、r large solutes Peritoneal leak,小分子溶质 弥散 : 对流转运： 中等或大分子溶质 腹膜渗漏,Diffusion 弥散,Definition: Solute movement due to concentration gradient of two solutes between components across a semi-permeable membrane Main driving force for small solute removal Factors involved in diffusion Size of solute Peritoneal

8、 surface area Hydrostatic pressure Electrical charge of solutes 定义: 溶质依靠溶液之间浓度梯度透过半透膜（腹膜）进行的转运 弥散是小分子溶质清除的主要机制 影响弥散的因素 溶质分子的大小 腹膜表面积 静水压 溶质的电负荷,Convective transport 对流转运,Solute transport along with fluid movement High during active ultrafiltration Terms used in convective transport Sieving coefficie

9、nt: Ratio of solute being passed the barrier Reflection coefficient Ratio of solute being rejected by the barrier Sieving coefficient=1-reflection coefficient Factors involved in convective transport Size of solute Electrical charge of solutes,定义：水分转运时伴随的溶质清除 高效超滤过程中对流作用大 对流转运应用的参数 筛选系数（Sieving coef

10、ficient）： 溶质通过膜屏障的比例 反射系数（Reflection coefficient）： 溶质被膜屏障阻挡的比例 筛选系数1反射系数 影响对流转运的因素 溶质分子的大小 溶质的电负荷,Osmotic Ultrafiltration Movement of water from a chamber with lower osmotic pressure to higher one across a semi-permeable membrane 渗透超滤 水分通过半透膜从低渗透压的腔室转移到高渗透压的腔室，静水压和渗透压的矢量和决定水分渗透的方向。,Removal of Water

11、in PD : Crystalloid Osmosis PD水分清除：晶体渗透压,High glucose-High osmolality Peritoneal Space 高糖高渗 腹膜部位,Capillary space 毛细血管 Normal osmolality 正常渗透压,Small pore: 50% 小孔：50,Aquaporin mediated: 50% 水孔蛋白介导：50， （只能使水通过，也叫水通道）,Pathways for Peritoneal Transport 腹膜转运途径,Endothelium 内皮,Capillaries 毛细血管,Peritoneal Ca

12、vity (Dialysate) 腹腔（透析液）,Small solutes 小分子溶质,Glucose 葡萄糖,Macro molecules 大分子溶质,Crystalloidosmosis 晶体渗透压,Colloidosmosis 胶体渗透压,Water 水,Interstitium 间质,Peritoneal tissue layer 腹膜组织层,Ultrafiltration 超滤,腹膜转运机理,小分子依靠弥散作用从毛细血管进入腹膜间质，再进入透析液中 透析液中的葡萄糖借助弥散作用从腹腔进入腹膜间质，加上弥散出来的小分子，使间质晶体渗透压升高，对毛细血管内水分形成超滤，水就从毛细血管

13、移出； 毛细血管中水分的超滤对毛细血管中大分子又产生对流作用，大分子就进入间质，使局部胶体渗透压升高，水被进一步超滤，这样，水和大分子然后分别进入透析液当中； 葡萄糖不断进入间质和毛细血管使渗透梯度下降，水的超滤下降。 通过上述过程，毛细血管内的水被超滤出来，小分子和大分子毒素通过弥散和对流作用也被排出，从而实现水和毒素的清除，同时伴随着透析液葡萄糖被机体摄入。,Solutes from the circulation to dialysis solutions 从血循环到透析液中的溶质,Solutes from dialysis solutions to the circulation 从透

14、析液到血循环的溶质,Protein,Dextrose concentration/osmolality/UF葡萄糖浓度 / 渗透压 / 超滤,The higher the osmotic pressure difference, the higher the ultrafiltration UFR 484 mOsm/L,Ultrafiltration Rate in Different Solutions 不同浓度的超滤率,Ultrafiltration rae (ml/min),-5,0,5,10,15,20,25,30,0,60,120,180,240,300,360,Time, min,

15、3.86% G (n = 25),2.27% G (n = 9),1.36% G (n = 9),Heimbrger et al. Kidney Int 38: 495-506, 1990,Intraperitoneal Dialysate Volume in Different Solutions 不同溶液在腹腔内容量,3.86% G (n=23),0,60,120,180,240,300,360,Time, min,3500,3000,2500,2000,Intraperitoneal dialysate volume, ml,2.27% G (n=9),1.36% G (n=9),Hei

16、mbrger et al. Kidney Int 41: 1320-1332, 1992,Peritoneal UF = water movement associated to permeable solutes through the peritoneal membrane Osmotic pressure = depends on the number of osmotic active moleculesin the solution: 腹膜超滤由渗透压驱动的水的清除方式 渗透压=取决于溶液中渗透活性分子的数量，分晶体和胶体渗透压。,Osmotic crystalloid pressu

17、re (glucose) 晶体渗透压 (葡萄糖),Small molecular weight molecules Fast and important osmotic pressure at start, gradual absorption and decrease of osmotic gradient over time 低分子量分子 开始时渗透压作用快而强，随时间延长逐步吸收，渗透梯度下降,Icodextrin : UF mechanism 艾考糊精的超滤机制,Ultrafiltration pattern 超滤模式,Changes of dialysate osmolality o

18、ver dwell time 透析液留腹期间渗透压的变化,Dwell time, min 留腹时间，分,mOsm/Kg,Peritoneal absorption 腹膜吸收作用,Peritoneal lymphatics constantly drain fluid from the peritoneal cavity. Bulk flow Negatively impact on water and solute removal Increased as increased peritoneal hydrostatic pressure 腹膜淋巴管持续的从腹腔引流液体. 流量巨大 对水分和溶

19、质清除的不利影响 因增加腹膜静水压而增加吸收,Net fluid and solute transport净超滤和溶质转运,Small solute transport Diffusion+convective transport-peritoneal absorption Fluid transport Ultrafilration (either crystaloid or colloid) peritoneal absorption Large and middle molecules Peritoneal leak-peritoneal absorption 小分子溶质的转运 弥散对流

20、转运腹膜吸收 水分转运 超滤(晶体或胶体渗透)腹膜吸收 中、大分子溶质 腹膜渗漏腹膜吸收,Temporal Decline of UF Potential 超滤曲线,CAPD Overnight,APD Daytime,Neg UF,Ho-Dac-Pannekeet et al. Kidney Int 1996;50:979-86; Douma et al. Kidney Int 1998;53:1014-1021; Mujais S et al. Kidney Int 2002; 62(Suppl 81): S17-S22,Time (hrs),Net UF (mL),1.5% dextro

21、se 1.5%葡萄糖透析液,Negative Net UF by Transport Type不同转运类型腹膜的负超滤,Patients With Negative Net UF (%),1Wolfson M et al. J Am Soc Nephrol 2001; 12: 317A. 2Data on file, Baxter Healthcare Corp. (Study RD-97-CA-130),13.4,5.6,20,20,0,0,0,0,Icodextrin vs 2.5% Dextrose in CAPDDwell 12+4h,Sodium removal in PD腹膜透析中

22、钠的清除,Sodium concentration Serum:135-145 mEq/L Dialysis solution : 132 mEq/L Sodium removal Diffusion due to concentration gradient Convective transport along with ultrafiltrate Sodium sieving Water transport: Small pore and aquaporin Sodium transport: Small pore,钠浓度 血清:135-145 mEq/L 透析液 : 132 mEq/L

23、钠清除 依赖浓度梯度的弥散作用 超滤伴随的对流转运 钠筛 水分转运：小孔和水孔蛋白 钠的转运: 小孔,0,100,200,300,400,500,115,120,125,130,135,140,7.5% D,3.86% G,1.36% G,Dialysate sodium, mmol/liter 透析液钠浓度,Time, min 时间，分,Computer Simulations of Dialysate Na Profiles 计算机模拟透析液钠浓度的模式,Rippe and Levin. Kidney Int 57(6): 2546-56, 2000,D/P Sodium Equilibr

24、ation Curve in Different Solutions 不同透析液中透析液/血浆(D/P)钠平衡曲线,0,60,120,180,240,300,360,Time, min,0.80,0.85,0.90,0.95,1.00,D/P Sodium,Heimbrger et al. Nephrol Dial Transplant 9: 47-59, 1994,3.86% G (n=25),2.27%G (n=9),1.36% G (n=9),Overall sodium removal during the dwell留腹期间总钠清除,Dialysate sodium concentr

25、ation decreases due to more water removal than sodium removal during the initial dwell Later in dwell, Na removal is increasing by diffusion as UF lessens and diffusion gradient is wider Therefore, later in dwell, serum Na falls and dialysateNa rises 1.5% dextrose x 4 hrs removes 5 mEq Na 4.25% dext

26、rose x 4 hrs removes c. 70 mEq Na 在留腹初期，因为水分的清除超过钠的清除，透析液中钠的浓度逐渐降低 留腹晚期，随着超滤减少和弥散梯度增加，钠的弥散清除逐渐增加 因此，留腹晚期，血清钠下降而透析液钠增加 1.5% 葡萄糖 x 4 hrs 清除 5 mEq Na 4.25% 葡萄糖 x 4 hrs 清除 c. 70 mEq Na,Na removal during the use of Icodextrin使用艾考糊精时的钠清除,Fluid movement during the dwell with Icodextrin is colloid osmosis and through small pore No sodium sieving: D/P sodium is maintained during t