腹膜透析清除钠的相关因素分析及其临床意义

目的揭示腹膜透析患者钠清除的相关因素。方法 156例维持性腹膜透析患者,行改良腹膜平衡试验和透析充分性检查,对结果做多元线性回归分析。结果揭示了腹膜对钠清除的影响因素有透析剂量、每日净超滤量、血钠与新鲜透析液钠浓度差值和钠沉降率,总钠清除的影响因素有每日净超滤量、每日尿量、血钠与新鲜透析液钠浓度差值和钠沉降率。多元线性回归分析显示有显著相关性(P<0.01)。结论使用传统的腹膜透析液和足够的液体清除量是保证足够的钠清除量的最重要条件;使用低钠透析液应该是解决钠潴留的有效办法;评价透析充分性应包含钠清除的指标。     

用动力学模型定量分析低钠透析液对钠清除量的影响

目的　定量地分析低钠透析液对钠清除量的影响以便为临床减少钠潴留的发生提供策略。方法　我们依据三孔模型 ,建立了单次透析过程中钠转运的数学模型 ,描述了低钠透析液对钠清除量的影响。并在合理假设的基础上探讨了低钠透析液中合适的钠浓度。结果　钠浓度每降低 5mmol/L ,清除量增加 0 .2 3g。低钠透析液中合适的钠浓度可能 1 2 8mmol/L。结论　低钠透析液能够明显增加钠的清除。     

腹膜透析病人的饮食护理

营养不良是透析病人的严重并发症和主要死亡原因之一。腹膜透析病人由于腹膜透析液中的葡萄糖被吸收使病人有饱足感,蛋白质摄入量减少;而每日由腹膜透析液中丢失的蛋白质8g～16g,由此造成营养不良,导致机体免疫力下降,影响病人生活质量。合理的饮食调配有利于改善病人的营养状况,提高生活质量,延长生命。现将我科腹膜透析病人的饮食护理介绍如下。     

腹膜透析病人的饮食护理

营养不良是透析病人的严重并发症和主要死亡原因之一[1].腹膜透析病人由于腹膜透析液中的葡萄糖被吸收使病人有饱足感,蛋白质摄入量减少;而每日由腹膜透析液中丢失的蛋白质8 g～16 g,由此造成营养不良,导致机体免疫力下降,影响病人生活质量.合理的饮食调配有利于改善病人的营养状况,提高生活质量,延长生命.现将我科腹膜透析病人的饮食护理介绍如下.     

腹膜透析患者不同透析龄和透析量水钠清除变化的观察

目的探讨腹膜透析患者不同透析龄水钠清除量的变化。方法选择北京大学第三医院肾内科稳定的腹膜透析患者81例，按透析龄分为3组：①透析3～6个月（n=16）：②透析6～24个月（n=32）：③透析≥24个月（n=33）。透析剂量随残余肾功能的下降而增加，测定腹膜透析出液和尿量及钠的清除、血钠、血压、细胞外液、细胞内液和超声心动图。结果3组总液体清除差异无显著性，腹膜透析液中钠浓度（133．52±4．26）mmol／L远高于尿钠的浓度（60．18±36．42）mmol／L，透析龄小于6个月者总钠清除量低于透析龄大于24个月者（P〈0．05），其血钠水平显著高于透析龄大于24个月者（P〈0．05）。3组血压、细胞外液、细胞内液、左心室舒张末期内径和室间隔厚度差异无显著性。结论腹膜透析和残余肾对水，钠的清除效力不同，单位体积超滤液比相同体积的残余尿量能清除更多的钠。因此严格控制水盐摄入，根据尿量调整透析剂量，虽透析龄延长，也能维持容量平衡。     

腹膜透析患者的钠清除不能反映其钠摄入

目的　控制饮食钠的摄入对持续不卧床腹膜透析 (CAPD)患者体液平衡有着重要的作用。由于直接测定患者的钠摄入有一定困难 ,一般通过测定钠清除来反映钠摄入。本课题拟对钠清除代表钠摄入的可靠性进行研究。方法　对 4 0名稳定的CAPD患者在开始时和 3个月后分别进行饮食钠摄入的调查 ,测定腹膜透析液及尿中钠清除量 ,并通过生物电阻抗法测定体液容量水平。结果　根据饮食中钠摄入量变化患者被分为 2组 :钠摄入增加组 1 5例和下降组 9例。2组间钠摄入的变化差异有显著性 (P <0 .0 5 ) ,体液容量变化差异亦有显著性 (P <0 .0 5 ) ,但 2组间腹膜透析液钠清除、尿液钠清除及总钠清除的变化无统计学意义。结论　腹膜透析液及尿中钠清除皆不能如实反映CAPD患者饮食中钠摄入 ,因此 ,对CAPD患者利用测定钠清除来反映钠摄入不够可靠。     

长期腹膜透析患儿的维生素状况

肾功能衰竭和透析被认为影响维生素的需要量,接受持续不卧床腹膜透析(CAPD)成人的研究提示,必须补充维生素C(VC)、维生素 B_6(VB_6)和叶酸来预防维生素的缺乏,一项研究报道了腹膜透析患儿必须补充 VB_6才能维持血浆正常的磷酸吡哆醛浓度,VC 和叶酸需要量增加部分原因是它们从透析液中丢失,但透析液中丢失 VB_6量却很少。与水溶性维生索相反,成人腹膜透析患者在没有补充维生素 A(VA)时血中VA 浓度仍增高,本文进行研究是评估长期腹膜透析患儿 VA 和水溶性维生素口服摄入量及血中浓度。     

低钠透析对血液透析患者大动脉僵硬度的影响

目的大动脉僵硬度的金标准--腹主动脉脉搏波传导速度(pulse wave velocity,PWV)是终末期肾脏病患者全因死亡和心血管死亡的独立危险因素。在非透析人群,饮食钠摄入增多可升高PWV;反之,限盐可降低PWV。本研究旨在观察应用低钠透析液增加透析钠清除对血液透析患者大动脉僵硬度的影响。方法选择处于干体质量的稳定血液透析患者16名。先应用标准透析液(钠浓度138mmol/L)透析一1个月,再将透析液钠浓度降为136mmol/L透析4个月(低钠透析)。研究期间未对饮食钠进行限制和干预,并且每个月应用生物电阻抗仪对干体质量进行调节,以保持透析后容量状态稳定。同时测量PWV、44h动态血压,记录透析间期体质量增长、每月透析中低血压和肌肉痉挛的发生率。结果随着低钠透析,腹主动脉PWV显著下降(12.61±2.30比11.74±2.65m/s,P=0.005);44h动态收缩压和舒张压分别较基线水平下降10mmHg和6mmHg(1mmHg=0.133kpa),而透析后容量状态无明显变化;透析间期体重增长轻度下降(2.89±0.66比2.67±0.63kg,P=0.051)。低血压和肌肉痉挛的发生率无明显变化。结论降低透析液钠浓度可显著改善透析患者的大动脉僵硬度。     

指数衰减透析液钠浓度对透析相关性高血压影响的研究

[目的]观察指数衰减透析液钠浓度对维持性血液透析(MHD)病人血液透析相关性高血压的影响.[方法]将透析过程中反复发生血液透析相关性高血压的MHD病人12例,采取单盲自身交叉对照设计,给予恒定透析液钠浓度和指数衰减透析液钠浓度血液透析各20次,观察比较血压、血钠浓度等变化.[结果]与恒定透析液钠浓度比较,指数衰减透析液钠浓度透析时MHD病人血液透析相关性高血压发生例次、透析中及透析后头痛、烦躁不安、恶心呕吐等症状均明显减少(P＜0.01).[结论]指数衰减透析液钠浓度透析可有效减少透析相关性高血压的发生.     

腹膜透析病人的健康教育

腹膜透析是利用人体腹膜作为半透膜,向腹腔内注入腹透液,借助腹膜两侧的毛细血管内血浆及腹腔内透析液中的溶质浓度和渗透压梯度,通过扩散和渗透原理,清除机体内代谢废物和潴留的水分,同时由透析液中补充必需的物质,达到清除毒素、超滤水分、纠正酸中毒和电解质紊乱的治疗目的[1].近年来,在腹膜透析过程中,融入了健康教育,既减少了腹膜透析并发症的发生,又提高了病人的生活质量.     

Changes in total sodium intake do not lead to proportionate changes in total sodium removal in CAPD patients.

BACKGROUND: Dietary salt and fluid restriction is important in controlling fluid balance in patients on continuous ambulatory peritoneal dialysis (CAPD). However, it is often difficult to monitor patients' dietary total sodium intake (TSI). Usually, total sodium removal (TSR), the sum of urinary sodium removal (USR) and dialysate sodium removal (DSR), is suggested to represent TSI. In the present study, we investigated the reliability of using TSR as a surrogate to TSI in CAPD patients. METHODS: 40 clinically stable CAPD patients were closely followed for 3 months. Their TSI, USR, DSR, and fluid status were measured twice: at baseline and at the end of this study respectively. Fluid status was evaluated by bioimpedance analysis. Patients with increased sodium intake (group ISI) or decreased sodium intake (group DSI) (both >0.5 g/day or >21.74 mmol/day elemental sodium) were included in this study. RESULTS: There were 15 patients in group ISI and 9 patients in group DSI. During the follow-up, although TSI increased in group ISI and decreased in group DSI (p < 0.05), there were no significant changes in USR, DSR, or TSR in either group. No relationship was found between TSI and TSR. Changes in weight, blood pressure, urine volume, ultra-filtration, and small solute removal (Kt/V and creatinine clearance) were not statistically significant between the two groups. Fluid status deteriorated in group ISI and improved in group DSI (p < 0.05). CONCLUSIONS: Our study suggests that changes in total sodium intake do not lead to proportionate changes in total sodium removal in CAPD patients. Therefore, TSR (the sum of USR and DSR) should be used cautiously to monitor TSI in this patient population.     

Clinical factors associated with sodium removal in peritoneal dialysis patients

A cross-sectional study was conducted in 156 clinically-stable peritoneal dialysis patients to identify the factors associated with sodium removal. Serum biochemistry, peritoneal function (modified peritoneal equilibration test [PET]) and the adequacy of dialysis were analysed in relation to sodium removal using multivariate linear regression. Factors significantly affecting peritoneal sodium removal included infusion volume and ultrafiltration volume per 24 h, sodium dip in the first hour of PET and sodium difference between serum and fresh dialysate. Factors significantly affecting total sodium removal included ultrafiltration and urine volume per 24 h, sodium dip in the first hour of PET and sodium difference between serum and fresh dialysate. With traditional dialysate, adequate fluid removal is required to ensure sufficient sodium removal, but a low-sodium dialysate may prevent sodium retention. Sodium removal should be included in evaluation of the adequacy of dialysis.     

Role of sodium in the protective effect of ticarcillin on gentamicin nephrotoxicity in rats.

Coadministration of sodium ticarcillin with an aminoglycoside is known to reduce the nephrotoxicity of the aminoglycoside. However, it is not known whether the penicillin or the obligatory sodium load confers protection. To investigate this, gentamicin has been administered intraperitoneally in doses of 50, 60, or 80 mg/kg per day for 12 days in groups of rats receiving either a normal or a low sodium intake. Alterations in creatinine clearance have been measured. Salt depletion resulted in an enhanced nephrotoxic response with a shift in the dose-response curve to the left. Administration of sodium ticarcillin to rats with a salt-depleted intake at a dose sufficient to replace sodium intake conferred an equal degree of protection to rats with a normal salt intake. We report that the obligatory salt supplement with ticarcillin is sufficient to account for the renal sparing effect of the combination treatment without having to infer a direct chemical interaction of penicillin with the aminoglycoside.     

Effects of salt loading during exercise in a hot dry climate

Strenuous work or sports activities in a hot environment can cause significant fluid and salt losses due to excessive sweating. Fluid replacement is commonly accepted to be beneficial, but controversy surrounds the necessity of adding salt to the dietary intake in hot climates. Five healthy young men participated in a self-controlled experiment designed to investigate the effects of salt loading on acclimatized people exercising under controlled laboratory conditions. The additional salt ingestion was found to cause an increase in body weight, rectal temperature, heart rate, urinary sodium and potassium concentrations and in the total amounts of sodium and chloride excreted in urine during the exercise. Furthermore, it decreased plasma aldosterone level and sweat chloride excretion, but did not affect fluid intake, urine output, sweat rate, skin temperature, excretion of sodium and potassium in sweat or urinary potassium content and chloride concentration. Neither did the additional salt intake affect plasma electrolyte levels, renin activity or acid base balance. It is concluded that acclimatized people living in a hot dry climate need no supplementary salt to their daily dietary intake while engaging in physical exercise or sports activities up to two hours a day. Salt loading has no beneficial effects in these conditions and may even be hazardous.     

Urinary excretion of dihydroxyphenylalanine and dopamine during alterations of dietary salt intake in humans

1. Urinary excretion of dopamine (DA) increases during dietary salt loading. The majority of urinary DA is derived from circulating dihydroxyphenylalanine (dopa). Whether the increase in urinary DA excretion during salt loading results from increased efficiency of uptake of dopa by proximal tubular cells of the kidney, facilitation of intracellular conversion of dopa to DA, or increased delivery of dopa to tubular uptake sites, has been unknown. 2. In 10 inpatient normal volunteers on a constant diet, daily excretion of dopa and DA was assessed during normal sodium intake (109 mmol/day) for 1 week, low sodium intake (9 mmol/day) for 1 week and high sodium intake (249 mmol/day) for 1 week. 3. Urinary DA excretion exceeded urinary dopa excretion by about tenfold, and the excretion of both DA and dopa increased by about twofold between the low and high salt diets, with similar proportionate changes. Plasma dopa was unchanged by dietary salt manipulation. 4. The results indicate that increases in urinary DA excretion during dietary salt loading can be accounted for by increased delivery of dopa to sites of uptake by proximal tubular cells. Since dopa is released into the bloodstream by sympathetic nerve endings and by the brain, and since interference with decarboxylation of dopa attenuates natriuretic responses, dopa may function indirectly as a neurohormone involved in homoeostatic regulation of sodium balance.     

Japanese dietary intake of salt and protein--relating to the strategy of salt restriction

The high level of Japanese salt intake, which has been the major risk factor for cerebrovascular disease and hypertension, has decreased since World War II, and reached a steady level. In the present study, the dietary salt intake in Tohoku (once the district of highest sodium intake) and that in Kyushu (once the district of median or low sodium intake) were studied in relation to nutritional status by the analysis of sodium and urea-nitrogen excretion in 24-hr urine samples collected from 305 healthy Japanese. When the amount of urinary creatinine and urea-nitrogen were adjusted, the mean value of urinary sodium in females was significantly larger in Tohoku than in Kyushu, but not significantly in males. The regional difference of salt intake still remains, although it seems to be disappearing. Traditionally, Japanese high intake of salt was accompanied by poor nutritional status. In the present study, however, a significant positive correlation was observed between sodium and urea-nitrogen. The excess of protein intake would cause the excess of salt intake. Therefore, the strategy of further salt restriction should be directed to not only traditional salty foods but also nutritional status such as protein intake.     

Lifestyle modification in the management of hypertension

Hypertension is the most common lifestyle related disease in Japan. Among the lifestyle modifications, salt restriction is most important especially in Japanese hypertensive patients. Although Japanese as well as international guidelines recommend the restriction of salt intake less than 6 g/day, very few Japanese hypertensive patients are able to achieve this goal. Other lifestyle modifications include the increased intake of vegetables and fruits, maintenance of appropriate body weight, regular exercise, the restriction of alcohol intake and cessation of smoking. It is emphasized that comprehensive lifestyle modification is more effective. Since the long-term compliance of lifestyle modification is difficult, a strategy to promote lifestyle modification by encouraging individual subject should be established.