腹膜透析初透剂量对患者残余肾功能的影响

目的 探讨腹膜透析（腹透）初透剂量对患者残余肾功能的影响。 方法 追踪观察我院3个月内连续门诊随访的178例开始腹透的患者,测定24 h尿量。根据透析第1、3个月尿量的变化分为少尿组（LU,97例）、尿量减少组（DU,19例）、尿量正常组（NU,62例）,记录并分析其透析剂量、腹透液葡萄糖含量、超滤量、尿素清除指数（Kt/V）、体质量、水肿程度及尿量变化等的相关性。 结果 3组患者的年龄和性别比例差异无统计学意义。透析1个月后,DU组的体质量和水肿程度大于LU和NU组（P < 0.05）;腹透液总入量、腹透液葡萄糖含量、超滤量、残余肾尿素清除指数Kt/V（rKt/V）高于LU组,与NU组差异无统计学意义。透析3个月后,DU组的体质量和水肿程度有所下降（P < 0.05）,但仍高于LU和NU组（P < 0.05）;腹透液总入量、超滤量、尿量下降速度比LU组和NU组高（P < 0.05）;rKt/V 比腹透前显著下降（P < 0.05）。3组的血清白蛋白和tKt/V差异无统计学意义。 结论 开始腹透患者过度超滤可引起残余肾功能下降。对于有一定残余肾功能的患者要注意避免快速或过多超滤。     

Peritoneal sodium mass removal in continuous ambulatory peritoneal dialysis and automated peritoneal dialysis: influence on blood pressure control.

BACKGROUND/AIM: Sodium and water retention is common in peritoneal dialysis patients and contributes to cardiovascular disease. As peritoneal sodium removal depends partly on dwell time, and automated peritoneal dialysis (APD) often uses short dwell time exchanges, the aim of this study was to compare the 24-hour peritoneal sodium removal in APD and standard continuous ambulatory peritoneal dialysis (CAPD) patients and to analyze its possible influence on blood pressure control. METHODS: A total of 53 sodium balance studies (30 in APD and 23 in CAPD) were performed in 36 stable peritoneal dialysis patients. The 24-hour net removal of sodium was calculated as follows: M = ViCi - VdCd, where Vd is the 24-hour drained volume, Cd is the solute sodium concentration in Vd, Vi is the amount of solution used during a 24-hour period, and Ci is the sodium concentration in Vi. Peritoneal sodium removal was compared between APD and CAPD patients. Residual renal function, serum sodium concentration, daily urinary sodium losses, weekly peritoneal Kt/V and creatinine clearance, 4-hour dialysate/plasma creatinine ratio, proportion of hypertonic solutions, net ultrafiltration, systolic and diastolic blood pressures, and need for antihypertensive therapy were also compared between the groups. RESULTS: Peritoneal sodium removal was higher (p < 0.001) in CAPD than in APD patients. There were no significant differences in residual renal function, serum sodium concentration, urinary sodium losses, peritoneal urea or creatinine clearances, 4-hour dialysate/plasma creatinine ratio, or proportion of hypertonic solutions between groups. The net ultrafiltration was higher in CAPD patients and correlated strongly (r = 0.82; p < 0.001) with peritoneal sodium removal. In APD patients, peritoneal sodium removal increased significantly only in those patients with a second daytime exchange. The systolic blood pressure was higher (p < 0.05) in APD patients, and the proportion of patients with antihypertensive therapy was also higher in APD patients, although no significant relationship between blood pressure values and amount of peritoneal sodium removal was found. CONCLUSIONS: The 24-hour sodium removal is higher in CAPD than in APD patients, and there is a trend towards better hypertension control in CAPD patients. As hypertension control and volume status are important indices of peritoneal dialysis adequacy, our results have to be considered in the choice of the peritoneal dialysis modality.     

Defining Peritoneal Dialysis Adequacy: Kt/Vurea Revisited

Background. Although adequate peritoneal dialysis is not well defined, Kt/Vurea has been used as an index, and various values have been proposed. However, conflicting evidence existed regarding the appropriateness of using Kt/Vurea to define dialysis adequacy and its optimal value. Therefore, the present study performed a theoretical analysis on whether we should use Kt/Vurea to define peritoneal dialysis adequacy and what the optimal value should be. Methods. The three-pore model was applied to evaluate the transport patterns of different molecular weight solutes and fluid. Optimal Kt/Vurea value was estimated based on urea kinetics and nitrogen balance. Results. The removal pattern of small solute, middle and large molecules, and fluid and sodium are quite different. Depending on the dwell time, higher urea removal does not necessarily mean higher sodium, fluid, and other molecular weight solute removals. To reach nitrogen balance, the dialysis doses and therefore Kt/Vurea values varied with different dietary protein intakes in a patient with a given weight and residual renal function. Conclusion. This study shows that Kt/Vurea in peritoneal dialysis cannot represent the removal of other solutes and fluid, indicating that Kt/Vurea alone should not be used as a sole indicator of peritoneal dialysis adequacy. The results also show that optimal Kt/Vurea cannot be a fixed value, but varies according to individual dietary protein intake and tolerable blood urea level.     

Reduced peritoneal protein selectivity may indicate peritoneal fibrosis in CAPD patients

Background. We investigated peritoneal protein selectivity to evaluate whether it may indicate changes in peritoneal pores and be related to the morphological changes in the peritoneal membrane during the course of continuous ambulatory peritoneal dialysis (CAPD) therapy. Methods. Seventeen patients on CAPD (11 men, 6 women; average age, 48.4 ± 2.8 years [mean ± SE]) were studied. The duration of CAPD ranged from 1 to 42 months (21.7 ± 3.8 months [mean ± SE]). Urea nitrogen, creatinine, transferrin, and IgG in both serum and CAPD waste fluid were measured, and dialysate/plasma (D/P) ratios for these substances were determined. To evaluate changes in the large pores, in the peritoneal membrane, the peritoneal selectivity index (PSI) was calculated in the same manner as the urinary protein selectivity index is determined; namely, as the ratio of IgG clearance to transferrin clearance into CAPD waste fluid. Results. There was no significant correlation among the D/P ratios for urea nitrogen, creatinine, transferrin, IgG, and the duration of CAPD therapy. However, the PSI showed low-grade selectivity in patients on relatively shorter periods of CAPD therapy, and high-grade selectivity in patients with longer periods of CAPD therapy. There was a significant inverse correlation between the PSI (Y) and the duration of CAPD therapy (X) (Y = −0.007X + 0.75; r = 0.75, P < 0.05). We performed a prospective study after 12 months, and 8 patients were available to measure PSI again, and almost all patients showed a decrease in the PSI (−22.8 ± 0.8%; P < 0.02). In addition, we carried out morphological evaluation of the peritoneum in 13 patients who stopped CAPD. There was a significant difference in PSI value between those with and without peritoneal fibrotic change, while there was no significant difference in PSI values for those with and without mesothelial damage or with and without arteriolar sclerosis. Conclusions. From these results, we hypothesize that reduction in the PSI may reflect the shrinkage of large peritoneal pores and the presence of peritoneal fibrotic change in CAPD patients. Received: January 9, 2001 / Accepted: July 30, 2001     

Urea kinetics and other dialysis indices in children undergoing ambulatory peritoneal dialysis

Background. Peritoneal dialysis (PD) is an established treatment for children with end-stage renal failure. Creatinine clearance and urea kinetics are used to quantitate the dialysis treatment, but the means to assess the adequacy of dialysis in children are still controversial. Methods. We studied serum chemistry, dietary protein intake (DPI), protein catabolic rate (PCR), weekly urea clearance/body water (Kt/V_urea), weekly creatinine clearance (Ccr/week), clinical signs and symptoms during PD treatment, and peritoneal transport function in 17 children (4 to 18 years of age) with end-stage renal disease treated with PD. Fourteen children were on continuous ambulatory peritoneal dialysis (CAPD) and 3 were on automated peritoneal dialysis. Results. The mean values of the parameters tested were: blood urea nitrogen, 71 mg/dl; creatinine, 9.8 mg/dl; total protein, 6.4 g/dl; albumin, 4.0 g/dl; total Ccr, 70 l/week per 1.73 m²; DPI, 1.76 g/kg per day; PCR, 1.17 g/kg per day, and total Kt/V_urea, 2.28/week. The mean patient's clinical assessment score was 11.7, out of 15 and the mean doctor's clinical assessment score was 11.7, out of 14. The correlation between Kt/V_urea and creatinine clearance was 0.84 (P < 0.0001). Kt/V_urea and clinical assessment scores (patient's and doctor's scores) did not show a good correlation (r = 0.32; P = 0.228, and r = 0.47; P = 0.064, respectively). Peritoneal function seemed to be preserved after an average duration of 32 months on PD. Conclusions. These patients appeared to be fairly well dialyzed, judging from the values for the various dialysis indices obtained in this study and comparing them with adult indices. Received: January 7, 1999 / Accepted: March 22, 2000     

Effect of changing membrane flux of biocompatible membranes on nutritional parameters in chronic hemodialysis patients

Background. The effect of changing membrane flux on nutritional status was evaluated retrospectively in chronic hemodialysis patients, based on four quarterly urea kinetics studies. We also prospectively analyzed whether these infrequent evaluations reflected the kinetics occurring at each dialysis session for 1 month in another group of chronic hemodialysis patients. Methods. A standard-flux polysulfone membrane (F-8) was changed to a high-flux polysulfore membrane (F-80) in 12 patients who had begun chronic hemodialysis. The actual delivered dialysis dose (Kt/Vurea) and normalized protein catabolic rate (nPCR) were evaluated monthly and quarterly, respectively. The two quarters before and after the membrane was changed were compared. In the prospective study, we measured Kt/Vurea and nPCR for each dialysis session in 11 other hospitalized chronic hemodialysis patients. The monthly means for Kt/Vurea and nPCR were compared with the mid-month values (mid-month session in the month). Results. The nPCR increased between the third and fourth quarters (on F80), from 0.83 ± 0.23 to 0.95 ± 0.18 g/kg per day (P = 0.05), with a constant delivered Kt/Vurea (1.11 ± 0.36 and 1.13 ± 0.21, P = 0.41) and did not increase in the first two quarters (on F8) with constant delivered Kt/Vurea. A linear relationship existed between Kt/Vurea and nPCR (r = 0.76; P < 0.002) during the last two quarters but not the first two quarters (r = 0.33; P < 0.2). In the prospective study, mid-month Kt/Vurea evaluation and mean Kt/Vurea were strongly correlated (r = 0.88; P < 0.002) as were the mid-month and mean values for nPCR (r = 0.89; P < 0.002). Single monthly measurements would be adequate for interpretation of a patient's monthly status. Conclusion. We conclude that the relationship between Kt/Vurea and nPCR is stronger during high-flux dialysis based on reliable infrequent urea kinetic study data. Received: February 12, 1998 / Accepted: November 13, 1998     

Defining peritoneal dialysis adequacy: Kt/Vurea revisited

BACKGROUND: Although adequate peritoneal dialysis is not well defined, Kt/Vurea has been used as an index, and various values have been proposed. However, conflicting evidence existed regarding the appropriateness of using Kt/Vurea to define dialysis adequacy and its optimal value. Therefore, the present study performed a theoretical analysis on whether we should use Kt/Vurea to define peritoneal dialysis adequacy and what the optimal value should be. METHODS: The three-pore model was applied to evaluate the transport patterns of different molecular weight solutes and fluid. Optimal Kt/Vurea value was estimated based on urea kinetics and nitrogen balance. RESULTS: The removal pattern of small solute, middle and large molecules, and fluid and sodium are quite different. Depending on the dwell time, higher urea removal does not necessarily mean higher sodium, fluid, and other molecular weight solute removals. To reach nitrogen balance, the dialysis doses and therefore Kt/Vurea values varied with different dietary protein intakes in a patient with a given weight and residual renal function. CONCLUSION: This study shows that Kt/Vurea in peritoneal dialysis cannot represent the removal of other solutes and fluid, indicating that Kt/Vurea alone should not be used as a sole indicator of peritoneal dialysis adequacy. The results also show that optimal Kt/Vurea cannot be a fixed value, but varies according to individual dietary protein intake and tolerable blood urea level.     

Sequential change of asymmetric dimethylarginine levels after initiation of peritoneal dialysis in patients with end-stage renal disease

Background: We hypothesized that the asymmetric dimethylarginine (ADMA) metabolism in end‐stage renal disease may be linked to the rate of protein turnover and to the vast pool of amino acids. In order to determine a correlation between the plasma levels of ADMA and the protein catabolic rate, we measured the ADMA levels as well as nutritional markers such as the normalized protein catabolic rate (nPCR) in patients with newly initiated continuous ambulatory peritoneal dialysis (CAPD). Methods: Twenty‐four patients were recruited for this study. All patients were on the standard CAPD protocol, and followed for at least 1 year. Blood samples were collected at baseline before the initiation of peritoneal dialysis, and every 6 months for 1 year. The blood parameters studied included the serum albumin, total cholesterol, glucose, urea nitrogen, creatinine and ADMA. Peritoneal equilibrium test and measurements of weekly Kt/Vurea and nPCR were performed within 4 weeks of the blood sampling. Results: The change of ADMA levels over 1 year was positively correlated with that of haemoglobin (r = 0.592, P = 0.002) and nPCR during the same period (r = 0.508, P = 0.026). Conclusion: The findings of our study suggest that nPCR might influence the change of ADMA levels after initiation of CAPD.     

不同腹膜溶质转运特性腹膜透析患者营养状况的比较

目的 探讨腹膜转运特性对腹膜透析患者营养状态的影响。方法 按照腹膜平衡试验(PET)计算结果,将82例稳定的CAPD患者分为高转运组和低转运组。检测患者血浆和腹透透出液总蛋白、白蛋白及氨基酸量,同步计算蛋白质摄入量(DPI)和蛋白质分解率(nPCR)。比较两组营养状态及分析相关因素。结果两组的残余肾功能、腹透治疗时间、每日透析液剂量、超滤量、葡萄糖吸收量、血糖、BUN、Scr和Kt／V均无显著性差异。高转运组每日经腹透透出液丢失的总蛋白质和多种氨基酸量明显高于低转运组;各项营养指标均低于低转运组,且体重及血清白蛋白有显著性差异。血中及经腹透透出液丢失的白蛋白和氨基酸量均与转运类型相关。结论 腹膜透析高转运患者营养状态较低转运者差。单纯提高透析充分性并不能明显改善营养状态。要加强对高转运患者的营养管理和指导。     

Peritoneal dialysis indices: weekly CrCl and weekly Kt/Vurea are linked

Peritoneal dialysis uses a biological "membrane," the peritoneum, to control solute movement between the patient and the dialysate. Equilibrium thermodynamic models predict that the movement of small molecules across the peritoneum will be restricted in proportion to their permeability indices, the available membrane surface area, and the solute concentration gradient between plasma water and dialysate. During peritoneal dialysis, the membrane surface area, dialysate flow, and solute concentration gradients are quite similar for small solutes such as creatinine and urea. Hence, the clearances of creatinine and urea should be proportional to one another in a ratio equal to that of their membrane permeabilities; if that ratio is known, a peritoneal creatinine clearance could be derived for any known peritoneal urea clearance, and vice versa. Analysis of patient data supports this hypothesis and suggests that if disparate normalization procedures are avoided, peritoneal dialysis patients without residual renal function will have difficulty consistently attaining the weekly normalized creatinine clearance of > or =60 L/1.73 m2 recommended by the National Kidney Foundation-Dialysis Outcomes Quality Indicators (NKF-DOQI) without achieving a weekly Kt/Vurea of > or =2.5.     

Comparative Effects of Carvedilol and Lercanidipine on Ultrafiltration and Solute Transport in CAPD Patients

Background. Peritonitis, the type of buffer used in the dialysate, continue ambulatory peritoneal dialysis (CAPD) of greater than two years duration, increased exposure to dialysate glucose, diabetes mellitus, and the use of beta blockers may contribute to impaired ultrafiltration. Objectives. The aim of the present study is to compare the effects of a calcium-channel blocker and a β-blocker on the peritoneal transport and clearance. Methods. We studied 48 patients with ESRD on chronic peritoneal dialysis, included 27 females and 19 males with mean age 42.6 ± 16.4 years. Two patients were excluded from the study due to peritonitis. Patients were treated either with carvedilol or lercanidipine. In all patients; peritoneal equilibration test (PET), ultrafiltration (UF), Kt/V ratio, creatinine clearance (CrCl), systolic blood pressure, diastolic blood pressure, serum BUN, creatinine, glucose, sodium, potassium, albumin, cholesterol, and triglyceride values were obtained before and after 8 weeks from the start of the drug treatment. Results. Lercanidipine and carvedilol showed a good antihypertensive effect in CAPD patients. Both drugs had a good tolerability profile and showed no effect on plasma lipids. There were no differences in terms of PET, ultrafiltration, Kt/V ratio, CrCl, systolic blood pressure, diastolic blood pressure, serum BUN, creatinine, glucose, sodium, and potassium values between both patient groups. After antihypertensive treatment, neither group showed a difference in the above-mentioned parameters (p > 0.05) except potassium, which was significantly higher in the carvedilol group (p < 0.05). Conclusions. In CAPD patients. short-term usage of carvedilol has no effect on ultrafiltration and solute transport like lercanidipine. Both drugs showed a good antihypertensive effect.     

The relation between nutrition indices and age in patients on continuous ambulatory peritoneal dialysis receiving similar small solute clearances

Objective: To analyze the effect of age on nutrition indices in subjects on the same continuous ambulatory peritoneal dialysis (CAPD) schedule. Methods: We analyzed 613 sets of clearance values and nutrition indices in 302 CAPD patients. Small solute clearances included urea clearance (Kt/V_urea) and creatinine clearance (C_cr). Nutrition indices included body mass index (BMI), serum albumin, urea and creatinine, 24-h urea nitrogen and creatinine excretion in urine plus dialysate, protein nitrogen appearance (PNA), PNA normalized by standard weight (nPNA), lean body mass (LBM) computed by creatinine kinetics, and LBM/Weight. CAPD subjects were classified in 4 age quartiles (Q): Group Q₁, age 33.7 ± 7.6 years, N = 149; group Q₂, age 49.5 ± 3.8 years, N = 158; group Q₃, age 61.5 ± 2.6 years, N = 154; and group Q₄, age 72.1 ± 5.4 years, N = 152. Group comparison was done by one-way ANOVA or chi-square. Predictors of low nutritional parameters were identified by logistic regression. Selected variables were compared by linear regression. Results: Mean Kt/V_urea and C_crwere above the current adequacy standards and did not differ between the age quartiles. In contrast, older quartiles had, in general, lower nutrition indices than younger quartiles. However, the youngest quartile had the lowest BMI. By logistic regression, young age was a predictor of low BMI, while advanced age was a predictor of low creatinine and urea nitrogen excretion, low nPNA, and low LBM/Weight. The regressions of nPNA on Kt/V_urea differed between the age quartiles. By these regressions, the youngest quartile had higher nPNA values for the same Kt/V_urea than the oldest quartile in the clinically relevant range of Kt/V_urea and nPNA values. Conclusions: Nutrition indices are worse in older than in younger CAPD patients with the same small solute clearances. Nutrition of CAPD patients is adversely affected by age and requires special attention in the older age group. This revised version was published online in September 2006 with corrections to the Cover Date.     

小剂量日间非卧床腹膜透析对残肾功能较好的糖尿病终末期肾病患者的疗效

目的　研究小剂量日间非卧床腹膜透析（DAPD）和小剂量持续非卧床腹膜透析（CAPD）对残肾功能较好的糖尿病终末期肾病（ESRD）患者的疗效。 方法 病情稳定、残肾功能较好（rGFR≥5 ml/min,且尿量≥750 ml/d）的40例糖尿病ESRD患者入选。按数字随机法分为小剂量DAPD组20例和小剂量CAPD组20例。DAPD组透析处方为1.5 L或2 L,3次/d,每次留腹3～4 h,夜间干腹。CAPD组透析处方为1.5～2 Ｌ,3次/d,或1.5 L,4次/d,夜间留腹。在研究开始及6个月后,分别计算两组腹膜尿素氮清除率（Kt/V）、残肾Kt/V、每周总Ｋt/V、Ccr、rGFR等指标;测定24 h尿蛋白量、24 h腹透液蛋白、血清白蛋白、空腹血糖、糖化血红蛋白及胰岛素剂量;用改良主观综合性营养评估法（SGA）评估患者营养状况。 结果 共35例患者完成研究。两组患者年龄、性别、体质量指数、透析龄、透析液肌酐/血肌酐（D/Pcr）等基线值差异无统计学意义。6个月后,CAPD组胰岛素剂量和24 h腹透液丢失蛋白明显高于DAPD组,分别为（33.6±10.9） U/d 比（20.6±6.2） U/d（P < 0.05）和（11.13±4.95） g比（5.66±2.88） g（P < 0.01）,而血清白蛋白明显低于DAPD组[（29.7±4.2） 比（36.5±3.9） g/L,P < 0.05]。DAPD组与CAPD组相比,24 h净超滤量为（554±187） ml比（309±177） ml,24 h尿量为（1090±361） ml比（750±258） ml,rGFR为（8.21±2.40） ml/min比（4.88±2.11） ml/min,DAPD组均显著高于CAPD组（均P < 0.05）。 结论 对于残肾功能较好的糖尿病ESRD患者,小剂量DAPD较小剂量CAPD能更好地控制血糖,改善营养状态及保护残肾功能。     

Evolution of clinical parameters and peritoneal function in a cohort of CAPD patients followed over 7 years

The clinical results and the long-term evolution of some peritonealtransport characteristics were retrospectively analysed in acohort of 23 patients who had been maintained continuously onCAPD for at least 7 years. Several clinical and biological resultslike blood pressure, peripheral nerve conductivity, total protein,and serum phosphorus showed relatively stable values. On the other hand increases were noted in body weight, consumptionof antihypertensive drugs; creati-nine, serum calcium and parathormoneconcentration. Haematocrit, cholesterol, and triglycerides significantly increasedduring the first 2–4 years but returned to the predialysisvalues after 5–7 years. In contrast with patients never exposed to acetate diaysate,there was a continuous loss of peritoneal ultrafiltration from1000 ml/day to 780 ml/day (P<0.05) in patients who had beentreated with acetate. However, peritoneal creatinine clearancesand the D/P creatinine ratios remained constant. The Kt/V urea index declined from 0.88±0.8 during thefirst year to 0.62±0.06 after 7 years (P<0.001). Thiswas due to a decline in contribution of the residual renal Kt/Vurea index from 21.6% at the start to less than 3% after 7 years. A negative correlation between the Kt/V urea index per yearand the hospitalization rate and a positive correlation withthe peripheral nerve conductivity were found. In conclusion, the long-term peritoneal diffusive capacity canremain stable over 7 years in CAPD; in some patients a continuousfall in peritoneal ultrafiltration appears which can be counterbalancedby stimulation of their daily diuresis with high doses of frusemide.Following the Kt/V urea index can be recommended since thisindex is correlated with at least some parameters of morbidityin CAPD patients.     

Brain natriuretic peptide and P wave duration in dialysis patients

Objectives P wave duration and dispersion, defined as the difference between the maximum and minimum P duration, are regarded as very important non-invasive ECG markers for assessing atrial arrhythmia risk. Plasma brain natriuretic peptide (BNP) level is an independent predictor of recurrence of atrial fibrillation. We compared the effects of hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) on P wave duration, P dispersion, and BNP in end-stage renal disease (ESRD) patients and examined the relationship between BNP levels, P wave duration, and P dispersion. Design and methods Age-matched 22 HD patients (mean age 52.3 ± 14.0 years) and 19 CAPD patients (mean age 46.7 ± 10.9 years) were studied. Results BNP levels were greater in HD patients before the HD session (459.0 ± 465.1 pg mL⁻¹) than in CAPD patients (139.0 ± 170.1 pg mL⁻¹). The maximum and minimum P duration, and P dispersion, were similar for both groups (P > 0.05). Whereas BNP levels were negatively related to minimum P duration (r = −0.518, P = 0.019), BNP levels were positively correlated with systolic blood pressure and diastolic blood pressure (r = 0.672, P = 0.001 and r = 0.497, P = 0.022, respectively) in HD patients. Conclusions Whereas BNP levels are higher in HD patients when they are at peak-volume status, just before HD, P wave duration and P dispersion were similar for both groups. A negative relationship was detected between BNP levels and minimum P duration in HD patients. Expansion of extra-cellular volume causing myocardial stretching may be the principal cause of increased BNP in HD patients. A functional relationship between BNP and the P wave was not found. Additional studies are needed to evaluate the effect of BNP on the P wave.