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.     

The outcome for pediatric patients on peritoneal dialysis

BACKGROUND: The adverse effects of peritonitis and of the duration of dialysis on dialysis adequacy and clinical outcome were evaluated in this study. METHODS: The study comprised 24 chronic peritoneal dialysis patients who were followed up at least for 12 months. Casual blood pressure (BP) measurements, echocardiographic evaluation, peritonitis rate, hemoglobin (Hb), serum albumin, normalized protein catabolic rate (nPCR), total Kt/Vurea, weekly creatinine clearance (CCr), residual renal function (RRF), removal of fluid and dose of recombinant human erythropoietin (EPO) were evaluated. RESULTS: Mean age of the patients was 15.3 +/- 3.6 years. Mean follow-up was 50.4 +/- 26.8 months. Peritonitis rate was calculated as 1 episode/32.7 patient-months. Systolic hypertension was detected in 14 patients (58%) and diastolic hypertension in 15 (63%). RRF showed a negative correlation with duration on dialysis (r=-0.623, p=0.006).There was no significant correlation between RRF and nPCR, Hb, hematocrit, albumin and dose of EPO. A negative correlation was found with left ventricular mass index and fluid removal (r=-0.461, p=0.041). Higher doses of Kt/Vurea are associated with higher protein intake (r=0.503, p=0.024). A positive correlation was found between Kt/Vurea and Hb and Hct levels (r=0.460, p=0.009, and r=0.528, p=0.017, respectively). Dialysis adequacy tests were found not to be affected by the frequency of peritonitis. CONCLUSION: The most important factor for the prevention of hypervolemia in chronic peritoneal dialysis patients is RRF. The concept of adequate dialysis should include normal volume homeostasis, control of blood pressure and adequate nutrition.     

Baseline hyponatremia does not predict two-year mortality in patients with chronic peritoneal dialysis

Purpose: Hyponatremia is a common electrolyte abnormality in a variety of medical conditions. Lower predialysis serum sodium concentration is associated with an increased risk of death in oligoanuric patients on hemodialysis. However, whether hyponatremia affects the short-term mortality in chronic peritoneal dialysis (CPD) patients remains unclear. Methods: We conducted a cross-sectional and two-year follow-up review retrospectively, and 318 patients with CPD were enrolled in a medical center. Serum sodium levels were measured at baseline and categorized as quartile of Na: quartile 1 (124–135?mEq/L), quartile 2 (136–139), quartile 3 (140–141) and quartile 4 (142–148). Mortality and cause of death were recorded for longitudinal analyses. Results: The patients with higher quartile (higher serum sodium) had a trend of lower age, peritoneal dialysis (PD) duration, co-morbidity index, D/P Cr and white blood cell counts and higher renal Kt/Vurea (Kt/V) and serum albumin level. Stepwise multiple linear regression analysis showed that serum sodium level was positively associated with albumin, residual renal Kt/V and negatively associated with age and PD duration in CPD patients. After two-year follow-up, stepwise multivariate Cox proportional hazards model demonstrated that age, co-morbidity index and serum albumin were the significant risk factors for all-cause two-year mortality, but not serum sodium levels. Conclusions: Serum sodium level in CPD patients is associated with nutritional status, residual renal function and duration of PD. However, baseline serum sodium level is not an independent predictor of two-year mortality in CPD patients.     

The status on achieving Kt/Vurea target and its relation with residual renal function and clinical characteristics of peritoneal dialysis patients

ObjectiveTo explore the present status on achieving Kt/Vurea target in Chinese peritoneal dialysis (PD) patients and its relation with residual renal function (RRF) and clinical characteristics. Methods This was a cross-sectional study carried out in 5 PD centers in different area of China. Totally 681 clinical stable PD patients with duration≥3 months who completed dialysis adequacy and biochemical test during April 1st, 2011 and August 31st, 2011 were enrolled in this study. The demographic data and clinical characteristics were compared according to varied Kt/Vurea and RRF levels. Results (1)The total Kt/Vurea was 1.95±0.59,and total Ccr was （63.80±30.84）L·week-1·(1.73 m2) -1 for the whole group, there were 67.4% subjects achieving the Kt/Vurea target. (2) Patients achieving Kt/Vurea targetwere prone to be female and had smaller size with higher RRF and urine volume (P＜0.05). The serum calcium and phosphorus were controlled well in these patients (P＜0.05). They also had better higher cholesterol and low-density lipoprotein, and lower CRP level and less complications (P＜0.05). (3)Serum albumin was higher but inflammation and complications were less in patients with Kt/Vurea value≥1.7 and RRF≥2 ml·min-1·（1.73 m2）-1 (subgroup 1), as compared to those with Kt/Vurea≥1.7 but RRF＜2 ml·min-1·（1.73 m2）-1 (subgroup 2) and those with Kt/Vurea＜1.7(subgroup 3) (P＜0.05). The subgroup 2 and 3 were statistically different in these clinical indices, serum calcium [(2.22±0.21) mmol/L vs (2.14±0.24) mmol/L, P＜0.01], serum phosphorous [(1.43±0.47) mmol/L vs (1.66±0.52) mmol/L, P＜0.01], cholesterol [(4.91±1.29) mmol/L vs (4.62±0.99) mmol/L, P＜0.05], low-density lipoprotein [(2.86±0.96) mmol/L vs (1.13±0.61) mmol/L, P＜0.01], high-density lipoprotein [(1.08±0.33) mmol/L vs (2.20±0.72) mmol/L, P＜0.01]. (4)The Kt/Vurea was positively correlated with RRF (R2＝0.317); if RRF decreased 1 ml/min, the hazard of Kt/Vurea un-targeting increased 40.3%. Conclusions About 67.4% of PD patients can reach the Kt/Vurea target recommended by K/DOQI. RRF makes a great contribution to Kt/Vurea target. The clinical characteristics are poorer in patients who can not achieve the Kt/Vurea target, or with worse RRF.     

长期腹膜透析患者转归临床分析

目的研究长期腹透患者临床转归,分析其临床特点。方法对本院1994年1月至2003年8月腹透龄超过3年以上的58例腹透患者进行分析。根据其临床转归分为继续腹透组、转向移植组、转向血透组及死亡组。比较各组间近期营养指标（半年以内血清白蛋白水平）、近期透析充分性指标（Kt／V、Ccr）、水清除指标及残肾功能等临床特点。对死亡组同时做回顾性前后自身对照研究（死亡前半年以内与死亡前1年资料比较）。对继续腹透组回顾性分析比较1年前资料,并前瞻性追踪随访1年。结果死亡组总Kt／V显著低于其余3组（P〈0．05）;总Ccr显著低于继续腹透组（P〈0．01）。继续腹透组、移植组及血透组3组间总Kt／V、总Cer及血清白蛋白水平差异无统计学意义。血透组水清除指标显著低于继续腹透组及移植组;继续腹透组水清除指标稍高于死亡组但无显著性差异。死亡组近期总Kt／V显著低于死亡前1年总Kt／V（P〈0．05）;近期总Ccr显著低于死亡前1年总Ccr（P〈0．01）。继续腹透组近期总Kt／V及总Ccr与1年前及1年后指标比较差异均无统计学意义,但残肾Kt／V或残肾Ccr随时间推移而显著下降（P〈0．05）。继续腹透组残肾Kt／V或残肾Ccr显著高于死亡组及血透组（P〈0．05）。死亡组血清白蛋白水平较其余3组降低但差异无统计学意义。死亡组13例中有7例死于心脑血管疾病。结论腹透3年以上患者大部分仍可继续腹透。透析不充分是长期腹透患者死亡的重要原因。死亡的病因主要为心脑血管疾病。残肾功能可影响长期腹透患者的转归。     

Clinical performance measures: the changing status of peritoneal dialysis.

BACKGROUND: The Peritoneal Dialysis-Clinical Performance Measures Project (PD-CPM) characterizes peritoneal dialysis within the U.S. Current survey results are reported and compared to those of previous years. METHODS: Prevalence data from random national samples of adult peritoneal dialysis (PD) patients participating in the United States End-Stage Renal Disease (ESRD) program have been collected annually since 1995. RESULTS: In 1995, 79% of the respondents used continuous ambulatory peritoneal dialysis (CAPD) rather than automated peritoneal dialysis (APD). The mean hematocrit (Hct) of PD patients was 32% and only 66% of individuals had a measurement of dialysis adequacy reported. The mean weekly Kt/Vurea (wKt/V) and weekly creatinine clearance (wCCr) reported for CAPD patients in 1995 were 1.9 and 67 L/1.73 m2/week, respectively. In 2000 the median age of PD patients was 55 years and 63% were white. The leading cause of ESRD was diabetes mellitus (34%) and 54% of adult PD patients performed some form of APD rather than CAPD. Age, sex, size, hematocrit, peritoneal permeability, dialysis adequacy, residual renal function and nutritional indices did not differ between APD and CAPD patients. The mean hemoglobin (Hb) for the 2000 PD-CPM population was 11.6 +/- 1.4 g/dL (mean +/- 1 SD) and 11% of patients had an average Hb below 10 g/dL. The average serum albumin was 3.5 +/- 0.5 g/dL by the bromcresol green method and 56% of subjects had an average serum albumin equal to or above 3.5 g/dL (or 3.2 g/dL by bromcresol purple). In 2000 85% of patients had a dialysis adequacy measurement reported and the mean calculated wKt/V and wCCr were 2.3 +/- 0.6 and 72.7 +/- 24.9 liters/1.73 m2/week for CAPD patients and 2.3 +/- 0.6 and 71.6 +/- 25.1 L/1.73 m2/week for APD patients. PD subjects had a mean body weight of 76 +/- 19 kg and body mass index (BMI) of 27.5 +/- 6.4 kg/m2. The protein equivalent of nitrogen appearance (nPNA) of these patients was 0.95 +/- 0.31 g/kg/day, their normalized creatinine appearance rate (nCAR) equaled 17 +/- 6.5 mg/kg/day, resulting in a percent lean body mass (%LBM) of 64 +/- 17% of actual body weight. Serum albumin correlated in a positive fashion with BMI, nPNA, nCAR and %LBM, but not with wCCr. CONCLUSIONS: The majority of indicator variables monitored by the PD-CPM have improved since 1995. PD patients have higher hemoglobins and a greater proportion of patients meet the criteria for adequate dialysis. Serum albumin values, however, remain marginal and unchanged over the five-year project. Furthermore, serum albumin values fail to correlate with the intensity of renal replacement therapy and are not strongly correlated with alternative estimates of nutritional status.     

Factors associated with increased plasma homocysteine in patients using an amino acid peritoneal dialysis fluid.

BACKGROUND: Although amino acid peritoneal dialysate (AAPD) substitution is thought to improve protein-energy malnutrition in patients undergoing peritoneal dialysis (PD), it may also increase plasma homocysteine (Hcy) levels due to the methionine load in the dialysate. However, it is still unclear which factors are important for elevating Hcy in patients treated with AAPD. METHODS: Sixteen malnourished PD patients (age 48+/-18 years) were treated daily with one exchange of 1.1% AAPD for 3 months. The effects of AAPD on nutrition, Hcy, methionine, leptin and insulin resistance were studied. We also analysed factors that influenced plasma Hcy levels. RESULTS: We found a transient increase in serum albumin (P<0.01) after 1 month treatment, especially in patients with serum albumin < or = 3.5 g/dl. Total plasma Hcy increased markedly after AAPD (the peak at month 2, P<0.001) and returned to baseline after ceasing AAPD, despite no changes in dietary methionine intake and serum methionine levels. Eight patients with Hcy increments >5.65 microM (the median) had lesser dietary intakes of protein (P = 0.01) and methionine (P = 0.028), lower body fat mass (P = 0.05) and lower aspartate transaminase (AST) (P = 0.008) before AAPD treatment than patients with lower increments. DeltaHcy was inversely correlated with baseline dietary methionine intake (r = -0.61), protein intake (r = -0.54) and AST (r = -0.51) (all P<0.05). There was no change in leptin or insulin resistance. AAPD treatment significantly increased Kt/Vurea (P<0.001), weekly creatinine clearance (P<0.05) and peritoneal glucose transport (P<0.05). CONCLUSIONS: Treatment with 1.1% AAPD transiently increased serum albumin in malnourished PD patients. However, the methionine load from the dialysate in this study significantly elevated plasma Hcy levels, especially in patients with lower protein and methionine intakes, and lower AST levels. Further long-term studies will be needed to clarify potential nutritional benefits and adverse effects of AAPD.     

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.     

Baseline peritoneal solute transport rate is not associated with markers of systemic inflammation or comorbidity in incident Korean peritoneal dialysis patients.

BACKGROUND: It is controversial whether comorbid status or systemic inflammation has an influence on the peritoneal solute transport rate (PSTR). Our aim is to elucidate whether baseline PSTR is associated with markers of systemic inflammation or degree of comorbidity in incident peritoneal dialysis (PD) patients. METHODS: One hundred and ninety-five incident PD patients were prospectively included. Results of their baseline peritoneal equilibration test (PET) using 3.86% glucose PD fluid were analysed. Clinical and laboratory parameters of inflammation, comorbidity, nutritional status, dialysis adequacy and residual renal function (RRF) were assessed at the time of PET. RESULTS: Mean dialysate-to-plasma ratio for creatinine at 4 h (D/Pcr(4)) of our patients was 0.72 +/- 0.11. High-sensitivity C-reactive protein (hsCRP), serum interleukin-6 (IL-6) and serum albumin concentrations were closely interrelated to one another and these markers of systemic inflammation were also related to the Davies comorbidity score. No differences in age, sex ratio, body mass index, body surface area and presence of diabetes were found among four transport groups. RRF, total Kt/V, haemoglobin, nitrogen appearance and the Davies comorbidity score were not different either. High-sensitivity CRP, serum IL-6 and albumin concentrations were not associated with the baseline PSTR. By multiple linear regression analysis, only the serum albumin concentration measured at the time of PET (beta = -0.081 +/- 0.020, P < 0.001) remained significantly associated with D/Pcr(4). CONCLUSION: In our study with incident Korean PD patients, the baseline PSTR was not influenced by markers of systemic inflammation or comorbidity. For a subgroup of PD patients without serious comorbidity, other mechanisms of high baseline PSTR need to be elucidated.     

Impact of dialysis adequacy on the mortality and morbidity of anuric Chinese patients receiving continuous ambulatory peritoneal dialysis

Dialysis adequacy has a major impact on the outcome of continuous ambulatory peritoneal dialysis (CAPD) patients. However, most studies on peritoneal dialysis adequacy have focused on patients with significant residual renal function. The present study examined the effect of dialysis adequacy on anuric CAPD patients. A single-center prospective observational study on 140 anuric CAPD patients was performed. These patients were followed for 22.0 +/- 11.9 mo. Dialysis adequacy and nutritional indices, including Kt/V, creatinine clearance (CCr), protein equivalent nitrogen appearance, percentage of lean body mass, and serum albumin level were monitored. Clinical outcomes included actuarial patient survival, technique survival, and duration of hospitalization. In the study population, 64 were male, 36 (25.7%) were diabetic, and 59 (42.1%) were treated with 6 L exchanges per day. The body weight was 59.2 +/- 10.2 kg. Average Kt/V was 1.72 +/- 0.31, and CCr was 43.7 +/- 11.5 L/wk per 1.73m(2). Two-yr patient survival was 68.8%, and technique survival was 61.4%. Multivariate analysis showed that DM, duration of dialysis before enrollment, serum albumin, and index of dialysis adequacy (Kt/V or CCr) were independent factors of both patient survival and technique survival. It was estimated that for two patients who differed only in weekly Kt/V, a 0.1 higher value was associated with a 6% decrease in the RR of death (P: < 0.05; 95% confidence interval, 0.92 to 0.99). Serum albumin and CCr were the only independent factors that predicted hospitalization. It was found that even when there is no residual renal function, higher dialysis dosage is associated with better actuarial patient survival, better technique survival, and shorter hospitalization. Dialysis adequacy has a significant impact on the clinical outcome of CAPD patients, and the beneficial effect is preserved in anuric patients as well as in an ethnic group that has a low overall mortality.     

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。     

Effect of fluid and sodium removal on mortality in peritoneal dialysis patients

Effect of fluid and sodium removal on mortality in peritoneal dialysis patients. BACKGROUND: Adequacy of peritoneal dialysis (PD) traditionally is assessed using Kt/V(urea) and total creatinine clearance (TCC). However, this approach underestimates the importance of fluid and sodium removal. The aim of this study was to determine the effect of fluid and sodium removal on morbidity and mortality in PD patients. METHODS: One hundred twenty-five PD patients were monitored for three years from the beginning of the treatment. The effects of demographic features, comorbidity, peritonitis rate, blood pressure, medications, blood biochemistry, peritoneal membrane transport characteristics, residual renal function (RRF), Kt/V(urea), TCC, normalized protein nitrogen appearance (nPNA), and removal of sodium and fluid on mortality were evaluated. Total and cardiovascular hospitalization rates were also recorded. A Cox proportional hazards model was used to determine factors predicting mortality. RESULTS: In the Cox model, comorbidity, total sodium and fluid removals, hypertensive status, serum creatinine, and RRF were independent factors affecting survival. In contrast, Kt/V(urea) or TCC did not affect the adjusted survivals. Total sodium and fluid removal and hypertensive status also significantly influenced the hospitalization rate. Systolic and diastolic blood pressures were negatively correlated with total fluid (P < 0.001) and sodium removal (P < 0.001). CONCLUSIONS: Together, these findings suggest that removal of sodium and fluid is a predictor of mortality in PD patients, whereas Kt/V(urea) and TCC are not factors. Adequate fluid and sodium balance is crucial for the management of patients on PD.     

Incremental peritoneal dialysis: New ideas about an old approach

Coping with the transition from end‐stage kidney disease to dialysis can be challenging for patients and their care partners. Introducing incident dialysis patients to incremental forms of dialysis is associated with better quality of life and reduced cost. Incremental hemodialysis (HD ) has generated significant interest over the last decade with treatments that focus on clinical criteria rather than prespecified Kt/V_urea targets. Incremental peritoneal dialysis (PD ) has traditionally focused on the sum of residual renal and peritoneal clearances to achieve a specific Kt/V_urea value. Gradual increases in the PD dose were prescribed as the residual kidney function declined. Adopting a new approach to incremental PD similar to what has been done for incremental HD would obviate the need for Kt/V_urea and focus exclusively on clinical criteria. New incremental PD may be considered less disruptive to incident dialysis patients, and may be more likely to be accepted as treatment. It will also reduce our obsession with small solute kinetics and enhance encounters with patients by focusing instead on the holisitc clinical assessment.     

Dissociation between the Correlation of Peritoneal and Urine Kt/V with Sodium and Fluid Removal: A Possible Explanation of their Difference on Patient Survival

Background: It has been shown that residual renal function but not peritoneal clearance predicted patients’ survival in peritoneal dialysis therapy. In the present study, we tried to explore the potential causes resulting in the difference between residual renal function and peritoneal dialysis in continuous ambulatory peritoneal dialysis (CAPD) patients. Methods: A cross sectional study was performed during July and August 2003 to evaluate the dialysis adequacy in CAPD patients who were clinically stable and had daily urinary volume more than 100 ml. Results: A total of 45 patients (male 27 and female 18) with an average ( ± SD) age of 61.76 ± 13.27 years were included in this study. The daily urinary volume and dialysate ultrafiltration volume were 570.33 ± 395.47 ml and 726.09 ± 454.01 ml, respectively. Peritoneal urea clearance (Kt/V) correlated significantly with the drained daily dialysate volume (r = 0.362, P < 0.01), but not with peritoneal net fluid removal (ultrafiltration) (r = 0.232, P > 0.05) and sodium removal (r = 0.139, P > 0.05). On the other hand, there were strong positive correlations between residual renal Kt/V and daily urine volume (r = 0.802, P < 0.001), as well as between residual renal Kt/V and urinary sodium removal (r = 0.670, P < 0.001). Conclusions: High residual renal Kt/Vurea represents both higher solute clearance and higher sodium and fluid removal, but higher peritoneal Kt/Vurea is not necessarily associated with better sodium and fluid removal. This dissociation might explain the differences on the survival of patients and peritoneal clearances.     

Long-term use of 1.1% amino acid dialysis solution in hypoalbuminemic continuous ambulatory peritoneal dialysis patients

INTRODUCTION: Malnutrition is a common problem in patients treated with continuous ambulatory peritoneal dialysis (CAPD). Hypoalbuminemia in CAPD patients is an independent risk factor for death and is associated with malnutrition. Previous short-term studies have examined the use of amino acid based PD solutions in terms of albumin levels and anthropometric changes, but not clinical outcome. We report on the extended use of 1.1% amino acid based peritoneal dialysis solution (Nutrineal) and have assessed clinical utility in terms of nutrition, biochemical indices, dialysis adequacy and clinical outcomes. METHODS: The effect of Nutrineal was studied retrospectively in 22 patients during the past 30 months. All patients had an albumin level of < 35 g/l prior to commencing Nutrineal, and had either a protein intake < 1.2 g/kg or weight loss of > 5% in the previous 3 months. 19 of the 22 patients underwent an 8-week trial of oral nutritional supplements with no improvement in serum albumin level. Albumin level, normalized protein catabolic rate, weight, Kt/V and creatinine clearance were assessed for all patients prior to Nutrineal and at the end of the study period. RESULTS: The mean time on Nutrineal therapy was 13.6 months (range 6-26 months). There were no reported side effects of the treatment. There was an average of 1 episode of peritonitis per 23 treatment months, and only 1 patient died (4% annually adjusted mortality cf 8.9% on the peritoneal dialysis program as a whole). There was a significant increase in albumin level from 22.45 +/- 0.97 range 14-33 g/l to 25.68 +/- 1.159 range 16-35 g/l (p = 0.0036). Normalized protein catabolic rate increased significantly, from 0.898 +/- 0.053 to 1.085 +/- 0.056 g/kg/day (p = 0.0057). Weight decreased slightly although this did not reach statistical significance. Kt/V and creatinine clearance both decreased significantly, but remained within the adequate range in > 80% of the patients. There was no significant change in residual renal function (mean residual creatinine clearance 3.8 +/- 0.59 ml/min at the start of the study period, cf 3.4 +/- 0.61 ml/min at the end). CONCLUSION: These data suggest that Nutrineal can be used safely and effectively for an extended period of time. Such use is associated with a low mortality rate and a low peritonitis rate, although dialysis adequacy is compromised to a degree.     

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.     

持续性非卧床腹膜透析患者119例死亡原因分析

目的 分析持续性非卧床腹膜透析（CAPD）患者的死亡原因,为延长患者生存时间提供依据.方法 回顾性分析119例CAPD患者的死亡原因,并与同期126例CAPD存活患者相比较,以寻找其死亡的高危因素.结果 心血管并发症、脑血管意外和营养不良是最主要的死亡原因,分别占30.3%、24.4%和16.8%.与存活组相比,死亡组的年龄、动脉血压（收缩压和舒张压）、胆固醇和C反应蛋白升高（P〈0.05或P〈0.01）,死亡组左心室肥大的比例升高（P〈0.01）,而心脏射血分数、血红蛋白、血浆白蛋白、主观综合性营养评估、尿素氮清除率、透析前残余肾功能和透析前尿量降低（P〈0.01）.结论 心脑血管并发症和营养不良是CAPD患者最主要的死亡原因,与残余肾功能减退、左心室肥大、高血压、蛋白质丢失和微炎症等因素有关.保护残余肾功能、积极有效地控制高血压、纠正营养不良和减少腹膜炎的发生率将有助于延长患者生存时间,降低死亡率.