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Objective Despite a lack of strong evidence, automated peritoneal dialysis (APD) is often prescribed on account of an expected better quality of life (QoL) than that expected with continuous ambulatory peritoneal dialysis (CAPD). Our aim was to analyze differences in QoL in patients starting dialysis on APD or on CAPD with a follow-up of 3 years.Methods Adult patients in the prospective NECOSAD cohort who started dialysis on APD or CAPD were included 3 months after the start of dialysis. The Medical Outcomes Survey Short Form 36 [SF-36 (Medical Outcomes Trust and QualityMetric, Lincoln, RI, USA)] and Kidney Disease and Quality of Life Short Form [KDQOL-SF (KDQOL Working Group, Santa Monica, CA, USA)] questionnaires were used to measure QoL. Differences in QoL over time were calculated using linear mixed models. Patients were followed until transplantation, death, or a first switch to any other dialysis modality.Results The clinical and social characteristics of the 64 APD and 486 CAPD patients were slightly different at baseline. In the crude analysis, the pattern of the mental summary score differed between the modalities (p= 0.03, adjusted p= 0.06), because of a different pattern for role function emotional (p= 0.03, adjusted p= 0.05). The pattern of the physical summary score was not different between the groups. Scores on dialysis staff encouragement had a different pattern over time (p= 0.01), because of an in-equality in scores 3 months after the start of dialysis, which disappeared after 18 months on dialysis. Over time, patients on APD scored higher on sexual function. After adjustment for age, sex, glomerular filtration rate, comorbidity, and primary kidney disease, that difference disappeared. This study showed no major differences in QoL on the KDQOL-SF and the SF-36 between the two modalities.

Background Many studies have shown the renoprotective effect of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARBs) in patients with chronic kidney disease stages I–IV. Two randomized controlled trials (RCTs) showed a positive effect of AII inhibitors on residual glomerular filtration rate (rGFR) in peritoneal dialysis (PD) patients. However, these studies were small and were performed in a highly selected group of PD patients. Our aim was to confirm the above findings in a larger number of prospectively followed PD patients.Methods First we analyzed the time course of decline of rGFR in 452 incident PD patients that were not anuric at the start of dialysis and that had structured follow-up data, with measurements at 3, 6, 12, 18, 24, 30, and 36 months after the start of dialysis. Changes in rGFR over time were analyzed with a linear mixed model for repeated measures. In addition, Cox regression models were used to estimate the risk of developing anuria. In a second approach, we aimed to repeat the above analyses in a selected group of patients that theoretically could have been randomized and therefore resembled the population studied in the 2 mentioned RCTs. In this group the follow-up was restricted to 1 year.Results 201 patients were treated with ACEi/ARBs and 251 did not take these drugs at the start of PD. More patients from the treated group had diabetes and used more antihypertensive medications. The time course of decline of rGFR was not different between the 2 groups over the 3 years of PD treatment (p= 0.52). Less than 25% of patients from each group became anuric and there was no difference in time to development of complete anuria between the treated and untreated groups. In the second approach, 130 patients were included: 37 were treated with ACEi/ARBs and 93 were not. Again, no difference was found between the 2 groups with respect to the rate of decline of rGFR and time of anuria development.Conclusion Our findings are not in line with the results of previous RCTs. The biggest limitation of observational studies is the inability to avoid confounding by indication. However, a RCT in such a setting also does not give a reliable answer. Given all the benefits of ACEi/ARBs, the medications should not be withheld from PD patients. However, their renoprotective effects may often be overruled by other factors influencing the time course of rGFR.

Background Peritoneal dialysis (PD) technique failure is high compared to hemodialysis (HD). There is a lack of data on the impact of duration of PD treatment on technique survival and on whether there is a difference in risk factors with respect to early and late failure. The aim of this study was to clarify these issues by performing a time-dependent analysis of PD technique and patient survival in a large cohort of incident PD patients.Methods We analyzed 709 incident PD patients participating in the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD), who started their treatment between 1997 and 2007. We compared technique and patient survival on PD in 4 periods of follow-up: within the first 3 months, and after 3 – 12 months, 12 – 24 months, and 24 – 36 months of treatment. Cox proportional hazards model was used to analyze survival on PD and technique failure. Risk factors were also identified by comparing patients that were transferred to HD with those that remained on PD. Incidence rates for every cause of dropout for each period of follow-up were calculated to establish their trends with respect to PD treatment duration.Results There was a significant increase in transplantation rate after the first year of treatment. The rate of switching to HD was highest during the first 3 months and decreased afterward. One-, 2- and 3-year technique survival was 87%, 76%, and 66%, respectively. Age, diabetes, and cardiovascular disease appeared to be risk factors for death on PD or switch to HD: a 1-year increase in age was associated with a relative risk (RR) of PD failure of 1.04 [95% confidence interval (CI) 1.003 – 1.06]; for diabetes, RR of stopping PD after 3 months of treatment increased from 1.8 (95% CI 1.1 – 3) during the first year to 2.2 (95% CI 1.3 – 4) after the second year; cardiovascular disease had a major impact in the earliest period (RR 2.5, 95% CI 1.2 – 5) and had a stable influence further on (RR 2, 95% CI 1.1 – 3.5). Loss of 1 mL/minute residual glomerular filtration rate (rGFR) appeared to be a significant predictor of PD failure after 3 months of treatment, but within the first 2 years, RR was 1.1 (95% CI 1.04 – 1.25).Conclusions In The Netherlands, transplantation is a main reason to stop PD treatment. The incidence of PD technique failure is at its highest during the earliest months after treatment initiation and decreases later due to fewer catheter and abdominal complications as well as less influence of psychosocial factors. Risk factors for PD discontinuation are those responsible for patient survival: age, cardiovascular disease, diabetes, and rGFR.

♦ Background Since the publication of opinion-based guidelines regarding the timing of dialysis treatment, there has been a trend toward earlier initiation.♦ Objective In this review, the existing guidelines and the currently published studies that evaluate them are discussed.♦ Results These studies could not demonstrate a clear benefit on survival or quality of life for patients who started with relatively higher renal function.♦ Conclusion Early start of dialysis treatment should not be confused with early referral to the nephrologist. It is concluded that initiation of dialysis should not depend on a predefined magnitude of renal function, but should be tailored to the individual patient.

Objective To assess employment status in new end-stage renal disease (ESRD) patients at the start of dialysis and after 1 year, and to determine whether demographic and clinical variables and physical and psychosocial functioning at the start of dialysis are risk factors for loss of employment after 1 year of dialysis.Design Prospective follow-up study in which 38 of 48 Dutch dialysis centers participate.Patients 659 patients who had started on dialysis and who were between 18 and 65 years old were included. Patients were re-examined after 12 months.Main Outcome Measures Demographic data, physical and psychosocial functioning with the Short-Form Health Survey (SF-36), and data on employment status were obtained using questionnaires. Nephrologists provided the clinical data.Results At the start of dialysis, 35% of patients were employed, in contrast to 61% of the general Dutch population. Within 1 year, the proportion of employed patients decreased from 31% to 25% of hemodialysis patients, and from 48% to 40% of peritoneal dialysis patients. In patients who were working at the start of dialysis, independent risk factors for loss of work within 1 year were impaired physical and psychosocial functioning [odds ratio physical: 3.4, 95% confidence interval (%CI), 1.0 – 11.2; odds ratio psychosocial: 4.2, 95% CI, 1.2 – 14.2].Conclusions As the percentage of employed patients at the start of dialysis is about half the expected percent-age, loss of work is an important issue in both predialysis and dialysis patients. Improvements in physical and psychosocial functioning are potentially preventive of loss of work in patients who are employed when they start dialysis.

Objective It is unknown whether a given level of urea clearance by the native kidneys provides better or similar control of uremia than the same level of urea clearance by continuous peritoneal dialysis (PD). More insight into possible differences between renal and peritoneal urea clearances is warranted. Therefore, we investigated the relationship between Kt/Vureaand protein equivalent of total nitrogen appearance normalized to body weight (nPNA), the relationship between urea clearance and creatinine appearance, and other nutritional parameters in PD patients without residual renal function, and in predialysis end-stage renal disease patients.Patients All patients participated in the Netherlands Cooperative Study on the Adequacy of Dialysis. This is a prospective cohort study of incident dialysis patients, in whom regular assessments of renal function are done. A group of 75 PD patients was identified at the first follow-up assessment in which their urine production was less than 100 mL/day. These patients were considered the anuric group. This group was compared with a control group of 97 predialysis patients studied 0 – 4 weeks before the start of dialysis treatment.Results Linear relationships were present between Kt/Vureaand nPNA, in both the predialysis patients and the anuric PD patients. A significant difference was present between the slopes of the two regression lines (0.40 vs 0.18, p= 0.007). When Kt/Vureaexceeded 1.3/week, a given level of Kt/Vureawas associated with a higher nPNA in predialysis than in anuric PD patients. Similar relationships were found between Ktureaand PNA. Ktureawas also significantly related to urine or dialysate creatinine appearance. A significant difference existed between the slopes of the regression lines in the two groups of patients (p< 0.001). A weekly Ktureaof 70 L was associated with a urine creatinine appearance of 11.0 mmol/day and a dialysate creatinine appearance of 8.4 mmol/day. Nutritional status measured with creatinine appearance and Subjective Global Assessment was better in the predialysis population, despite much lower values for Kt/Vureain these patients.Conclusions The relationship between Kt/Vureaand nPNA in anuric PD patients is different from that in a predialysis population. It follows from our results that, when Kt/Vureais above 1.3/week, a given level of Kt/Vureais associated with a higher nPNA in predialysis than in anuric PD patients. This challenges the concept of equivalency between renal and peritoneal Kt/Vureawith respect to control of uremic morbidity.

Objective To assess health-related quality of life (QL) in a group of Dutch predialysis end-stage renal disease (ESRD) patients prior to the initiation of dialysis, and to compare QL between patients with different intended initial dialysis treatments.Design In a prospective cohort study, demographic, clinical, and QL data were obtained from Dutch adult patients who were consecutively enrolled from 27 different centers 0 – 4 weeks prior to the beginning of their chronic dialysis treatment.Patients Of the 301 patients who completed the QL questionnaires (of a possible 337 enrolled patients), 152 intended to start with hemodialysis (pre-HD) and 149 patients with peritoneal dialysis (pre-PD).Main Outcome Measure Perceived QL of pre-HD and pre-PD patients. Quality of life was assessed with two generic health assessment instruments: the SF-36 and the EuroQol.Results After correction for group differences, pre-HD patients scored consistently, but not significantly, lower for all separate dimensions of the SF-36 and the overall health score of the EuroQol compared to pre-PD patients. However, analyzing the dimensions of the SF-36 together, adjusted for case-mix, pre-HD patients scored significantly lower than pre-PD patients. Mean difference was 6.5 points (p= 0.04).Conclusion Multivariate adjustment for known case-mix differences at the start of dialysis therapy was not sufficient to adjust for all patient selection effects on QL. Consequently, published QL comparisons between HD and PD in nonrandomized cohort studies should be interpreted with caution. Assessment of QL just before start of dialysis therapy and subsequent adjustment for baseline values may be the only valid alternative for randomized studies.

Peritoneal transport of water, low-molecular-weight solutes and proteins was studied on 75 occasions in 38 CAPD patients. Maximal ultrafiltration capacity decreased with time on CAPD, while there was an increase in the number of hypertonic bags used and the peritoneal absorption of glucose. A relationship was found between maximal ultrafiltration capacity and glucose kinetics. The duration of CAPD was longer in the patients with poor ultrafiltration, while they had a faster transport of glucose and creatinine, but not of proteins. In the group as a whole, no obvious changes were found in the mass transfer area coefficients of urea, creatinine and glucose, nor in the clearances of albumin and IgG. In the five patients with severe ultrafiltration loss, we found evidence of either decreased or increased peritoneal solute transport. Contrasting findings in transport of small solutes and proteins may reflect increased effective peritoneal surface area combined with decreased peritoneal permeability.

Our objective was to determine the incidence of peritonitis episodes with an impaired initial cell reaction (IICR: neutrophil number <100 x 1 061L) over a period often years, and to find possible explanations for this unusual presentation of peritonitis. A retrospective review of the files of continuous ambulatory peritoneal dialysis (CAPD) patients included in the CAPD program between 1984 and 1993 was done. Analysis of cytokine and prostanoid patterns during four peritonitis episodes with an IICR was compared to 12 episodes with a normal initial cell reaction (NICR). Dialysate cell numbers and immunoeffector characteristics of peritoneal cells were compared in 7 IICR patients in a stable situation and a control group of 70 stable CAPD patients. The setting was a CAPD unit in the Academic Medical Center in Amsterdam. Thirty-five CAPD patients who had one or more peritonitis episodes with an IICR and a control group of 249 CAPD patients were included in the study.The incidence of peritonitis with an IICR was 6%. These episodes occurred more than once in 51% of the patients who presented with IICR. In 72% the cell reaction was only delayed: a cell number exceeding 100 x 1 061L was reached later. Staphylococcus aureuswas significantly more frequently the causative microorganism compared to all peritonitis episodes (PE) that occurred during the study period. Patients with IICR had lower dialysate cell counts in a stable situation, compared to a control group (p < 0.01). This was caused by a lower number of macro-phages and CD4 positive lymphocytes. The phagocytosis capacity of the macrophages appeared to be normal. In a comparison of four PE with an IICR and 12 episodes with an NICR, the tumor necrosis factor-α (TNF-α) response was similar and occurred on day 1, also pointing to normally functioning macrophages. However, the maximal appearance rates of interleukin-6 (IL-6) and IL-8 occurred later in the episodes with IICR compared to NICR (day 2 vs day 1, p < 0.05). No differences were found in vasodilating prostaglandins, mesothelial cell markers (cancer antigen 125, phospholipids, hyaluronan), and mesothelial cell numbers in the stable situation nor during peritonitis.Peritonitis can present as abdominal pain in the absence of a cloudy dialysate. In some of the patients this presentation occurred more than once. This impaired, most often delayed, cell reaction was associated with a delayed secondary cytokine response. As IL-6 and IL-8 can be synthesized by mesothelial cells, this suggests an impaired functioning mesothelium. This could not be confirmed, however, by a lower number of mesothelial cells in effluent or lower dialysate levels of mesothelial cell markers.

To elucidate the importance of possible trapping of macromolecules in peritoneal tissue on the calculation of peritoneal lymphatic drainage, we compared the transport of inulin administered i.v. and i.p. in nine continuous ambulatory peritoneal dialysis (CAPD) patients on two separate days. In the intraperitoneal study inulin (5 g) was added to the dialysate and in the intravenous study inulin (5 g) was given i.v. 3 h before the test. No differences were found in the mass transfer area coefficients (MTC) of urea, creatinine, and glucose between the two tests. The MTC after inulin i.p. was 3.2 ± 0.7 mLlmin (mean ± SD) and after inulin i.v. 1.8 ± 0.5 (p< 10-5). As the difference in transport kinetics between i.v. and i.p. administration is likely to be caused by lymphatic absorption, a mean lymphatic flow of 1.4 mLlmin could be calculated. This value corresponds to the data obtained with macromolecules. Our results therefore favor the hypothesis that no local accumulation of macromolecules in the peritoneal tissues takes place and that their disappearance from the peritoneal cavity represents lymphatic absorption.

Objective To analyze the effect of serum albumin using immunoturbidimetry, demographic, biochemical, and kinetic factors on survival of continuous ambulatory peritoneal dialysis (CAPD) patients.Design A review of prospectively collected data in a 2-year follow-up study of peritoneal transport kinetics.Setting University medical center.Participants Sixty-one patients, evaluated within 3 months after the start of CAPD.Main Outcome Measures Covariables used in the survival analysis were plasma urea, and creatinine, albumin, hemoglobin, mass transfer area coefficient of creatinine, peritoneal albumin clearance, 4-hour peritoneal albumin loss, net ultrafiltration, age, blood pressure, body mass index, difference between actual and ideal body weight, and presence or absence of systemicdisease.Results Overall survival was 64% at 2 years. Median serum albumin was 30.9 g/L, range 18.1 -43.9 g/L. Patients with a serum albumin below the median had a lower survival rate than those higher than the median (2-year survival 49% vs 79%, p = 0.01). Using the Cox model, survival was related to systemic disease (p = 0.004), age (p = 0.02), hemoglobin (p = 0.03), and serum albumin (p = 0.1).Conclusions The results confirm the strength of serum albumin as predictor of survival. However, in this study serum albumin merely reflected the presence of a systemic disease, which was the most important risk factor for patient survival.

The possible relationship between Initial changes In functional characteristics of the peritoneal membrane In time and hemoglobin (Hb) or hematocrit (Ht) was analyzed as part of a prospective longitudinal study. The patients were Investigated twice: the first time within 3 months after the start of continuous ambulatory peritoneal dialysis (CAPD), and again 4 months later. Mass transfer area coefficients (MTC) for low molecular weight solutes and net fluid removal were calculated during a 4-hour dwell, glucose 1.36%. Thirty-four patients were analyzed. MTC (mean±SD, mL/min/1.73 m2) were higher during the first examination: urea 22.6 versus 19.9, p<0.05; lactate 15.6 versus 13.8, p<0.001; creatinine 10.5 versus 9.3, p<0.05; glucose 9.4 versus 7.9, p<0.001. Net fluid removal was lower during the first examination: 28 versus 99 mL/mln/1.73 m2, p<0.05. Hb and Ht increased between the two examinations (Hb: 5.4 vs 6.1 mmol/L, p<0.001; Ht: 0.26 vs 0.29, p<0.001). No relation was found between the absolute or relative change In Hb or Ht and the absolute or relative change In solute and fluid transport between the same examinations. In conclusion, Hb and Ht Increased between the first and second examinations. The simultaneously observed changes in peritoneal transport kinetics could not be attributed to changes In Hb or Ht. Therefore, the changes In transport kinetics during the first months on CAPD are probably due to the recent start of the treatment, possibly by an Increase In peritoneal surface area. LocalIrritation by the dialysate may be the causative mechanism.