No increase in small-solute transport in peritoneal dialysis patients treated without hypertonic glucose for fifty-four months.

BACKGROUND: Glucose is widely used as an osmotic agent in peritoneal dialysis (PD), but exerts untoward effects on the peritoneum. The potential protective effect of a reduced exposure to hypertonic glucose has never been investigated. METHODS: The cohort of PD patients attending our center which tackled the challenge of a restricted use of hypertonic glucose solutions has been prospectively followed since 1992. Small-solute transport was assessed using an equivalent of the glucose peritoneal equilibration test after 6 months, and then every year. Study was stopped on July 1st, 2008, before use of biocompatible solutions. Repeated measures in patients treated with PD for 54 months were analyzed by using (1) the slopes of the linear regression for D4/D0 ratios over time computed for each individual, and (2) a linear mixed model. RESULTS: In the study period, 44 patients were treated for a total of 2376 months, 2058 without hypertonic glucose. There was one episode of peritoneal infection every 18 patient-months. The mean of slopes of the linear regression for D4/D0 ratios was found to be significantly positive (Student's test, p < .001) and the results of the mixed model reflected a similar significant increase for D4/D0 ratios over time. These results reflected a significant decrease of small-solute transport. CONCLUSION: In this large series, minimizing the use of hypertonic glucose solutions was associated in patients on long term PD with an overall decrease of small-solute transport within 54 months, despite a high rate of peritoneal infection.

Registration on the renal transplantation waiting list and mortality on dialysis: an analysis of the French REIN registry using a multi-state model.

BACKGROUND: Access to the renal transplantation (RT) waiting list depends on factors related to lower mortality rates and often occurs after dialysis initiation. The aim of the study was to use a flexible regression model to determine if registration on the RT waiting list is associated with mortality on dialysis, independent of the comorbidities associated with such registration. METHODS: Data from the French REIN registry on 7138 incident hemodialysis (HD) patients were analyzed. A multi-state model including four states ('HD, not wait-listed', 'HD, wait-listed', 'death', and 'RT') was used to estimate the effect of being wait-listed on the probability of death. RESULTS: During the study, 1392 (19.5%) patients were wait-listed. Of the 2954 deaths observed in the entire cohort during follow-up, 2921 (98.9%) were observed in the not wait-listed group compared with only 33 (1.1%) in the wait-listed group. In the multivariable analysis, the adjusted hazard ratio for death associated with non-registration on the waiting list was 3.52 (95% CI, 1.70-7.30). The risk factors for death identified for not wait-listed patients were not found to be significant risk factors for wait-listed patients, with the exception of age. CONCLUSIONS: The use of a multi-state model allowed a flexible analysis of mortality on dialysis. Patients who were not wait-listed had a much higher risk of death, regardless of co-morbidities associated with being wait-listed, and did not share the same risk factors of death as wait-listed patients. Registration on the waiting list should therefore be taken into account in survival analysis of patients on dialysis.

Overestimation of the probability of death on peritoneal dialysis by the Kaplan-Meier method: advantages of a competing risks approach.

BACKGROUND: In survival analysis, patients on peritoneal dialysis are confronted with three different outcomes: transfer to hemodialysis, renal transplantation, or death. The Kaplan-Meier method takes into account one event only, so whether it adequately considers these different risks is questionable. The more recent competing risks method has been shown to be more appropriate in analyzing such situations. METHODS: We compared the estimations obtained by the Kaplan-Meier method and the competing risks method (namely the Kalbfleisch and Prentice approach), in 383 consecutive incident peritoneal dialysis patients. By means of simulations, we then compared the Kaplan-Meier estimations obtained in two virtual centers where patients had exactly the same probability of death. The only difference between these two virtual centers was whether renal transplantation was available or not. RESULTS: At five years, 107 (27.9%) patients had died, 109 (28.4%) had been transferred to hemodialysis, 91 (23.8%) had been transplanted, and 37 (9.7%) were still alive on peritoneal dialysis; before five years, 39 (10.2%) patients were censored alive on peritoneal dialysis. The five-year probabilities estimated by the Kaplan-Meier and the competing risks methods were respectively: death: 50% versus 30%; transfer to hemodialysis: 59% versus 32%; renal transplantation: 39% versus 26%; event-free survival: 12% versus 12%. The sum of the Kaplan-Meier estimations exceeded 100%, implying that patients could experience more than one event, death and transplantation for example, which is impossible. In the simulations, the probability of death estimated by the Kaplan-Meier method increased as the probability of renal transplantation increased, although the probability of death actually remained constant. CONCLUSION: The competing risks method appears more appropriate than the Kaplan-Meier method for estimating the probability of events in peritoneal dialysis in the context of univariable survival analysis.

Paracoccus yeei: a new unusual opportunistic bacterium in ambulatory peritoneal dialysis.

Paracoccus yeei was identified as the etiologic agent of peritonitis in an ambulatory peritoneal dialysis patient. While the old biochemical identification kits are not able to identify this species, the new colorimetric VITEK 2 GN card correctly identified this isolate in 7hours. Its identity was confirmed by sequencing of the 16S rRNA gene.

Effect of iodinated contrast agents on residual renal function in PD patients.

BACKGROUND: Residual renal function (RRF) is an important predictor of outcome in peritoneal dialysis (PD) patients. Although increasing emphasis has been placed on preserving RRF, the nephrotoxicity associated with contrast medium administration in PD patients remains a controversial issue. In the present prospective study, we evaluated the evolution of RRF 2 weeks after iodinated contrast medium administration (ICMA) in a group of stable PD patients, and compared it with that in a non-treated control group of stable PD subjects. METHODS: The study was conducted from January 2003 to October 2004. RRF was quantified by the average of 24 h urinary urea and creatinine clearance and peritoneal creatinine clearance (PcrCl) were analyzed, the levels of which were analysed prior to and 2 weeks following ICMA in 36 PD patients and also assessed at the same time points in a group of 36 PD non-ICMA control subjects, matched according to RRF characteristics. Two weeks following ICMA, the values for RRF, daily urine volume and PcrCl were assessed against those at baseline, and the evolution of RRF was compared between the two groups. In the ICMA group, this study was performed with adequate pre-hydration and a minimum dose of contrast medium. RESULTS: Compared with baseline values, RRF, daily urine volume and PcrCl were not found to be significantly different 2 weeks after ICMA (7.0+/-4.3 vs 7.2+/-4.3 ml/min/1.73 m(2), P = 0.12; 1324+/-696 vs 1360+/-755 ml/day, P = 0.5; and 41.1+/-9 vs 40.6+/-9 l/week/1.73 m(2), P = 0.6, respectively). Following ICMA, variations in RRF and daily urine volume were found to be comparable with those of the control group (0.1+/-0.5 vs 0.1+/-0.5 ml/min/1.73 m(2), P = 0.9; 36+/-440 vs 40+/-493 ml/day, P = 0.8, respectively). CONCLUSION: In this study, 2 weeks following ICMA, no accelerated decline in RRF was determined in stable PD patients with adequate pre-hydration, i.e. subjects treated under optimal circumstances compared with the control group.

[Biocompatibility of peritoneal dialysis fluids]. / La biocompatibilité des solutions de dialyse péritonéale.

Repeated and long-term exposure to conventional glucose-based peritoneal dialysis fluids (PDFs) with poor biocompatibility plays a central role in the pathogenesis of the functional and structural changes of the peritoneal membrane. We have used immortalized human peritoneal mesothelial cells in culture to assess in vitro the biocompatibility of PDFs. Low pH, high glucose concentration and heat sterilization represent major factors of low biocompatibility. Two recent groups of glucose derivatives have been described. Glucose degradation products (GDPs) are formed during heat sterilization (glycoxidation) and storage. GDPs can bind protein and form AGEs (Advanced Glycation End-products), which can also result from the binding of glucose to free NH2 residues of proteins (glycation). The physiological pH, and the separation of glucose during heat sterilization (low GDP content) in the most recent PDFs dramatically increase the biocompatibility. The choice of PD programs with high biocompatibility PDFs allows preserving the function of the peritoneal membrane. Improvement of PDF biocompatibility may limit the occurrence of chronic chemical peritonitis and may allow long-term PD treatment.