Randomized controlled study of biocompatible peritoneal dialysis solutions: effect on residual renal function.

Residual kidney function is important for patient and technique survival in peritoneal dialysis (PD). Biocompatible dialysis solutions are thought to improve function and viability of peritoneal mesothelial cells and to preserve residual renal function (RRF). We conducted a randomized controlled study comparing use of biocompatible (B) with standard (S) solutions in 93 incident PD patients during a 1-year period. The demographics, comorbidities, and RRF of both groups were similar. At 3 and 12 months, 24-h urine samples were collected to measure volume and the mean of urea and creatinine clearance normalized to body surface area. Surrogate markers of fluid status, diuretic usage, C-reactive protein concentration, peritonitis episodes, survival data, and peritoneal equilibrium tests were also collected. Changes in the normalized mean urea and creatinine clearance were the same for both groups, with no significant differences in secondary end points. Despite non-randomized studies suggesting benefits of these newer biocompatible solutions, we could not detect any clinically significant advantages. Additional studies are needed to determine if advantages are seen with longer term use.

Re-training and switching of PD system to reduce recurrent gram-positive PD peritonitis.

Intensive training and re-education of peritoneal dialysis (PD) exchange technique has been advocated to minimize peritonitis rate. However, re-education of patients that are established on PD for some years can be difficult and a minority of patients on PD remain susceptible to repeated episodes of peritonitis. The UV Flash Compact system (Baxter Healthcare) automates patient connection and disconnection during the PD exchange procedure and uses bactericidal UV irradiation to minimise the effects of touch contamination. We have explored the efficacy of retraining patients using this system for reducing peritonitis rates in a cohort of 10 patients in who repeated episodes of peritonitis due to gram +ve organisms suggest irrevocable breaches in sterile technique. These patients were converted from their existing PD system (6 Staysafe [Fresenius Medical Care], 4 Mini-solo [Baxter]). Mean follow up post-conversion was 10 months. There was a striking reduction in peritonitis caused by gram +ve pathogens from 1 in 8.5 to 1 in 50.5 months. Although it is not possible in this study to differentiate the impact of the UV Flash Compact as opposed to the effect of re-training, we advocate that patients with a high peritonitis burden from gram +ve organisms should be considered for conversion to the UV Compact system.

Haemodialysis access: a single centre UK Experience.

BACKGROUND: The aim of this study was to determine whether the US National Kidney Foundation Disease Outcome Quality Initiative (K/DOQI) guidelines on haemodialysis access could be achieved and to examine its relevance to patients on dialysis in the UK. METHOD: A cross sectional study of chronic haemodialysis patients at our institution which involved case note review and measurements of biochemical parameters and dynamic venous pressure (dVP) was performed. Patients with polytetrafluoroethylene (PTFE) grafts were followed prospectively for 18 months. RESULTS: 262 patients were studied - 12%, 43%, 30% and 15% underwent dialysis through dialysis catheters, radial-cephalic fistulae (rAVF), brachial-cephalic fistulae (bAVF) and PTFE grafts respectively. RAVFs, bAVFs and PTFE grafts were the primary access (i.e. the first access created for the patient) in 58%, 35% and 7% respectively. Compared with patients of Caucasian origin, patients of Afro-Caribbean race were 3.80 times (95% confidence limit: 1.51 - 9.53) more likely to have a PTFE graft. Patients with higher 'dry weights' were more likely to have PTFE grafts (p<0.005 by ANOVA). Dialysis adequacy was similar irrespective of type and site of access. We found that 64% of PTFE grafts, 46% of bAVFs and 13% of rAVF had dVPs greater than 150 mmHg, (p<0.0001 by c2). This threshold recommended by DOQI predicted 12 of 13 dysfunctional grafts, but had a positive predictive value of only 50%. CONCLUSION: We have demonstrated that the K/DOQI guidelines are not only achievable, but that they can be exceeded by a considerable margin. Our data also suggest that the demographic details of patients within a unit will influence the achievable proportion of AVF: PTFE grafts (the proportion of PTFE grafts in Afro-Caribbeans being 3 times higher than in whites). Although a dVP >150 mmHg proved sensitive in predicting future graft dysfunction, it had low specificity.