The peritoneal catheter is the PD patient's lifeline. Advances in catheter knowledge have made it possible to obtain access to the peritoneal cavity safely and to maintain access over an extended period of time. Catheter-related infections remain a major problem, solutions for which are being actively researched. Nevertheless, the successful outcome of a catheter is very much dependent on meticulous care and attention to detail. Adherence to the principles of catheter insertion and subsequent management and care remain the cornerstone of successful PD access. The guidelines provided in this publication represent a consensus view based on studies from the literature and opinions of experts in this field; it is hoped that implementation of these guidelines will improve catheter-related outcomes and, therefore, enhance patient care.

Hyperkalemia contributes to significant mortality and limits the use of cardioprotective and renoprotective renin–angiotensin–aldosterone blockers. Current therapies are poorly tolerated and not always effective. Here we conducted a phase 2 randomized, double-blind, placebo-controlled dose-escalation study to assess safety and efficacy of ZS-9. This oral selective cation exchanger that preferentially entraps potassium in the gastrointestinal tract was given to patients with stable Stage 3 chronic kidney disease and hyperkalemia (5.0 to 6.0 mEq/l) during a 2-day period. Of 90 eligible patients with mean baseline serum potassium of 5.1 mEq/l, 30 were randomized to placebo, 12–0.3 g, 24–3 g, or 24 to 10 g of ZS-9 three times daily for 2 days with regular meals. None withdrew and ZS-9 dose-dependently reduced serum potassium. The primary efficacy end point (rate of serum potassium decline in the first 48 h) was met with significance in the 3- and 10-g cohorts. From baseline, mean serum potassium was significantly decreased by 0.92±0.52 mEq/l at 38 h. Urinary potassium excretion significantly decreased with 10-g ZS-9 as compared to placebo at day 2 (+15.8 +/− 21.8 vs. +8.9 +/− 22.9 mEq per 24h) from placebo at day 2. In this short-term study, no serious adverse events were reported; only mild constipation in the 3-g dose group was possibly related to treatment. Thus, ZS-9 was well-tolerated in patients with stable chronic kidney disease and hyperkalemia leading to a rapid, sustained reduction in serum potassium.

Over 70% of patients initiating chronic hemodialysis in the United States have a tunneled central venous catheter (CVC) for dialysis as their first blood access device. Tunneled CVC have requirements that are unparalleled by other access devices: high blood flow rates at moderate pressure drops without obstruction, minimal trauma to the vein, resistance to occlusion by fibrous sheathing, prevention of infection, avoidance of clotting, biocompatibility, avoidance of lumen collapse and kinking and breaks, resistance to antiseptic agents, placement with minimal trauma, and radiopaque appearance on X-ray. This publication reviews the numerous designs for tunneled CVC and evaluates the advantages and disadvantages of each design. A catheter that self-centers in the superior vena cava (CentrosÔ) is described, along with early clinical results. Current challenges and future directions for tunneled CVC for dialysis are discussed, included means to diminish catheter-related infections, catheter tip clotting, fibrous sheathing, central venous stenosis, and external component bulk.

The novel C-MB-P lock solution is well tolerated, significantly reduces the risk of catheter-related bloodstream infection, and provides protection comparable to heparin against patency failure.

Hemodiafiltration combines diffusive and convective solute removal in a single therapy by ultrafiltering 20% or more of the blood volume processed using a high-flux hemodialyzer and maintaining fluid balance by infusing sterile nonpyrogenic replacement fluid directly into the patient's blood. In online hemodiafiltration, the large volumes of replacement fluid required are obtained by online filtration of standard dialysate through a series of bacteria- and endotoxin-retaining filters. Currently available systems for online hemodiafiltration are on the basis of conventional dialysis machines with added features to safely prepare and infuse replacement fluid and closely control fluid balance. Hemodiafiltration provides greater removal of higher molecular weight uremic retention solutes than conventional high-flux hemodialysis, and recently completed randomized, controlled clinical trials suggest better patient survival with online hemodiafiltration compared with standard high-flux hemodialysis when a high convection volume is delivered. Hemodiafiltration is also associated with improvements in other clinical outcomes, such as a reduction in intradialytic hypotension, and it is now used routinely to treat >100,000 patients, mainly in Europe and Japan.

There is wide variation in the use of solutions to "lock" or fill tunneled central venous catheters for dialysis. Some centers use undiluted heparin concentrations ranging from 1000 to 10,000 U/ml and other centers place from 1000 to 10,000 U per lumen. Based on available evidence, it appears that heparin 1000 U/ml, or 4% sodium citrate are suitable choices for lock solution to maintain patency of tunneled central venous catheters for dialysis. Risks from systemic anticoagulation are lower with heparin 1000 U/ml and 4% sodium citrate, compared with higher concentrations of heparin (5000 and 10,000 U/ml). The need for use of tissue plasminogen activator for maintaining catheter patency is increased by using heparin lock at 1000 U/ml, vs. higher concentrations. Higher concentrations of heparin lock should be reserved for patients who have evidence of catheter occlusion or thrombosis when heparin is used at 1000 U/ml. Similar choices for lock solution are sensible for acute hemodialysis catheters. When heparin is used for catheter lock, the injected volume should not exceed the internal volume of the catheter.

The success of chronic peritoneal dialysis (PD) depends to a large extent on the success of the chronic PD access device. For the nephrologist placing and removing PD catheters, or for the nephrologist advising surgeons in this role, this article provides a review of designs of PD catheters and differences in function and complications, methods of insertion of PD catheters and relation to catheter outcomes, techniques for "burying" the external portion of the PD catheter and benefits of this technique, and techniques for removing PD catheters. As nephrologists become more closely involved in the creation, monitoring, and maintenance of access devices for end-stage renal disease (ESRD) patients, the successful function of these devices will increase. Nephrologists should make the critical decisions regarding the choice of access devices and methods for placement as they do for the choice to remove such access devices.

No abstract