This publication represents the second revision of the Kidney Disease Outcomes Quality Initiative (KDOQI) Guidelines for Peritoneal Dialysis (PD) Adequacy. The revision was precipitated in part by the publication of 2 prospective randomized trials that evaluated the relationship between small-solute clearance and short-term outcomes in patients on PD therapy. These studies represent a higher level of evidence for guideline formation than were available to formulate the first 2 Dialysis Outcome Quality Initiative (DOQI) and KDOQI Guidelines for PD Adequacy. The results of both studies suggested that improving survival on currently available PD therapies likely is related to factors other than increasing small-solute clearances. Data continued to emerge that confirmed the importance of maintaining residual kidney function (RKF) and a guideline reflecting the importance of RKF on patient outcomes was added. In addition, there were preliminary data suggesting that surrogates for cardiovascular risk (peritoneal ultrafiltration and volume removal) were predictive of relative risk (RR) for death in cohort observational studies. Although the Work Group acknowledges that these data are preliminary, we believed that recommendations for volume and blood pressure control in PD patients could now be added.
In contrast to the second version of the KDOQI Guidelines for PD Adequacy, the current guidelines represent a complete revision of the original. In addition to modifications of the actual guidelines based on new medical evidence, clinical and practical experiences with use of the original guidelines also were reviewed and, when appropriate, incorporated. Most importantly, we attempted to address issues related to experiences with implementation of the guidelines, work load on dialysis unit staff, and use of the guidelines for formulating clinical performance measurements by some oversight bodies.
These guidelines are primarily for patients on continuous ambulatory PD (CAPD) therapy. There are limited data for automated PD (APD) and no randomized controlled trials (RCTs). Therefore, we cannot formulate guidelines for APD, and any comments on this form of therapy are mainly opinion based. Further study is needed in this area.
Because children are not “small adults,” guidelines for children have been separated into 1 section (Guideline 6). These mirror the adult guidelines, but follow the pediatric literature. For areas in which no pediatric-specific data exist, the adult guidelines should serve as a minimum standard for pediatric patients.
Despite voicing concerns in the original DOQI publications, at times guidelines were used by oversight bodies in a way not intended by the Work Group and—at other times—not in keeping with the spirit in which the guidelines were formulated. As a result, this publication is organized differently, into: (1) Clinical Practice Guidelines (CPGs); and (2) Clinical Practice Recommendations (CPRs). The guidelines are based on available evidence such as it exists. Much more information is needed; therefore, we would strongly discourage oversight bodies from using these CPGs for clinical performance measurements. The CPRs are based on weak evidence or opinion and as such, should not be used for clinical performance measurements. In particular, because of the absence of RCTs for patients on APD therapy, no clinical performance measurements regarding this form of therapy are appropriate. Guidelines are meant to inform, but not replace, clinical judgment.
Finally, we must express some caveats and cautions about the guidelines. In contrast to the original guidelines, in which a target total solute clearance was recommended, in the present guidelines, a minimal dose is recommended. When using a target, even if a patient was below target, solute clearance would still likely be adequate. Conversely, when using a minimal dose, there is less room for error. All patients should be above the minimal. Additionally, data from prospective randomized trials are based on relatively short-term trials of patients on PD therapy in Mexico and Hong Kong. These patients likely are on different protein intakes and perhaps are more likely to be adherent with the PD prescription than the typical patient in the United States. As a result, the current document emphasizes patient observations and adjustment of the PD prescription if the patient is not doing well clinically. There is a paucity of knowledge regarding small-molecule clearance targets and long-term complications, such as calcium-phosphate product effects and uremic neuropathy. Additional data are required to make recommendations for optimization of long-term health.
The prior publications recognized that there was an absence of RCTs to answer important questions regarding PD adequacy and optimal practice. The prior guidelines identified research needs, some of which have been met. We hope that the present guidelines identify questions that will stimulate further research, improve patient outcomes, and advance the clinical practice of PD.