Thomas A. Golper,1 Zbylut J. Twardowski,2 Bradley A. Warady,3 John E. Lewy,4 Frank A. Gotch,5. Catherine Firanek,6 and Garabed Eknoyan7. University of ...
Status of Peritoneal Dialysis in the U.S. May 6-7, 1996, Bethesda, Maryland, U.S. Peritoneal Dialysil International, Vol. 17, Suppl. 3
0896-8608197 $3.00 + .00 1997 International Society for Peritoneal Dialysis Printed in Canada. All rights reserved.
DOSE AND ADEQUACY IN PERITONEAL DIALYSIS
DOSE AND ADEQUACY 8
Thomas A. Golper, 1 Zbylut J. Twardowski,2 Bradley A. Warady, 3 John E. Lewy, 4 Frank A. Gotch, 5 Catherine Firanek, 6 and Garabed Eknoyan7 University of Arkansas tor Medical Sciences, 1 Little Rock, Arkansas; University of Missouri, 2 Harry S. Truman Veterans Administration Hospital, Dalton Research Center, Columbia, Missouri; University of Missouri, 3 Kansas City School of Medicine, Kansas City, Missouri; Tulane University School of Medicine, 4 New Orleans; San Francisco, 5 California; Circle Medical Management, 6 Chicago, Illinois; Baylor College of Medicine, 7 Houston, Texas, U.S.A.
CURRENT KNOWLEDGE 1. Peritoneal dialysis (PD) can provide adequate
dialysis. · 2. The dose of therapy delivered varies widely in clinical practice. Overdialysis is not a problem in current practice. 3. Available results from intervention trials are scanty or include too small a sample to allow for definitive statements on: a. A quantitative comparison of the various modalities of PD. b. How the normalized protein catabolic rate and Kt/V urea relate in cross sectional studies in the assessment of individual patients. c. What outcome parameters might be expected to respond to adequate PD. 4. Current recommendations for continuous ambulatory peritoneal dialysis (CAPD) are a KTN urea ~2.0/week or a total creatinine clearance ~60 U week/1. 73 m 2 • For continuous cycling peritoneal dialysis (CCPD) the figures are 2.2 and 60- 70, respectively, but a. Most caregivers feel these figures are too low by some 25%-30%. Thus any currently prescribed
dose should be used in conjunction with clinical assessment of the patient. b. It is not known what percent of current patients are evaluated for adequacy on a regular basis or have their prescription altered accordingly. c. In measuring the dose of dialysis delivered, the current methods to quantify peritoneal transport (peritoneal equilibration test, peritoneal fluid transport, mass transfer coefficients), position (supine or ambulatory), and sampling (batch or aliquot) are not normalized. d. Normalized creatinine clearance and Kt/V u:r:ea are considered equivalent measures of dialysis adequacy. However, consideration should be given to the inconsistencies in these two methods of normalization, which can lead to incommensurable dosage criteria. e. The residual renal function (Curea' Ccr) should be measured. f. The appropriate measure to determine total body water when determining the dose of Kt/V to be delivered remains to be defined. 5. Noncompliance in prescribed dose contributes to inadequacy of PD. The determinants, magnitude, and corrective measures to resolve this issue remain to be determined.
KEY WORDS: Dose; adequacy. Correspondence to: G. Eknoyan, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 7703-3498 U.S.A.
a This report, developed by the Dose and Adequacy Subcommitte, reflects the shared opinions ofT. Golper, Z. Twardowski, B. Warady, J. Lewy, F. Gotch, C. Firanek, and G. Eknoyan.
JULY 1997- VOL.l7, SUPPL. 3
6. There are no published target doses for pediatrlc PD. Prescription, in most cases, is dictated by ultrafiltration and "acceptable" laboratory results.
DOSE AND ADEQUACY SUBCOMMITTEE
(APD) regimens compared to those ofCAPD or HD is not known. RESEARCH NEEDS
RECOMMENDATIONS THAT CAN BE MADE GIVEN THE CURRENT STATE OF KNOWL· EDGE 1. A person weighing 2!:70 kg and without residual
renal function should probably not even consider PD or should have vascular access as a back-up. 2. At the adequate dialysis dose patients eat well and feel well. 3. At an as yet undetermined level of PD, protein losses, glucose exposure, increased peritonitis, and costs of solutions become prohibitive in the quest of optimal dialysis. 4. Defining a uniform optimal dose is difficult and will vary by patient characteristics more so than it does in hemodialysis (HD). Individual modeling is required to optimally prescribe a specific dose of PD. 5. Residual renal function contributes significantly to the adequacy of PD and must be measured regularly (3 - 4 months) until it is stable and subsequently whenever there is a significant change in serum creatinine. 6. The delivered dose of dialysis should be monitored regularly. The frequency with which the delivered dose ofPD should be measured in clinical practice remains to be established, but should be obtained every 2 - 3 months. 7. The equivalency of dose in various automated PD
There is an urgent need for a multicenter randomized prospective clinical outcome trial to determine (tightly controlled) target dose and adequacy ofPD. The issues to address in a study would include, but are not limited to: 1. The contribution of residual renal function. 2. Standards for collection, sampling, and processing of dialysate. 3. The level of PD dose at which protein losses, glucose exposure, peritonitis, and cost become prohibitive. 4. The clinical outcomes of PD that are dose-dependent. 5. The quality-of-life issues that define adequate and optimal dialysis. 6. Whether clearances should be proportional to total body water, body surface area, or some other parameter. 7. The target dose for pediatric patients. 8. The limits on accuracy of prescribed and delivered doses. 9. Whether ideal or dry weight should be utilized in calculations. 10. Evaluation of computer programs to assist in prescription. 11. Comparison of different modalities (CAPD, CCPD,APD).